Serviceless rewrite, part 1

Signed-off-by: Samuel Holland <samuel@sholland.org>

47 files changed, 2065 insertions, 1846 deletions

diff --git a/app/src/main/java/com/wireguard/android/AddActivity.java b/app/src/main/java/com/wireguard/android/AddActivity.java
deleted file mode 100644
index 5b57e634..00000000
--- a/app/src/main/java/com/wireguard/android/AddActivity.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package com.wireguard.android;
-
-import android.app.FragmentManager;
-import android.app.FragmentTransaction;
-import android.os.Bundle;
-
-import com.wireguard.config.Config;
-
-/**
- * Standalone activity for creating configurations.
- */
-
-public class AddActivity extends BaseConfigActivity {
-    @Override
-    public void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.add_activity);
-    }
-
-    @Override
-    protected void onCurrentConfigChanged(final Config oldConfig, final Config newConfig) {
-        // Do nothing (this never happens).
-    }
-
-    @Override
-    protected void onEditingStateChanged(final boolean isEditing) {
-        // Go back to the main activity once the new configuration is created.
-        if (!isEditing)
-            finish();
-    }
-
-    @Override
-    protected void onServiceAvailable() {
-        super.onServiceAvailable();
-        final FragmentManager fm = getFragmentManager();
-        ConfigEditFragment fragment = (ConfigEditFragment) fm.findFragmentById(R.id.master_fragment);
-        if (fragment == null) {
-            fragment = new ConfigEditFragment();
-            final FragmentTransaction transaction = fm.beginTransaction();
-            transaction.add(R.id.master_fragment, fragment);
-            transaction.commit();
-        }
-        // Prime the state for the fragment to tell us it is finished.
-        setIsEditing(true);
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/Application.java b/app/src/main/java/com/wireguard/android/Application.java
new file mode 100644
index 00000000..c0fb046a
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/Application.java
@@ -0,0 +1,124 @@
+package com.wireguard.android;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.os.AsyncTask;
+import android.os.Handler;
+import android.os.Looper;
+import android.preference.PreferenceManager;
+
+import com.gabrielittner.threetenbp.LazyThreeTen;
+import com.wireguard.android.backend.Backend;
+import com.wireguard.android.backend.WgQuickBackend;
+import com.wireguard.android.configStore.ConfigStore;
+import com.wireguard.android.configStore.FileConfigStore;
+import com.wireguard.android.model.TunnelManager;
+import com.wireguard.android.util.AsyncWorker;
+import com.wireguard.android.util.RootShell;
+
+import java.util.concurrent.Executor;
+
+import javax.inject.Qualifier;
+import javax.inject.Scope;
+
+import dagger.Component;
+import dagger.Module;
+import dagger.Provides;
+
+/**
+ * Base context for the WireGuard Android application. This class (instantiated once during the
+ * application lifecycle) maintains and mediates access to the global state of the application.
+ */
+
+public class Application extends android.app.Application {
+    private static ApplicationComponent component;
+
+    public static ApplicationComponent getComponent() {
+        if (component == null)
+            throw new IllegalStateException("Application instance not yet created");
+        return component;
+    }
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        component = DaggerApplication_ApplicationComponent.builder()
+                .applicationModule(new ApplicationModule(this))
+                .build();
+        component.getTunnelManager().onCreate();
+        LazyThreeTen.init(this);
+    }
+
+    @ApplicationScope
+    @Component(modules = ApplicationModule.class)
+    public interface ApplicationComponent {
+        AsyncWorker getAsyncWorker();
+
+        SharedPreferences getPreferences();
+
+        TunnelManager getTunnelManager();
+    }
+
+    @Qualifier
+    public @interface ApplicationContext {
+    }
+
+    @Qualifier
+    public @interface ApplicationHandler {
+    }
+
+    @Scope
+    public @interface ApplicationScope {
+    }
+
+    @Module
+    public static final class ApplicationModule {
+        private final Context context;
+
+        private ApplicationModule(final Application application) {
+            context = application.getApplicationContext();
+        }
+
+        @ApplicationScope
+        @Provides
+        public static Backend getBackend(final AsyncWorker asyncWorker,
+                                         @ApplicationContext final Context context,
+                                         final RootShell rootShell) {
+            return new WgQuickBackend(asyncWorker, context, rootShell);
+        }
+
+        @ApplicationScope
+        @Provides
+        public static ConfigStore getConfigStore(final AsyncWorker asyncWorker,
+                                                 @ApplicationContext final Context context) {
+            return new FileConfigStore(asyncWorker, context);
+        }
+
+
+        @ApplicationScope
+        @Provides
+        public static Executor getExecutor() {
+            return AsyncTask.SERIAL_EXECUTOR;
+        }
+
+        @ApplicationHandler
+        @ApplicationScope
+        @Provides
+        public static Handler getHandler() {
+            return new Handler(Looper.getMainLooper());
+        }
+
+        @ApplicationScope
+        @Provides
+        public static SharedPreferences getPreferences(@ApplicationContext final Context context) {
+            return PreferenceManager.getDefaultSharedPreferences(context);
+        }
+
+        @ApplicationContext
+        @ApplicationScope
+        @Provides
+        public Context getContext() {
+            return context;
+        }
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/BaseConfigActivity.java b/app/src/main/java/com/wireguard/android/BaseConfigActivity.java
deleted file mode 100644
index 1bd5c70d..00000000
--- a/app/src/main/java/com/wireguard/android/BaseConfigActivity.java
+++ /dev/null
@@ -1,103 +0,0 @@
-package com.wireguard.android;
-
-import android.app.Activity;
-import android.content.ComponentName;
-import android.content.Context;
-import android.content.Intent;
-import android.content.ServiceConnection;
-import android.os.Bundle;
-import android.os.IBinder;
-
-import com.wireguard.android.backends.VpnService;
-import com.wireguard.config.Config;
-
-/**
- * Base class for activities that need to remember the current configuration and wait for a service.
- */
-
-abstract class BaseConfigActivity extends Activity {
-    protected static final String KEY_CURRENT_CONFIG = "currentConfig";
-    protected static final String KEY_IS_EDITING = "isEditing";
-
-    private Config currentConfig;
-    private String initialConfig;
-    private boolean isEditing;
-    private boolean wasEditing;
-
-    protected Config getCurrentConfig() {
-        return currentConfig;
-    }
-
-    protected boolean isEditing() {
-        return isEditing;
-    }
-
-    @Override
-    protected void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        // Restore the saved configuration if there is one; otherwise grab it from the intent.
-        if (savedInstanceState != null) {
-            initialConfig = savedInstanceState.getString(KEY_CURRENT_CONFIG);
-            wasEditing = savedInstanceState.getBoolean(KEY_IS_EDITING, false);
-        } else {
-            final Intent intent = getIntent();
-            initialConfig = intent.getStringExtra(KEY_CURRENT_CONFIG);
-            wasEditing = intent.getBooleanExtra(KEY_IS_EDITING, false);
-        }
-        // Trigger starting the service as early as possible
-        if (VpnService.getInstance() != null)
-            onServiceAvailable();
-        else
-            bindService(new Intent(this, VpnService.class), new ServiceConnectionCallbacks(),
-                    Context.BIND_AUTO_CREATE);
-    }
-
-    protected abstract void onCurrentConfigChanged(Config oldCconfig, Config newConfig);
-
-    protected abstract void onEditingStateChanged(boolean isEditing);
-
-    @Override
-    public void onSaveInstanceState(final Bundle outState) {
-        super.onSaveInstanceState(outState);
-        if (currentConfig != null)
-            outState.putString(KEY_CURRENT_CONFIG, currentConfig.getName());
-        outState.putBoolean(KEY_IS_EDITING, isEditing);
-    }
-
-    protected void onServiceAvailable() {
-        // Make sure the subclass activity is initialized before setting its config.
-        if (initialConfig != null && currentConfig == null)
-            setCurrentConfig(VpnService.getInstance().get(initialConfig));
-        setIsEditing(wasEditing);
-    }
-
-    public void setCurrentConfig(final Config config) {
-        if (currentConfig == config)
-            return;
-        final Config oldConfig = currentConfig;
-        currentConfig = config;
-        onCurrentConfigChanged(oldConfig, config);
-    }
-
-    public void setIsEditing(final boolean isEditing) {
-        if (this.isEditing == isEditing)
-            return;
-        this.isEditing = isEditing;
-        onEditingStateChanged(isEditing);
-    }
-
-    private class ServiceConnectionCallbacks implements ServiceConnection {
-        @Override
-        public void onServiceConnected(final ComponentName component, final IBinder binder) {
-            // We don't actually need a binding, only notification that the service is started.
-            unbindService(this);
-            onServiceAvailable();
-        }
-
-        @Override
-        public void onServiceDisconnected(final ComponentName component) {
-            // This can never happen; the service runs in the same thread as the activity.
-            throw new IllegalStateException();
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/BaseConfigFragment.java b/app/src/main/java/com/wireguard/android/BaseConfigFragment.java
deleted file mode 100644
index c92d127e..00000000
--- a/app/src/main/java/com/wireguard/android/BaseConfigFragment.java
+++ /dev/null
@@ -1,50 +0,0 @@
-package com.wireguard.android;
-
-import android.app.Fragment;
-import android.os.Bundle;
-
-import com.wireguard.android.backends.VpnService;
-import com.wireguard.config.Config;
-
-/**
- * Base class for fragments that need to remember the current configuration.
- */
-
-abstract class BaseConfigFragment extends Fragment {
-    private static final String KEY_CURRENT_CONFIG = "currentConfig";
-
-    private Config currentConfig;
-
-    protected Config getCurrentConfig() {
-        return currentConfig;
-    }
-
-    protected abstract void onCurrentConfigChanged(Config config);
-
-    @Override
-    public void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        // Restore the saved configuration if there is one; otherwise grab it from the arguments.
-        String initialConfig = null;
-        if (savedInstanceState != null)
-            initialConfig = savedInstanceState.getString(KEY_CURRENT_CONFIG);
-        else if (getArguments() != null)
-            initialConfig = getArguments().getString(KEY_CURRENT_CONFIG);
-        if (initialConfig != null && currentConfig == null)
-            setCurrentConfig(VpnService.getInstance().get(initialConfig));
-    }
-
-    @Override
-    public void onSaveInstanceState(final Bundle outState) {
-        super.onSaveInstanceState(outState);
-        if (currentConfig != null)
-            outState.putString(KEY_CURRENT_CONFIG, currentConfig.getName());
-    }
-
-    public void setCurrentConfig(final Config config) {
-        if (currentConfig == config)
-            return;
-        currentConfig = config;
-        onCurrentConfigChanged(currentConfig);
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/BootCompletedReceiver.java b/app/src/main/java/com/wireguard/android/BootCompletedReceiver.java
deleted file mode 100644
index 0bf28912..00000000
--- a/app/src/main/java/com/wireguard/android/BootCompletedReceiver.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package com.wireguard.android;
-
-import android.content.BroadcastReceiver;
-import android.content.Context;
-import android.content.Intent;
-
-import com.wireguard.android.backends.VpnService;
-
-public class BootCompletedReceiver extends BroadcastReceiver {
-
-    @Override
-    public void onReceive(final Context context, final Intent intent) {
-        if (!intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED))
-            return;
-        context.startService(new Intent(context, VpnService.class));
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/BootShutdownReceiver.java b/app/src/main/java/com/wireguard/android/BootShutdownReceiver.java
new file mode 100644
index 00000000..37de83c0
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/BootShutdownReceiver.java
@@ -0,0 +1,28 @@
+package com.wireguard.android;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.util.Log;
+
+import com.wireguard.android.model.TunnelManager;
+import com.wireguard.android.util.ExceptionLoggers;
+
+public class BootShutdownReceiver extends BroadcastReceiver {
+    private static final String TAG = BootShutdownReceiver.class.getSimpleName();
+
+    @Override
+    public void onReceive(final Context context, final Intent intent) {
+        final String action = intent.getAction();
+        if (action == null)
+            return;
+        final TunnelManager tunnelManager = Application.getComponent().getTunnelManager();
+        if (Intent.ACTION_BOOT_COMPLETED.equals(action)) {
+            Log.d(TAG, "Broadcast receiver restoring state (boot)");
+            tunnelManager.restoreState().whenComplete(ExceptionLoggers.D);
+        } else if (Intent.ACTION_SHUTDOWN.equals(action)) {
+            Log.d(TAG, "Broadcast receiver saving state (shutdown)");
+            tunnelManager.saveState().whenComplete(ExceptionLoggers.D);
+        }
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/ConfigActivity.java b/app/src/main/java/com/wireguard/android/ConfigActivity.java
deleted file mode 100644
index b92b34e3..00000000
--- a/app/src/main/java/com/wireguard/android/ConfigActivity.java
+++ /dev/null
@@ -1,289 +0,0 @@
-package com.wireguard.android;
-
-import android.app.Fragment;
-import android.app.FragmentManager;
-import android.app.FragmentTransaction;
-import android.content.Intent;
-import android.databinding.Observable;
-import android.os.Bundle;
-import android.view.Menu;
-import android.view.MenuItem;
-
-import com.wireguard.config.Config;
-
-/**
- * Activity that allows creating/viewing/editing/deleting WireGuard configurations.
- */
-
-public class ConfigActivity extends BaseConfigActivity {
-    private static final String KEY_EDITOR_STATE = "editorState";
-    private static final String TAG_DETAIL = "detail";
-    private static final String TAG_EDIT = "edit";
-    private static final String TAG_LIST = "list";
-
-    private Fragment.SavedState editorState;
-    private final FragmentManager fm = getFragmentManager();
-    private final FragmentCache fragments = new FragmentCache(fm);
-    private boolean isLayoutFinished;
-    private boolean isServiceAvailable;
-    private boolean isSingleLayout;
-    private boolean isStateSaved;
-    private int mainContainer;
-    private Observable.OnPropertyChangedCallback nameChangeCallback;
-    private String visibleFragmentTag;
-
-    /**
-     * Updates the fragment visible in the UI.
-     * Sets visibleFragmentTag.
-     *
-     * @param config The config that should be visible.
-     * @param tag    The tag of the fragment that should be visible.
-     */
-    private void moveToFragment(final Config config, final String tag) {
-        // Sanity check.
-        if (tag == null && config != null)
-            throw new IllegalArgumentException("Cannot set a config on a null fragment");
-        if ((tag == null && isSingleLayout) || (TAG_LIST.equals(tag) && !isSingleLayout))
-            throw new IllegalArgumentException("Requested tag " + tag + " does not match layout");
-        // First tear down fragments as necessary.
-        if (tag == null || TAG_LIST.equals(tag) || (TAG_DETAIL.equals(tag)
-                && TAG_EDIT.equals(visibleFragmentTag))) {
-            while (visibleFragmentTag != null && !visibleFragmentTag.equals(tag) &&
-                    fm.getBackStackEntryCount() > 0) {
-                final Fragment removedFragment = fm.findFragmentById(mainContainer);
-                // The fragment *must* be removed first, or it will stay attached to the layout!
-                fm.beginTransaction().remove(removedFragment).commit();
-                fm.popBackStackImmediate();
-                // Recompute the visible fragment.
-                if (TAG_EDIT.equals(visibleFragmentTag))
-                    visibleFragmentTag = TAG_DETAIL;
-                else if (isSingleLayout && TAG_DETAIL.equals(visibleFragmentTag))
-                    visibleFragmentTag = TAG_LIST;
-                else
-                    throw new IllegalStateException();
-            }
-        }
-        // Now build up intermediate entries in the back stack as necessary.
-        if (TAG_EDIT.equals(tag) && !TAG_EDIT.equals(visibleFragmentTag) &&
-                !TAG_DETAIL.equals(visibleFragmentTag))
-            moveToFragment(config, TAG_DETAIL);
-        // Finally, set the main container's content to the new top-level fragment.
-        if (tag == null) {
-            if (visibleFragmentTag != null) {
-                final BaseConfigFragment fragment = fragments.get(visibleFragmentTag);
-                fm.beginTransaction().remove(fragment).commit();
-                fm.executePendingTransactions();
-                visibleFragmentTag = null;
-            }
-        } else if (!TAG_LIST.equals(tag)) {
-            final BaseConfigFragment fragment = fragments.get(tag);
-            if (!tag.equals(visibleFragmentTag)) {
-                // Restore any saved editor state the first time its fragment is added.
-                if (TAG_EDIT.equals(tag) && editorState != null) {
-                    fragment.setInitialSavedState(editorState);
-                    editorState = null;
-                }
-                final FragmentTransaction transaction = fm.beginTransaction();
-                if (TAG_EDIT.equals(tag) || (isSingleLayout && TAG_DETAIL.equals(tag))) {
-                    transaction.addToBackStack(null);
-                    transaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
-                }
-                transaction.replace(mainContainer, fragment, tag).commit();
-                visibleFragmentTag = tag;
-            }
-            if (fragment.getCurrentConfig() != config)
-                fragment.setCurrentConfig(config);
-        }
-    }
-
-    /**
-     * Transition the state machine to the desired state, if possible.
-     * Sets currentConfig and isEditing.
-     *
-     * @param config          The desired config to show in the UI.
-     * @param shouldBeEditing Whether or not the config should be in the editing state.
-     */
-    private void moveToState(final Config config, final boolean shouldBeEditing) {
-        // Update the saved state.
-        setCurrentConfig(config);
-        setIsEditing(shouldBeEditing);
-        // Avoid performing fragment transactions when the app is not fully initialized.
-        if (!isLayoutFinished || !isServiceAvailable || isStateSaved)
-            return;
-        // Ensure the list is present in the master pane. It will be restored on activity restarts!
-        final BaseConfigFragment listFragment = fragments.get(TAG_LIST);
-        if (fm.findFragmentById(R.id.master_fragment) == null)
-            fm.beginTransaction().add(R.id.master_fragment, listFragment, TAG_LIST).commit();
-        // In the single-pane layout, the main container starts holding the list fragment.
-        if (isSingleLayout && visibleFragmentTag == null)
-            visibleFragmentTag = TAG_LIST;
-        // Forward any config changes to the list (they may have come from the intent or editing).
-        listFragment.setCurrentConfig(config);
-        // Ensure the correct main fragment is visible, adjusting the back stack as necessary.
-        moveToFragment(config, shouldBeEditing ? TAG_EDIT :
-                (config != null ? TAG_DETAIL : (isSingleLayout ? TAG_LIST : null)));
-        // Show the current config as the title if the list of configurations is not visible.
-        setTitle(isSingleLayout && config != null ? config.getName() : getString(R.string.app_name));
-        // Show or hide the action bar back button if the back stack is not empty.
-        if (getActionBar() != null) {
-            getActionBar().setDisplayHomeAsUpEnabled(config != null &&
-                    (isSingleLayout || shouldBeEditing));
-        }
-    }
-
-    @Override
-    public void onBackPressed() {
-        final ConfigListFragment listFragment = (ConfigListFragment) fragments.get(TAG_LIST);
-        if (listFragment.isVisible() && listFragment.tryCollapseMenu())
-            return;
-        super.onBackPressed();
-        // The visible fragment is now the one that was on top of the back stack, if there was one.
-        if (isEditing())
-            visibleFragmentTag = TAG_DETAIL;
-        else if (isSingleLayout && TAG_DETAIL.equals(visibleFragmentTag))
-            visibleFragmentTag = TAG_LIST;
-        // If the user went back from the detail screen to the list, clear the current config.
-        moveToState(isEditing() ? getCurrentConfig() : null, false);
-    }
-
-    @Override
-    public void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        if (savedInstanceState != null)
-            editorState = savedInstanceState.getParcelable(KEY_EDITOR_STATE);
-        setContentView(R.layout.config_activity);
-        isSingleLayout = findViewById(R.id.detail_fragment) == null;
-        mainContainer = isSingleLayout ? R.id.master_fragment : R.id.detail_fragment;
-        if (isSingleLayout) {
-            nameChangeCallback = new ConfigNameChangeCallback();
-            if (getCurrentConfig() != null)
-                getCurrentConfig().addOnPropertyChangedCallback(nameChangeCallback);
-        }
-        isLayoutFinished = true;
-        moveToState(getCurrentConfig(), isEditing());
-    }
-
-    @Override
-    public boolean onCreateOptionsMenu(final Menu menu) {
-        getMenuInflater().inflate(R.menu.main, menu);
-        return true;
-    }
-
-    @Override
-    protected void onCurrentConfigChanged(final Config oldConfig, final Config newConfig) {
-        if (nameChangeCallback != null && oldConfig != null)
-            oldConfig.removeOnPropertyChangedCallback(nameChangeCallback);
-        // Abandon editing a config when the current config changes.
-        moveToState(newConfig, false);
-        if (nameChangeCallback != null && newConfig != null)
-            newConfig.addOnPropertyChangedCallback(nameChangeCallback);
-    }
-
-    @Override
-    protected void onEditingStateChanged(final boolean isEditing) {
-        moveToState(getCurrentConfig(), isEditing);
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(final MenuItem item) {
-        switch (item.getItemId()) {
-            case android.R.id.home:
-                // The back arrow in the action bar should act the same as the back button.
-                onBackPressed();
-                return true;
-            case R.id.menu_action_edit:
-                // Try to make the editing fragment visible.
-                setIsEditing(true);
-                return true;
-            case R.id.menu_action_save:
-                // This menu item is handled by the editing fragment.
-                return false;
-            case R.id.menu_settings:
-                startActivity(new Intent(this, SettingsActivity.class));
-                return true;
-            default:
-                return super.onOptionsItemSelected(item);
-        }
-    }
-
-    @Override
-    public void onPostResume() {
-        super.onPostResume();
-        // Allow changes to fragments.
-        isStateSaved = false;
-        moveToState(getCurrentConfig(), isEditing());
-    }
-
-    @Override
-    public void onSaveInstanceState(final Bundle outState) {
-        // We cannot save fragments that might switch between containers if the layout changes.
-        if (isLayoutFinished && isServiceAvailable && !isStateSaved) {
-            // Save the editor state before destroying it.
-            if (TAG_EDIT.equals(visibleFragmentTag)) {
-                // For the case where the activity is resumed.
-                editorState = fm.saveFragmentInstanceState(fragments.get(TAG_EDIT));
-                // For the case where the activity is restarted.
-                outState.putParcelable(KEY_EDITOR_STATE, editorState);
-            }
-            moveToFragment(null, isSingleLayout ? TAG_LIST : null);
-        }
-        // Prevent further changes to fragments.
-        isStateSaved = true;
-        super.onSaveInstanceState(outState);
-    }
-
-    @Override
-    protected void onServiceAvailable() {
-        super.onServiceAvailable();
-        // Allow creating fragments.
-        isServiceAvailable = true;
-        moveToState(getCurrentConfig(), isEditing());
-    }
-
-    private class ConfigNameChangeCallback extends Observable.OnPropertyChangedCallback {
-        @Override
-        public void onPropertyChanged(final Observable sender, final int propertyId) {
-            if (sender != getCurrentConfig())
-                sender.removeOnPropertyChangedCallback(this);
-            if (propertyId != 0 && propertyId != BR.name)
-                return;
-            setTitle(getCurrentConfig().getName());
-        }
-    }
-
-    private static class FragmentCache {
-        private ConfigDetailFragment detailFragment;
-        private ConfigEditFragment editFragment;
-        private final FragmentManager fm;
-        private ConfigListFragment listFragment;
-
-        private FragmentCache(final FragmentManager fm) {
-            this.fm = fm;
-        }
-
-        private BaseConfigFragment get(final String tag) {
-            switch (tag) {
-                case TAG_DETAIL:
-                    if (detailFragment == null)
-                        detailFragment = (ConfigDetailFragment) fm.findFragmentByTag(tag);
-                    if (detailFragment == null)
-                        detailFragment = new ConfigDetailFragment();
-                    return detailFragment;
-                case TAG_EDIT:
-                    if (editFragment == null)
-                        editFragment = (ConfigEditFragment) fm.findFragmentByTag(tag);
-                    if (editFragment == null)
-                        editFragment = new ConfigEditFragment();
-                    return editFragment;
-                case TAG_LIST:
-                    if (listFragment == null)
-                        listFragment = (ConfigListFragment) fm.findFragmentByTag(tag);
-                    if (listFragment == null)
-                        listFragment = new ConfigListFragment();
-                    return listFragment;
-                default:
-                    throw new IllegalArgumentException();
-            }
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/ConfigDetailFragment.java b/app/src/main/java/com/wireguard/android/ConfigDetailFragment.java
deleted file mode 100644
index d6c02935..00000000
--- a/app/src/main/java/com/wireguard/android/ConfigDetailFragment.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package com.wireguard.android;
-
-import android.os.Bundle;
-import android.view.LayoutInflater;
-import android.view.Menu;
-import android.view.MenuInflater;
-import android.view.View;
-import android.view.ViewGroup;
-
-import com.wireguard.android.databinding.ConfigDetailFragmentBinding;
-import com.wireguard.config.Config;
-
-/**
- * Fragment for viewing information about a WireGuard configuration.
- */
-
-public class ConfigDetailFragment extends BaseConfigFragment {
-    private ConfigDetailFragmentBinding binding;
-
-    @Override
-    public void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setHasOptionsMenu(true);
-    }
-
-    @Override
-    public void onCreateOptionsMenu(final Menu menu, final MenuInflater inflater) {
-        inflater.inflate(R.menu.config_detail, menu);
-    }
-
-    @Override
-    public View onCreateView(final LayoutInflater inflater, final ViewGroup parent,
-                             final Bundle savedInstanceState) {
-        binding = ConfigDetailFragmentBinding.inflate(inflater, parent, false);
-        binding.setConfig(getCurrentConfig());
-        return binding.getRoot();
-    }
-
-    @Override
-    protected void onCurrentConfigChanged(final Config config) {
-        if (binding != null)
-            binding.setConfig(config);
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/ConfigEditFragment.java b/app/src/main/java/com/wireguard/android/ConfigEditFragment.java
deleted file mode 100644
index f29f20fe..00000000
--- a/app/src/main/java/com/wireguard/android/ConfigEditFragment.java
+++ /dev/null
@@ -1,139 +0,0 @@
-package com.wireguard.android;
-
-import android.app.Activity;
-import android.content.ClipData;
-import android.content.ClipboardManager;
-import android.content.Context;
-import android.os.Bundle;
-import android.view.LayoutInflater;
-import android.view.Menu;
-import android.view.MenuInflater;
-import android.view.MenuItem;
-import android.view.View;
-import android.view.ViewGroup;
-import android.view.inputmethod.InputMethodManager;
-import android.widget.Toast;
-
-import com.wireguard.android.backends.VpnService;
-import com.wireguard.android.databinding.ConfigEditFragmentBinding;
-import com.wireguard.config.Config;
-
-/**
- * Fragment for editing a WireGuard configuration.
- */
-
-public class ConfigEditFragment extends BaseConfigFragment {
-    private static final String KEY_MODIFIED_CONFIG = "modifiedConfig";
-    private static final String KEY_ORIGINAL_NAME = "originalName";
-
-    public static void copyPublicKey(final Context context, final String publicKey) {
-        if (publicKey == null || publicKey.isEmpty())
-            return;
-        final ClipboardManager clipboard =
-                (ClipboardManager) context.getSystemService(Context.CLIPBOARD_SERVICE);
-        final String description =
-                context.getResources().getString(R.string.public_key_description);
-        clipboard.setPrimaryClip(ClipData.newPlainText(description, publicKey));
-        final String message = context.getResources().getString(R.string.public_key_copied_message);
-        Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
-    }
-
-    private Config localConfig;
-    private String originalName;
-
-    @Override
-    protected void onCurrentConfigChanged(final Config config) {
-        // Only discard modifications when the config *they are based on* changes.
-        if (config == null || config.getName().equals(originalName) || localConfig == null)
-            return;
-        localConfig.copyFrom(config);
-        originalName = config.getName();
-    }
-
-    @Override
-    public void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        // Restore more saved information.
-        if (savedInstanceState != null) {
-            localConfig = savedInstanceState.getParcelable(KEY_MODIFIED_CONFIG);
-            originalName = savedInstanceState.getString(KEY_ORIGINAL_NAME);
-        } else if (getArguments() != null) {
-            final Bundle arguments = getArguments();
-            localConfig = arguments.getParcelable(KEY_MODIFIED_CONFIG);
-            originalName = arguments.getString(KEY_ORIGINAL_NAME);
-        }
-        if (localConfig == null) {
-            localConfig = new Config();
-            originalName = null;
-        }
-        onCurrentConfigChanged(getCurrentConfig());
-        setHasOptionsMenu(true);
-    }
-
-    @Override
-    public void onCreateOptionsMenu(final Menu menu, final MenuInflater inflater) {
-        inflater.inflate(R.menu.config_edit, menu);
-    }
-
-    @Override
-    public View onCreateView(final LayoutInflater inflater, final ViewGroup parent,
-                             final Bundle savedInstanceState) {
-        final ConfigEditFragmentBinding binding =
-                ConfigEditFragmentBinding.inflate(inflater, parent, false);
-        binding.setConfig(localConfig);
-        return binding.getRoot();
-    }
-
-    @Override
-    public void onDestroy() {
-        super.onDestroy();
-        // Reset changes to the config when the user cancels editing. See also the comment below.
-        if (isRemoving())
-            localConfig.copyFrom(getCurrentConfig());
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(final MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.menu_action_save:
-                saveConfig();
-                return true;
-            default:
-                return super.onOptionsItemSelected(item);
-        }
-    }
-
-    @Override
-    public void onSaveInstanceState(final Bundle outState) {
-        super.onSaveInstanceState(outState);
-        // When ConfigActivity unwinds the back stack, isRemoving() is true, so localConfig will be
-        // reset. Since outState is not serialized yet, it resets the saved config too. Avoid this
-        // by copying the local config. originalName is fine because it is replaced, not modified.
-        outState.putParcelable(KEY_MODIFIED_CONFIG, localConfig.copy());
-        outState.putString(KEY_ORIGINAL_NAME, originalName);
-    }
-
-    private void saveConfig() {
-        final VpnService service = VpnService.getInstance();
-        try {
-            if (getCurrentConfig() != null)
-                service.update(getCurrentConfig().getName(), localConfig);
-            else
-                service.add(localConfig);
-        } catch (final IllegalArgumentException | IllegalStateException e) {
-            Toast.makeText(getActivity(), e.getMessage(), Toast.LENGTH_SHORT).show();
-            return;
-        }
-        // Hide the keyboard; it rarely goes away on its own.
-        final Activity activity = getActivity();
-        final View focusedView = activity.getCurrentFocus();
-        if (focusedView != null) {
-            final InputMethodManager inputManager =
-                    (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
-            inputManager.hideSoftInputFromWindow(focusedView.getWindowToken(),
-                    InputMethodManager.HIDE_NOT_ALWAYS);
-        }
-        // Tell the activity to finish itself or go back to the detail view.
-        ((BaseConfigActivity) activity).setIsEditing(false);
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/ConfigListFragment.java b/app/src/main/java/com/wireguard/android/ConfigListFragment.java
deleted file mode 100644
index b7460134..00000000
--- a/app/src/main/java/com/wireguard/android/ConfigListFragment.java
+++ /dev/null
@@ -1,198 +0,0 @@
-package com.wireguard.android;
-
-import android.annotation.SuppressLint;
-import android.app.Activity;
-import android.content.Intent;
-import android.content.res.Resources;
-import android.os.Bundle;
-import android.view.ActionMode;
-import android.view.LayoutInflater;
-import android.view.Menu;
-import android.view.MenuItem;
-import android.view.MotionEvent;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.AbsListView;
-import android.widget.AdapterView;
-
-import com.wireguard.android.backends.VpnService;
-import com.wireguard.android.databinding.ObservableMapAdapter;
-import com.wireguard.android.databinding.ConfigListFragmentBinding;
-import com.wireguard.config.Config;
-
-import java.util.LinkedList;
-import java.util.List;
-
-/**
- * Fragment containing the list of known WireGuard configurations.
- */
-
-public class ConfigListFragment extends BaseConfigFragment {
-    private static final int REQUEST_IMPORT = 1;
-
-    private ConfigListFragmentBinding binding;
-
-    @Override
-    public void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
-        if (requestCode == REQUEST_IMPORT) {
-            if (resultCode == Activity.RESULT_OK)
-                VpnService.getInstance().importFrom(data.getData());
-        } else {
-            super.onActivityResult(requestCode, resultCode, data);
-        }
-    }
-
-    @Override
-    public void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-    }
-
-    @Override
-    public View onCreateView(final LayoutInflater inflater, final ViewGroup parent,
-                             final Bundle savedInstanceState) {
-        binding = ConfigListFragmentBinding.inflate(inflater, parent, false);
-        binding.setConfigs(VpnService.getInstance().getConfigs());
-        binding.addFromFile.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(final View view) {
-                final Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
-                intent.addCategory(Intent.CATEGORY_OPENABLE);
-                intent.setType("*/*");
-                startActivityForResult(intent, REQUEST_IMPORT);
-                binding.addMenu.collapse();
-            }
-        });
-        binding.addFromScratch.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(final View view) {
-                startActivity(new Intent(getActivity(), AddActivity.class));
-                binding.addMenu.collapse();
-            }
-        });
-        binding.configList.setMultiChoiceModeListener(new ConfigListModeListener());
-        binding.configList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
-            @Override
-            public void onItemClick(final AdapterView<?> parent, final View view,
-                                    final int position, final long id) {
-                final Config config = (Config) parent.getItemAtPosition(position);
-                setCurrentConfig(config);
-            }
-        });
-        binding.configList.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
-            @Override
-            public boolean onItemLongClick(final AdapterView<?> parent, final View view,
-                                           final int position, final long id) {
-                setConfigChecked(null);
-                binding.configList.setChoiceMode(AbsListView.CHOICE_MODE_MULTIPLE_MODAL);
-                binding.configList.setItemChecked(position, true);
-                return true;
-            }
-        });
-        binding.configList.setOnTouchListener(new View.OnTouchListener() {
-            @Override
-            @SuppressLint("ClickableViewAccessibility")
-            public boolean onTouch(final View view, final MotionEvent event) {
-                binding.addMenu.collapse();
-                return false;
-            }
-        });
-        binding.executePendingBindings();
-        setConfigChecked(getCurrentConfig());
-        return binding.getRoot();
-    }
-
-    @Override
-    protected void onCurrentConfigChanged(final Config config) {
-        final BaseConfigActivity activity = ((BaseConfigActivity) getActivity());
-        if (activity != null)
-            activity.setCurrentConfig(config);
-        if (binding != null)
-            setConfigChecked(config);
-    }
-
-    @Override
-    public void onDestroyView() {
-        super.onDestroyView();
-        binding = null;
-    }
-
-    private void setConfigChecked(final Config config) {
-        if (config != null) {
-            @SuppressWarnings("unchecked") final ObservableMapAdapter<String, Config> adapter =
-                    (ObservableMapAdapter<String, Config>) binding.configList.getAdapter();
-            final int position = adapter.getPosition(config.getName());
-            if (position >= 0)
-                binding.configList.setItemChecked(position, true);
-        } else {
-            final int position = binding.configList.getCheckedItemPosition();
-            if (position >= 0)
-                binding.configList.setItemChecked(position, false);
-        }
-    }
-
-    public boolean tryCollapseMenu() {
-        if (binding != null && binding.addMenu.isExpanded()) {
-            binding.addMenu.collapse();
-            return true;
-        }
-        return false;
-    }
-
-    private class ConfigListModeListener implements AbsListView.MultiChoiceModeListener {
-        private final List<Config> configsToRemove = new LinkedList<>();
-
-        @Override
-        public boolean onActionItemClicked(final ActionMode mode, final MenuItem item) {
-            switch (item.getItemId()) {
-                case R.id.menu_action_delete:
-                    // Ensure an unmanaged config is never the current config.
-                    if (configsToRemove.contains(getCurrentConfig()))
-                        setCurrentConfig(null);
-                    for (final Config config : configsToRemove)
-                        VpnService.getInstance().remove(config.getName());
-                    configsToRemove.clear();
-                    mode.finish();
-                    return true;
-                default:
-                    return false;
-            }
-        }
-
-        @Override
-        public void onItemCheckedStateChanged(final ActionMode mode, final int position,
-                                              final long id, final boolean checked) {
-            if (checked)
-                configsToRemove.add((Config) binding.configList.getItemAtPosition(position));
-            else
-                configsToRemove.remove(binding.configList.getItemAtPosition(position));
-            final int count = configsToRemove.size();
-            final Resources resources = binding.getRoot().getContext().getResources();
-            mode.setTitle(resources.getQuantityString(R.plurals.list_delete_title, count, count));
-        }
-
-        @Override
-        public boolean onCreateActionMode(final ActionMode mode, final Menu menu) {
-            mode.getMenuInflater().inflate(R.menu.config_list_delete, menu);
-            return true;
-        }
-
-        @Override
-        public void onDestroyActionMode(final ActionMode mode) {
-            configsToRemove.clear();
-            binding.configList.post(new Runnable() {
-                @Override
-                public void run() {
-                    binding.configList.setChoiceMode(AbsListView.CHOICE_MODE_SINGLE);
-                    // Restore the previous selection (before entering the action mode).
-                    setConfigChecked(getCurrentConfig());
-                }
-            });
-        }
-
-        @Override
-        public boolean onPrepareActionMode(final ActionMode mode, final Menu menu) {
-            configsToRemove.clear();
-            return false;
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/NotSupportedActivity.java b/app/src/main/java/com/wireguard/android/NotSupportedActivity.java
deleted file mode 100644
index 7b4d0bab..00000000
--- a/app/src/main/java/com/wireguard/android/NotSupportedActivity.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package com.wireguard.android;
-
-import android.app.Activity;
-import android.databinding.DataBindingUtil;
-import android.os.Build;
-import android.os.Bundle;
-import android.text.Html;
-import android.text.Spanned;
-import android.text.method.LinkMovementMethod;
-
-import com.wireguard.android.databinding.NotSupportedActivityBinding;
-
-public class NotSupportedActivity extends Activity {
-    @Override
-    protected void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        final NotSupportedActivityBinding binding =
-                DataBindingUtil.setContentView(this, R.layout.not_supported_activity);
-        final String messageHtml = getString(R.string.not_supported_message);
-        final Spanned messageText;
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N)
-            messageText = Html.fromHtml(messageHtml, Html.FROM_HTML_MODE_COMPACT);
-        else
-            messageText = Html.fromHtml(messageHtml);
-        binding.notSupportedMessage.setMovementMethod(LinkMovementMethod.getInstance());
-        binding.notSupportedMessage.setText(messageText);
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/QuickTileService.java b/app/src/main/java/com/wireguard/android/QuickTileService.java
index e512b1ad..9de4322a 100644
--- a/app/src/main/java/com/wireguard/android/QuickTileService.java
+++ b/app/src/main/java/com/wireguard/android/QuickTileService.java
@@ -1,40 +1,57 @@
 package com.wireguard.android;
 
