using System;
using System.Collections.ObjectModel;
using System.Linq;
using Avalonia.Controls;
using Avalonia.Markup.Xaml;
using Avalonia.Media;
using Avalonia.Threading;
using Microsoft.Extensions.DependencyInjection;
using PolyTrader.App.Avalonia.Shell;
using PolyTrader.Core.Modularity;
using PolyTraderSharp;

namespace PolyTrader.App.Avalonia.Views
{
    /// <summary>
    /// „Startleiste" der Anwendung – Gegenstück zur bisherigen LauncherForm. Öffnet die Fenster,
    /// spiegelt deren Offen-Status und zeigt die Kernkennzahlen in der Statusleiste.
    /// Layout vollständig in LauncherWindow.axaml.
    /// </summary>
    public partial class LauncherWindow : Window
    {
        private readonly AvaloniaUiHost _uiHost;
        private readonly IServiceProvider _services;
        private readonly TradingState _state;
        private readonly DispatcherTimer _statusTimer = new() { Interval = TimeSpan.FromSeconds(1) };
        private readonly ObservableCollection<WindowMenuEntry> _windowButtons = new();

        public LauncherWindow() => AvaloniaXamlLoader.Load(this);

        public LauncherWindow(AvaloniaUiHost uiHost, IServiceProvider services) : this()
        {
            _uiHost = uiHost;
            _services = services;
            _state = services.GetRequiredService<TradingState>();

            // currentViewId == null => dies ist der Launcher (rechte Menueaktion "Beenden").
            this.FindControl<Controls.WindowMenuBar>("menuBar")!.Attach(uiHost, null, this);

            this.FindControl<ItemsControl>("windowButtons")!.ItemsSource = _windowButtons;
            RebuildWindowButtons();
            _uiHost.OpenStateChanged += OnOpenStateChanged;

            this.FindControl<Button>("btnLiveTrading")!.Click += (_, _) =>
            {
                _state.LiveTradingMode = Next(_state.LiveTradingMode);
                UpdateTradingToggles();
            };
            this.FindControl<Button>("btnDemoTrading")!.Click += (_, _) =>
            {
                _state.DemoTradingMode = Next(_state.DemoTradingMode);
                UpdateTradingToggles();
            };

            _statusTimer.Tick += (_, _) => UpdateStatus();
            _statusTimer.Start();
            UpdateStatus();

            // Schliessen des Launchers laeuft ueber dieselbe Sicherheitsabfrage wie "Beenden".
            Closing += (_, e) =>
            {
                if (_uiHost.ShutdownConfirmed) return;
                e.Cancel = true;
                Dispatcher.UIThread.Post(_uiHost.RequestShutdown);
            };
            // Die Umschalterflaechen werden im Code gesetzt und folgen dem Thema nicht von selbst.
            ThemeManager.ThemeChanged += UpdateTradingToggles;

            Closed += (_, _) =>
            {
                _statusTimer.Stop();
                _uiHost.OpenStateChanged -= OnOpenStateChanged;
                ThemeManager.ThemeChanged -= UpdateTradingToggles;
            };
        }

        /// <summary>Dreistufiger Wechsel wie bisher: Inactive -> SellOnly -> Active -> Inactive.</summary>
        private static TradingMode Next(TradingMode mode) => mode switch
        {
            TradingMode.Inactive => TradingMode.SellOnly,
            TradingMode.SellOnly => TradingMode.Active,
            _ => TradingMode.Inactive
        };

        private void OnOpenStateChanged()
        {
            if (Dispatcher.UIThread.CheckAccess()) RebuildWindowButtons();
            else Dispatcher.UIThread.Post(RebuildWindowButtons);
        }

        private void RebuildWindowButtons()
        {
            _windowButtons.Clear();
            foreach (var view in _uiHost.Views.OrderBy(v => v.Order).ThenBy(v => v.Title))
            {
                string id = view.Id;
                bool open = _uiHost.IsOpen(id);
                _windowButtons.Add(new WindowMenuEntry
                {
                    Title = view.Title,
                    Icon = ViewIcons.Resolve(view.IconKey),
                    IsCurrent = open,
                    IsChecked = open,
                    Command = new RelayCommand(() => _uiHost.OpenView(id))
                });
            }
        }

        private void UpdateTradingToggles()
        {
            Apply(this.FindControl<Button>("btnLiveTrading")!, "LiveTrading", _state.LiveTradingMode);
            Apply(this.FindControl<Button>("btnDemoTrading")!, "DemoTrading", _state.DemoTradingMode);

            // Aussage wie in der WinForms-Oberflaeche (gruen/orange/rot); die konkreten Toene
            // kommen aus dem Thema, damit sie auf hellem wie dunklem Grund lesbar bleiben.
            static void Apply(Button btn, string label, TradingMode mode)
            {
                (string text, string brushKey) = mode switch
                {
                    TradingMode.Active => ($"{label} (AKTIV)", "AppToggleActiveBrush"),
                    TradingMode.SellOnly => ($"{label} (SELL-ONLY)", "AppToggleSellOnlyBrush"),
                    _ => ($"{label} (DEAKTIVIERT)", "AppToggleInactiveBrush")
                };
                btn.Content = text;
                btn.Background = ThemeManager.Brush(brushKey);
            }
        }

        private void UpdateStatus()
        {
            string trading = _state.GlobalTradingPaused
                ? "Pausiert"
                : $"Live={_state.LiveTradingMode} / Demo={_state.DemoTradingMode}";
            this.FindControl<TextBlock>("lblTrading")!.Text = $"Trading: {trading}";

            int moduleCount = _services.GetServices<IPolyTraderModule>().Count();
            this.FindControl<TextBlock>("lblModules")!.Text = $"Module: {moduleCount}";

            this.FindControl<TextBlock>("lblRatelimit")!.Text =
                $"API: {(_state.IsAlchemyHealthy ? "WSS aktiv" : "Polling")}";

            UpdateTradingToggles();
        }
    }
}