using System.ComponentModel;
using System.Windows;
using System.Windows.Threading;
using AutoShutdown.Models;
using AutoShutdown.Services;
using Forms = System.Windows.Forms;

namespace AutoShutdown;

public partial class MainWindow : Window
{
    private readonly PowerService _powerService = new();
    private readonly WakeService _wakeService = new();
    private readonly NotificationSettingsStore _settingsStore = new();
    private readonly DispatcherTimer _timer = new() { Interval = TimeSpan.FromSeconds(1) };
    private readonly Dictionary<PowerAction, System.Windows.Controls.Button> _actionButtons;
    private readonly Forms.NotifyIcon? _trayIcon;
    private readonly bool _enableTray;

    private NotificationSettings _notificationSettings;
    private NotificationService _notificationService;
    private PowerAction _selectedAction = PowerAction.Shutdown;
    private PowerAction? _scheduledAction;
    private DateTime? _scheduledAt;
    private bool _hasExecuted;
    private bool _reminderShown;
    private bool _allowExit;

    public MainWindow(bool enableTray = true)
    {
        _enableTray = enableTray;
        _notificationSettings = _settingsStore.Load();
        _notificationService = new NotificationService(_notificationSettings);

        InitializeComponent();

        _actionButtons = new Dictionary<PowerAction, System.Windows.Controls.Button>
        {
            [PowerAction.Shutdown] = ShutdownButton,
            [PowerAction.Restart] = RestartButton,
            [PowerAction.Sleep] = SleepButton,
            [PowerAction.Hibernate] = HibernateButton,
            [PowerAction.Wake] = WakeButton,
            [PowerAction.Lock] = LockButton,
            [PowerAction.LogOff] = LogOffButton
        };

        foreach (var (action, button) in _actionButtons)
        {
            button.Tag = action;
            button.ToolTip = action.Description();
        }

        DateInput.Text = DateTime.Today.ToString("yyyy/M/d");
        TimeInput.Text = DateTime.Now.AddMinutes(30).ToString("HH:mm");
        ForceCheck.ToolTip = "强制关闭未响应程序，仅用于关机、重启、注销等动作。";

        _trayIcon = _enableTray ? CreateTrayIcon() : null;

        SelectAction(PowerAction.Shutdown);
        UpdateScheduleInputs();
        UpdateStatus();

        _timer.Tick += (_, _) => OnTick();
        _timer.Start();
    }

    protected override void OnClosing(CancelEventArgs e)
    {
        if (_enableTray && !_allowExit)
        {
            e.Cancel = true;
            HideToTray();
            return;
        }

        _trayIcon?.Dispose();
        base.OnClosing(e);
    }

    private Forms.NotifyIcon CreateTrayIcon()
    {
        var menu = new Forms.ContextMenuStrip();
        menu.Items.Add("显示/收起主窗口", null, (_, _) => Dispatcher.Invoke(ToggleMainWindowFromTray));
        menu.Items.Add("取消当前计划", null, async (_, _) => await Dispatcher.InvokeAsync(CancelCurrentPlanAsync));
        menu.Items.Add("OmniNotify 适配设置", null, (_, _) => Dispatcher.Invoke(OpenNotificationSettings));
        menu.Items.Add(new Forms.ToolStripSeparator());
        menu.Items.Add("退出 AutoShutdown", null, (_, _) => ExitFromTray());

        var icon = new Forms.NotifyIcon
        {
            Icon = LoadTrayIcon(),
            Text = "AutoShutdown",
            ContextMenuStrip = menu,
            Visible = true
        };
        icon.MouseClick += (_, e) =>
        {
            if (e.Button == Forms.MouseButtons.Left)
            {
                Dispatcher.Invoke(ToggleMainWindowFromTray);
            }
        };
        return icon;
    }

    private static System.Drawing.Icon LoadTrayIcon()
    {
        var processPath = Environment.ProcessPath;
        return !string.IsNullOrWhiteSpace(processPath) && System.Drawing.Icon.ExtractAssociatedIcon(processPath) is { } icon
            ? icon
            : System.Drawing.SystemIcons.Application;
    }

    private void HideToTray(bool showHint = true)
    {
        Hide();
        if (!showHint)
        {
            return;
        }

        if (_notificationSettings.Mode == NotificationMode.OmniNotify)
        {
            _ = _notificationService.NotifyAsync("AutoShutdown 已在托盘运行", "关闭窗口不会退出应用，可在托盘菜单中退出。");
            return;
        }