 import android.annotation.TargetApi;
-import android.content.ComponentName;
-import android.content.Context;
 import android.content.Intent;
-import android.content.ServiceConnection;
 import android.content.SharedPreferences;
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
+import android.databinding.Observable;
+import android.databinding.Observable.OnPropertyChangedCallback;
+import android.databinding.ObservableMap.OnMapChangedCallback;
 import android.graphics.drawable.Icon;
 import android.os.Build;
-import android.os.IBinder;
-import android.preference.PreferenceManager;
 import android.service.quicksettings.Tile;
 import android.service.quicksettings.TileService;
+import android.util.Log;
+import android.widget.Toast;
 
-import com.wireguard.android.backends.VpnService;
-import com.wireguard.config.Config;
+import com.wireguard.android.Application.ApplicationComponent;
+import com.wireguard.android.activity.MainActivity;
+import com.wireguard.android.activity.SettingsActivity;
+import com.wireguard.android.model.Tunnel;
+import com.wireguard.android.model.Tunnel.State;
+import com.wireguard.android.model.TunnelCollection;
+import com.wireguard.android.model.TunnelManager;
+
+import java.util.Objects;
+
+/**
+ * Service that maintains the application's custom Quick Settings tile. This service is bound by the
+ * system framework as necessary to update the appearance of the tile in the system UI, and to
+ * forward click events to the application.
+ */
 
 @TargetApi(Build.VERSION_CODES.N)
-public class QuickTileService extends TileService {
-    private Config config;
+public class QuickTileService extends TileService implements OnSharedPreferenceChangeListener {
+    private static final String TAG = QuickTileService.class.getSimpleName();
+
+    private final OnTunnelStateChangedCallback tunnelCallback = new OnTunnelStateChangedCallback();
+    private final OnTunnelMapChangedCallback tunnelMapCallback = new OnTunnelMapChangedCallback();
     private SharedPreferences preferences;
-    private VpnService service;
+    private Tunnel tunnel;
+    private TunnelManager tunnelManager;
 
     @Override
     public void onClick() {
-        if (service != null && config != null) {
-            if (config.isEnabled())
-                service.disable(config.getName());
-            else
-                service.enable(config.getName());
+        if (tunnel != null) {
+            tunnel.setState(State.TOGGLE).handle(this::onToggleFinished);
         } else {
-            if (service != null && service.getConfigs().isEmpty()) {
-                startActivityAndCollapse(new Intent(this, ConfigActivity.class));
+            if (tunnelManager.getTunnels().isEmpty()) {
+                // Prompt the user to create or import a tunnel configuration.
+                startActivityAndCollapse(new Intent(this, MainActivity.class));
             } else {
+                // Prompt the user to select a tunnel for use with the quick settings tile.
                 final Intent intent = new Intent(this, SettingsActivity.class);
-                intent.putExtra("showQuickTile", true);
+                intent.putExtra(SettingsActivity.KEY_SHOW_QUICK_TILE_SETTINGS, true);
                 startActivityAndCollapse(intent);
             }
         }
@@ -42,50 +59,101 @@ public class QuickTileService extends TileService {
 
