/*
 * Copyright © 2017-2023 WireGuard LLC. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

package com.wireguard.android.backend;

import com.wireguard.config.InetNetwork;
import com.wireguard.util.NonNullForAll;

import java.time.Duration;
import java.time.Instant;
import java.time.LocalTime;
import java.time.ZoneId;
import java.util.LinkedHashSet;
import java.util.Set;

/**
 * Class representing DHCP info for a {@link Tunnel} instance.
 */
@NonNullForAll
public class Dhcp {
    private Set<Lease> leases = new LinkedHashSet<>();

    public class Lease {
        private InetNetwork address;
        private Duration validLt;
        private Duration preferredLt;
        private Instant validTs;
        private Instant preferredTs;

        public Lease(InetNetwork address, Duration validLt, Duration preferredLt) {
            this.address = address;
            this.validLt = validLt;
            this.preferredLt = preferredLt;

            Instant now = Instant.now();
            this.validTs = now.plus(validLt);
            this.preferredTs = now.plus(preferredLt);
        }

        public final InetNetwork getAddress() {
            return this.address;
        }

        public String toString() {
            ZoneId zone = ZoneId.systemDefault();
            LocalTime validLocal = validTs.atZone(zone).toLocalTime().withNano(0);
            LocalTime preferredLocal = preferredTs.atZone(zone).toLocalTime().withNano(0);
            // TODO add date when needed
            return address.toString() + " (valid " + validLocal + ", preferred " + preferredLocal + ")";
        }
    }

    public void addLease(InetNetwork address, Duration valid, Duration preferred) {
        this.leases.add(new Lease(address, valid, preferred));
    }

    public final Set<Lease> getLeases() {
        return leases;
    }

    public String toString() {
        return "DHCP";
    }
}