/*
 * Copyright © 2017-2021 WireGuard LLC. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */
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 androidx.databinding.DataBindingUtil
import androidx.lifecycle.lifecycleScope
import com.wireguard.android.R
import com.wireguard.android.backend.Tunnel
import com.wireguard.android.databinding.TunnelDetailFragmentBinding
import com.wireguard.android.databinding.TunnelDetailPeerBinding
import com.wireguard.android.model.ObservableTunnel
import com.wireguard.android.util.QuantityFormatter
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch

/**
 * Fragment that shows details about a specific tunnel.
 */
class TunnelDetailFragment : BaseFragment() {
    private var binding: TunnelDetailFragmentBinding? = null
    private var lastState = Tunnel.State.TOGGLE
    private var timerActive = true

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setHasOptionsMenu(true)
    }

    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
        inflater.inflate(R.menu.tunnel_detail, menu)
    }

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        super.onCreateView(inflater, container, savedInstanceState)
        binding = TunnelDetailFragmentBinding.inflate(inflater, container, false)
        binding?.executePendingBindings()
        return binding?.root
    }

    override fun onDestroyView() {
        binding = null
        super.onDestroyView()
    }

    override fun onResume() {
        super.onResume()
        timerActive = true
        lifecycleScope.launch {
            while (timerActive) {
                updateStats()
                delay(1000)
            }
        }
    }

    override fun onSelectedTunnelChanged(oldTunnel: ObservableTunnel?, newTunnel: ObservableTunnel?) {
        val binding = binding ?: return
        binding.tunnel = newTunnel
        if (newTunnel == null) {
            binding.config = null
        } else {
            lifecycleScope.launch {
                try {
                    binding.config = newTunnel.getConfigAsync()
                } catch (_: Throwable) {
                    binding.config = null
                }
            }
        }
        lastState = Tunnel.State.TOGGLE
        lifecycleScope.launch { updateStats() }
    }

    override fun onStop() {
        timerActive = false
        super.onStop()
    }

    override fun onViewStateRestored(savedInstanceState: Bundle?) {
        binding ?: return
        binding!!.fragment = this
        onSelectedTunnelChanged(null, selectedTunnel)
        super.onViewStateRestored(savedInstanceState)
    }

    private suspend fun updateStats() {
        val binding = binding ?: return
        val tunnel = binding.tunnel ?: return
        if (!isResumed) return
        val state = tunnel.state
        if (state != Tunnel.State.UP && lastState == state) return
        lastState = state
        try {
            val statistics = tunnel.getStatisticsAsync()
            for (i in 0 until binding.peersLayout.childCount) {
                val peer: TunnelDetailPeerBinding = DataBindingUtil.getBinding(binding.peersLayout.getChildAt(i))
                        ?: continue
                val publicKey = peer.item!!.publicKey
                val rx = statistics.peerRx(publicKey)
                val tx = statistics.peerTx(publicKey)
                if (rx == 0L && tx == 0L) {
                    peer.transferLabel.visibility = View.GONE
                    peer.transferText.visibility = View.GONE
                    continue
                }
                peer.transferText.text = getString(R.string.transfer_rx_tx, QuantityFormatter.formatBytes(rx), QuantityFormatter.formatBytes(tx))
                peer.transferLabel.visibility = View.VISIBLE
                peer.transferText.visibility = View.VISIBLE
            }
        } catch (e: Throwable) {
            for (i in 0 until binding.peersLayout.childCount) {
                val peer: TunnelDetailPeerBinding = DataBindingUtil.getBinding(binding.peersLayout.getChildAt(i))
                        ?: continue
                peer.transferLabel.visibility = View.GONE
                peer.transferText.visibility = View.GONE
            }
        }
    }
}