     @Override
     public void onCreate() {
-        preferences = PreferenceManager.getDefaultSharedPreferences(this);
-        service = VpnService.getInstance();
-        if (service == null)
-            bindService(new Intent(this, VpnService.class), new ServiceConnectionCallbacks(),
-                    Context.BIND_AUTO_CREATE);
-        TileService.requestListeningState(this, new ComponentName(this, getClass()));
+        super.onCreate();
+        final ApplicationComponent component = Application.getComponent();
+        preferences = component.getPreferences();
+        tunnelManager = component.getTunnelManager();
+    }
+
+    @Override
+    public void onSharedPreferenceChanged(final SharedPreferences preferences, final String key) {
+        if (!TunnelManager.KEY_PRIMARY_TUNNEL.equals(key))
+            return;
+        updateTile();
     }
 
     @Override
     public void onStartListening() {
-        // Since this is an active tile, this only gets called when we want to update the tile.
+        preferences.registerOnSharedPreferenceChangeListener(this);
+        tunnelManager.getTunnels().addOnMapChangedCallback(tunnelMapCallback);
+        if (tunnel != null)
+            tunnel.addOnPropertyChangedCallback(tunnelCallback);
+        updateTile();
+    }
+
+    @Override
+    public void onStopListening() {
+        preferences.unregisterOnSharedPreferenceChangeListener(this);
+        tunnelManager.getTunnels().removeOnMapChangedCallback(tunnelMapCallback);
+        if (tunnel != null)
+            tunnel.removeOnPropertyChangedCallback(tunnelCallback);
+    }
+
+    @SuppressWarnings("unused")
+    private Void onToggleFinished(final State state, final Throwable throwable) {
+        if (throwable == null)
+            return null;
+        Log.e(TAG, "Cannot toggle tunnel", throwable);
+        final String message = "Cannot toggle tunnel: " + throwable.getCause().getMessage();
+        Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
+        return null;
+    }
+
+    private void updateTile() {
+        // Update the tunnel.
+        final String currentName = tunnel != null ? tunnel.getName() : null;
+        final String newName = preferences.getString(TunnelManager.KEY_PRIMARY_TUNNEL, null);
+        if (!Objects.equals(currentName, newName)) {
+            final TunnelCollection tunnels = tunnelManager.getTunnels();
+            final Tunnel newTunnel = newName != null ? tunnels.get(newName) : null;
+            if (tunnel != null)
+                tunnel.removeOnPropertyChangedCallback(tunnelCallback);
+            tunnel = newTunnel;
+            if (tunnel != null)
+                tunnel.addOnPropertyChangedCallback(tunnelCallback);
+        }
+        // Update the tile contents.
+        final String label;
+        final int state;
         final Tile tile = getQsTile();
-        final String configName = preferences.getString(VpnService.KEY_PRIMARY_CONFIG, null);
-        config = configName != null && service != null ? service.get(configName) : null;
-        if (config != null) {
-            tile.setLabel(config.getName());
-            final int state = config.isEnabled() ? Tile.STATE_ACTIVE : Tile.STATE_INACTIVE;
-            if (tile.getState() != state) {
-                // The icon must be changed every time the state changes, or the color won't change.
-                final Integer iconResource = (state == Tile.STATE_ACTIVE) ?
-                        R.drawable.ic_tile : R.drawable.ic_tile_disabled;
-                tile.setIcon(Icon.createWithResource(this, iconResource));
-                tile.setState(state);
-            }
+        if (tunnel != null) {
+            label = tunnel.getName();
+            state = tunnel.getState() == Tunnel.State.UP ? Tile.STATE_ACTIVE : Tile.STATE_INACTIVE;
         } else {
-            tile.setIcon(Icon.createWithResource(this, R.drawable.ic_tile_disabled));
-            tile.setLabel(getString(R.string.app_name));
-            tile.setState(Tile.STATE_INACTIVE);
+            label = getString(R.string.app_name);
+            state = Tile.STATE_INACTIVE;
+        }
+        tile.setLabel(label);
+        if (tile.getState() != state) {
+            // The icon must be changed every time the state changes, or the shade will not change.
+            final Integer iconResource = (state == Tile.STATE_ACTIVE)
+                    ? R.drawable.ic_tile : R.drawable.ic_tile_disabled;
+            tile.setIcon(Icon.createWithResource(this, iconResource));
+            tile.setState(state);
         }
         tile.updateTile();
     }
 
-    private class ServiceConnectionCallbacks implements ServiceConnection {
+    private final class OnTunnelMapChangedCallback
+            extends OnMapChangedCallback<TunnelCollection, String, Tunnel> {
         @Override
-        public void onServiceConnected(final ComponentName component, final IBinder binder) {
-            // We don't actually need a binding, only notification that the service is started.
-            unbindService(this);
-            service = VpnService.getInstance();
+        public void onMapChanged(final TunnelCollection sender, final String key) {
+            if (!key.equals(preferences.getString(TunnelManager.KEY_PRIMARY_TUNNEL, null)))
+                return;
+            updateTile();
         }
+    }
 
+    private final class OnTunnelStateChangedCallback extends OnPropertyChangedCallback {
         @Override
-        public void onServiceDisconnected(final ComponentName component) {
-            // This can never happen; the service runs in the same thread as this service.
-            throw new IllegalStateException();
+        public void onPropertyChanged(final Observable sender, final int propertyId) {
+            if (!Objects.equals(sender, tunnel)) {
+                sender.removeOnPropertyChangedCallback(this);
+                return;
+            }
+            if (propertyId != 0 && propertyId != BR.state)
+                return;
+            updateTile();
         }
     }
 }
diff --git a/app/src/main/java/com/wireguard/android/activity/BaseActivity.java b/app/src/main/java/com/wireguard/android/activity/BaseActivity.java
new file mode 100644
index 00000000..4bd3407e
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/activity/BaseActivity.java
@@ -0,0 +1,94 @@
+package com.wireguard.android.activity;
+
+import android.app.Activity;
+import android.databinding.CallbackRegistry;
+import android.databinding.CallbackRegistry.NotifierCallback;
+import android.os.Bundle;
+
+import com.wireguard.android.Application;
+import com.wireguard.android.model.Tunnel;
+import com.wireguard.android.model.TunnelManager;
+
+import java.util.Objects;
+
+/**
+ * Base class for activities that need to remember the currently-selected tunnel.
+ */
+
+public abstract class BaseActivity extends Activity {
+    private static final String TAG = BaseActivity.class.getSimpleName();
+
+    private final SelectionChangeRegistry selectionChangeRegistry = new SelectionChangeRegistry();
+    private Tunnel selectedTunnel;
+
+    public void addOnSelectedTunnelChangedListener(
+            final OnSelectedTunnelChangedListener listener) {
+        selectionChangeRegistry.add(listener);
+    }
+
+    public Tunnel getSelectedTunnel() {
+        return selectedTunnel;
+    }
+
+    @Override
+    protected void onCreate(final Bundle savedInstanceState) {
+        // Restore the saved tunnel if there is one; otherwise grab it from the arguments.
+        String savedTunnelName = null;
+        if (savedInstanceState != null)
+            savedTunnelName = savedInstanceState.getString(TunnelManager.KEY_SELECTED_TUNNEL);
+        else if (getIntent() != null)
+            savedTunnelName = getIntent().getStringExtra(TunnelManager.KEY_SELECTED_TUNNEL);
+        if (savedTunnelName != null) {
+            final TunnelManager manager = Application.getComponent().getTunnelManager();
+            selectedTunnel = manager.getTunnels().get(savedTunnelName);
+        }
+        // The selected tunnel must be set before the superclass method recreates fragments.
+        super.onCreate(savedInstanceState);
+    }
+
+    @Override
+    protected void onSaveInstanceState(final Bundle outState) {
+        if (selectedTunnel != null)
+            outState.putString(TunnelManager.KEY_SELECTED_TUNNEL, selectedTunnel.getName());
+        super.onSaveInstanceState(outState);
+    }
+
+    protected abstract Tunnel onSelectedTunnelChanged(Tunnel oldTunnel, Tunnel newTunnel);
+
+    public void removeOnSelectedTunnelChangedListener(
+            final OnSelectedTunnelChangedListener listener) {
+        selectionChangeRegistry.remove(listener);
+    }
+
+    public void setSelectedTunnel(final Tunnel tunnel) {
+        final Tunnel oldTunnel = selectedTunnel;
+        if (Objects.equals(oldTunnel, tunnel))
+            return;
+        // Give the activity a chance to override the tunnel change.
+        selectedTunnel = onSelectedTunnelChanged(oldTunnel, tunnel);
+        if (Objects.equals(oldTunnel, selectedTunnel))
+            return;
+        selectionChangeRegistry.notifyCallbacks(oldTunnel, 0, selectedTunnel);
+    }
+
+    public interface OnSelectedTunnelChangedListener {
+        void onSelectedTunnelChanged(Tunnel oldTunnel, Tunnel newTunnel);
+    }
+
+    private static final class SelectionChangeNotifier
+            extends NotifierCallback<OnSelectedTunnelChangedListener, Tunnel, Tunnel> {
+        @Override
+        public void onNotifyCallback(final OnSelectedTunnelChangedListener listener,
+                                     final Tunnel oldTunnel, final int ignored,
+                                     final Tunnel newTunnel) {
+            listener.onSelectedTunnelChanged(oldTunnel, newTunnel);
+        }
+    }
+
+    private static final class SelectionChangeRegistry
+            extends CallbackRegistry<OnSelectedTunnelChangedListener, Tunnel, Tunnel> {
+        private SelectionChangeRegistry() {
+            super(new SelectionChangeNotifier());
+        }
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/activity/MainActivity.java b/app/src/main/java/com/wireguard/android/activity/MainActivity.java
new file mode 100644
index 00000000..2d06a9a9
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/activity/MainActivity.java
@@ -0,0 +1,146 @@
+package com.wireguard.android.activity;
+
+import android.app.Fragment;
+import android.app.FragmentTransaction;
+import android.content.Intent;
+import android.os.Bundle;
+import android.util.Log;
+import android.view.Menu;
+import android.view.MenuItem;
+
+import com.wireguard.android.R;
+import com.wireguard.android.fragment.ConfigEditorFragment;
+import com.wireguard.android.fragment.TunnelDetailFragment;
+import com.wireguard.android.fragment.TunnelListFragment;
+import com.wireguard.android.model.Tunnel;
+
+import java9.util.stream.Stream;
+
+/**
+ * CRUD interface for WireGuard tunnels. This activity serves as the main entry point to the
+ * WireGuard application, and contains several fragments for listing, viewing details of, and
+ * editing the configuration and interface state of WireGuard tunnels.
+ */
+
+public class MainActivity extends BaseActivity {
+    private static final String KEY_STATE = "fragment_state";
+    private static final String TAG = MainActivity.class.getSimpleName();
+    private State state = State.EMPTY;
+
+    private boolean moveToState(final State nextState) {
+        Log.i(TAG, "Moving from " + state.name() + " to " + nextState.name());
+        if (nextState == state) {
+            return false;
+        } else if (nextState.layer > state.layer + 1) {
+            moveToState(State.ofLayer(state.layer + 1));
+            moveToState(nextState);
+            return true;
+        } else if (nextState.layer == state.layer + 1) {
+            final Fragment fragment = Fragment.instantiate(this, nextState.fragment);
+            final FragmentTransaction transaction = getFragmentManager().beginTransaction()
+                    .replace(R.id.master_fragment, fragment)
+                    .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
+            if (state.layer > 0)
+                transaction.addToBackStack(null);
+            transaction.commit();
+        } else if (nextState.layer == state.layer - 1) {
+            if (getFragmentManager().getBackStackEntryCount() == 0)
+                return false;
+            getFragmentManager().popBackStack();
+        } else if (nextState.layer < state.layer - 1) {
+            moveToState(State.ofLayer(state.layer - 1));
+            moveToState(nextState);
+            return true;
+        }
+        state = nextState;
+        if (state.layer > 1) {
+            if (getActionBar() != null)
+                getActionBar().setDisplayHomeAsUpEnabled(true);
+        } else {
+            if (getActionBar() != null)
+                getActionBar().setDisplayHomeAsUpEnabled(false);
+            setSelectedTunnel(null);
+        }
+        return true;
+    }
+
+    @Override
+    public void onBackPressed() {
+        if (!moveToState(State.ofLayer(state.layer - 1)))
+            super.onBackPressed();
+    }
+
+    @Override
+    protected void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.main_activity);
+        if (savedInstanceState != null && savedInstanceState.getString(KEY_STATE) != null)
+            state = State.valueOf(savedInstanceState.getString(KEY_STATE));
+        if (state == State.EMPTY) {
+            State initialState = getSelectedTunnel() != null ? State.DETAIL : State.LIST;
+            if (getIntent() != null && getIntent().getStringExtra(KEY_STATE) != null)
+                initialState = State.valueOf(getIntent().getStringExtra(KEY_STATE));
+            moveToState(initialState);
+        }
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(final Menu menu) {
+        getMenuInflater().inflate(R.menu.main_activity, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(final MenuItem item) {
+        switch (item.getItemId()) {
+            case android.R.id.home:
+                // The back arrow in the action bar should act the same as the back button.
+                moveToState(State.ofLayer(state.layer - 1));
+                return true;
+            case R.id.menu_action_edit:
+                if (getSelectedTunnel() != null)
+                    moveToState(State.EDITOR);
+                return true;
+            case R.id.menu_action_save:
+                // This menu item is handled by the editor fragment.
+                return false;
+            case R.id.menu_settings:
+                startActivity(new Intent(this, SettingsActivity.class));
+                return true;
+            default:
+                return super.onOptionsItemSelected(item);
+        }
+    }
+
+    @Override
+    protected void onSaveInstanceState(final Bundle outState) {
+        outState.putString(KEY_STATE, state.name());
+        super.onSaveInstanceState(outState);
+    }
+
+
+    @Override
+    protected Tunnel onSelectedTunnelChanged(final Tunnel oldTunnel, final Tunnel newTunnel) {
+        moveToState(newTunnel != null ? State.DETAIL : State.LIST);
+        return newTunnel;
+    }
+
+    private enum State {
+        EMPTY(null, 0),
+        LIST(TunnelListFragment.class, 1),
+        DETAIL(TunnelDetailFragment.class, 2),
+        EDITOR(ConfigEditorFragment.class, 3);
+
+        private final String fragment;
+        private final int layer;
+
+        State(final Class<? extends Fragment> fragment, final int layer) {
+            this.fragment = fragment != null ? fragment.getName() : null;
+            this.layer = layer;
+        }
+
+        private static State ofLayer(final int layer) {
+            return Stream.of(State.values()).filter(s -> s.layer == layer).findFirst().get();
+        }
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/SettingsActivity.java b/app/src/main/java/com/wireguard/android/activity/SettingsActivity.java
index 70912a48..c6c69789 100644
--- a/app/src/main/java/com/wireguard/android/SettingsActivity.java
+++ b/app/src/main/java/com/wireguard/android/activity/SettingsActivity.java
@@ -1,23 +1,34 @@
-package com.wireguard.android;
+package com.wireguard.android.activity;
 
 import android.app.Activity;
-import android.app.FragmentTransaction;
+import android.app.Fragment;
 import android.content.Context;
 import android.os.AsyncTask;
 import android.os.Bundle;
 import android.preference.Preference;
 import android.preference.PreferenceFragment;
 
-import com.wireguard.android.backends.RootShell;
+import com.wireguard.android.R;
+import com.wireguard.android.preference.TunnelListPreference;
+import com.wireguard.android.util.RootShell;
+
+/**
+ * Interface for changing application-global persistent settings.
+ */
 
 public class SettingsActivity extends Activity {
+    public static final String KEY_SHOW_QUICK_TILE_SETTINGS = "show_quick_tile_settings";
+
     @Override
     protected void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        final FragmentTransaction transaction = getFragmentManager().beginTransaction();
-        final SettingsFragment fragment = new SettingsFragment();
-        fragment.setArguments(getIntent().getExtras());
-        transaction.replace(android.R.id.content, fragment).commit();
+        if (getFragmentManager().findFragmentById(android.R.id.content) == null) {
+            final Fragment fragment = new SettingsFragment();
+            fragment.setArguments(getIntent().getExtras());
+            getFragmentManager().beginTransaction()
+                    .add(android.R.id.content, fragment)
+                    .commit();
+        }
     }
 
     public static class SettingsFragment extends PreferenceFragment {
@@ -25,44 +36,42 @@ public class SettingsActivity extends Activity {
         public void onCreate(final Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);
             addPreferencesFromResource(R.xml.preferences);
-            if (getArguments() != null && getArguments().getBoolean("showQuickTile"))
-                ((ConfigListPreference) findPreference("primary_config")).show();
-
             final Preference installTools = findPreference("install_cmd_line_tools");
-            installTools.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
-                public boolean onPreferenceClick(Preference preference) {
-                    new ToolsInstaller(installTools).execute();
-                    return true;
-                }
+            installTools.setOnPreferenceClickListener(preference -> {
+                new ToolsInstaller(preference).execute();
+                return true;
             });
+            if (getArguments() != null && getArguments().getBoolean(KEY_SHOW_QUICK_TILE_SETTINGS))
+                ((TunnelListPreference) findPreference("primary_config")).show();
         }
     }
 
-    private static class ToolsInstaller extends AsyncTask<Void, Void, Integer> {
-        Preference installTools;
+    private static final class ToolsInstaller extends AsyncTask<Void, Void, Integer> {
+        private static final String[][] LIBRARY_NAMED_EXECUTABLES = {
+                {"libwg.so", "wg"},
+                {"libwg-quick.so", "wg-quick"}
+        };
 
-        public ToolsInstaller(Preference installTools) {
-            this.installTools = installTools;
-            installTools.setEnabled(false);
-            installTools.setSummary(installTools.getContext().getString(R.string.install_cmd_line_tools_progress));
-        }
+        private final Context context;
+        private final Preference preference;
 
-        private static final String[][] libraryNamedExecutables = {
-                { "libwg.so", "wg" },
-                { "libwg-quick.so", "wg-quick" }
-        };
+        private ToolsInstaller(final Preference preference) {
+            context = preference.getContext();
+            this.preference = preference;
+            preference.setEnabled(false);
+            preference.setSummary(context.getString(R.string.install_cmd_line_tools_progress));
+        }
 
         @Override
         protected Integer doInBackground(final Void... voids) {
-            final Context context = installTools.getContext();
             final String libDir = context.getApplicationInfo().nativeLibraryDir;
             final StringBuilder cmd = new StringBuilder();
 
             cmd.append("set -ex;");
 
-            for (final String[] libraryNamedExecutable : libraryNamedExecutables) {
-                final String arg1 = "'" + libDir + "/" + libraryNamedExecutable[0] + "'";
-                final String arg2 = "'/system/xbin/" + libraryNamedExecutable[1] + "'";
+            for (final String[] libraryNamedExecutable : LIBRARY_NAMED_EXECUTABLES) {
+                final String arg1 = '\'' + libDir + '/' + libraryNamedExecutable[0] + '\'';
+                final String arg2 = "'/system/xbin/" + libraryNamedExecutable[1] + '\'';
 
                 cmd.append(String.format("cmp -s %s %s && ", arg1, arg2));
             }
@@ -71,9 +80,9 @@ public class SettingsActivity extends Activity {
             cmd.append("trap 'mount -o ro,remount /system' EXIT;");
             cmd.append("mount -o rw,remount /system;");
 
-            for (final String[] libraryNamedExecutable : libraryNamedExecutables) {
-                final String arg1 = "'" + libDir + "/" + libraryNamedExecutable[0] + "'";
-                final String arg2 = "'/system/xbin/" + libraryNamedExecutable[1] + "'";
+            for (final String[] libraryNamedExecutable : LIBRARY_NAMED_EXECUTABLES) {
+                final String arg1 = '\'' + libDir + '/' + libraryNamedExecutable[0] + '\'';
+                final String arg2 = "'/system/xbin/" + libraryNamedExecutable[1] + '\'';
                 cmd.append(String.format("cp %s %s; chmod 755 %s;", arg1, arg2, arg2));
             }
 