        _trayIcon?.ShowBalloonTip(2500, "AutoShutdown 已在托盘运行", "关闭窗口不会退出应用，可在托盘菜单中退出。", Forms.ToolTipIcon.Info);
    }

    private void ToggleMainWindowFromTray()
    {
        if (IsVisible && WindowState != WindowState.Minimized)
        {
            HideToTray(showHint: false);
            return;
        }

        RestoreFromTray();
    }

    private void RestoreFromTray()
    {
        Show();
        WindowState = WindowState.Normal;
        Activate();
    }

    private void ExitFromTray()
    {
        _allowExit = true;
        Dispatcher.Invoke(Close);
    }

    private void UpdateTrayText(string text)
    {
        if (_trayIcon is null)
        {
            return;
        }

        _trayIcon.Text = text.Length > 63 ? text[..63] : text;
    }

    private void ActionButton_Click(object sender, RoutedEventArgs e)
    {
        if (sender is System.Windows.Controls.Button { Tag: PowerAction action })
        {
            SelectAction(action);
        }
    }

    private void ScheduleModeChanged(object sender, RoutedEventArgs e) => UpdateScheduleInputs();

    private async void StartButton_Click(object sender, RoutedEventArgs e) => await StartPlanAsync();

    private async void CancelButton_Click(object sender, RoutedEventArgs e) => await CancelPlanAsync();

    private async void AbortButton_Click(object sender, RoutedEventArgs e) => await AbortSystemShutdownAsync();

    private void SettingsButton_Click(object sender, RoutedEventArgs e) => OpenNotificationSettings();

    private void OpenNotificationSettings()
    {
        var window = new NotificationSettingsWindow(_notificationSettings, _notificationService)
        {
            Owner = this
        };

        if (window.ShowDialog() != true)
        {
            return;
        }

        _notificationSettings = window.Settings;
        _settingsStore.Save(_notificationSettings);
        _notificationService.UpdateSettings(_notificationSettings);
        UpdateStatus();
    }

    private void SelectAction(PowerAction action)
    {
        _selectedAction = action;
        ActionTitleText.Text = action.Label();
        ActionDescriptionText.Text = action.Description();

        foreach (var (item, button) in _actionButtons)
        {
            var selected = item == action;
            button.Background = selected ? BrushFrom("#E2ECFF") : BrushFrom("#FFFFFF");
            button.Foreground = selected ? BrushFrom("#2563EB") : BrushFrom("#111827");
            button.BorderBrush = selected ? BrushFrom("#2563EB") : BrushFrom("#DEE6F2");
            button.BorderThickness = selected ? new Thickness(2) : new Thickness(1);
        }
    }

    private async Task StartPlanAsync()
    {
        if (!TryResolveScheduleTime(out var scheduledAt))
        {
            await _notificationService.NotifyAsync(this, "计划无效", "请检查时间或倒计时输入。", MessageBoxImage.Warning);
            return;
        }

        if (scheduledAt <= DateTime.Now.AddSeconds(1))
        {
            await _notificationService.NotifyAsync(this, "计划无效", "请选择一个晚于当前时间的计划。", MessageBoxImage.Warning);
            return;
        }

        var scheduledAction = _selectedAction;
        var forceApps = ForceCheck.IsChecked == true;
        _scheduledAt = scheduledAt;
        _scheduledAction = scheduledAction;
        _hasExecuted = false;
        _reminderShown = false;
        UpdateStatus();
        await Dispatcher.Yield(DispatcherPriority.Background);

