using AcDream.App.UI;
using AcDream.App.UI.Layout;
using AcDream.UI.Abstractions.Panels.Settings;

namespace AcDream.App.Tests.UI;

public sealed class RetailWindowLayoutPersistenceTests : IDisposable
{
    private readonly string _directory = Path.Combine(
        Path.GetTempPath(), "acdream-window-layout-tests-" + Guid.NewGuid().ToString("N"));
    private string PathName => Path.Combine(_directory, "settings.json");

    [Fact]
    public void CompletedInteractions_SaveCompleteCharacterResolutionLayout()
    {
        var store = new SettingsStore(PathName);
        var root = new UiRoot { Width = 800, Height = 600 };
        RetailWindowHandle handle = Mount(root, "chat");
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager, store, () => "Alice", () => (800, 600));

        handle.MoveTo(44f, 55f);
        handle.ResizeTo(320f, 180f);
        handle.Hide();

        UiWindowLayout saved = Assert.IsType<UiWindowLayout>(
            store.LoadWindowLayout("Alice", "800x600", "chat", default));
        Assert.Equal((44f, 55f, 320f, 180f), (saved.X, saved.Y, saved.Width, saved.Height));
        Assert.False(saved.Visible);
    }

    [Fact]
    public void MainPanelMove_PersistsCanonicalPositionForEveryPrimaryChild()
    {
        var store = new SettingsStore(PathName);
        var root = new UiRoot { Width = 800, Height = 600 };
        RetailWindowHandle inventory = Mount(root, WindowNames.Inventory);
        RetailWindowHandle character = Mount(root, WindowNames.Character);
        inventory.Hide();
        character.Hide();

        using var panels = new RetailPanelUiController(
            root.IsWindowVisible,
            root.ShowWindow,
            root.HideWindow);
        panels.RegisterMainPanel(
            RetailPanelCatalog.Inventory,
            WindowNames.Inventory,
            inventory);
        panels.RegisterMainPanel(
            RetailPanelCatalog.Character,
            WindowNames.Character,
            character);
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager,
            store,
            () => "Alice",
            () => (800, 600));

        panels.SetPanelVisibility(RetailPanelCatalog.Inventory, visible: true);
        inventory.MoveTo(244f, 133f);

        UiWindowLayout savedInventory = Assert.IsType<UiWindowLayout>(
            store.LoadWindowLayout(
                "Alice", "800x600", WindowNames.Inventory, default));
        UiWindowLayout savedCharacter = Assert.IsType<UiWindowLayout>(
            store.LoadWindowLayout(
                "Alice", "800x600", WindowNames.Character, default));
        Assert.Equal((244f, 133f), (savedInventory.X, savedInventory.Y));
        Assert.Equal((244f, 133f), (savedCharacter.X, savedCharacter.Y));
    }

    [Fact]
    public void Restore_ClampsBoundsAndReappliesPanelStateAndVisibility()
    {
        var store = new SettingsStore(PathName);
        store.SaveWindowLayout(
            "Alice",
            "640x480",
            "chat",
            new UiWindowLayout(900f, 700f, 500f, 300f, false, false, true));

        var root = new UiRoot { Width = 640, Height = 480 };
        var state = new FakeWindowState();
        RetailWindowHandle handle = Mount(root, "chat", state);
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager, store, () => "Alice", () => (640, 480));

        persistence.RestoreAll();

        Assert.Equal((500f, 300f), (handle.Width, handle.Height));
        Assert.Equal((140f, 180f), (handle.Left, handle.Top));
        Assert.False(handle.IsVisible);
        Assert.True(state.Restored.Maximized);
    }

    [Fact]
    public void Restore_OlderAuthoredGeometryRevision_ResetsOnlySavedExtent()
    {
        var store = new SettingsStore(PathName);
        store.SaveWindowLayout(
            "Alice",
            "800x600",
            WindowNames.Examination,
            new UiWindowLayout(
                44f,
                55f,
                310f,
                545f,
                true,
                false,
                false,
                AuthoredGeometryRevision: 0));

        var root = new UiRoot { Width = 800, Height = 600 };
        RetailWindowHandle handle = Mount(
            root,
            WindowNames.Examination,
            authoredGeometryRevision: 1,
            width: 310f,
            height: 400f);
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager,
            store,
            () => "Alice",
            () => (800, 600));

        persistence.RestoreAll();