@@ -82,8 +91,7 @@ public class SettingsActivity extends Activity {
 
         @Override
         protected void onPostExecute(final Integer ret) {
-            final Context context = installTools.getContext();
-            String status;
+            final String status;
 
             switch (ret) {
                 case 0:
@@ -96,8 +104,8 @@ public class SettingsActivity extends Activity {
                     status = context.getString(R.string.install_cmd_line_tools_failure);
                     break;
             }
-            installTools.setSummary(status);
-            installTools.setEnabled(true);
+            preference.setSummary(status);
+            preference.setEnabled(true);
         }
     }
 }
diff --git a/app/src/main/java/com/wireguard/android/activity/TunnelCreatorActivity.java b/app/src/main/java/com/wireguard/android/activity/TunnelCreatorActivity.java
new file mode 100644
index 00000000..2e0454ee
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/activity/TunnelCreatorActivity.java
@@ -0,0 +1,28 @@
+package com.wireguard.android.activity;
+
+import android.os.Bundle;
+
+import com.wireguard.android.fragment.ConfigEditorFragment;
+import com.wireguard.android.model.Tunnel;
+
+/**
+ * Created by samuel on 12/29/17.
+ */
+
+public class TunnelCreatorActivity extends BaseActivity {
+    @Override
+    protected void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        if (getFragmentManager().findFragmentById(android.R.id.content) == null) {
+            getFragmentManager().beginTransaction()
+                    .add(android.R.id.content, new ConfigEditorFragment())
+                    .commit();
+        }
+    }
+
+    @Override
+    protected Tunnel onSelectedTunnelChanged(final Tunnel oldTunnel, final Tunnel newTunnel) {
+        finish();
+        return null;
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/backend/Backend.java b/app/src/main/java/com/wireguard/android/backend/Backend.java
new file mode 100644
index 00000000..c44f626a
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/backend/Backend.java
@@ -0,0 +1,57 @@
+package com.wireguard.android.backend;
+
+import com.wireguard.android.model.Tunnel;
+import com.wireguard.android.model.Tunnel.State;
+import com.wireguard.android.model.Tunnel.Statistics;
+import com.wireguard.config.Config;
+
+import java9.util.concurrent.CompletionStage;
+
+/**
+ * Interface for implementations of the WireGuard secure network tunnel.
+ */
+
+public interface Backend {
+    /**
+     * Update the volatile configuration of a running tunnel, asynchronously, and return the
+     * resulting configuration. If the tunnel is not up, return the configuration that would result
+     * (if known), or else simply return the given configuration.
+     *
+     * @param tunnel The tunnel to apply the configuration to.
+     * @param config The new configuration for this tunnel.
+     * @return A future completed when the configuration of the tunnel has been updated, and the new
+     * volatile configuration has been determined. This future will always be completed on the main
+     * thread.
+     */
+    CompletionStage<Config> applyConfig(Tunnel tunnel, Config config);
+
+    /**
+     * Get the actual state of a tunnel, asynchronously.
+     *
+     * @param tunnel The tunnel to examine the state of.
+     * @return A future completed when the state of the tunnel has been determined. This future will
+     * always be completed on the main thread.
+     */
+    CompletionStage<State> getState(Tunnel tunnel);
+
+    /**
+     * Get statistics about traffic and errors on this tunnel, asynchronously. If the tunnel is not
+     * running, the statistics object will be filled with zero values.
+     *
+     * @param tunnel The tunnel to retrieve statistics for.
+     * @return A future completed when statistics for the tunnel are available. This future will
+     * always be completed on the main thread.
+     */
+    CompletionStage<Statistics> getStatistics(Tunnel tunnel);
+
+    /**
+     * Set the state of a tunnel, asynchronously.
+     *
+     * @param tunnel The tunnel to control the state of.
+     * @param state  The new state for this tunnel. Must be {@code UP}, {@code DOWN}, or
+     *               {@code TOGGLE}.
+     * @return A future completed when the state of the tunnel has changed, containing the new state
+     * of the tunnel. This future will always be completed on the main thread.
+     */
+    CompletionStage<State> setState(Tunnel tunnel, State state);
+}
diff --git a/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java b/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
new file mode 100644
index 00000000..af6bc771
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java
@@ -0,0 +1,94 @@
+package com.wireguard.android.backend;
+
+import android.content.Context;
+import android.util.Log;
+
+import com.wireguard.android.model.Tunnel;
+import com.wireguard.android.model.Tunnel.State;
+import com.wireguard.android.model.Tunnel.Statistics;
+import com.wireguard.android.util.AsyncWorker;
+import com.wireguard.android.util.RootShell;
+import com.wireguard.config.Config;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+
+import java9.util.concurrent.CompletableFuture;
+import java9.util.concurrent.CompletionStage;
+
+/**
+ * Created by samuel on 12/19/17.
+ */
+
+public final class WgQuickBackend implements Backend {
+    private static final String TAG = WgQuickBackend.class.getSimpleName();
+
+    private final AsyncWorker asyncWorker;
+    private final Context context;
+    private final RootShell rootShell;
+
+    public WgQuickBackend(final AsyncWorker asyncWorker, final Context context,
+                          final RootShell rootShell) {
+        this.asyncWorker = asyncWorker;
+        this.context = context;
+        this.rootShell = rootShell;
+    }
+
+    private static State resolveState(final State currentState, State requestedState) {
+        if (requestedState == State.UNKNOWN)
+            throw new IllegalArgumentException("Requested unknown state");
+        if (requestedState == State.TOGGLE)
+            requestedState = currentState == State.UP ? State.DOWN : State.UP;
+        return requestedState;
+    }
+
+    @Override
+    public CompletionStage<Config> applyConfig(final Tunnel tunnel, final Config config) {
+        if (tunnel.getState() == State.UP)
+            return CompletableFuture.failedFuture(new UnsupportedOperationException("stub"));
+        return CompletableFuture.completedFuture(config);
+    }
+
+    @Override
+    public CompletionStage<State> getState(final Tunnel tunnel) {
+        Log.v(TAG, "Requested state for tunnel " + tunnel.getName());
+        return asyncWorker.supplyAsync(() -> {
+            final List<String> output = new LinkedList<>();
+            final State state;
+            if (rootShell.run(output, "wg show interfaces") != 0) {
+                state = State.UNKNOWN;
+            } else if (output.isEmpty()) {
+                // There are no running interfaces.
+                state = State.DOWN;
+            } else {
+                // wg puts all interface names on the same line. Split them into separate elements.
+                final String[] names = output.get(0).split(" ");
+                state = Arrays.asList(names).contains(tunnel.getName()) ? State.UP : State.DOWN;
+            }
+            Log.v(TAG, "Got state " + state + " for tunnel " + tunnel.getName());
+            return state;
+        });
+    }
+
+    @Override
+    public CompletionStage<Statistics> getStatistics(final Tunnel tunnel) {
+        return CompletableFuture.completedFuture(new Statistics());
+    }
+
+    @Override
+    public CompletionStage<State> setState(final Tunnel tunnel, final State state) {
+        Log.v(TAG, "Requested state change to " + state + " for tunnel " + tunnel.getName());
+        return tunnel.getStateAsync().thenCompose(currentState -> asyncWorker.supplyAsync(() -> {
+            final String stateName = resolveState(currentState, state).name().toLowerCase();
+            final File file = new File(context.getFilesDir(), tunnel.getName() + ".conf");
+            final String path = file.getAbsolutePath();
+            // FIXME: Assumes file layout from FIleConfigStore. Use a temporary file.
+            if (rootShell.run(null, String.format("wg-quick %s '%s'", stateName, path)) != 0)
+                throw new IOException("wg-quick failed");
+            return tunnel;
+        })).thenCompose(this::getState);
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/backends/VpnService.java b/app/src/main/java/com/wireguard/android/backends/VpnService.java
deleted file mode 100644
index 5002a835..00000000
--- a/app/src/main/java/com/wireguard/android/backends/VpnService.java
+++ /dev/null
@@ -1,559 +0,0 @@
-package com.wireguard.android.backends;
-
-import android.app.Service;
-import android.content.ComponentName;
-import android.content.ContentResolver;
-import android.content.Intent;
-import android.content.SharedPreferences;
-import android.database.Cursor;
-import android.net.Uri;
-import android.os.AsyncTask;
-import android.os.Binder;
-import android.os.Build;
-import android.os.IBinder;
-import android.preference.PreferenceManager;
-import android.provider.OpenableColumns;
-import android.service.quicksettings.TileService;
-import android.system.OsConstants;
-import android.util.Log;
-import android.widget.Toast;
-
-import com.wireguard.android.NotSupportedActivity;
-import com.wireguard.android.QuickTileService;
-import com.wireguard.android.R;
-import com.wireguard.android.databinding.ObservableSortedMap;
-import com.wireguard.android.databinding.ObservableTreeMap;
-import com.wireguard.config.Config;
-import com.wireguard.config.Peer;
-
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.FilenameFilter;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Set;
-
-/**
- * Service that handles config state coordination and all background processing for the application.
- */
-
-public class VpnService extends Service
-        implements SharedPreferences.OnSharedPreferenceChangeListener {
-    public static final String KEY_ENABLED_CONFIGS = "enabled_configs";
-    public static final String KEY_PRIMARY_CONFIG = "primary_config";
-    public static final String KEY_RESTORE_ON_BOOT = "restore_on_boot";
-    private static final String TAG = "WireGuard/VpnService";
-
-    private static VpnService instance;
-    private final IBinder binder = new Binder();
-    private final ObservableTreeMap<String, Config> configurations = new ObservableTreeMap<>();
-    private final Set<String> enabledConfigs = new HashSet<>();
-    private SharedPreferences preferences;
-    private String primaryName;
-    private RootShell rootShell;
-
-    public static VpnService getInstance() {
-        return instance;
-    }
-
-    /**
-     * Add a new configuration to the set of known configurations. The configuration will initially
-     * be disabled. The configuration's name must be unique within the set of known configurations.
-     *
-     * @param config The configuration to add.
-     */
-    public void add(final Config config) {
-        new ConfigUpdater(null, config, false).execute();
-    }
-
-    /**
-     * Attempt to disable and tear down an interface for this configuration. The configuration's
-     * enabled state will be updated the operation is successful. If this configuration is already
-     * disconnected, or it is not a known configuration, no changes will be made.
-     *
-     * @param name The name of the configuration (in the set of known configurations) to disable.
-     */
-    public void disable(final String name) {
-        final Config config = configurations.get(name);
-        if (config == null || !config.isEnabled())
-            return;
-        new ConfigDisabler(config).execute();
-    }
-
-    /**
-     * Attempt to set up and enable an interface for this configuration. The configuration's enabled
-     * state will be updated if the operation is successful. If this configuration is already
-     * enabled, or it is not a known configuration, no changes will be made.
-     *
-     * @param name The name of the configuration (in the set of known configurations) to enable.
-     */
-    public void enable(final String name) {
-        final Config config = configurations.get(name);
-        if (config == null || config.isEnabled())
-            return;
-        new ConfigEnabler(config).execute();
-    }
-
-    /**
-     * Retrieve a configuration known and managed by this service. The returned object must not be
-     * modified directly.
-     *
-     * @param name The name of the configuration (in the set of known configurations) to retrieve.
-     * @return An object representing the configuration. This object must not be modified.
-     */
-    public Config get(final String name) {
-        return configurations.get(name);
-    }
-
-    /**
-     * Retrieve the set of configurations known and managed by the service. Configurations in this
-     * set must not be modified directly. If a configuration is to be updated, first create a copy
-     * of it by calling getCopy().
-     *
-     * @return The set of known configurations.
-     */
-    public ObservableSortedMap<String, Config> getConfigs() {
-        return configurations;
-    }
-
-    public void importFrom(final Uri... uris) {
-        new ConfigImporter().execute(uris);
-    }
-
-    @Override
-    public IBinder onBind(final Intent intent) {
-        instance = this;
-        return binder;
-    }
-
-    @Override
-    public void onCreate() {
-        // Ensure the service sticks around after being unbound. This only needs to happen once.
-        startService(new Intent(this, getClass()));
-        rootShell = new RootShell(this);
-        new ConfigLoader().execute(getFilesDir().listFiles(new FilenameFilter() {
-            @Override
-            public boolean accept(final File dir, final String name) {
-                return name.endsWith(".conf");
-            }
-        }));
-        preferences = PreferenceManager.getDefaultSharedPreferences(this);
-        preferences.registerOnSharedPreferenceChangeListener(this);
-    }
-
-    @Override
-    public void onDestroy() {
-        preferences.unregisterOnSharedPreferenceChangeListener(this);
-    }
-
-    @Override
-    public void onSharedPreferenceChanged(final SharedPreferences preferences,
-                                          final String key) {
-        if (!KEY_PRIMARY_CONFIG.equals(key))
-            return;
-        boolean changed = false;
-        final String newName = preferences.getString(key, null);
-        if (primaryName != null && !primaryName.equals(newName)) {
-            final Config oldConfig = configurations.get(primaryName);
-            if (oldConfig != null)
-                oldConfig.setIsPrimary(false);
-            changed = true;
-        }
-        if (newName != null && !newName.equals(primaryName)) {
-            final Config newConfig = configurations.get(newName);
-            if (newConfig != null)
-                newConfig.setIsPrimary(true);
-            else
-                preferences.edit().remove(KEY_PRIMARY_CONFIG).apply();
-            changed = true;
-        }
-        primaryName = newName;
-        if (changed)
-            updateTile();
-    }
-
-    @Override
-    public int onStartCommand(final Intent intent, final int flags, final int startId) {
-        instance = this;
-        return START_STICKY;
-    }
-
-    /**
-     * Remove a configuration from being managed by the service. If it is currently enabled, the
-     * the configuration will be disabled before removal. If successful, the configuration will be
-     * removed from persistent storage. If the configuration is not known to the service, no changes
-     * will be made.
-     *
-     * @param name The name of the configuration (in the set of known configurations) to remove.
-     */
-    public void remove(final String name) {
-        final Config config = configurations.get(name);
-        if (config == null)
-            return;
-        if (config.isEnabled())
-            new ConfigDisabler(config).execute();
-        new ConfigRemover(config).execute();
-    }
-
-    /**
-     * Update the attributes of the named configuration. If the configuration is currently enabled,
-     * it will be disabled before the update, and the service will attempt to re-enable it
-     * afterward. If successful, the updated configuration will be saved to persistent storage.
-     *
-     * @param name   The name of an existing configuration to update.
-     * @param config A copy of the configuration, with updated attributes.
-     */
-    public void update(final String name, final Config config) {
-        if (name == null)
-            return;
-        if (configurations.containsValue(config))
-            throw new IllegalArgumentException("Config " + config.getName() + " modified directly");
-        final Config oldConfig = configurations.get(name);
-        if (oldConfig == null)
-            return;
-        final boolean wasEnabled = oldConfig.isEnabled();
-        if (wasEnabled)
-            new ConfigDisabler(oldConfig).execute();
-        new ConfigUpdater(oldConfig, config, wasEnabled).execute();
-    }
-
-    private void updateTile() {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
-            return;
-        Log.v(TAG, "Requesting quick tile update");
-        TileService.requestListeningState(this, new ComponentName(this, QuickTileService.class));
-    }
-
-    private class ConfigDisabler extends AsyncTask<Void, Void, Boolean> {
-        private final Config config;
-
-        private ConfigDisabler(final Config config) {
-            this.config = config;
-        }
-
-        @Override
-        protected Boolean doInBackground(final Void... voids) {
-            Log.i(TAG, "Running wg-quick down for " + config.getName());
-            final File configFile = new File(getFilesDir(), config.getName() + ".conf");
-            return rootShell.run(null, "wg-quick down '" + configFile.getPath() + "'") == 0;
-        }
-
-        @Override
-        protected void onPostExecute(final Boolean result) {
-            config.setIsEnabled(!result);
-            if (!result) {
-                Toast.makeText(getApplicationContext(), getString(R.string.error_down),
-                        Toast.LENGTH_SHORT).show();
-                return;
-            }
-            enabledConfigs.remove(config.getName());
-            preferences.edit().putStringSet(KEY_ENABLED_CONFIGS, enabledConfigs).apply();
-            if (config.getName().equals(primaryName))
-                updateTile();
-        }
-    }
-
-    private class ConfigEnabler extends AsyncTask<Void, Void, Integer> {
-        private final Config config;
-
-        private ConfigEnabler(final Config config) {
-            this.config = config;
-        }
-
-        @Override
-        protected Integer doInBackground(final Void... voids) {
-            if (!new File("/sys/module/wireguard").exists())
-                return -0xfff0001;
-            if (!existsInPath("su"))
-                return -0xfff0002;
-            Log.i(TAG, "Running wg-quick up for " + config.getName());
-            final File configFile = new File(getFilesDir(), config.getName() + ".conf");
-            final int ret = rootShell.run(null, "wg-quick up '" + configFile.getPath() + "'");
-            if (ret == OsConstants.EACCES)
-                return -0xfff0002;
-            return ret;
-        }
-
-        private boolean existsInPath(final String file) {
-            final String pathEnv = System.getenv("PATH");
-            if (pathEnv == null)
-                return false;
-            final String[] paths = pathEnv.split(":");
-            for (final String path : paths)
-                if (new File(path, file).exists())
-                    return true;
-            return false;
-        }
-
-        @Override
-        protected void onPostExecute(final Integer ret) {
-            config.setIsEnabled(ret == 0);
-            if (ret != 0) {
-                if (ret == -0xfff0001) {
-                    startActivity(new Intent(getApplicationContext(), NotSupportedActivity.class));
-                } else if (ret == -0xfff0002) {
-                    Toast.makeText(getApplicationContext(), getString(R.string.error_su),
-                            Toast.LENGTH_LONG).show();
-                } else {
-                    Toast.makeText(getApplicationContext(), getString(R.string.error_up),
-                            Toast.LENGTH_SHORT).show();
-                }
-                return;
-            }
-            enabledConfigs.add(config.getName());
-            preferences.edit().putStringSet(KEY_ENABLED_CONFIGS, enabledConfigs).apply();
-            if (config.getName().equals(primaryName))
-                updateTile();
-        }
-    }
-
-    private class ConfigImporter extends AsyncTask<Uri, String, List<File>> {
-        @Override
-        protected List<File> doInBackground(final Uri... uris) {
-            final ContentResolver contentResolver = getContentResolver();
-            final List<File> files = new ArrayList<>(uris.length);
-            for (final Uri uri : uris) {
-                if (isCancelled())
-                    return null;
-                String name = null;
-                if ("file".equals(uri.getScheme())) {
-                    name = uri.getLastPathSegment();
-                } else {
-                    final String[] columns = {OpenableColumns.DISPLAY_NAME};
-                    try (final Cursor cursor =
-                                 getContentResolver().query(uri, columns, null, null, null)) {
-                        if (cursor != null && cursor.moveToFirst() && !cursor.isNull(0)) {
-                            name = cursor.getString(0);
-                            Log.v(getClass().getSimpleName(), "Got name via cursor");
-                        }
-                    }
-                    if (name == null) {
-                        name = Uri.decode(uri.getLastPathSegment());
-                        if (name.indexOf('/') >= 0)
-                            name = name.substring(name.lastIndexOf('/') + 1);
-                        Log.v(getClass().getSimpleName(), "Got name from urlencoded path");
-                    }
-                }
-                if (!name.endsWith(".conf"))
-                    name = name + ".conf";
-                if (!Config.isNameValid(name.substring(0, name.length() - 5))) {
-                    Log.v(getClass().getSimpleName(), "Detected name is not valid: " + name);
-                    publishProgress(name + ": Invalid config filename");
-                    continue;
-                }
-                Log.d(getClass().getSimpleName(), "Mapped URI " + uri + " to file name " + name);
-                final File output = new File(getFilesDir(), name);
-                if (output.exists()) {
-                    Log.w(getClass().getSimpleName(), "Config file " + name + " already exists");
-                    publishProgress(name + " already exists");
-                    continue;
-                }
-                try (final InputStream in = contentResolver.openInputStream(uri);
-                     final OutputStream out = new FileOutputStream(output, false)) {
-                    if (in == null)
-                        throw new IOException("Failed to open input");
-                    // FIXME: This is a rather arbitrary size.
-                    final byte[] buffer = new byte[4096];
-                    int bytes;
-                    while ((bytes = in.read(buffer)) != -1)
-                        out.write(buffer, 0, bytes);
-                    files.add(output);
-                } catch (final IOException e) {
-                    Log.w(getClass().getSimpleName(), "Failed to import config from " + uri, e);
-                    publishProgress(name + ": " + e.getMessage());
-                }
-            }
-            return files;
-        }
-
-        @Override
-        protected void onProgressUpdate(final String... errors) {
-            Toast.makeText(getApplicationContext(), errors[0], Toast.LENGTH_SHORT).show();
-        }
-
-        @Override
-        protected void onPostExecute(final List<File> files) {
-            new ConfigLoader().execute(files.toArray(new File[files.size()]));
-        }
-    }
-
-    private class ConfigLoader extends AsyncTask<File, String, List<Config>> {
-        @Override
-        protected List<Config> doInBackground(final File... files) {
-            final List<Config> configs = new LinkedList<>();
-            final List<String> interfaces = new LinkedList<>();
-            final String command = "wg show interfaces";
-            if (rootShell.run(interfaces, command) == 0 && interfaces.size() == 1) {
-                // wg puts all interface names on the same line. Split them into separate elements.
-                final String nameList = interfaces.get(0);
-                Collections.addAll(interfaces, nameList.split(" "));
-                interfaces.remove(0);
-            } else {
-                interfaces.clear();
-                Log.w(TAG, "No existing WireGuard interfaces found. Maybe they are all disabled?");
-            }
-            for (final File file : files) {
-                if (isCancelled())
-                    return null;
-                final String fileName = file.getName();
-                final String configName = fileName.substring(0, fileName.length() - 5);
-                Log.v(TAG, "Attempting to load config " + configName);
-                try {
-                    final Config config = new Config();
-                    config.parseFrom(openFileInput(fileName));
-                    config.setIsEnabled(interfaces.contains(configName));
-                    config.setName(configName);
-                    configs.add(config);
-                } catch (IllegalArgumentException | IOException e) {
-                    if (!file.delete()) {
-                        Log.e(TAG, "Could not delete configuration for config " + configName);
-                    }
-                    Log.w(TAG, "Failed to load config from " + fileName, e);
-                    publishProgress(fileName + ": " + e.getMessage());
-                }
-            }
-            return configs;
-        }
-
-        @Override
-        protected void onProgressUpdate(final String... errors) {
-            Toast.makeText(getApplicationContext(), errors[0], Toast.LENGTH_SHORT).show();
-        }
-
-        @Override
-        protected void onPostExecute(final List<Config> configs) {
-            if (configs == null)
-                return;
-            for (final Config config : configs)
-                configurations.put(config.getName(), config);
-            // Run the handler to avoid duplicating the code here.
-            onSharedPreferenceChanged(preferences, KEY_PRIMARY_CONFIG);
-            if (preferences.getBoolean(KEY_RESTORE_ON_BOOT, false)) {
-                final Set<String> configsToEnable =
-                        preferences.getStringSet(KEY_ENABLED_CONFIGS, null);
-                if (configsToEnable != null) {
-                    for (final String name : configsToEnable) {
-                        final Config config = configurations.get(name);
-                        if (config != null && !config.isEnabled())
-                            new ConfigEnabler(config).execute();
-                    }
-                }
-            }
-        }
-    }
-
-    private class ConfigRemover extends AsyncTask<Void, Void, Boolean> {
-        private final Config config;
-
-        private ConfigRemover(final Config config) {
-            this.config = config;
-        }
-
-        @Override
-        protected Boolean doInBackground(final Void... voids) {
-            Log.i(TAG, "Removing config " + config.getName());
-            final File configFile = new File(getFilesDir(), config.getName() + ".conf");
-            if (configFile.delete()) {
-                return true;
-            } else {
-                Log.e(TAG, "Could not delete configuration for config " + config.getName());
-                return false;
-            }
-        }
-
-        @Override
-        protected void onPostExecute(final Boolean result) {
-            if (!result)
-                return;
-            configurations.remove(config.getName());
-            if (config.getName().equals(primaryName)) {
-                // This will get picked up by the preference change listener.
-                preferences.edit().remove(KEY_PRIMARY_CONFIG).apply();
-            }
-        }
-    }
-
-    private class ConfigUpdater extends AsyncTask<Void, Void, Boolean> {
-        private final Config newConfig;
-        private final String newName;
-        private final String oldName;
-        private final Boolean shouldConnect;
-        private Config knownConfig;
-
-        private ConfigUpdater(final Config knownConfig, final Config newConfig,
-                              final Boolean shouldConnect) {
-            this.knownConfig = knownConfig;
-            this.newConfig = newConfig.copy();
-            newName = newConfig.getName();
-            // When adding a config, "old file" and "new file" are the same thing.
-            oldName = knownConfig != null ? knownConfig.getName() : newName;
-            this.shouldConnect = shouldConnect;
-            if (newName == null || !Config.isNameValid(newName))
-                throw new IllegalArgumentException("This configuration does not have a valid name");
-            if (isAddOrRename() && configurations.containsKey(newName))
-                throw new IllegalStateException("Configuration " + newName + " already exists");
-            if (newConfig.getInterface().getPublicKey() == null)
-                throw new IllegalArgumentException("This configuration needs a valid private key");
-            for (final Peer peer : newConfig.getPeers())
-                if (peer.getPublicKey() == null || peer.getPublicKey().isEmpty())
-                    throw new IllegalArgumentException("Each peer must have a valid public key");
-        }
-
-        @Override
-        protected Boolean doInBackground(final Void... voids) {
-            Log.i(TAG, (knownConfig == null ? "Adding" : "Updating") + " config " + newName);
-            final File newFile = new File(getFilesDir(), newName + ".conf");
-            final File oldFile = new File(getFilesDir(), oldName + ".conf");
-            if (isAddOrRename() && newFile.exists()) {
-                Log.w(TAG, "Refusing to overwrite existing config configuration");
-                return false;
-            }
-            try {
-                final FileOutputStream stream = openFileOutput(oldFile.getName(), MODE_PRIVATE);
-                stream.write(newConfig.toString().getBytes(StandardCharsets.UTF_8));
-                stream.close();
-            } catch (final IOException e) {
-                Log.e(TAG, "Could not save configuration for config " + oldName, e);
-                return false;
-            }
-            if (isRename() && !oldFile.renameTo(newFile)) {
-                Log.e(TAG, "Could not rename " + oldFile.getName() + " to " + newFile.getName());
-                return false;
-            }
-            return true;
-        }
-
-        private boolean isAddOrRename() {
-            return knownConfig == null || !newName.equals(oldName);
-        }
-
-        private boolean isRename() {
-            return knownConfig != null && !newName.equals(oldName);
-        }
-
-        @Override
-        protected void onPostExecute(final Boolean result) {
-            if (!result)
-                return;
-            if (knownConfig != null)
-                configurations.remove(oldName);
-            if (knownConfig == null)
-                knownConfig = new Config();
-            knownConfig.copyFrom(newConfig);
-            knownConfig.setIsEnabled(false);
-            knownConfig.setIsPrimary(oldName != null && oldName.equals(primaryName));
-            configurations.put(newName, knownConfig);
-            if (isRename() && oldName != null && oldName.equals(primaryName))
-                preferences.edit().putString(KEY_PRIMARY_CONFIG, newName).apply();
-            if (shouldConnect)
-                new ConfigEnabler(knownConfig).execute();
-        }
-    }
-}
diff --git a/app/src/main/java/com/wireguard/android/configStore/ConfigStore.java b/app/src/main/java/com/wireguard/android/configStore/ConfigStore.java
new file mode 100644
index 00000000..19bb6bf5
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/configStore/ConfigStore.java
@@ -0,0 +1,65 @@
+package com.wireguard.android.configStore;
+
+import com.wireguard.config.Config;
+
+import java.util.Set;
+
+import java9.util.concurrent.CompletionStage;
+
+/**
+ * Interface for persistent storage providers for WireGuard configurations.
+ */
+
+public interface ConfigStore {
+    /**
+     * Create a persistent tunnel, which must have a unique name within the persistent storage
+     * medium.
+     *
+     * @param name   The name of the tunnel to create.
+     * @param config Configuration for the new tunnel.
+     * @return A future completed when the tunnel and its configuration have been saved to
+     * persistent storage. This future encapsulates the configuration that was actually saved to
+     * persistent storage. This future will always be completed on the main thread.
+     */
+    CompletionStage<Config> create(final String name, final Config config);
+
+    /**
+     * Delete a persistent tunnel.
+     *
+     * @param name The name of the tunnel to delete.
+     * @return A future completed when the tunnel and its configuration have been deleted. This
+     * future will always be completed on the main thread.
+     */
+    CompletionStage<Void> delete(final String name);
+
+    /**
+     * Enumerate the names of tunnels present in persistent storage.
+     *
+     * @return A future completed when the set of present tunnel names is available. This future
+     * will always be completed on the main thread.
+     */
+    CompletionStage<Set<String>> enumerate();
+
+    /**
+     * Load the configuration for the tunnel given by {@code name}.
+     *
+     * @param name The identifier for the configuration in persistent storage (i.e. the name of the
+     *             tunnel).
+     * @return A future completed when an in-memory representation of the configuration is
+     * available. This future encapsulates the configuration loaded from persistent storage. This
+     * future will always be completed on the main thread.
+     */
+    CompletionStage<Config> load(final String name);
+
+    /**
+     * Save the configuration for an existing tunnel given by {@code name}.
+     *
+     * @param name   The identifier for the configuration in persistent storage (i.e. the name of
+     *               the tunnel).
+     * @param config An updated configuration object for the tunnel.
+     * @return A future completed when the configuration has been saved to persistent storage. This
+     * future encapsulates the configuration that was actually saved to persistent storage. This
+     * future will always be completed on the main thread.
+     */
+    CompletionStage<Config> save(final String name, final Config config);
+}
diff --git a/app/src/main/java/com/wireguard/android/configStore/FileConfigStore.java b/app/src/main/java/com/wireguard/android/configStore/FileConfigStore.java
new file mode 100644
index 00000000..099bc0d3
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/configStore/FileConfigStore.java
@@ -0,0 +1,98 @@
+package com.wireguard.android.configStore;
+
+import android.content.Context;
+import android.util.Log;
+
+import com.wireguard.android.Application.ApplicationContext;
+import com.wireguard.android.util.AsyncWorker;
+import com.wireguard.config.Config;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.Set;
+
+import java9.util.concurrent.CompletionStage;
+import java9.util.stream.Collectors;
+import java9.util.stream.Stream;
+
+/**
+ * Created by samuel on 12/28/17.
+ */
+
+public final class FileConfigStore implements ConfigStore {
+    private static final String TAG = FileConfigStore.class.getSimpleName();
+
+    private final AsyncWorker asyncWorker;
+    private final Context context;
+
+    public FileConfigStore(final AsyncWorker asyncWorker,
+                           @ApplicationContext final Context context) {
+        this.asyncWorker = asyncWorker;
+        this.context = context;
+    }
+
+    @Override
+    public CompletionStage<Config> create(final String name, final Config config) {
+        return asyncWorker.supplyAsync(() -> {
+            final File file = fileFor(name);
+            if (!file.createNewFile()) {
+                final String message = "Configuration file " + file.getName() + " already exists";
+                throw new IllegalStateException(message);
+            }
+            try (FileOutputStream stream = new FileOutputStream(file, false)) {
+                stream.write(config.toString().getBytes(StandardCharsets.UTF_8));
+                return config;
+            }
+        });
+    }
+
+    @Override
+    public CompletionStage<Void> delete(final String name) {
+        return asyncWorker.runAsync(() -> {
+            final File file = fileFor(name);
+            if (!file.delete())
+                throw new IOException("Cannot delete configuration file " + file.getName());
+        });
+    }
+
+    @Override
+    public CompletionStage<Set<String>> enumerate() {
+        return asyncWorker.supplyAsync(() -> Stream.of(context.fileList())
+                .filter(name -> name.endsWith(".conf"))
+                .map(name -> name.substring(0, name.length() - ".conf".length()))
+                .collect(Collectors.toUnmodifiableSet()));
+    }
+
+    private File fileFor(final String name) {
+        return new File(context.getFilesDir(), name + ".conf");
+    }
+
+    @Override
+    public CompletionStage<Config> load(final String name) {
+        return asyncWorker.supplyAsync(() -> {
+            try (FileInputStream stream = new FileInputStream(fileFor(name))) {
+                return Config.from(stream);
+            }
+        });
+    }
+
+    @Override
+    public CompletionStage<Config> save(final String name, final Config config) {
+        Log.d(TAG, "Requested save config for tunnel " + name);
+        return asyncWorker.supplyAsync(() -> {
+            final File file = fileFor(name);
+            if (!file.isFile()) {
+                final String message = "Configuration file " + file.getName() + " not found";
+                throw new IllegalStateException(message);
+            }
+            try (FileOutputStream stream = new FileOutputStream(file, false)) {
+                Log.d(TAG, "Writing out config for tunnel " + name);
+                stream.write(config.toString().getBytes(StandardCharsets.UTF_8));
+                return config;
+            }
+        });
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/databinding/BindingAdapters.java b/app/src/main/java/com/wireguard/android/databinding/BindingAdapters.java
index 5dfc2d19..072a9fdc 100644
--- a/app/src/main/java/com/wireguard/android/databinding/BindingAdapters.java
+++ b/app/src/main/java/com/wireguard/android/databinding/BindingAdapters.java
@@ -12,13 +12,22 @@ import android.widget.TextView;
 import com.wireguard.android.R;
 import com.wireguard.android.widget.ToggleSwitch;
 
