using System.Runtime.CompilerServices;
using AcDream.App.Combat;
using AcDream.App.Composition;
using AcDream.App.Diagnostics;
using AcDream.App.Rendering;
using AcDream.App.UI;
using AcDream.App.UI.Layout;
using AcDream.App.World;

namespace AcDream.App.Tests.Composition;

public sealed class InteractionRetainedUiCompositionTests
{
    private static readonly InteractionRetainedUiCompositionPoint[] UiPoints =
    [
        InteractionRetainedUiCompositionPoint.UiHostAcquired,
        InteractionRetainedUiCompositionPoint.InputCaptureBound,
        InteractionRetainedUiCompositionPoint.CursorAssetsCreated,
        InteractionRetainedUiCompositionPoint.CharacterSheetCreated,
        InteractionRetainedUiCompositionPoint.MagicRuntimeCreated,
        InteractionRetainedUiCompositionPoint.MouseInputWired,
        InteractionRetainedUiCompositionPoint.KeyboardInputWired,
        InteractionRetainedUiCompositionPoint.UiAssetsCreated,
        InteractionRetainedUiCompositionPoint.UiProbeCreated,
        InteractionRetainedUiCompositionPoint.UiRuntimeMounted,
        InteractionRetainedUiCompositionPoint.InventoryContainerBound,
    ];

    [Fact]
    public void EnabledUiPublishesOneExactResultAfterFrozenConstructionOrder()
    {
        var fixture = new Fixture(retailUi: true);

        InteractionRetainedUiResult result = fixture.Compose();

        Assert.Same(result, fixture.Publication.Result);
        Assert.Equal(
        [
            InteractionRetainedUiCompositionPoint.LateBindingsCreated,
            InteractionRetainedUiCompositionPoint.CombatAttackCreated,
            InteractionRetainedUiCompositionPoint.CombatTargetCreated,
            InteractionRetainedUiCompositionPoint.ExternalContainerLifecycleCreated,
            InteractionRetainedUiCompositionPoint.ItemInteractionCreated,
            .. UiPoints,
            InteractionRetainedUiCompositionPoint.ResultPublished,
        ], fixture.Points);
        Assert.NotNull(result.RetainedUi);
        Assert.Empty(fixture.Factory.Releases);
    }

    [Fact]
    public void DisabledUiAcquiresNoRetainedFrontendResource()
    {
        var fixture = new Fixture(retailUi: false);

        InteractionRetainedUiResult result = fixture.Compose();

        Assert.Null(result.RetainedUi);
        Assert.Equal(
        [
            InteractionRetainedUiCompositionPoint.LateBindingsCreated,
            InteractionRetainedUiCompositionPoint.CombatAttackCreated,
            InteractionRetainedUiCompositionPoint.CombatTargetCreated,
            InteractionRetainedUiCompositionPoint.ExternalContainerLifecycleCreated,
            InteractionRetainedUiCompositionPoint.ItemInteractionCreated,
            InteractionRetainedUiCompositionPoint.RetainedUiDisabled,
            InteractionRetainedUiCompositionPoint.ResultPublished,
        ], fixture.Points);
        Assert.Equal(0, fixture.Factory.RetainedUiCalls);
    }

    [Theory]
    [MemberData(nameof(EnabledFailurePoints))]
    public void FaultAtEveryEnabledBoundaryStopsSuffixAndRollsBackUnpublishedPrefix(
        int pointValue)
    {
        var point = (InteractionRetainedUiCompositionPoint)pointValue;
        var fixture = new Fixture(retailUi: true, failurePoint: point);

        Assert.Throws<InvalidOperationException>(fixture.Compose);