        Assert.Equal((44f, 55f), (handle.Left, handle.Top));
        Assert.Equal((310f, 400f), (handle.Width, handle.Height));
        UiWindowLayout migrated = Assert.IsType<UiWindowLayout>(
            store.LoadWindowLayout(
                "Alice",
                "800x600",
                WindowNames.Examination,
                default));
        Assert.Equal(1, migrated.AuthoredGeometryRevision);
    }

    [Fact]
    public void RestoreNamed_OlderRevisionUsesMountedAuthoredExtent_NotCurrentSize()
    {
        var store = new SettingsStore(PathName);
        store.SaveNamedWindowLayout(
            "legacy",
            WindowNames.Examination,
            new UiWindowLayout(
                44f,
                55f,
                310f,
                545f,
                true,
                false,
                false,
                AuthoredGeometryRevision: 0));

        var root = new UiRoot { Width = 800, Height = 600 };
        RetailWindowHandle handle = Mount(
            root,
            WindowNames.Examination,
            authoredGeometryRevision: 1,
            width: 310f,
            height: 400f);
        handle.ResizeTo(500f, 300f);
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager,
            store,
            () => "Alice",
            () => (800, 600));

        persistence.RestoreNamed("legacy");

        Assert.Equal((44f, 55f), (handle.Left, handle.Top));
        Assert.Equal((310f, 400f), (handle.Width, handle.Height));
    }

    [Fact]
    public void DefaultPreLoginKey_NeverOverwritesCharacterLayouts()
    {
        var store = new SettingsStore(PathName);
        var root = new UiRoot { Width = 800, Height = 600 };
        RetailWindowHandle handle = Mount(root, "radar");
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager, store, () => "default", () => (800, 600));

        handle.MoveTo(123f, 234f);

        Assert.Null(store.LoadWindowLayout("default", "800x600", "radar", default));
    }

    [Fact]
    public void Restore_StateManagedWindow_PreservesAuthoritativeVisibility()
    {
        var store = new SettingsStore(PathName);
        store.SaveWindowLayout(
            "Alice",
            "800x600",
            "combat",
            new UiWindowLayout(44f, 55f, 200f, 100f, true, false, false));

        var root = new UiRoot { Width = 800, Height = 600 };
        RetailWindowHandle handle = Mount(root, "combat");
        handle.Hide();
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager,
            store,
            () => "Alice",
            () => (800, 600),
            stateManagedVisibilityWindows: ["combat"]);

        persistence.RestoreAll();

        Assert.Equal((44f, 55f), (handle.Left, handle.Top));
        Assert.False(handle.IsVisible);

        // Combat mode owns subsequent show/hide transitions as well; they must
        // not turn into saved user visibility preferences.
        handle.Show();
        UiWindowLayout saved = Assert.IsType<UiWindowLayout>(
            store.LoadWindowLayout("Alice", "800x600", "combat", default));
        Assert.False(saved.Visible);
    }

    [Fact]
    public void NamedProfile_SaveAndRestore_AppliesEveryMountedWindow()
    {
        var store = new SettingsStore(PathName);
        var root = new UiRoot { Width = 800, Height = 600 };
        RetailWindowHandle chat = Mount(root, "chat");
        RetailWindowHandle radar = Mount(root, "radar");
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager, store, () => "Alice", () => (800, 600));

        chat.MoveTo(44f, 55f);
        radar.MoveTo(300f, 120f);
        radar.Hide();
        persistence.SaveNamed("hunting");

        chat.MoveTo(1f, 2f);
        radar.MoveTo(3f, 4f);
        radar.Show();
        persistence.RestoreNamed("hunting");

        Assert.Equal((44f, 55f), (chat.Left, chat.Top));
        Assert.Equal((300f, 120f), (radar.Left, radar.Top));
        Assert.False(radar.IsVisible);
    }

    // ── #390: retail's display-change anti-stranding cascade ────────────
    // The clamp rule is each floating window's own MoveTo override,
    // x = max(0, min(x, parentW − selfW)) (top-left priority), re-applied
    // unconditionally on every display change — see
    // docs/research/2026-08-13-retail-ui-display-change.md.