+import org.threeten.bp.Instant;
+import org.threeten.bp.ZoneId;
+import org.threeten.bp.ZonedDateTime;
+import org.threeten.bp.format.DateTimeFormatter;
+
 /**
  * Static methods for use by generated code in the Android data binding library.
  */
 
-@SuppressWarnings("unused")
+@SuppressWarnings({"unused", "WeakerAccess"})
 public final class BindingAdapters {
-    @BindingAdapter({"app:checked"})
+    private BindingAdapters() {
+        // Prevent instantiation.
+    }
+
+    @BindingAdapter({"checked"})
     public static void setChecked(final ToggleSwitch view, final boolean checked) {
         view.setCheckedInternal(checked);
     }
@@ -80,9 +89,9 @@ public final class BindingAdapters {
 
     @BindingAdapter({"items", "layout"})
     public static <K extends Comparable<K>, V> void setItems(final ListView view,
-                                                             final ObservableSortedMap<K, V> oldMap,
+                                                             final ObservableNavigableMap<K, V> oldMap,
                                                              final int oldLayoutId,
-                                                             final ObservableSortedMap<K, V> newMap,
+                                                             final ObservableNavigableMap<K, V> newMap,
                                                              final int newLayoutId) {
         if (oldMap == newMap && oldLayoutId == newLayoutId)
             return;
@@ -105,19 +114,26 @@ public final class BindingAdapters {
         adapter.setMap(newMap);
     }
 
-    @BindingAdapter({"app:onBeforeCheckedChanged"})
+    @BindingAdapter({"onBeforeCheckedChanged"})
     public static void setOnBeforeCheckedChanged(final ToggleSwitch view,
                                                  final ToggleSwitch.OnBeforeCheckedChangeListener
                                                          listener) {
         view.setOnBeforeCheckedChangeListener(listener);
     }
 
+    @BindingAdapter({"android:text"})
+    public static void setText(final TextView view, final Instant instant) {
+        if (instant == null || Instant.EPOCH.equals(instant)) {
+            view.setText(R.string.never);
+        } else {
+            final ZoneId defaultZone = ZoneId.systemDefault();
+            final ZonedDateTime zonedDateTime = ZonedDateTime.ofInstant(instant, defaultZone);
+            view.setText(zonedDateTime.format(DateTimeFormatter.RFC_1123_DATE_TIME));
+        }
+    }
+
     @BindingAdapter({"android:textStyle"})
     public static void setTextStyle(final TextView view, final Typeface typeface) {
         view.setTypeface(typeface);
     }
-
-    private BindingAdapters() {
-        // Prevent instantiation.
-    }
 }
diff --git a/app/src/main/java/com/wireguard/android/databinding/ItemChangeListener.java b/app/src/main/java/com/wireguard/android/databinding/ItemChangeListener.java
index 6d8debf2..2b693c9f 100644
--- a/app/src/main/java/com/wireguard/android/databinding/ItemChangeListener.java
+++ b/app/src/main/java/com/wireguard/android/databinding/ItemChangeListener.java
@@ -32,6 +32,7 @@ class ItemChangeListener<T> {
         ViewDataBinding binding = DataBindingUtil.getBinding(convertView);
         if (binding == null)
             binding = DataBindingUtil.inflate(layoutInflater, layoutId, container, false);
+        binding.setVariable(BR.collection, list);
         binding.setVariable(BR.item, list.get(position));
         binding.executePendingBindings();
         return binding.getRoot();
@@ -49,7 +50,7 @@ class ItemChangeListener<T> {
         }
     }
 
-    private static class OnListChangedCallback<T>
+    private static final class OnListChangedCallback<T>
             extends ObservableList.OnListChangedCallback<ObservableList<T>> {
 
         private final WeakReference<ItemChangeListener<T>> weakListener;
diff --git a/app/src/main/java/com/wireguard/android/databinding/ObservableListAdapter.java b/app/src/main/java/com/wireguard/android/databinding/ObservableListAdapter.java
index 5727900d..5c4e8c0a 100644
--- a/app/src/main/java/com/wireguard/android/databinding/ObservableListAdapter.java
+++ b/app/src/main/java/com/wireguard/android/databinding/ObservableListAdapter.java
@@ -8,7 +8,6 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.BaseAdapter;
-import android.widget.ListAdapter;
 
 import com.wireguard.android.BR;
 
@@ -18,7 +17,7 @@ import java.lang.ref.WeakReference;
  * A generic ListAdapter backed by an ObservableList.
  */
 
-class ObservableListAdapter<T> extends BaseAdapter implements ListAdapter {
+class ObservableListAdapter<T> extends BaseAdapter {
     private final OnListChangedCallback<T> callback = new OnListChangedCallback<>(this);
     private final int layoutId;
     private final LayoutInflater layoutInflater;
@@ -54,6 +53,7 @@ class ObservableListAdapter<T> extends BaseAdapter implements ListAdapter {
         ViewDataBinding binding = DataBindingUtil.getBinding(convertView);
         if (binding == null)
             binding = DataBindingUtil.inflate(layoutInflater, layoutId, parent, false);
+        binding.setVariable(BR.collection, list);
         binding.setVariable(BR.item, getItem(position));
         binding.executePendingBindings();
         return binding.getRoot();
@@ -74,7 +74,7 @@ class ObservableListAdapter<T> extends BaseAdapter implements ListAdapter {
         notifyDataSetChanged();
     }
 
-    private static class OnListChangedCallback<U>
+    private static final class OnListChangedCallback<U>
             extends ObservableList.OnListChangedCallback<ObservableList<U>> {
 
         private final WeakReference<ObservableListAdapter<U>> weakAdapter;
diff --git a/app/src/main/java/com/wireguard/android/databinding/ObservableMapAdapter.java b/app/src/main/java/com/wireguard/android/databinding/ObservableMapAdapter.java
index 70180728..4f63d6dd 100644
--- a/app/src/main/java/com/wireguard/android/databinding/ObservableMapAdapter.java
+++ b/app/src/main/java/com/wireguard/android/databinding/ObservableMapAdapter.java
@@ -8,28 +8,27 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.BaseAdapter;
-import android.widget.ListAdapter;
 
 import com.wireguard.android.BR;
 
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 
 /**
  * A generic ListAdapter backed by a TreeMap that adds observability.
  */
 
-public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapter
-        implements ListAdapter {
+public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapter {
     private final OnMapChangedCallback<K, V> callback = new OnMapChangedCallback<>(this);
-    private ArrayList<K> keys;
     private final int layoutId;
     private final LayoutInflater layoutInflater;
-    private ObservableSortedMap<K, V> map;
+    private List<K> keys;
+    private ObservableNavigableMap<K, V> map;
 
     ObservableMapAdapter(final Context context, final int layoutId,
-                         final ObservableSortedMap<K, V> map) {
+                         final ObservableNavigableMap<K, V> map) {
         this.layoutId = layoutId;
         layoutInflater = LayoutInflater.from(context);
         setMap(map);
@@ -51,14 +50,17 @@ public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapte
     public long getItemId(final int position) {
         if (map == null || position < 0 || position >= map.size())
             return -1;
-        return getItem(position).hashCode();
+        //final V item = getItem(position);
+        //return item != null ? item.hashCode() : -1;
+        final K key = getKey(position);
+        return key.hashCode();
     }
 
     private K getKey(final int position) {
         return getKeys().get(position);
     }
 
-    private ArrayList<K> getKeys() {
+    private List<K> getKeys() {
         if (keys == null)
             keys = new ArrayList<>(map.keySet());
         return keys;
@@ -75,6 +77,7 @@ public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapte
         ViewDataBinding binding = DataBindingUtil.getBinding(convertView);
         if (binding == null)
             binding = DataBindingUtil.inflate(layoutInflater, layoutId, parent, false);
+        binding.setVariable(BR.collection, map);
         binding.setVariable(BR.key, getKey(position));
         binding.setVariable(BR.item, getItem(position));
         binding.executePendingBindings();
@@ -86,7 +89,7 @@ public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapte
         return true;
     }
 
-    void setMap(final ObservableSortedMap<K, V> newMap) {
+    void setMap(final ObservableNavigableMap<K, V> newMap) {
         if (map != null)
             map.removeOnMapChangedCallback(callback);
         keys = null;
@@ -97,8 +100,8 @@ public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapte
         notifyDataSetChanged();
     }
 
-    private static class OnMapChangedCallback<K extends Comparable<K>, V>
-            extends ObservableMap.OnMapChangedCallback<ObservableSortedMap<K, V>, K, V> {
+    private static final class OnMapChangedCallback<K extends Comparable<K>, V>
+            extends ObservableMap.OnMapChangedCallback<ObservableNavigableMap<K, V>, K, V> {
 
         private final WeakReference<ObservableMapAdapter<K, V>> weakAdapter;
 
@@ -107,7 +110,7 @@ public class ObservableMapAdapter<K extends Comparable<K>, V> extends BaseAdapte
         }
 
         @Override
-        public void onMapChanged(final ObservableSortedMap<K, V> sender, final K key) {
+        public void onMapChanged(final ObservableNavigableMap<K, V> sender, final K key) {
             final ObservableMapAdapter<K, V> adapter = weakAdapter.get();
             if (adapter != null) {
                 adapter.keys = null;
diff --git a/app/src/main/java/com/wireguard/android/databinding/ObservableSortedMap.java b/app/src/main/java/com/wireguard/android/databinding/ObservableNavigableMap.java
index 1cbfeb6b..ab8a4a1f 100644
--- a/app/src/main/java/com/wireguard/android/databinding/ObservableSortedMap.java
+++ b/app/src/main/java/com/wireguard/android/databinding/ObservableNavigableMap.java
@@ -2,12 +2,12 @@ package com.wireguard.android.databinding;
 
 import android.databinding.ObservableMap;
 
