using System;
using System.Collections.Generic;
using System.Linq;
using AcDream.App.UI;
using AcDream.App.UI.Layout;
using AcDream.Core.Input;
using AcDream.UI.Abstractions.Input;

namespace AcDream.App.Tests.UI.Layout;

/// <summary>
/// Campaign OP slice OP8 conformance + behavior tests for
/// <see cref="KeyboardConfigController"/> — built against the committed
/// <c>keyboard_config_21000009.json</c> fixture (real DAT structure, no live dat
/// access at test time), fed a small synthetic <see cref="RetailActionMapSnapshot"/>
/// so the behavioral assertions stay focused. Live-DAT row-count/label conformance
/// lives in <c>AcDream.Core.Tests.Input.RetailActionMapReaderTests</c> and
/// <c>RetailActionIdentityRoundTripTests</c>.
/// </summary>
public sealed class KeyboardConfigControllerTests
{
    private static (uint, int, int) NoTex(uint _) => (0, 0, 0);

    private static ElementInfo? Find(ElementInfo n, uint id)
    {
        if (n.Id == id) return n;
        foreach (ElementInfo c in n.Children)
        {
            ElementInfo? f = Find(c, id);
            if (f is not null) return f;
        }
        return null;
    }

    private static Func<uint, uint, UiElement?> MakeTemplateResolver()
    {
        ElementInfo root = FixtureLoader.LoadKeyboardConfigInfos();
        return (layoutId, elementId) =>
        {
            if (layoutId != KeyboardConfigController.LayoutId) return null;
            ElementInfo? templateInfo = Find(root, elementId);
            return templateInfo is null ? null : LayoutImporter.Build(templateInfo, NoTex, null).Root;
        };
    }

    private static RetailActionMapRow Row(
        uint inputMapId, uint actionId, RetailActionClass cls,
        uint labelHash = 0, uint tooltipHash = 0,
        params RetailKeyChord[] defaults) =>
        new(inputMapId, actionId, cls, labelHash, tooltipHash, defaults);

    private sealed class FakeBindings
    {
        public Dictionary<InputAction, List<KeyChord>> Mapped { get; } = new();
        public Dictionary<(uint, uint), List<KeyChord>> Unmapped { get; } = new();
        public List<(InputAction Action, IReadOnlyList<KeyChord> Value)> MappedSets { get; } = new();
        public List<((uint, uint) Row, IReadOnlyList<KeyChord> Value)> UnmappedSets { get; } = new();
        public List<string> Messages { get; } = new();
        public int SaveCalls { get; private set; }
        public int ToggleCalls { get; private set; }
        public Action<KeyChord?>? PendingCapture { get; private set; }

        public void Capture(KeyChord? chord)
        {
            Action<KeyChord?>? cb = PendingCapture;
            PendingCapture = null;
            cb?.Invoke(chord);
        }

        public KeyboardConfigController.Bindings ToBindings() => new(
            CurrentForAction: a => Mapped.TryGetValue(a, out var v) ? v : Array.Empty<KeyChord>(),
            SetForAction: (a, v) =>
            {
                Mapped[a] = v.ToList();
                MappedSets.Add((a, v));
            },
            CurrentForUnmapped: k => Unmapped.TryGetValue(k, out var v) ? v : Array.Empty<KeyChord>(),
            SetForUnmapped: (k, v) =>
            {
                Unmapped[k] = v.ToList();
                UnmappedSets.Add((k, v));
            },
            BeginCapture: cb => PendingCapture = cb,
            Save: () => SaveCalls++,
            Toggle: () => ToggleCalls++,
            DisplaySystemMessage: msg => Messages.Add(msg),
            NonBindableRefusalText: "cannot overwrite",
            NotifyReassigned: label => $"reassigned from {label}");
    }

    private static readonly KeyChord ChordW = new(Silk.NET.Input.Key.W, ModifierMask.None);
    private static readonly KeyChord ChordUp = new(Silk.NET.Input.Key.Up, ModifierMask.None);
    private static readonly KeyChord ChordA = new(Silk.NET.Input.Key.A, ModifierMask.None);