        var seconds = (int)Math.Ceiling((scheduledAt - DateTime.Now).TotalSeconds);
        if (scheduledAction == PowerAction.Wake)
        {
            await TryRunAsync(
                () => _wakeService.ScheduleWake(scheduledAt),
                "计划已启动",
                "已创建 Windows 唤醒任务。请确保电源选项允许唤醒计时器。");
        }
        else if (scheduledAction is PowerAction.Shutdown or PowerAction.Restart)
        {
            await TryRunAsync(
                () => _powerService.Execute(scheduledAction, seconds, forceApps),
                "计划已启动",
                "已交给 Windows 系统计划执行。");
        }
        else
        {
            await _notificationService.NotifyAsync(this, "计划已启动", $"{scheduledAction.Label()} 将在 {scheduledAt:yyyy-MM-dd HH:mm} 执行。");
        }
    }

    private async Task CancelPlanAsync()
    {
        var hadPlan = _scheduledAt is not null;
        var scheduledAction = _scheduledAction;
        _scheduledAt = null;
        _scheduledAction = null;
        _hasExecuted = false;
        _reminderShown = false;
        UpdateStatus();

        if (scheduledAction == PowerAction.Wake)
        {
            await TryCancelWakeAsync();
        }

        if (hadPlan && scheduledAction is not null)
        {
            await _notificationService.NotifyAsync(this, "计划已取消", $"已取消 {scheduledAction.Value.Label()} 计划。");
        }
    }

    private Task CancelCurrentPlanAsync()
    {
        return _scheduledAction is PowerAction.Shutdown or PowerAction.Restart
            ? AbortSystemShutdownAsync()
            : CancelPlanAsync();
    }

    private async Task AbortSystemShutdownAsync()
    {
        if (_powerService.CancelShutdown())
        {
            _scheduledAt = null;
            _scheduledAction = null;
            _hasExecuted = false;
            _reminderShown = false;
            UpdateStatus();
            await _notificationService.NotifyAsync(this, "已撤销", "已请求 Windows 撤销待执行的关机/重启任务。");
            return;
        }

        await _notificationService.NotifyAsync(this, "无需撤销", "当前没有可撤销的系统关机/重启任务，或系统拒绝了该请求。");
    }

    private async void OnTick()
    {
        if (_scheduledAt is null)
        {
            UpdateStatus();
            return;
        }

        var remaining = _scheduledAt.Value - DateTime.Now;
        if (remaining.TotalSeconds <= 0 && !_hasExecuted)
        {
            _hasExecuted = true;
            var scheduledAction = _scheduledAction ?? _selectedAction;
            var forceApps = ForceCheck.IsChecked == true;
            if (scheduledAction is not (PowerAction.Shutdown or PowerAction.Restart or PowerAction.Wake))
            {
                await TryRunAsync(
                    () => _powerService.Execute(scheduledAction, 0, forceApps),
                    "执行完成",
                    $"{scheduledAction.Label()} 已执行。",
                    showSuccess: false);
            }

            _scheduledAt = null;
            _scheduledAction = null;
        }
        else if (!_reminderShown && TryReadInt(ReminderInput.Text, 0, 120, out var reminder) && reminder > 0 && remaining.TotalMinutes <= reminder)
        {
            _reminderShown = true;
            var scheduledAction = _scheduledAction ?? _selectedAction;
            await _notificationService.NotifyAsync(this, "任务提醒", $"{scheduledAction.Label()} 将在 {FormatRemaining(remaining)} 后执行。");
        }