-import java.util.SortedMap;
+import java.util.NavigableMap;
 
 /**
  * Interface for maps that are both observable and sorted.
  */
 
-public interface ObservableSortedMap<K, V> extends ObservableMap<K, V>, SortedMap<K, V> {
+public interface ObservableNavigableMap<K, V> extends NavigableMap<K, V>, ObservableMap<K, V> {
     // No additional methods.
 }
diff --git a/app/src/main/java/com/wireguard/android/databinding/ObservableTreeMap.java b/app/src/main/java/com/wireguard/android/databinding/ObservableTreeMap.java
index dc5f705b..074e122c 100644
--- a/app/src/main/java/com/wireguard/android/databinding/ObservableTreeMap.java
+++ b/app/src/main/java/com/wireguard/android/databinding/ObservableTreeMap.java
@@ -12,16 +12,10 @@ import java.util.TreeMap;
  * views. This behavior is in line with that of ObservableArrayMap.
  */
 
-public class ObservableTreeMap<K, V> extends TreeMap<K, V> implements ObservableSortedMap<K, V> {
+public class ObservableTreeMap<K, V> extends TreeMap<K, V> implements ObservableNavigableMap<K, V> {
     private transient MapChangeRegistry listeners;
 
     @Override
-    public void clear() {
-        super.clear();
-        notifyChange(null);
-    }
-
-    @Override
     public void addOnMapChangedCallback(
             final OnMapChangedCallback<? extends ObservableMap<K, V>, K, V> listener) {
         if (listeners == null)
@@ -29,6 +23,12 @@ public class ObservableTreeMap<K, V> extends TreeMap<K, V> implements Observable
         listeners.add(listener);
     }
 
+    @Override
+    public void clear() {
+        super.clear();
+        notifyChange(null);
+    }
+
     private void notifyChange(final K key) {
         if (listeners != null)
             listeners.notifyChange(this, key);
@@ -51,8 +51,7 @@ public class ObservableTreeMap<K, V> extends TreeMap<K, V> implements Observable
     @Override
     public V remove(final Object key) {
         final V oldValue = super.remove(key);
-        @SuppressWarnings("unchecked")
-        final K k = (K) key;
+        @SuppressWarnings("unchecked") final K k = (K) key;
         notifyChange(k);
         return oldValue;
     }
diff --git a/app/src/main/java/com/wireguard/android/fragment/BaseFragment.java b/app/src/main/java/com/wireguard/android/fragment/BaseFragment.java
new file mode 100644
index 00000000..9e188bc0
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/fragment/BaseFragment.java
@@ -0,0 +1,45 @@
+package com.wireguard.android.fragment;
+
+import android.app.Fragment;
+import android.content.Context;
+
+import com.wireguard.android.activity.BaseActivity;
+import com.wireguard.android.activity.BaseActivity.OnSelectedTunnelChangedListener;
+import com.wireguard.android.model.Tunnel;
+
+/**
+ * Base class for fragments that need to know the currently-selected tunnel. Only does anything when
+ * attached to a {@code BaseActivity}.
+ */
+
+public abstract class BaseFragment extends Fragment implements OnSelectedTunnelChangedListener {
+    private BaseActivity activity;
+
+    protected Tunnel getSelectedTunnel() {
+        return activity != null ? activity.getSelectedTunnel() : null;
+    }
+
+    @Override
+    public void onAttach(final Context context) {
+        super.onAttach(context);
+        if (context instanceof BaseActivity) {
+            activity = (BaseActivity) context;
+            activity.addOnSelectedTunnelChangedListener(this);
+        } else {
+            activity = null;
+        }
+    }
+
+    @Override
+    public void onDetach() {
+        if (activity != null)
+            activity.removeOnSelectedTunnelChangedListener(this);
+        activity = null;
+        super.onDetach();
+    }
+
+    protected void setSelectedTunnel(final Tunnel tunnel) {
+        if (activity != null)
+            activity.setSelectedTunnel(tunnel);
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/fragment/ConfigEditorFragment.java b/app/src/main/java/com/wireguard/android/fragment/ConfigEditorFragment.java
new file mode 100644
index 00000000..e2f5aa02
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/fragment/ConfigEditorFragment.java
@@ -0,0 +1,205 @@
+package com.wireguard.android.fragment;
+
+import android.app.Activity;
+import android.content.Context;
+import android.databinding.ObservableField;
+import android.os.Bundle;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.inputmethod.InputMethodManager;
+
+import com.commonsware.cwac.crossport.design.widget.CoordinatorLayout;
+import com.commonsware.cwac.crossport.design.widget.Snackbar;
+import com.wireguard.android.Application;
+import com.wireguard.android.R;
+import com.wireguard.android.databinding.ConfigEditorFragmentBinding;
+import com.wireguard.android.model.Tunnel;
+import com.wireguard.android.model.TunnelManager;
+import com.wireguard.android.util.ExceptionLoggers;
+import com.wireguard.config.Config;
+
+/**
+ * Fragment for editing a WireGuard configuration.
+ */
+
+public class ConfigEditorFragment extends BaseFragment {
+    private static final String KEY_LOCAL_CONFIG = "local_config";
+    private static final String KEY_LOCAL_NAME = "local_name";
+    private static final String TAG = ConfigEditorFragment.class.getSimpleName();
+
+    private final ObservableField<String> localName = new ObservableField<>();
+    private ConfigEditorFragmentBinding binding;
+    private boolean isViewStateRestored;
+    private Config localConfig = new Config();
+    private String originalName;
+
+    private static <T extends Parcelable> T copyParcelable(final T original) {
+        if (original == null)
+            return null;
+        final Parcel parcel = Parcel.obtain();
+        parcel.writeParcelable(original, 0);
+        parcel.setDataPosition(0);
+        final T copy = parcel.readParcelable(original.getClass().getClassLoader());
+        parcel.recycle();
+        return copy;
+    }
+
+    private void onConfigCreated(final Tunnel tunnel, final Throwable throwable) {
+        if (throwable != null) {
+            Log.e(TAG, "Cannot create tunnel", throwable);
+            final String message = "Cannot create tunnel: "
+                    + ExceptionLoggers.unwrap(throwable).getMessage();
+            if (binding != null) {
+                final CoordinatorLayout container = binding.mainContainer;
+                Snackbar.make(container, message, Snackbar.LENGTH_LONG).show();
+            }
+        } else {
+            Log.d(TAG, "Successfully created tunnel " + tunnel.getName());
+            onFinished(tunnel);
+        }
+    }
+
+    private void onConfigLoaded(final Config config) {
+        localConfig = copyParcelable(config);
+        if (binding != null && isViewStateRestored)
+            binding.setConfig(localConfig);
+    }
+
+    private void onConfigSaved(final Config config, final Throwable throwable) {
+        if (throwable != null) {
+            Log.e(TAG, "Cannot save configuration", throwable);
+            final String message = "Cannot save configuration: "
+                    + ExceptionLoggers.unwrap(throwable).getMessage();
+            if (binding != null) {
+                final CoordinatorLayout container = binding.mainContainer;
+                Snackbar.make(container, message, Snackbar.LENGTH_LONG).show();
+            }
+        } else {
+            Log.d(TAG, "Successfully saved configuration for " + getSelectedTunnel().getName());
+            onFinished(getSelectedTunnel());
+        }
+    }
+
+    @Override
+    public void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        if (savedInstanceState != null) {
+            localConfig = savedInstanceState.getParcelable(KEY_LOCAL_CONFIG);
+            localName.set(savedInstanceState.getString(KEY_LOCAL_NAME));
+            originalName = savedInstanceState.getString(TunnelManager.KEY_SELECTED_TUNNEL);
+        }
+        // Erase the remains of creating or editing a different tunnel.
+        if (getSelectedTunnel() != null && !getSelectedTunnel().getName().equals(originalName)) {
+            // The config must be loaded asynchronously since it's not an observable property.
+            localConfig = null;
+            getSelectedTunnel().getConfigAsync().thenAccept(this::onConfigLoaded);
+            originalName = getSelectedTunnel().getName();
+            localName.set(originalName);
+        } else if (getSelectedTunnel() == null && originalName != null) {
+            localConfig = new Config();
+            originalName = null;
+            localName.set(null);
+        }
+        setHasOptionsMenu(true);
+    }
+
+    @Override
+    public void onCreateOptionsMenu(final Menu menu, final MenuInflater inflater) {
+        inflater.inflate(R.menu.config_editor, menu);
+    }
+
+    @Override
+    public View onCreateView(final LayoutInflater inflater, final ViewGroup container,
+                             final Bundle savedInstanceState) {
+        super.onCreateView(inflater, container, savedInstanceState);
+        binding = ConfigEditorFragmentBinding.inflate(inflater, container, false);
+        binding.executePendingBindings();
+        return binding.getRoot();
+    }
+
+    @Override
+    public void onDestroyView() {
+        binding = null;
+        super.onDestroyView();
+    }
+
+    private void onFinished(final Tunnel tunnel) {
+        // Hide the keyboard; it rarely goes away on its own.
+        final Activity activity = getActivity();
+        final View focusedView = activity.getCurrentFocus();
+        if (focusedView != null) {
+            final Object service = activity.getSystemService(Context.INPUT_METHOD_SERVICE);
+            final InputMethodManager inputManager = (InputMethodManager) service;
+            if (inputManager != null)
+                inputManager.hideSoftInputFromWindow(focusedView.getWindowToken(),
+                        InputMethodManager.HIDE_NOT_ALWAYS);
+        }
+        // Tell the activity to finish itself or go back to the detail view.
+        getActivity().runOnUiThread(() -> {
+            setSelectedTunnel(null);
+            setSelectedTunnel(tunnel);
+        });
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(final MenuItem item) {
+        switch (item.getItemId()) {
+            case R.id.menu_action_save:
+                if (getSelectedTunnel() != null) {
+                    Log.d(TAG, "Attempting to save config to " + getSelectedTunnel().getName());
+                    getSelectedTunnel().setConfig(localConfig)
+                            .whenComplete(this::onConfigSaved);
+                } else {
+                    Log.d(TAG, "Attempting to create new tunnel " + localName.get());
+                    final TunnelManager manager = Application.getComponent().getTunnelManager();
+                    manager.create(localName.get(), localConfig)
+                            .whenComplete(this::onConfigCreated);
+                }
+                return true;
+            default:
+                return super.onOptionsItemSelected(item);
+        }
+    }
+
+    @Override
+    public void onSaveInstanceState(final Bundle outState) {
+        outState.putParcelable(KEY_LOCAL_CONFIG, localConfig);
+        outState.putString(KEY_LOCAL_NAME, localName.get());
+        outState.putString(TunnelManager.KEY_SELECTED_TUNNEL, originalName);
+        super.onSaveInstanceState(outState);
+    }
+
+    @Override
+    public void onSelectedTunnelChanged(final Tunnel oldTunnel, final Tunnel newTunnel) {
+        // Erase the remains of creating or editing a different tunnel.
+        if (newTunnel != null) {
+            // The config must be loaded asynchronously since it's not an observable property.
+            localConfig = null;
+            newTunnel.getConfigAsync().thenAccept(this::onConfigLoaded);
+            originalName = newTunnel.getName();
+        } else {
+            localConfig = new Config();
+            if (binding != null && isViewStateRestored)
+                binding.setConfig(localConfig);
+            originalName = null;
+        }
+        localName.set(originalName);
+    }
+
+    @Override
+    public void onViewStateRestored(final Bundle savedInstanceState) {
+        super.onViewStateRestored(savedInstanceState);
+        binding.setConfig(localConfig);
+        binding.setName(localName);
+        // FIXME: Remove this when renaming works.
+        binding.interfaceNameText.setEnabled(originalName == null);
+        isViewStateRestored = true;
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/fragment/TunnelDetailFragment.java b/app/src/main/java/com/wireguard/android/fragment/TunnelDetailFragment.java
new file mode 100644
index 00000000..e236da71
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/fragment/TunnelDetailFragment.java
@@ -0,0 +1,60 @@
+package com.wireguard.android.fragment;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.wireguard.android.R;
+import com.wireguard.android.databinding.TunnelDetailFragmentBinding;
+import com.wireguard.android.model.Tunnel;
+
+/**
+ * Fragment that shows details about a specific tunnel.
+ */
+
+public class TunnelDetailFragment extends BaseFragment {
+    private TunnelDetailFragmentBinding binding;
+    private boolean isViewStateRestored;
+
+    @Override
+    public void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setHasOptionsMenu(true);
+    }
+
+    @Override
+    public void onCreateOptionsMenu(final Menu menu, final MenuInflater inflater) {
+        inflater.inflate(R.menu.tunnel_detail, menu);
+    }
+
+    @Override
+    public View onCreateView(final LayoutInflater inflater, final ViewGroup container,
+                             final Bundle savedInstanceState) {
+        super.onCreateView(inflater, container, savedInstanceState);
+        binding = TunnelDetailFragmentBinding.inflate(inflater, container, false);
+        binding.executePendingBindings();
+        return binding.getRoot();
+    }
+
+    @Override
+    public void onDestroyView() {
+        binding = null;
+        super.onDestroyView();
+    }
+
+    @Override
+    public void onSelectedTunnelChanged(final Tunnel oldTunnel, final Tunnel newTunnel) {
+        if (binding != null && isViewStateRestored)
+            binding.setTunnel(newTunnel);
+    }
+
+    @Override
+    public void onViewStateRestored(final Bundle savedInstanceState) {
+        super.onViewStateRestored(savedInstanceState);
+        binding.setTunnel(getSelectedTunnel());
+        isViewStateRestored = true;
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/fragment/TunnelListFragment.java b/app/src/main/java/com/wireguard/android/fragment/TunnelListFragment.java
new file mode 100644
index 00000000..ed14a82f
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/fragment/TunnelListFragment.java
@@ -0,0 +1,270 @@
+package com.wireguard.android.fragment;
+
+import android.annotation.SuppressLint;
+import android.app.Activity;
+import android.content.ContentResolver;
+import android.content.Intent;
+import android.content.res.Resources;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.Bundle;
+import android.provider.OpenableColumns;
+import android.util.Log;
+import android.util.SparseBooleanArray;
+import android.view.ActionMode;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuItem;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.View.OnTouchListener;
+import android.view.ViewGroup;
+import android.widget.AbsListView;
+import android.widget.AbsListView.MultiChoiceModeListener;
+import android.widget.AdapterView;
+import android.widget.AdapterView.OnItemClickListener;
+import android.widget.AdapterView.OnItemLongClickListener;
+
+import com.commonsware.cwac.crossport.design.widget.CoordinatorLayout;
+import com.commonsware.cwac.crossport.design.widget.Snackbar;
+import com.wireguard.android.Application;
+import com.wireguard.android.Application.ApplicationComponent;
+import com.wireguard.android.R;
+import com.wireguard.android.activity.TunnelCreatorActivity;
+import com.wireguard.android.databinding.TunnelListFragmentBinding;
+import com.wireguard.android.model.Tunnel;
+import com.wireguard.android.model.TunnelManager;
+import com.wireguard.android.util.AsyncWorker;
+import com.wireguard.android.util.ExceptionLoggers;
+import com.wireguard.config.Config;
+
+import java9.util.concurrent.CompletableFuture;
+import java9.util.concurrent.CompletionStage;
+import java9.util.function.Function;
+import java9.util.stream.IntStream;
+
+/**
+ * Fragment containing a list of known WireGuard tunnels. It allows creating and deleting tunnels.
+ */
+
+public class TunnelListFragment extends BaseFragment {
+    private static final int REQUEST_IMPORT = 1;
+    private static final String TAG = TunnelListFragment.class.getSimpleName();
+
+    private final MultiChoiceModeListener actionModeListener = new ActionModeListener();
+    private final ListViewCallbacks listViewCallbacks = new ListViewCallbacks();
+    private ActionMode actionMode;
+    private AsyncWorker asyncWorker;
+    private TunnelListFragmentBinding binding;
+    private TunnelManager tunnelManager;
+
+    private void importTunnel(final Uri uri) {
+        final Activity activity = getActivity();
+        if (activity == null)
+            return;
+        final ContentResolver contentResolver = activity.getContentResolver();
+        final CompletionStage<String> nameFuture = asyncWorker.supplyAsync(() -> {
+            final String[] columns = {OpenableColumns.DISPLAY_NAME};
+            String name = null;
+            try (final Cursor cursor = contentResolver.query(uri, columns, null, null, null)) {
+                if (cursor != null && cursor.moveToFirst() && !cursor.isNull(0))
+                    name = cursor.getString(0);
+            }
+            if (name == null)
+                name = Uri.decode(uri.getLastPathSegment());
+            if (name.indexOf('/') >= 0)
+                name = name.substring(name.lastIndexOf('/') + 1);
+            if (name.endsWith(".conf"))
+                name = name.substring(0, name.length() - ".conf".length());
+            Log.d(TAG, "Import mapped URI " + uri + " to tunnel name " + name);
+            return name;
+        });
+        asyncWorker.supplyAsync(() -> Config.from(contentResolver.openInputStream(uri)))
+                .thenCombine(nameFuture, (config, name) -> tunnelManager.create(name, config))
+                .thenCompose(Function.identity())
+                .handle(this::onTunnelImportFinished);
+    }
+
+    @Override
+    public void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
+        switch (requestCode) {
+            case REQUEST_IMPORT:
+                if (resultCode == Activity.RESULT_OK)
+                    importTunnel(data.getData());
+                return;
+            default:
+                super.onActivityResult(requestCode, resultCode, data);
+        }
+    }
+
+    @Override
+    public void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        final ApplicationComponent applicationComponent = Application.getComponent();
+        asyncWorker = applicationComponent.getAsyncWorker();
+        tunnelManager = applicationComponent.getTunnelManager();
+    }
+
+    @Override
+    public View onCreateView(final LayoutInflater inflater, final ViewGroup container,
+                             final Bundle savedInstanceState) {
+        super.onCreateView(inflater, container, savedInstanceState);
+        binding = TunnelListFragmentBinding.inflate(inflater, container, false);
+        binding.tunnelList.setMultiChoiceModeListener(actionModeListener);
+        binding.tunnelList.setOnItemClickListener(listViewCallbacks);
+        binding.tunnelList.setOnItemLongClickListener(listViewCallbacks);
+        binding.tunnelList.setOnTouchListener(listViewCallbacks);
+        binding.executePendingBindings();
+        return binding.getRoot();
+    }
+
+    @Override
+    public void onDestroyView() {
+        binding = null;
+        super.onDestroyView();
+    }
+
+    public void onRequestCreateConfig(@SuppressWarnings("unused") final View view) {
+        startActivity(new Intent(getActivity(), TunnelCreatorActivity.class));
+        binding.createMenu.collapse();
+    }
+
+    public void onRequestImportConfig(@SuppressWarnings("unused") final View view) {
+        final Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
+        intent.addCategory(Intent.CATEGORY_OPENABLE);
+        intent.setType("*/*");
+        startActivityForResult(intent, REQUEST_IMPORT);
+        binding.createMenu.collapse();
+    }
+
+    @Override
+    public void onSelectedTunnelChanged(final Tunnel oldTunnel, final Tunnel newTunnel) {
+        // Do nothing.
+    }
+
+    private Void onTunnelDeletionFinished(final Integer count, final Throwable throwable) {
+        final String message;
+        if (throwable == null) {
+            message = "Successfully deleted " + count + " tunnels";
+        } else {
+            message = "Could not delete some tunnels: "
+                    + ExceptionLoggers.unwrap(throwable).getMessage();
+            Log.e(TAG, "Cannot delete tunnel", throwable);
+        }
+        if (binding != null) {
+            final CoordinatorLayout container = binding.mainContainer;
+            Snackbar.make(container, message, Snackbar.LENGTH_LONG).show();
+        }
+        return null;
+    }
+
+    private Void onTunnelImportFinished(final Tunnel tunnel, final Throwable throwable) {
+        final String message;
+        if (throwable == null) {
+            message = "Successfully imported tunnel '" + tunnel.getName() + '\'';
+        } else {
+            message = "Cannot import tunnel: "
+                    + ExceptionLoggers.unwrap(throwable).getMessage();
+            Log.e(TAG, "Cannot import tunnel", throwable);
+        }
+        if (binding != null) {
+            final CoordinatorLayout container = binding.mainContainer;
+            Snackbar.make(container, message, Snackbar.LENGTH_LONG).show();
+        }
+        return null;
+    }
+
+    @Override
+    public void onViewStateRestored(final Bundle savedInstanceState) {
+        super.onViewStateRestored(savedInstanceState);
+        binding.setFragment(this);
+        binding.setTunnels(tunnelManager.getTunnels());
+    }
+
+    private final class ActionModeListener implements MultiChoiceModeListener {
+        private Resources resources;
+        private AbsListView tunnelList;
+
+        private IntStream getCheckedPositions() {
+            final SparseBooleanArray checkedItemPositions = tunnelList.getCheckedItemPositions();
+            return IntStream.range(0, checkedItemPositions.size())
+                    .filter(checkedItemPositions::valueAt)
+                    .map(checkedItemPositions::keyAt);
+        }
+
+        @Override
+        public boolean onActionItemClicked(final ActionMode mode, final MenuItem item) {
+            switch (item.getItemId()) {
+                case R.id.menu_action_delete:
+                    final CompletableFuture[] futures = getCheckedPositions()
+                            .mapToObj(pos -> (Tunnel) tunnelList.getItemAtPosition(pos))
+                            .map(tunnelManager::delete)
+                            .toArray(CompletableFuture[]::new);
+                    CompletableFuture.allOf(futures)
+                            .thenApply(x -> futures.length)
+                            .handle(TunnelListFragment.this::onTunnelDeletionFinished);
+                    mode.finish();
+                    return true;
+                default:
+                    return false;
+            }
+        }
+
+        @Override
+        public boolean onCreateActionMode(final ActionMode mode, final Menu menu) {
+            actionMode = mode;
+            resources = getActivity().getResources();
+            tunnelList = binding.tunnelList;
+            mode.getMenuInflater().inflate(R.menu.tunnel_list_action_mode, menu);
+            return true;
+        }
+
+        @Override
+        public void onDestroyActionMode(final ActionMode mode) {
+            actionMode = null;
+            resources = null;
+        }
+
+        @Override
+        public void onItemCheckedStateChanged(final ActionMode mode, final int position,
+                                              final long id, final boolean checked) {
+            updateTitle(mode);
+        }
+
+        @Override
+        public boolean onPrepareActionMode(final ActionMode mode, final Menu menu) {
+            updateTitle(mode);
+            return false;
+        }
+
+        private void updateTitle(final ActionMode mode) {
+            final int count = (int) getCheckedPositions().count();
+            mode.setTitle(resources.getQuantityString(R.plurals.list_delete_title, count, count));
+        }
+    }
+
+    private final class ListViewCallbacks
+            implements OnItemClickListener, OnItemLongClickListener, OnTouchListener {
+        @Override
+        public void onItemClick(final AdapterView<?> parent, final View view,
+                                final int position, final long id) {
+            setSelectedTunnel((Tunnel) parent.getItemAtPosition(position));
+        }
+
+        @Override
+        public boolean onItemLongClick(final AdapterView<?> parent, final View view,
+                                       final int position, final long id) {
+            if (actionMode != null)
+                return false;
+            binding.tunnelList.setItemChecked(position, true);
+            return true;
+        }
+
+        @Override
+        @SuppressLint("ClickableViewAccessibility")
+        public boolean onTouch(final View view, final MotionEvent motionEvent) {
+            binding.createMenu.collapse();
+            return false;
+        }
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/model/Tunnel.java b/app/src/main/java/com/wireguard/android/model/Tunnel.java
new file mode 100644
index 00000000..b196eaa5
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/model/Tunnel.java
@@ -0,0 +1,166 @@
+package com.wireguard.android.model;
+
+import android.databinding.BaseObservable;
+import android.databinding.Bindable;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import com.wireguard.android.BR;
+import com.wireguard.android.backend.Backend;
+import com.wireguard.android.configStore.ConfigStore;
+import com.wireguard.android.util.ExceptionLoggers;
+import com.wireguard.config.Config;
+
+import org.threeten.bp.Instant;
+
+import java.util.Objects;
+import java.util.regex.Pattern;
+
+import java9.util.concurrent.CompletableFuture;
+import java9.util.concurrent.CompletionStage;
+
+/**
+ * Encapsulates the volatile and nonvolatile state of a WireGuard tunnel.
+ */
+
+public class Tunnel extends BaseObservable implements Comparable<Tunnel> {
+    public static final int NAME_MAX_LENGTH = 16;
+    private static final Pattern NAME_PATTERN = Pattern.compile("[a-zA-Z0-9_=+.-]{1,16}");
+    private static final String TAG = Tunnel.class.getSimpleName();
+
+    private final Backend backend;
+    private final ConfigStore configStore;
+    private final String name;
+    private Config config;
+    private Instant lastStateChange = Instant.EPOCH;
+    private State state = State.UNKNOWN;
+    private Statistics statistics;
+
+    Tunnel(@NonNull final Backend backend, @NonNull final ConfigStore configStore,
+           @NonNull final String name, @Nullable final Config config) {
+        this.backend = backend;
+        this.configStore = configStore;
+        this.name = name;
+        this.config = config;
+    }
+
+    public static boolean isNameValid(final CharSequence name) {
+        return name != null && NAME_PATTERN.matcher(name).matches();
+    }
+
+    @Override
+    public int compareTo(@NonNull final Tunnel tunnel) {
+        return name.compareTo(tunnel.name);
+    }
+
+    @Bindable
+    public Config getConfig() {
+        if (config == null)
+            getConfigAsync().whenComplete(ExceptionLoggers.D);
+        return config;
+    }
+
+    public CompletionStage<Config> getConfigAsync() {
+        if (config == null)
+            return configStore.load(name).thenApply(this::setConfigInternal);
+        return CompletableFuture.completedFuture(config);
+    }
+
+    @Bindable
+    public Instant getLastStateChange() {
+        return lastStateChange;
+    }
+
+    @Bindable
+    public String getName() {
+        return name;
+    }
+
+    @Bindable
+    public State getState() {
+        if (state == State.UNKNOWN)
+            getStateAsync().whenComplete(ExceptionLoggers.D);
+        return state;
+    }
+
+    public CompletionStage<State> getStateAsync() {
+        if (state == State.UNKNOWN)
+            return backend.getState(this).thenApply(this::setStateInternal);
+        return CompletableFuture.completedFuture(state);
+    }
+
+    @Bindable
+    public Statistics getStatistics() {
+        // FIXME: Check age of statistics.
+        if (statistics == null)
+            getStatisticsAsync().whenComplete(ExceptionLoggers.D);
+        return statistics;
+    }
+
+    public CompletionStage<Statistics> getStatisticsAsync() {
+        // FIXME: Check age of statistics.
+        if (statistics == null)
+            return backend.getStatistics(this).thenApply(this::setStatisticsInternal);
+        return CompletableFuture.completedFuture(statistics);
+    }
+
+    private void onStateChanged(final State oldState, final State newState) {
+        if (oldState != State.UNKNOWN) {
+            lastStateChange = Instant.now();
+            notifyPropertyChanged(BR.lastStateChange);
+        }
+        if (newState != State.UP)
+            setStatisticsInternal(null);
+    }
+
+    public CompletionStage<Config> setConfig(@NonNull final Config config) {
+        if (!config.equals(this.config)) {
+            return backend.applyConfig(this, config)
+                    .thenCompose(cfg -> configStore.save(name, cfg))
+                    .thenApply(this::setConfigInternal);
+        }
+        return CompletableFuture.completedFuture(this.config);
+    }
+
+    private Config setConfigInternal(final Config config) {
+        if (Objects.equals(this.config, config))
+            return config;
+        this.config = config;
+        notifyPropertyChanged(BR.config);
+        return config;
+    }
+
+    public CompletionStage<State> setState(@NonNull final State state) {
+        if (state != this.state)
+            return backend.setState(this, state)
+                    .thenApply(this::setStateInternal);
+        return CompletableFuture.completedFuture(this.state);
+    }
+
+    private State setStateInternal(final State state) {
+        if (Objects.equals(this.state, state))
+            return state;
+        onStateChanged(this.state, state);
+        this.state = state;
+        notifyPropertyChanged(BR.state);
+        return state;
+    }
+
+    private Statistics setStatisticsInternal(final Statistics statistics) {
+        if (Objects.equals(this.statistics, statistics))
+            return statistics;
+        this.statistics = statistics;
+        notifyPropertyChanged(BR.statistics);
+        return statistics;
+    }
+
+    public enum State {
+        DOWN,
+        TOGGLE,
+        UNKNOWN,
+        UP
+    }
+
+    public static class Statistics extends BaseObservable {
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/model/TunnelCollection.java b/app/src/main/java/com/wireguard/android/model/TunnelCollection.java
new file mode 100644
index 00000000..38b5165a
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/model/TunnelCollection.java
@@ -0,0 +1,10 @@
+package com.wireguard.android.model;
+
+import com.wireguard.android.databinding.ObservableTreeMap;
+
+/**
+ * Created by samuel on 12/19/17.
+ */
+
+public class TunnelCollection extends ObservableTreeMap<String, Tunnel> {
+}
diff --git a/app/src/main/java/com/wireguard/android/model/TunnelManager.java b/app/src/main/java/com/wireguard/android/model/TunnelManager.java
new file mode 100644
index 00000000..5122f9bf
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/model/TunnelManager.java
@@ -0,0 +1,111 @@
+package com.wireguard.android.model;
+
+import android.content.SharedPreferences;
+import android.util.Log;
+
+import com.wireguard.android.Application.ApplicationScope;
+import com.wireguard.android.backend.Backend;
+import com.wireguard.android.configStore.ConfigStore;
+import com.wireguard.android.model.Tunnel.State;
+import com.wireguard.android.util.ExceptionLoggers;
+import com.wireguard.config.Config;
+
+import java.util.Collections;
+import java.util.Set;
+
+import javax.inject.Inject;
+
+import java9.util.concurrent.CompletableFuture;
+import java9.util.concurrent.CompletionStage;
+import java9.util.stream.Collectors;
+import java9.util.stream.StreamSupport;
+
+/**
+ * Maintains and mediates changes to the set of available WireGuard tunnels,
+ */
+
+@ApplicationScope
+public final class TunnelManager {
+    public static final String KEY_PRIMARY_TUNNEL = "primary_config";
+    public static final String KEY_SELECTED_TUNNEL = "selected_tunnel";
+    private static final String KEY_RESTORE_ON_BOOT = "restore_on_boot";
+    private static final String KEY_RUNNING_TUNNELS = "enabled_configs";
+    private static final String TAG = TunnelManager.class.getSimpleName();
+
+    private final Backend backend;
+    private final ConfigStore configStore;
+    private final SharedPreferences preferences;
+    private final TunnelCollection tunnels = new TunnelCollection();
+
+    @Inject
+    public TunnelManager(final Backend backend, final ConfigStore configStore,
+                         final SharedPreferences preferences) {
+        this.backend = backend;
+        this.configStore = configStore;
+        this.preferences = preferences;
+    }
+
+    private Tunnel add(final String name, final Config config) {
+        final Tunnel tunnel = new Tunnel(backend, configStore, name, config);
+        tunnels.put(name, tunnel);
+        return tunnel;
+    }
+
+    private Tunnel add(final String name) {
+        return add(name, null);
+    }
+
+    public CompletionStage<Tunnel> create(final String name, final Config config) {
+        Log.v(TAG, "Requested create tunnel " + name + " with config\n" + config);
+        if (!Tunnel.isNameValid(name))
+            return CompletableFuture.failedFuture(new IllegalArgumentException("Invalid name"));
+        if (tunnels.containsKey(name)) {
+            final String message = "Tunnel " + name + " already exists";
+            return CompletableFuture.failedFuture(new IllegalArgumentException(message));
+        }
+        return configStore.create(name, config).thenApply(savedConfig -> add(name, savedConfig));
+    }
+
+    public CompletionStage<Void> delete(final Tunnel tunnel) {
+        Log.v(TAG, "Requested delete tunnel " + tunnel.getName() + " state=" + tunnel.getState());
+        return backend.setState(tunnel, State.DOWN)
+                .thenCompose(x -> configStore.delete(tunnel.getName()))
+                .thenAccept(x -> tunnels.remove(tunnel.getName()));
+    }
+
+    public TunnelCollection getTunnels() {
+        return tunnels;
+    }
+
+    public void onCreate() {
+        Log.v(TAG, "onCreate triggered");
+        configStore.enumerate()
+                .thenApply(names -> StreamSupport.stream(names)
+                        .map(this::add)
+                        .map(Tunnel::getStateAsync)
+                        .toArray(CompletableFuture[]::new))
+                .thenCompose(CompletableFuture::allOf)
+                .whenComplete(ExceptionLoggers.E);
+    }
+
+    public CompletionStage<Void> restoreState() {
+        if (!preferences.getBoolean(KEY_RESTORE_ON_BOOT, false))
+            return CompletableFuture.completedFuture(null);
+        final Set<String> tunnelsToEnable =
+                preferences.getStringSet(KEY_RUNNING_TUNNELS, Collections.emptySet());
+        final CompletableFuture[] futures = StreamSupport.stream(tunnelsToEnable)
+                .map(tunnels::get)
+                .map(tunnel -> tunnel.setState(State.UP))
+                .toArray(CompletableFuture[]::new);
+        return CompletableFuture.allOf(futures);
+    }
+
+    public CompletionStage<Void> saveState() {
+        final Set<String> runningTunnels = StreamSupport.stream(tunnels.values())
+                .filter(tunnel -> tunnel.getState() == State.UP)
+                .map(Tunnel::getName)
+                .collect(Collectors.toUnmodifiableSet());
+        preferences.edit().putStringSet(KEY_RUNNING_TUNNELS, runningTunnels).apply();
+        return CompletableFuture.completedFuture(null);
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/ConfigListPreference.java b/app/src/main/java/com/wireguard/android/preference/TunnelListPreference.java
index e0bcc672..541afa28 100644
--- a/app/src/main/java/com/wireguard/android/ConfigListPreference.java
+++ b/app/src/main/java/com/wireguard/android/preference/TunnelListPreference.java
@@ -1,10 +1,10 @@
-package com.wireguard.android;
+package com.wireguard.android.preference;
 