        Assert.Equal(point, fixture.Points[^1]);
        if (point == InteractionRetainedUiCompositionPoint.ResultPublished)
        {
            Assert.Empty(fixture.Factory.Releases);
            Assert.NotNull(fixture.Publication.Result);
        }
        else
        {
            Assert.Null(fixture.Publication.Result);
            Assert.Equal(ExpectedRollback(point), fixture.Factory.Releases);
        }
    }

    public static TheoryData<int> EnabledFailurePoints()
    {
        var data = new TheoryData<int>();
        foreach (InteractionRetainedUiCompositionPoint point in
                 Enum.GetValues<InteractionRetainedUiCompositionPoint>())
        {
            if (point != InteractionRetainedUiCompositionPoint.RetainedUiDisabled)
                data.Add((int)point);
        }
        return data;
    }

    private static string[] ExpectedRollback(
        InteractionRetainedUiCompositionPoint point)
    {
        var acquired = new List<string> { "late bindings" };
        if (point >= InteractionRetainedUiCompositionPoint.CombatAttackCreated)
            acquired.Add("combat attack");
        if (point >= InteractionRetainedUiCompositionPoint.CombatTargetCreated)
            acquired.Add("combat target");
        if (point >= InteractionRetainedUiCompositionPoint.ExternalContainerLifecycleCreated)
            acquired.Add("external container");
        if (point >= InteractionRetainedUiCompositionPoint.ItemInteractionCreated)
            acquired.Add("item interaction");
        if (point >= InteractionRetainedUiCompositionPoint.UiHostAcquired)
            acquired.Add("retained UI lease");
        acquired.Reverse();
        return acquired.ToArray();
    }

    [Fact]
    public void PublicationFailureRollsBackCompleteUnpublishedPrefix()
    {
        var fixture = new Fixture(retailUi: true, publicationFailure: true);

        Assert.Throws<InvalidOperationException>(fixture.Compose);

        Assert.Equal(
        [
            "retained UI lease",
            "item interaction",
            "external container",
            "combat target",
            "combat attack",
            "late bindings",
        ], fixture.Factory.Releases);
    }

    [Fact]
    public void GameWindowUsesPhaseAndContainsNoRetainedUiConstructionBody()
    {
        string source = File.ReadAllText(Path.Combine(
            FindRepoRoot(),
            "src",
            "AcDream.App",
            "Rendering",
            "GameWindow.cs"));

        Assert.Contains("new InteractionRetainedUiCompositionPhase(", source);
        Assert.DoesNotContain("new AcDream.App.UI.ItemInteractionController(", source);
        Assert.DoesNotContain("_retailUiLease.AcquireHost(", source);
        Assert.DoesNotContain("RetailUiRuntime.CreateUninitialized(", source);
        Assert.DoesNotContain("private void UseItemByGuid(", source);
        Assert.DoesNotContain("private uint? PickWorldGuidAtCursor(", source);
    }

    private sealed class Fixture
    {
        private readonly InteractionRetainedUiCompositionPoint? _failurePoint;

        public Fixture(
            bool retailUi,
            InteractionRetainedUiCompositionPoint? failurePoint = null,
            bool publicationFailure = false)
        {
            _failurePoint = failurePoint;
            Factory = new FakeFactory();
            Publication = new Publication(publicationFailure);
            RuntimeOptions options = RuntimeOptions.Parse("dat", static _ => null)
                with { RetailUi = retailUi };
            Dependencies = new InteractionRetainedUiDependencies(
                Options: options,
                Gl: null!,
                Window: null!,
                Input: null!,
                ShadersDirectory: "shaders",
                Dats: null!,
                DatLock: new object(),
                TextureCache: null!,
                DebugFont: null,
                HostQuiescence: null!,
                RetainedInputCapture: null!,
                InputDispatcher: null,
                Settings: null!,
                Combat: null!,
                CombatAttackOperations: null!,
                Selection: null!,
                ExternalContainers: null!,
                Objects: null!,
                MagicCatalog: null!,
                Spellbook: null!,
                Chat: null!,
                LocalPlayer: null!,
                ItemMana: null!,
                StackSplitQuantity: null!,
                UiRegistry: null,
                CombatModeCommands: null!,
                PlayerIdentity: null!,
                PlayerController: null!,
                PlayerMode: null!,
                CharacterOptions: null!,
                Shortcuts: null!,
                SelectionCameraFactory: static _ => Stub<SelectionCameraSource>(),
                FrameDiagnostics: new DeferredRenderFrameDiagnosticsSource(),
                ExistingVitals: null,
                Toast: null,
                ClientTime: static () => 0d,
                Log: static _ => { });
        }