    [Fact]
    public void ClampAllToScreen_ReclampsStrandedWindows_TopLeftPriority()
    {
        var store = new SettingsStore(PathName);
        var root = new UiRoot { Width = 2560, Height = 1440 };
        RetailWindowHandle handle = Mount(
            root, WindowNames.Examination, width: 310f, height: 400f);
        handle.MoveTo(2200f, 1000f);   // parked near the bottom-right corner
        (int Width, int Height) screen = (2560, 1440);
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager, store, () => "Alice", () => screen);

        screen = (1280, 720);          // the display shrank
        persistence.ClampAllToScreen();

        Assert.Equal(1280f - 310f, handle.Left);
        Assert.Equal(720f - 400f, handle.Top);
    }

    [Fact]
    public void ClampAllToScreen_OversizedWindow_PinsTopLeftToZero()
    {
        // max(0, min(...)) — the max applies LAST, so a window larger than
        // the screen pins to 0 and its top-left chrome stays reachable.
        var store = new SettingsStore(PathName);
        var root = new UiRoot { Width = 800, Height = 600 };
        RetailWindowHandle handle = Mount(
            root, WindowNames.Examination, width: 310f, height: 400f);
        handle.MoveTo(400f, 300f);
        (int Width, int Height) screen = (800, 600);
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager, store, () => "Alice", () => screen);

        screen = (200, 200);           // smaller than the window itself
        persistence.ClampAllToScreen();

        Assert.Equal(0f, handle.Left);
        Assert.Equal(0f, handle.Top);
    }

    [Fact]
    public void ClampAllToScreen_InBoundsWindow_DoesNotMove()
    {
        var store = new SettingsStore(PathName);
        var root = new UiRoot { Width = 2560, Height = 1440 };
        RetailWindowHandle handle = Mount(
            root, WindowNames.Examination, width: 310f, height: 400f);
        handle.MoveTo(100f, 120f);
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager, store, () => "Alice", () => (1280, 720));

        persistence.ClampAllToScreen();

        Assert.Equal((100f, 120f), (handle.Left, handle.Top));
    }

    [Fact]
    public void ClampAllToScreen_DoesNotSaveTheClampedPositions()
    {
        // The clamp runs per resize FRAME during a live window drag; its
        // MoveTo must not trip the per-move save (settings.json writes per
        // frame, keyed by whatever intermediate resolution the drag passes
        // through). Only USER moves save.
        var store = new SettingsStore(PathName);
        var root = new UiRoot { Width = 2560, Height = 1440 };
        RetailWindowHandle handle = Mount(
            root, WindowNames.Examination, width: 310f, height: 400f);
        handle.MoveTo(2200f, 1000f);   // pre-attach: no save subscription yet
        (int Width, int Height) screen = (2560, 1440);
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager, store, () => "Alice", () => screen);

        screen = (1280, 720);
        persistence.ClampAllToScreen();

        Assert.Equal(1280f - 310f, handle.Left);   // it DID clamp…
        Assert.Null(store.LoadWindowLayout(       // …and did NOT write.
            "Alice", "1280x720", WindowNames.Examination, default));
    }

    [Fact]
    public void RestoreAll_WithoutSaveBack_WritesNothingToTheStore()
    {
        // The live display-change reload (#390) must not persist — retail
        // saves layouts only via @saveui/@saveautoui, and a mid-drag reload
        // writing would litter settings.json with intermediate-resolution
        // keys.
        var store = new SettingsStore(PathName);
        var root = new UiRoot { Width = 800, Height = 600 };
        _ = Mount(root, WindowNames.Examination, width: 310f, height: 400f);
        using var persistence = new RetailWindowLayoutPersistence(
            root.WindowManager, store, () => "Alice", () => (800, 600));

        persistence.RestoreAll(saveBack: false);

        Assert.Null(store.LoadWindowLayout(
            "Alice", "800x600", WindowNames.Examination, default));
    }

    private static RetailWindowHandle Mount(
        UiRoot root,
        string name,
        IRetainedWindowStateController? state = null,
        int authoredGeometryRevision = 0,
        float width = 200f,
        float height = 100f)
    {
        var frame = new UiPanel
        {
            Left = 10f,
            Top = 20f,
            Width = width,
            Height = height,
            MinWidth = 100f,
            MinHeight = 80f,
            MaxWidth = 600f,
            MaxHeight = 400f,
            Draggable = true,
            Resizable = true,
        };
        root.AddChild(frame);
        return root.RegisterWindow(
            name,
            frame,
            stateController: state,
            authoredGeometryRevision: authoredGeometryRevision);
    }

    public void Dispose()
    {
        if (Directory.Exists(_directory)) Directory.Delete(_directory, recursive: true);
    }

    private sealed class FakeWindowState : IRetainedWindowStateController
    {
        public RetainedWindowState Restored { get; private set; }
        public RetainedWindowState CaptureWindowState() => Restored;
        public void RestoreWindowState(RetainedWindowState state) => Restored = state;
    }
}