 import android.content.Context;
 import android.preference.ListPreference;
 import android.util.AttributeSet;
 
-import com.wireguard.android.backends.VpnService;
+import com.wireguard.android.Application;
 
 import java.util.Set;
 
@@ -12,28 +12,30 @@ import java.util.Set;
  * ListPreference that is automatically filled with the list of configurations.
  */
 
-public class ConfigListPreference extends ListPreference {
-    public ConfigListPreference(final Context context, final AttributeSet attrs,
+public class TunnelListPreference extends ListPreference {
+    public TunnelListPreference(final Context context, final AttributeSet attrs,
                                 final int defStyleAttr, final int defStyleRes) {
         super(context, attrs, defStyleAttr, defStyleRes);
-        final Set<String> entrySet = VpnService.getInstance().getConfigs().keySet();
+        final Set<String> entrySet = Application.getComponent().getTunnelManager().getTunnels().keySet();
         final CharSequence[] entries = entrySet.toArray(new CharSequence[entrySet.size()]);
         setEntries(entries);
         setEntryValues(entries);
     }
 
-    public ConfigListPreference(final Context context, final AttributeSet attrs,
+    public TunnelListPreference(final Context context, final AttributeSet attrs,
                                 final int defStyleAttr) {
         this(context, attrs, defStyleAttr, 0);
     }
 
-    public ConfigListPreference(final Context context, final AttributeSet attrs) {
+    public TunnelListPreference(final Context context, final AttributeSet attrs) {
         this(context, attrs, android.R.attr.dialogPreferenceStyle);
     }
 
-    public ConfigListPreference(final Context context) {
+    public TunnelListPreference(final Context context) {
         this(context, null);
     }
 
-    public void show() { showDialog(null); }
+    public void show() {
+        showDialog(null);
+    }
 }
diff --git a/app/src/main/java/com/wireguard/android/util/AsyncWorker.java b/app/src/main/java/com/wireguard/android/util/AsyncWorker.java
new file mode 100644
index 00000000..5f9f0a83
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/util/AsyncWorker.java
@@ -0,0 +1,65 @@
+package com.wireguard.android.util;
+
+import android.os.Handler;
+
+import com.wireguard.android.Application.ApplicationHandler;
+import com.wireguard.android.Application.ApplicationScope;
+
+import java.util.concurrent.Executor;
+
+import javax.inject.Inject;
+
+import java9.util.concurrent.CompletableFuture;
+import java9.util.concurrent.CompletionStage;
+
+/**
+ * Helper class for running asynchronous tasks and ensuring they are completed on the main thread.
+ */
+
+@ApplicationScope
+public class AsyncWorker {
+    private final Executor executor;
+    private final Handler handler;
+
+    @Inject
+    public AsyncWorker(final Executor executor, @ApplicationHandler final Handler handler) {
+        this.executor = executor;
+        this.handler = handler;
+    }
+
+    public CompletionStage<Void> runAsync(final AsyncRunnable<?> runnable) {
+        final CompletableFuture<Void> future = new CompletableFuture<>();
+        executor.execute(() -> {
+            try {
+                runnable.run();
+                handler.post(() -> future.complete(null));
+            } catch (final Throwable t) {
+                handler.post(() -> future.completeExceptionally(t));
+            }
+        });
+        return future;
+    }
+
+    public <T> CompletionStage<T> supplyAsync(final AsyncSupplier<T, ?> supplier) {
+        final CompletableFuture<T> future = new CompletableFuture<>();
+        executor.execute(() -> {
+            try {
+                final T result = supplier.get();
+                handler.post(() -> future.complete(result));
+            } catch (final Throwable t) {
+                handler.post(() -> future.completeExceptionally(t));
+            }
+        });
+        return future;
+    }
+
+    @FunctionalInterface
+    public interface AsyncRunnable<E extends Throwable> {
+        void run() throws E;
+    }
+
+    @FunctionalInterface
+    public interface AsyncSupplier<T, E extends Throwable> {
+        T get() throws E;
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/util/ClipboardUtils.java b/app/src/main/java/com/wireguard/android/util/ClipboardUtils.java
new file mode 100644
index 00000000..20aeffff
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/util/ClipboardUtils.java
@@ -0,0 +1,32 @@
+package com.wireguard.android.util;
+
+import android.content.ClipData;
+import android.content.ClipboardManager;
+import android.content.Context;
+import android.view.View;
+import android.widget.TextView;
+
+import com.commonsware.cwac.crossport.design.widget.Snackbar;
+
+/**
+ * Created by samuel on 12/30/17.
+ */
+
+public final class ClipboardUtils {
+    private ClipboardUtils() {
+    }
+
+    public static void copyTextView(final View view) {
+        if (!(view instanceof TextView))
+            return;
+        final CharSequence text = ((TextView) view).getText();
+        if (text == null || text.length() == 0)
+            return;
+        final Object service = view.getContext().getSystemService(Context.CLIPBOARD_SERVICE);
+        if (!(service instanceof ClipboardManager))
+            return;
+        final CharSequence description = view.getContentDescription();
+        ((ClipboardManager) service).setPrimaryClip(ClipData.newPlainText(description, text));
+        Snackbar.make(view, description + " copied to clipboard", Snackbar.LENGTH_LONG).show();
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java b/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java
new file mode 100644
index 00000000..a11529f4
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java
@@ -0,0 +1,38 @@
+package com.wireguard.android.util;
+
+import android.util.Log;
+
+import java9.util.concurrent.CompletionException;
+import java9.util.function.BiConsumer;
+
+/**
+ * Helpers for logging exceptions from asynchronous tasks. These can be passed to
+ * {@code CompletionStage.handle()} at the end of an asynchronous future chain.
+ */
+
+public enum ExceptionLoggers implements BiConsumer<Object, Throwable> {
+    D(Log.DEBUG),
+    E(Log.ERROR);
+
+    private static final String TAG = ExceptionLoggers.class.getSimpleName();
+
+    private final int priority;
+
+    ExceptionLoggers(final int priority) {
+        this.priority = priority;
+    }
+
+    public static Throwable unwrap(final Throwable throwable) {
+        if (throwable instanceof CompletionException)
+            return throwable.getCause();
+        return throwable;
+    }
+
+    @Override
+    public void accept(final Object result, final Throwable throwable) {
+        if (throwable != null)
+            Log.println(Log.ERROR, TAG, Log.getStackTraceString(throwable));
+        else if (priority <= Log.DEBUG)
+            Log.println(priority, TAG, "Future completed successfully");
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/backends/RootShell.java b/app/src/main/java/com/wireguard/android/util/RootShell.java
index cab39730..35f4735b 100644
--- a/app/src/main/java/com/wireguard/android/backends/RootShell.java
+++ b/app/src/main/java/com/wireguard/android/util/RootShell.java
@@ -1,9 +1,12 @@
-package com.wireguard.android.backends;
+package com.wireguard.android.util;
 
 import android.content.Context;
 import android.system.OsConstants;
 import android.util.Log;
 
+import com.wireguard.android.Application.ApplicationContext;
+import com.wireguard.android.Application.ApplicationScope;
+
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
@@ -11,29 +14,32 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
-import java.util.regex.Pattern;
 import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import javax.inject.Inject;
 
 /**
  * Helper class for running commands as root.
  */
 
+@ApplicationScope
 public class RootShell {
+    private static final Pattern ERRNO_EXTRACTOR = Pattern.compile("error=(\\d+)");
     /**
      * Setup commands that are run at the beginning of each root shell. The trap command ensures
      * access to the return value of the last command, since su itself always exits with 0.
      */
     private static final String TAG = "WireGuard/RootShell";
-    private static final Pattern ERRNO_EXTRACTOR = Pattern.compile("error=(\\d+)");
-
     private static final String[][] libraryNamedExecutables = {
-        { "libwg.so", "wg" },
-        { "libwg-quick.so", "wg-quick" }
+            {"libwg.so", "wg"},
+            {"libwg-quick.so", "wg-quick"}
     };
 
     private final String preamble;
 
