using System.Runtime.InteropServices;
using MusicBridge.Agent.Media;
using MusicBridge.Agent.Network;

namespace MusicBridge.Agent.Desktop;

internal sealed class DesktopHost(Func<MediaState> read, IMediaService media, PairingService pairing,
    Func<string> network, Action showQr, Action exit, bool visible = true,
    StartupSettings? startup = null, bool minimized = false) : IDisposable
{
    private readonly object gate = new();
    private readonly TaskCompletionSource ready = new(TaskCreationOptions.RunContinuationsAsynchronously);
    private Thread? thread;
    private AgentWindow? window;
    private bool disposed;

    public Task StartAsync()
    {
        thread = new Thread(Run) { IsBackground = true, Name = "MusicBridge Desktop" };
        thread.SetApartmentState(ApartmentState.STA);
        thread.Start();
        return ready.Task;
    }

    private void Run()
    {
        try
        {
            Application.EnableVisualStyles();
            using var view = new AgentWindow(read, media, pairing, network, showQr);
            view.Opacity = visible ? 1 : 0;
            view.ShowInTaskbar = visible;
            using var menu = new ContextMenuStrip();
            void ShowWindow() { view.Show(); view.WindowState = FormWindowState.Normal; view.Activate(); }
            menu.Items.Add("Открыть MusicBridge", null, (_, _) => ShowWindow());
            var toggle = menu.Items.Add("Play / Pause", null, async (_, _) => await view.SendAsync(new("toggle")));
            menu.Items.Add("Подключить iPhone", null, (_, _) => { pairing.Open(); showQr(); });
            if (startup is not null)
            {
                var autoStart = new ToolStripMenuItem("Запускать вместе с Windows");
                try { autoStart.Checked = startup.Enabled; }
                catch (Exception) { autoStart.Enabled = false; }
                autoStart.Click += (_, _) =>
                {
                    try { startup.SetEnabled(!startup.Enabled); autoStart.Checked = startup.Enabled; }
                    catch (Exception ex) { MessageBox.Show(view, ex.Message, "Автозапуск MusicBridge", MessageBoxButtons.OK, MessageBoxIcon.Warning); }
                };
                menu.Items.Add(autoStart);
            }
            menu.Items.Add(new ToolStripSeparator());
            menu.Items.Add("Завершить MusicBridge", null, (_, _) => { view.AllowClose = true; view.Close(); });
            using var icon = new NotifyIcon { Icon = SystemIcons.Application, Text = "MusicBridge", ContextMenuStrip = menu, Visible = visible };
            icon.DoubleClick += (_, _) => ShowWindow();
            using var timer = new System.Windows.Forms.Timer { Interval = 1000 };
            timer.Tick += (_, _) =>
            {
                var state = read();
                toggle.Enabled = state.Capabilities.Toggle;
                var text = state.HasSession ? $"MusicBridge — {state.Title}" : "MusicBridge — нет плеера";
                icon.Text = text.Length > 63 ? text[..63] : text;
            };
            view.Shown += (_, _) => { if (minimized) view.Hide(); timer.Start(); ready.TrySetResult(); };
            lock (gate)
            {
                if (disposed) { ready.TrySetCanceled(); return; }
                window = view;
            }
            Application.Run(view);
            icon.Visible = false;
        }
        catch (Exception ex) { ready.TrySetException(ex); }
        finally
        {
            lock (gate) window = null;
            exit();
        }
    }

    public void Dispose()
    {
        lock (gate)
        {
            disposed = true;
            if (window is { IsHandleCreated: true } view)
            {
                try { view.BeginInvoke(() => { view.AllowClose = true; view.Close(); }); }
                catch (InvalidOperationException) { }
            }
        }
        thread?.Join(TimeSpan.FromSeconds(2));
    }

    // Detach only this process; never hide or close the user's shared terminal window.
    [DllImport("kernel32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool FreeConsole();
}