using System.IO;
using System.Threading;
using System.Windows;
using Forms = System.Windows.Forms;

namespace OmniNotify;

public partial class App : System.Windows.Application
{
    private const string SingleInstanceMutexName = @"Local\OmniNotify.SingleInstance";
    private const string ActivateEventName = @"Local\OmniNotify.Activate";
    private Forms.NotifyIcon? _notifyIcon;
    private AppStore? _store;
    private LocalHttpServer? _server;
    private Mutex? _singleInstanceMutex;
    private bool _ownsSingleInstanceMutex;
    private EventWaitHandle? _activateEvent;
    private RegisteredWaitHandle? _activateWait;

    public AppState State { get; private set; } = new();
    public NotificationRouter Router { get; private set; } = null!;
    public PopupCoordinator PopupCoordinator { get; private set; } = null!;
    public string ListenUrl => _server?.Url ?? "";
    public string? ServerError => _server?.LastError;

    protected override void OnStartup(StartupEventArgs e)
    {
        _singleInstanceMutex = new Mutex(true, SingleInstanceMutexName, out var createdNew);
        _ownsSingleInstanceMutex = createdNew;
        _activateEvent = new EventWaitHandle(false, EventResetMode.AutoReset, ActivateEventName);
        if (!createdNew)
        {
            _activateEvent.Set();
            Shutdown();
            return;
        }

        RegisterActivationListener();
        base.OnStartup(e);

        _store = new AppStore();
        State = _store.Load();
        PopupCoordinator = new PopupCoordinator();
        Router = new NotificationRouter(State, _store, PopupCoordinator);
        Router.StateChanged += UpdateTrayMenu;

        _server = new LocalHttpServer(Router);
        _server.Start(State.Settings.LocalPort);

        CreateTrayIcon();
        ShowMainWindow();
    }

    public void SaveState()
    {
        _store?.Save(State);
        UpdateTrayMenu();
    }

    public void ShowMainWindow()
    {
        if (MainWindow is null)
        {
            MainWindow = new MainWindow();
        }

        MainWindow.Show();
        MainWindow.WindowState = WindowState.Normal;
        MainWindow.Activate();
    }

    private void RegisterActivationListener()
    {
        if (_activateEvent is null)
        {
            return;
        }

        _activateWait = ThreadPool.RegisterWaitForSingleObject(
            _activateEvent,
            (_, _) => Dispatcher.Invoke(ShowMainWindow),
            null,
            Timeout.InfiniteTimeSpan,
            false);
    }

    private void CreateTrayIcon()
    {
        var iconPath = Path.Combine(AppContext.BaseDirectory, "app.ico");
        _notifyIcon = new Forms.NotifyIcon
        {
            Icon = new System.Drawing.Icon(iconPath),
            Text = "Omni-Notify",
            Visible = true
        };
        _notifyIcon.MouseClick += (_, args) =>
        {
            if (args.Button == Forms.MouseButtons.Left)
            {
                Dispatcher.Invoke(ShowMainWindow);
            }
        };
        UpdateTrayMenu();
    }

    private void UpdateTrayMenu()
    {
        if (_notifyIcon is null)
        {
            return;
        }

        var menu = new Forms.ContextMenuStrip();
        menu.Items.Add("打开主控制面板", null, (_, _) => Dispatcher.Invoke(ShowMainWindow));
        menu.Items.Add("全局设置", null, (_, _) => Dispatcher.Invoke(() =>
        {
            ShowMainWindow();
            if (MainWindow is MainWindow window)
            {
                window.FocusSettingsTab();
            }
        }));
        menu.Items.Add(State.Settings.DndEnabled ? "关闭免打扰" : "开启免打扰", null, (_, _) => Dispatcher.Invoke(() =>
        {
            State.Settings.DndEnabled = !State.Settings.DndEnabled;
            SaveState();
        }));

        var resetBreaker = menu.Items.Add("解除熔断", null, (_, _) => Dispatcher.Invoke(() => Router.ResetCircuitBreaker()));
        resetBreaker.Enabled = State.Settings.CircuitBreakerOpen;
        resetBreaker.ForeColor = State.Settings.CircuitBreakerOpen ? System.Drawing.Color.Firebrick : System.Drawing.SystemColors.ControlText;

        menu.Items.Add(new Forms.ToolStripSeparator());
        menu.Items.Add("退出软件", null, (_, _) => Dispatcher.Invoke(Shutdown));
        _notifyIcon.ContextMenuStrip = menu;
    }

    protected override void OnExit(ExitEventArgs e)
    {
        _activateWait?.Unregister(null);
        _activateEvent?.Dispose();
        if (_ownsSingleInstanceMutex)
        {
            _singleInstanceMutex?.ReleaseMutex();
        }
        _singleInstanceMutex?.Dispose();
        _notifyIcon?.Dispose();
        _server?.Dispose();
        _store?.Save(State);
        base.OnExit(e);
    }
}