        public InteractionRetainedUiDependencies Dependencies { get; }
        public FakeFactory Factory { get; }
        public Publication Publication { get; }
        public List<InteractionRetainedUiCompositionPoint> Points { get; } = [];

        public InteractionRetainedUiResult Compose() =>
            new InteractionRetainedUiCompositionPhase(
                Dependencies,
                new RetailUiRuntimeLease(),
                Publication,
                Factory,
                point =>
                {
                    Points.Add(point);
                    if (_failurePoint == point)
                        throw new InvalidOperationException($"fault at {point}");
                }).Compose();
    }

    private sealed class FakeFactory : IInteractionRetainedUiCompositionFactory
    {
        private readonly Dictionary<object, string> _names =
            new(ReferenceEqualityComparer.Instance);

        public List<string> Releases { get; } = [];
        public int RetainedUiCalls { get; private set; }

        public CombatAttackController CreateCombatAttack(
            InteractionRetainedUiDependencies dependencies) =>
            Resource<CombatAttackController>("combat attack");

        public CombatTargetController CreateCombatTarget(
            InteractionRetainedUiDependencies dependencies,
            DeferredSelectionUiAuthority selection) =>
            Resource<CombatTargetController>("combat target");

        public ExternalContainerLifecycleController CreateExternalContainerLifecycle(
            InteractionRetainedUiDependencies dependencies,
            DeferredLiveSessionUiAuthority session) =>
            Resource<ExternalContainerLifecycleController>("external container");

        public ItemInteractionController CreateItemInteraction(
            InteractionRetainedUiDependencies dependencies,
            InteractionUiLateBindings lateBindings) =>
            Resource<ItemInteractionController>("item interaction");

        public RetainedUiComposition CreateRetainedUi(
            InteractionRetainedUiDependencies dependencies,
            InteractionUiLateBindings lateBindings,
            RetailUiRuntimeLease lease,
            CombatAttackController combatAttack,
            ItemInteractionController itemInteraction,
            Action<InteractionRetainedUiCompositionPoint> checkpoint)
        {
            RetainedUiCalls++;
            _names.Add(lease, "retained UI lease");
            foreach (InteractionRetainedUiCompositionPoint point in UiPoints)
                checkpoint(point);
            return new RetainedUiComposition(
                Stub<UiHost>(),
                Stub<RetailUiRuntime>(),
                Stub<AcDream.UI.Abstractions.Panels.Vitals.VitalsVM>(),
                Stub<AcDream.UI.Abstractions.Panels.Chat.ChatVM>(),
                Stub<CharacterSheetProvider>(),
                Stub<AcDream.App.Spells.MagicRuntime>(),
                null);
        }

        public void Release(IDisposable resource)
        {
            string name = _names.TryGetValue(resource, out string? found)
                ? found
                : resource switch
                {
                    InteractionUiLateBindings => "late bindings",
                    RetailUiRuntimeLease => "retained UI lease",
                    _ => throw new InvalidOperationException(
                        $"Unknown test resource {resource.GetType().Name}"),
                };
            Releases.Add(name);
        }

        private T Resource<T>(string name) where T : class
        {
            T value = Stub<T>();
            _names.Add(value, name);
            return value;
        }
    }

    private sealed class Publication(bool fail)
        : IGameWindowInteractionRetainedUiPublication
    {
        public InteractionRetainedUiResult? Result { get; private set; }

        public void PublishInteractionRetainedUi(InteractionRetainedUiResult result)
        {
            if (fail)
                throw new InvalidOperationException("publication failed");
            Result = result;
        }
    }

    private static T Stub<T>() where T : class =>
        (T)RuntimeHelpers.GetUninitializedObject(typeof(T));

    private static string FindRepoRoot()
    {
        DirectoryInfo? directory = new(AppContext.BaseDirectory);
        while (directory is not null)
        {
            if (File.Exists(Path.Combine(directory.FullName, "AcDream.slnx")))
                return directory.FullName;
            directory = directory.Parent;
        }
        throw new DirectoryNotFoundException("Could not find AcDream.slnx.");
    }
}