using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using PolyTrader.Core.Modularity;
using Xunit;

namespace PolyTrader.Tests
{
    /// <summary>Sicherheitsnetz für das gemeinsame „Fenster"-Menü (Slice 1): Inhalt + Verhalten.</summary>
    public class WindowMenuTests
    {
        private sealed class FakeUiHost : IModuleUiHost
        {
            public List<ModuleView> ViewList { get; } = new();
            public HashSet<string> OpenIds { get; } = new();
            public List<string> Opened { get; } = new();
            public bool MainActivated { get; private set; }

            public bool ShutdownRequested { get; private set; }

            public IReadOnlyList<ModuleView> Views => ViewList;
            public bool IsOpen(string viewId) => OpenIds.Contains(viewId);
            public void OpenView(string viewId) => Opened.Add(viewId);
            public void ActivateMain() => MainActivated = true;
            public void RequestShutdown() => ShutdownRequested = true;
            public void RegisterView(ModuleView view) => ViewList.Add(view);
            public event Action? OpenStateChanged { add { } remove { } }
        }

        private static FakeUiHost Host()
        {
            var h = new FakeUiHost();
            h.RegisterView(new ModuleView { Id = "core.dashboard", Title = "Dashboard", Order = 1 });
            h.RegisterView(new ModuleView { Id = "core.terminal", Title = "Terminal / Logs", Order = 2 });
            h.OpenIds.Add("core.terminal");   // Terminal ist offen
            return h;
        }

        [Fact]
        public void Populate_lists_launcher_views_and_exit_side_by_side()
        {
            var host = Host();
            var menu = new MenuStrip();

            // currentViewId == null => Launcher (Hauptprozess): rechte Aktion ist „Beenden".
            WindowMenu.Populate(menu, host, currentViewId: null);

            var texts = menu.Items.OfType<ToolStripMenuItem>().Select(i => i.Text).ToList();
            Assert.Equal("Launcher", texts[0]);            // Launcher als erster Top-Level-Eintrag
            Assert.Contains("Dashboard", texts);
            Assert.Contains("Terminal / Logs", texts);
            Assert.Contains("Beenden", texts);
        }

        [Fact]
        public void Non_launcher_window_offers_close_window_not_exit()
        {
            var host = Host();
            var menu = new MenuStrip();

            // currentViewId != null => Modul-/Core-Fenster: KEIN „Beenden", nur „Fenster schließen".
            WindowMenu.Populate(menu, host, currentViewId: "core.dashboard");

            var texts = menu.Items.OfType<ToolStripMenuItem>().Select(i => i.Text).ToList();
            Assert.Contains("Fenster schließen", texts);
            Assert.DoesNotContain("Beenden", texts);

            // Klick auf „Fenster schließen" fordert NICHT das App-Shutdown an.
            menu.Items.OfType<ToolStripMenuItem>().First(i => i.Text == "Fenster schließen").PerformClick();
            Assert.False(host.ShutdownRequested);
        }

        [Fact]
        public void Views_carry_their_icon_in_the_menu()
        {
            var host = new FakeUiHost();
            using var icon = new System.Drawing.Bitmap(16, 16);
            host.RegisterView(new ModuleView { Id = "core.dashboard", Title = "Dashboard", Order = 1, Icon = icon });
            var menu = new MenuStrip();

            WindowMenu.Populate(menu, host, currentViewId: null);

            var dashboard = menu.Items.OfType<ToolStripMenuItem>().First(i => i.Text == "Dashboard");
            Assert.Same(icon, dashboard.Image);
            Assert.Equal(ToolStripItemDisplayStyle.ImageAndText, dashboard.DisplayStyle);
        }

        [Fact]
        public void Current_view_is_bold_and_checked_open_view_is_checked()
        {
            var host = Host();
            var menu = new MenuStrip();

            WindowMenu.Populate(menu, host, currentViewId: "core.dashboard");

            var dashboard = menu.Items.OfType<ToolStripMenuItem>().First(i => i.Text == "Dashboard");
            var terminal = menu.Items.OfType<ToolStripMenuItem>().First(i => i.Text == "Terminal / Logs");

            Assert.True(dashboard.Checked);                 // aktuelles Fenster
            Assert.True(dashboard.Font.Bold);
            Assert.True(terminal.Checked);                  // offenes Fenster
            Assert.False(terminal.Font.Bold);
        }

        [Fact]
        public void Clicking_items_navigates()
        {
            var host = Host();
            var menu = new MenuStrip();
            WindowMenu.Populate(menu, host, currentViewId: null);

            var items = menu.Items.OfType<ToolStripMenuItem>().ToList();
            items.First(i => i.Text == "Launcher").PerformClick();
            items.First(i => i.Text == "Terminal / Logs").PerformClick();

            Assert.True(host.MainActivated);
            Assert.Contains("core.terminal", host.Opened);
        }

        [Fact]
        public void Clicking_exit_requests_shutdown_not_immediate_exit()
        {
            var host = Host();
            var menu = new MenuStrip();
            WindowMenu.Populate(menu, host, currentViewId: null);

            menu.Items.OfType<ToolStripMenuItem>().First(i => i.Text == "Beenden").PerformClick();

            Assert.True(host.ShutdownRequested);
        }
    }
}