        UpdateStatus();
    }

    private bool TryResolveScheduleTime(out DateTime scheduledAt)
    {
        if (ClockRadio.IsChecked == true)
        {
            if (!DateTime.TryParse(DateInput.Text, out var date) || !TimeSpan.TryParse(TimeInput.Text, out var time))
            {
                scheduledAt = default;
                return false;
            }

            scheduledAt = date.Date.Add(time);
            return true;
        }

        if (!TryReadInt(HoursInput.Text, 0, 168, out var hours) || !TryReadInt(MinutesInput.Text, 0, 59, out var minutes))
        {
            scheduledAt = default;
            return false;
        }

        scheduledAt = DateTime.Now.AddHours(hours).AddMinutes(minutes);
        return true;
    }

    private void UpdateScheduleInputs()
    {
        if (DateInput is null || TimeInput is null || HoursInput is null || MinutesInput is null)
        {
            return;
        }

        var byClock = ClockRadio.IsChecked == true;
        DateInput.IsEnabled = byClock;
        TimeInput.IsEnabled = byClock;
        HoursInput.IsEnabled = !byClock;
        MinutesInput.IsEnabled = !byClock;
    }

    private void UpdateStatus()
    {
        UpdatePlanActionButtons();

        if (_scheduledAt is null)
        {
            StatusText.Text = _notificationSettings.Mode == NotificationMode.OmniNotify
                ? $"当前没有运行中的计划。提示：OmniNotify / {_notificationSettings.Channel}"
                : "当前没有运行中的计划。";
            CountdownText.Text = "待命";
            UpdateTrayText("AutoShutdown - 待命");
            return;
        }

        var remaining = _scheduledAt.Value - DateTime.Now;
        if (remaining < TimeSpan.Zero)
        {
            remaining = TimeSpan.Zero;
        }

        var scheduledAction = _scheduledAction ?? _selectedAction;
        StatusText.Text = $"下一次任务：{_scheduledAt:yyyy-MM-dd HH:mm} 执行 {scheduledAction.Label()}";
        CountdownText.Text = FormatRemaining(remaining);
        UpdateTrayText($"AutoShutdown - {scheduledAction.Label()} {FormatRemaining(remaining)}");
    }

    private void UpdatePlanActionButtons()
    {
        if (StartPlanButton is null || CancelPlanButton is null || AbortShutdownButton is null)
        {
            return;
        }

        var hasPlan = _scheduledAt is not null;
        var needsSystemAbort = hasPlan && _scheduledAction is PowerAction.Shutdown or PowerAction.Restart;

        StartPlanButton.Visibility = hasPlan ? Visibility.Collapsed : Visibility.Visible;
        CancelPlanButton.Visibility = hasPlan && !needsSystemAbort ? Visibility.Visible : Visibility.Collapsed;
        AbortShutdownButton.Visibility = needsSystemAbort ? Visibility.Visible : Visibility.Collapsed;
    }

    private async Task TryRunAsync(Action action, string title, string successMessage, bool showSuccess = true)
    {
        try
        {
            await Task.Run(action);
            if (showSuccess)
            {
                await _notificationService.NotifyAsync(this, title, successMessage);
            }
        }
        catch (Exception ex)
        {
            _scheduledAt = null;
            _scheduledAction = null;
            UpdateStatus();
            await _notificationService.NotifyAsync(this, "启动失败", ex.Message, MessageBoxImage.Error);
        }
    }

    private async Task TryCancelWakeAsync()
    {
        try
        {
            await Task.Run(_wakeService.CancelWake);
        }
        catch
        {
            // 取消普通计划时不因为系统任务不存在或权限差异打断用户。
        }
    }

    private static bool TryReadInt(string text, int min, int max, out int value)
    {
        return int.TryParse(text, out value) && value >= min && value <= max;
    }

    private static string FormatRemaining(TimeSpan value)
    {
        if (value.TotalDays >= 1)
        {
            return $"{(int)value.TotalDays}天 {value.Hours:D2}:{value.Minutes:D2}:{value.Seconds:D2}";
        }

        return $"{Math.Max(0, (int)value.TotalHours):D2}:{value.Minutes:D2}:{value.Seconds:D2}";
    }

    private static System.Windows.Media.Brush BrushFrom(string hex)
    {
        return (System.Windows.Media.Brush)new System.Windows.Media.BrushConverter().ConvertFromString(hex)!;
    }
}