-    public RootShell(final Context context) {
+    @Inject
+    public RootShell(@ApplicationContext final Context context) {
         final String binDir = context.getCacheDir().getPath() + "/bin";
         final String tmpDir = context.getCacheDir().getPath() + "/tmp";
         final String libDir = context.getApplicationInfo().nativeLibraryDir;
@@ -55,9 +61,9 @@ public class RootShell {
     /**
      * Run a command in a root shell.
      *
-     * @param output   Lines read from stdout are appended to this list. Pass null if the
-     *                 output from the shell is not important.
-     * @param command  Command to run as root.
+     * @param output  Lines read from stdout are appended to this list. Pass null if the
+     *                output from the shell is not important.
+     * @param command Command to run as root.
      * @return The exit value of the last command run, or -1 if there was an internal error.
      */
     public int run(final List<String> output, final String command) {
diff --git a/app/src/main/java/com/wireguard/android/KeyInputFilter.java b/app/src/main/java/com/wireguard/android/widget/KeyInputFilter.java
index d8eabd6c..45652ed5 100644
--- a/app/src/main/java/com/wireguard/android/KeyInputFilter.java
+++ b/app/src/main/java/com/wireguard/android/widget/KeyInputFilter.java
@@ -1,4 +1,4 @@
-package com.wireguard.android;
+package com.wireguard.android.widget;
 
 import android.text.InputFilter;
 import android.text.SpannableStringBuilder;
diff --git a/app/src/main/java/com/wireguard/android/NameInputFilter.java b/app/src/main/java/com/wireguard/android/widget/NameInputFilter.java
index cd653c11..8c91e682 100644
--- a/app/src/main/java/com/wireguard/android/NameInputFilter.java
+++ b/app/src/main/java/com/wireguard/android/widget/NameInputFilter.java
@@ -1,10 +1,10 @@
-package com.wireguard.android;
+package com.wireguard.android.widget;
 
 import android.text.InputFilter;
 import android.text.SpannableStringBuilder;
 import android.text.Spanned;
 
-import com.wireguard.config.Config;
+import com.wireguard.android.model.Tunnel;
 
 /**
  * InputFilter for entering WireGuard configuration names (Linux interface names).
@@ -28,8 +28,8 @@ public class NameInputFilter implements InputFilter {
             final int dIndex = dStart + (sIndex - sStart);
             // Restrict characters to those valid in interfaces.
             // Ensure adding this character does not push the length over the limit.
-            if ((dIndex < Config.NAME_MAX_LENGTH && isAllowed(c)) &&
-                    dLength + (sIndex - sStart) < Config.NAME_MAX_LENGTH) {
+            if ((dIndex < Tunnel.NAME_MAX_LENGTH && isAllowed(c)) &&
+                    dLength + (sIndex - sStart) < Tunnel.NAME_MAX_LENGTH) {
                 ++rIndex;
             } else {
                 if (replacement == null)
diff --git a/app/src/main/java/com/wireguard/android/widget/ToggleSwitch.java b/app/src/main/java/com/wireguard/android/widget/ToggleSwitch.java
index c8f9ab2d..1b3dee71 100644
--- a/app/src/main/java/com/wireguard/android/widget/ToggleSwitch.java
+++ b/app/src/main/java/com/wireguard/android/widget/ToggleSwitch.java
@@ -17,17 +17,15 @@
 package com.wireguard.android.widget;
 
 import android.content.Context;
+import android.os.Parcelable;
 import android.util.AttributeSet;
 import android.widget.Switch;
 
 public class ToggleSwitch extends Switch {
     private boolean hasPendingStateChange;
+    private boolean isRestoringState;
     private OnBeforeCheckedChangeListener listener;
 
-    public interface OnBeforeCheckedChangeListener {
-        void onBeforeCheckedChanged(ToggleSwitch toggleSwitch, boolean checked);
-    }
-
     public ToggleSwitch(final Context context) {
         super(context);
     }
@@ -45,21 +43,25 @@ public class ToggleSwitch extends Switch {
         super(context, attrs, defStyleAttr, defStyleRes);
     }
 
-    public void setOnBeforeCheckedChangeListener(final OnBeforeCheckedChangeListener listener) {
-        this.listener = listener;
+    @Override
+    public void onRestoreInstanceState(final Parcelable state) {
+        isRestoringState = true;
+        super.onRestoreInstanceState(state);
+        isRestoringState = false;
+
     }
 
     @Override
     public void setChecked(final boolean checked) {
-        if (listener != null) {
-            if (!isEnabled())
-                return;
-            setEnabled(false);
-            hasPendingStateChange = true;
-            listener.onBeforeCheckedChanged(this, checked);
-        } else {
+        if (isRestoringState || listener == null) {
             super.setChecked(checked);
+            return;
         }
+        if (hasPendingStateChange)
+            return;
+        hasPendingStateChange = true;
+        setEnabled(false);
+        listener.onBeforeCheckedChanged(this, checked);
     }
 
     public void setCheckedInternal(final boolean checked) {
@@ -69,4 +71,12 @@ public class ToggleSwitch extends Switch {
         }
         super.setChecked(checked);
     }
+
+    public void setOnBeforeCheckedChangeListener(final OnBeforeCheckedChangeListener listener) {
+        this.listener = listener;
+    }
+
+    public interface OnBeforeCheckedChangeListener {
+        void onBeforeCheckedChanged(ToggleSwitch toggleSwitch, boolean checked);
+    }
 }
diff --git a/app/src/main/java/com/wireguard/config/Attribute.java b/app/src/main/java/com/wireguard/config/Attribute.java
index b2aa0d53..ee7fea33 100644
--- a/app/src/main/java/com/wireguard/config/Attribute.java
+++ b/app/src/main/java/com/wireguard/config/Attribute.java
@@ -21,38 +21,38 @@ enum Attribute {
     PRIVATE_KEY("PrivateKey"),
     PUBLIC_KEY("PublicKey");
 
-    private static final Map<String, Attribute> map;
+    private static final Map<String, Attribute> KEY_MAP;
+    private static final Pattern SEPARATOR_PATTERN = Pattern.compile("\\s|=");
 
     static {
-        map = new HashMap<>(Attribute.values().length);
-        for (final Attribute key : Attribute.values())
-            map.put(key.getToken(), key);
+        KEY_MAP = new HashMap<>(Attribute.values().length);
+        for (final Attribute key : Attribute.values()) {
+            KEY_MAP.put(key.token, key);
+        }
     }
 
-    public static Attribute match(final String line) {
-        return map.get(line.split("\\s|=")[0]);
-    }
-
-    private final String token;
     private final Pattern pattern;
+    private final String token;
 
     Attribute(final String token) {
         pattern = Pattern.compile(token + "\\s*=\\s*(\\S.*)");
         this.token = token;
     }
 
-    public String composeWith(final String value) {
-        return token + " = " + value + "\n";
+    public static Attribute match(final CharSequence line) {
+        return KEY_MAP.get(SEPARATOR_PATTERN.split(line)[0]);
+    }
+
+    public String composeWith(final Object value) {
+        return String.format("%s = %s%n", token, value);
     }
 
     public String getToken() {
         return token;
     }
 
-    public String parseFrom(final String line) {
+    public String parse(final CharSequence line) {
         final Matcher matcher = pattern.matcher(line);
-        if (matcher.matches())
-            return matcher.group(1);
-        return null;
+        return matcher.matches() ? matcher.group(1) : null;
     }
 }
diff --git a/app/src/main/java/com/wireguard/config/Config.java b/app/src/main/java/com/wireguard/config/Config.java
index a3935302..a3341d5f 100644
--- a/app/src/main/java/com/wireguard/config/Config.java
+++ b/app/src/main/java/com/wireguard/config/Config.java
@@ -1,32 +1,23 @@
 package com.wireguard.config;
 
 import android.databinding.BaseObservable;
-import android.databinding.Bindable;
-import android.databinding.Observable;
 import android.databinding.ObservableArrayList;
 import android.databinding.ObservableList;
 import android.os.Parcel;
 import android.os.Parcelable;
-import android.support.annotation.NonNull;
-
-import com.wireguard.android.BR;
 
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.regex.Pattern;
 
 /**
  * Represents a wg-quick configuration file, its name, and its connection state.
  */
 
-public class Config extends BaseObservable
-        implements Comparable<Config>, Copyable<Config>, Observable, Parcelable {
-    public static final Parcelable.Creator<Config> CREATOR = new Parcelable.Creator<Config>() {
+public class Config extends BaseObservable implements Parcelable {
+    public static final Creator<Config> CREATOR = new Creator<Config>() {
         @Override
         public Config createFromParcel(final Parcel in) {
             return new Config(in);
@@ -37,104 +28,22 @@ public class Config extends BaseObservable
             return new Config[size];
         }
     };
-    public static final int NAME_MAX_LENGTH = 16;
-    private static final Pattern PATTERN = Pattern.compile("^[a-zA-Z0-9_=+.-]{1,16}$");
-
-    public static boolean isNameValid(final String name) {
-        return name.length() <= NAME_MAX_LENGTH && PATTERN.matcher(name).matches();
-    }
 
-    private final Interface iface;
-    private boolean isEnabled;
-    private boolean isPrimary;
-    private String name;
+    private final Interface interfaceSection;
     private final ObservableList<Peer> peers = new ObservableArrayList<>();
 
     public Config() {
-        iface = new Interface();
+        interfaceSection = new Interface();
     }
 
-    protected Config(final Parcel in) {
-        iface = in.readParcelable(Interface.class.getClassLoader());
-        name = in.readString();
-        // The flattened peers must be recreated to associate them with this config.
-        final List<Peer> flattenedPeers = new LinkedList<>();
-        in.readTypedList(flattenedPeers, Peer.CREATOR);
-        for (final Peer peer : flattenedPeers)
-            addPeer(peer);
+    private Config(final Parcel in) {
+        interfaceSection = in.readParcelable(Interface.class.getClassLoader());
+        in.readTypedList(peers, Peer.CREATOR);
     }
 
-    public Peer addPeer() {
-        final Peer peer = new Peer(this);
-        peers.add(peer);
-        return peer;
-    }
-
-    private Peer addPeer(final Peer peer) {
-        final Peer copy = peer.copy(this);
-        peers.add(copy);
-        return copy;
-    }
-
-    @Override
-    public int compareTo(@NonNull final Config config) {
-        return getName().compareTo(config.getName());
-    }
-
-    @Override
-    public Config copy() {
-        final Config copy = new Config();
-        copy.copyFrom(this);
-        return copy;
-    }
-
-    @Override
-    public void copyFrom(final Config source) {
-        if (source != null) {
-            iface.copyFrom(source.iface);
-            name = source.name;
-            peers.clear();
-            for (final Peer peer : source.peers)
-                addPeer(peer);
-        } else {
-            iface.copyFrom(null);
-            name = null;
-            peers.clear();
-        }
-        notifyChange();
-    }
-
-    @Override
-    public int describeContents() {
-        return 0;
-    }
-
-    public Interface getInterface() {
-        return iface;
-    }
-
-    @Bindable
-    public String getName() {
-        return name;
-    }
-
-    public ObservableList<Peer> getPeers() {
-        return peers;
-    }
-
-    @Bindable
-    public boolean isEnabled() {
-        return isEnabled;
-    }
-
-    @Bindable
-    public boolean isPrimary() {
-        return isPrimary;
-    }
-
-    public void parseFrom(final InputStream stream)
+    public static Config from(final InputStream stream)
             throws IOException {
-        peers.clear();
+        final Config config = new Config();
         try (BufferedReader reader = new BufferedReader(
                 new InputStreamReader(stream, StandardCharsets.UTF_8))) {
             Peer currentPeer = null;
@@ -147,10 +56,11 @@ public class Config extends BaseObservable
                     currentPeer = null;
                     inInterfaceSection = true;
                 } else if ("[Peer]".equals(line)) {
-                    currentPeer = addPeer();
+                    currentPeer = new Peer();
+                    config.peers.add(currentPeer);
                     inInterfaceSection = false;
                 } else if (inInterfaceSection) {
-                    iface.parse(line);
+                    config.interfaceSection.parse(line);
                 } else if (currentPeer != null) {
                     currentPeer.parse(line);
                 } else {
@@ -161,28 +71,25 @@ public class Config extends BaseObservable
                 throw new IllegalArgumentException("Could not find any config information");
             }
         }
+        return config;
     }
 
-    public void setIsEnabled(final boolean isEnabled) {
-        this.isEnabled = isEnabled;
-        notifyPropertyChanged(BR.enabled);
+    @Override
+    public int describeContents() {
+        return 0;
     }
 
-    public void setIsPrimary(final boolean isPrimary) {
-        this.isPrimary = isPrimary;
-        notifyPropertyChanged(BR.primary);
+    public Interface getInterface() {
+        return interfaceSection;
     }
 
-    public void setName(final String name) {
-        if (name != null && !name.isEmpty() && !isNameValid(name))
-            throw new IllegalArgumentException();
-        this.name = name;
-        notifyPropertyChanged(BR.name);
+    public ObservableList<Peer> getPeers() {
+        return peers;
     }
 
     @Override
     public String toString() {
-        final StringBuilder sb = new StringBuilder().append(iface);
+        final StringBuilder sb = new StringBuilder().append(interfaceSection);
         for (final Peer peer : peers)
             sb.append('\n').append(peer);
         return sb.toString();
@@ -190,8 +97,7 @@ public class Config extends BaseObservable
 
     @Override
     public void writeToParcel(final Parcel dest, final int flags) {
-        dest.writeParcelable(iface, flags);
-        dest.writeString(name);
+        dest.writeParcelable(interfaceSection, flags);
         dest.writeTypedList(peers);
     }
 }
diff --git a/app/src/main/java/com/wireguard/config/Copyable.java b/app/src/main/java/com/wireguard/config/Copyable.java
deleted file mode 100644
index 826cfbb5..00000000
--- a/app/src/main/java/com/wireguard/config/Copyable.java
+++ /dev/null
@@ -1,10 +0,0 @@
-package com.wireguard.config;
-
-/**
- * Interface for classes that can perform a deep copy of their objects.
- */
-
-public interface Copyable<T> {
-    T copy();
-    void copyFrom(T source);
-}
diff --git a/app/src/main/java/com/wireguard/config/Interface.java b/app/src/main/java/com/wireguard/config/Interface.java
index b291844a..431f0e31 100644
--- a/app/src/main/java/com/wireguard/config/Interface.java
+++ b/app/src/main/java/com/wireguard/config/Interface.java
@@ -2,7 +2,6 @@ package com.wireguard.config;
 
 import android.databinding.BaseObservable;
 import android.databinding.Bindable;
-import android.databinding.Observable;
 import android.os.Parcel;
 import android.os.Parcelable;
 
@@ -14,10 +13,8 @@ import com.wireguard.crypto.Keypair;
  * Represents the configuration for a WireGuard interface (an [Interface] block).
  */
 
-public class Interface extends BaseObservable
-        implements Copyable<Interface>, Observable, Parcelable {
-    public static final Parcelable.Creator<Interface> CREATOR
-            = new Parcelable.Creator<Interface>() {
+public class Interface extends BaseObservable implements Parcelable {
+    public static final Creator<Interface> CREATOR = new Creator<Interface>() {
         @Override
         public Interface createFromParcel(final Parcel in) {
             return new Interface(in);
@@ -31,8 +28,8 @@ public class Interface extends BaseObservable
 
     private String address;
     private String dns;
-    private String listenPort;
     private Keypair keypair;
+    private String listenPort;
     private String mtu;
     private String privateKey;
 
@@ -40,7 +37,7 @@ public class Interface extends BaseObservable
         // Do nothing.
     }
 
-    protected Interface(final Parcel in) {
+    private Interface(final Parcel in) {
         address = in.readString();
         dns = in.readString();
         listenPort = in.readString();
@@ -49,31 +46,6 @@ public class Interface extends BaseObservable
     }
 
     @Override
-    public Interface copy() {
-        final Interface copy = new Interface();
-        copy.copyFrom(this);
-        return copy;
-    }
-
-    @Override
-    public void copyFrom(final Interface source) {
-        if (source != null) {
-            address = source.address;
-            dns = source.dns;
-            listenPort = source.listenPort;
-            mtu = source.mtu;
-            setPrivateKey(source.privateKey);
-        } else {
-            address = null;
-            dns = null;
-            listenPort = null;
-            mtu = null;
-            setPrivateKey(null);
-        }
-        notifyChange();
-    }
-
-    @Override
     public int describeContents() {
         return 0;
     }
@@ -118,15 +90,15 @@ public class Interface extends BaseObservable
     public void parse(final String line) {
         final Attribute key = Attribute.match(line);
         if (key == Attribute.ADDRESS)
-            setAddress(key.parseFrom(line));
+            setAddress(key.parse(line));
         else if (key == Attribute.DNS)
-            setDns(key.parseFrom(line));
+            setDns(key.parse(line));
         else if (key == Attribute.LISTEN_PORT)
-            setListenPort(key.parseFrom(line));
+            setListenPort(key.parse(line));
         else if (key == Attribute.MTU)
-            setMtu(key.parseFrom(line));
+            setMtu(key.parse(line));
         else if (key == Attribute.PRIVATE_KEY)
-            setPrivateKey(key.parseFrom(line));
+            setPrivateKey(key.parse(line));
         else
             throw new IllegalArgumentException(line);
     }
diff --git a/app/src/main/java/com/wireguard/config/Peer.java b/app/src/main/java/com/wireguard/config/Peer.java
index ea73155f..29a55f9b 100644
--- a/app/src/main/java/com/wireguard/config/Peer.java
+++ b/app/src/main/java/com/wireguard/config/Peer.java
@@ -2,7 +2,6 @@ package com.wireguard.config;
 
 import android.databinding.BaseObservable;
 import android.databinding.Bindable;
-import android.databinding.Observable;
 import android.os.Parcel;
 import android.os.Parcelable;
 
@@ -12,8 +11,8 @@ import com.android.databinding.library.baseAdapters.BR;
  * Represents the configuration for a WireGuard peer (a [Peer] block).
  */
 
-public class Peer extends BaseObservable implements Copyable<Peer>, Observable, Parcelable {
-    public static final Parcelable.Creator<Peer> CREATOR = new Parcelable.Creator<Peer>() {
+public class Peer extends BaseObservable implements Parcelable {
+    public static final Creator<Peer> CREATOR = new Creator<Peer>() {
         @Override
         public Peer createFromParcel(final Parcel in) {
             return new Peer(in);
@@ -26,44 +25,25 @@ public class Peer extends BaseObservable implements Copyable<Peer>, Observable,
     };
 
     private String allowedIPs;
-    private final Config config;
     private String endpoint;
     private String persistentKeepalive;
     private String preSharedKey;
     private String publicKey;
 
-    public Peer(final Config config) {
-        this.config = config;
+    public Peer() {
+        // Do nothing.
     }
 
-    protected Peer(final Parcel in) {
+    private Peer(final Parcel in) {
         allowedIPs = in.readString();
-        config = null;
         endpoint = in.readString();
         persistentKeepalive = in.readString();
         preSharedKey = in.readString();
         publicKey = in.readString();
     }
 
-    @Override
-    public Peer copy() {
-        return copy(config);
-    }
-
-    public Peer copy(final Config config) {
-        final Peer copy = new Peer(config);
-        copy.copyFrom(this);
-        return copy;
-    }
-
-    @Override
-    public void copyFrom(final Peer source) {
-        allowedIPs = source.allowedIPs;
-        endpoint = source.endpoint;
-        persistentKeepalive = source.persistentKeepalive;
-        preSharedKey = source.preSharedKey;
-        publicKey = source.publicKey;
-        notifyChange();
+    public static Peer newInstance() {
+        return new Peer();
     }
 
     @Override
@@ -99,24 +79,19 @@ public class Peer extends BaseObservable implements Copyable<Peer>, Observable,
     public void parse(final String line) {
         final Attribute key = Attribute.match(line);
         if (key == Attribute.ALLOWED_IPS)
-            setAllowedIPs(key.parseFrom(line));
+            setAllowedIPs(key.parse(line));
         else if (key == Attribute.ENDPOINT)
-            setEndpoint(key.parseFrom(line));
+            setEndpoint(key.parse(line));
         else if (key == Attribute.PERSISTENT_KEEPALIVE)
-            setPersistentKeepalive(key.parseFrom(line));
+            setPersistentKeepalive(key.parse(line));
         else if (key == Attribute.PRESHARED_KEY)
-            setPreSharedKey(key.parseFrom(line));
+            setPreSharedKey(key.parse(line));
         else if (key == Attribute.PUBLIC_KEY)
-            setPublicKey(key.parseFrom(line));
+            setPublicKey(key.parse(line));
         else
             throw new IllegalArgumentException(line);
     }
 
-    public void removeSelf() {
-        if (!config.getPeers().remove(this))
-            throw new IllegalStateException("This peer was already removed from its config");
-    }
-
     public void setAllowedIPs(String allowedIPs) {
         if (allowedIPs != null && allowedIPs.isEmpty())
             allowedIPs = null;