    [Fact]
    public void Bind_Succeeds_AndBuildsOneRowPerSnapshotRow()
    {
        var snapshot = new RetailActionMapSnapshot(new[]
        {
            Row(0x4, 0x29, RetailActionClass.Movement),       // MovementForward
            Row(0x4, 0x2A, RetailActionClass.Movement),       // MovementBackup
            Row(0x5, 0x33, RetailActionClass.Camera),         // CameraMoveToward
        });

        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        var fake = new FakeBindings();
        KeyboardConfigController? controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings());

        Assert.NotNull(controller);
        Assert.Equal(3, controller!.Rows.Count);
        Assert.Equal(3, controller.Page.Rows.Count);
    }

    [Fact]
    public void Bind_MapsKnownActionsAndLeavesUnknownOnesUnmapped()
    {
        var snapshot = new RetailActionMapSnapshot(new[]
        {
            Row(0x4, 0x29, RetailActionClass.Movement),                 // -> MovementForward
            Row(0x10000006, 0x100000A0, RetailActionClass.Emote),       // "Bow Deep" -> no InputAction
        });

        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        var fake = new FakeBindings();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView forward = controller.Rows.Single(r => r.ActionId == 0x29u);
        Assert.Equal(InputAction.MovementForward, forward.MappedAction);

        KeyboardConfigController.RowView bowDeep = controller.Rows.Single(r => r.ActionId == 0x100000A0u);
        Assert.Null(bowDeep.MappedAction);
    }

    [Fact]
    public void Bind_SeedsRowFromLiveBindings_MappedAndUnmapped()
    {
        var snapshot = new RetailActionMapSnapshot(new[]
        {
            Row(0x4, 0x29, RetailActionClass.Movement),
            Row(0x10000006, 0x100000A0, RetailActionClass.Emote),
        });

        var fake = new FakeBindings();
        fake.Mapped[InputAction.MovementForward] = new List<KeyChord> { ChordW, ChordUp };
        fake.Unmapped[(0x10000006u, 0x100000A0u)] = new List<KeyChord> { ChordA };

        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView forward = controller.Rows.Single(r => r.ActionId == 0x29u);
        Assert.Equal(new[] { ChordW, ChordUp }, forward.Model.Current);

        KeyboardConfigController.RowView bowDeep = controller.Rows.Single(r => r.ActionId == 0x100000A0u);
        Assert.Equal(new[] { ChordA }, bowDeep.Model.Current);
    }

    [Fact]
    public void KeyButtonClick_CapturesAndAppliesNewBinding()
    {
        var snapshot = new RetailActionMapSnapshot(new[] { Row(0x4, 0x29, RetailActionClass.Movement) });
        var fake = new FakeBindings();
        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView row = controller.Rows.Single();
        Assert.NotEmpty(row.KeyButtons);

        row.KeyButtons[0].OnClick!.Invoke();
        Assert.NotNull(fake.PendingCapture);
        fake.Capture(ChordW);

        Assert.Contains(ChordW, row.Model.Current);
        Assert.Contains((InputAction.MovementForward, (IReadOnlyList<KeyChord>)row.Model.Current), fake.MappedSets);
        Assert.Equal("W", row.KeyButtons[0].Label);
    }

    [Fact]
    public void KeyButtonCapture_EscapeCancel_LeavesBindingUnchanged()
    {
        var snapshot = new RetailActionMapSnapshot(new[] { Row(0x4, 0x29, RetailActionClass.Movement) });
        var fake = new FakeBindings();
        fake.Mapped[InputAction.MovementForward] = new List<KeyChord> { ChordW };
        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView row = controller.Rows.Single();
        row.KeyButtons[0].OnClick!.Invoke();
        fake.Capture(null); // Escape sentinel

        Assert.Equal(new[] { ChordW }, row.Model.Current);
        Assert.Empty(fake.MappedSets);
    }

    [Fact]
    public void KeyButtonRightClick_ErasesThatSlot()
    {
        var snapshot = new RetailActionMapSnapshot(new[] { Row(0x4, 0x29, RetailActionClass.Movement) });
        var fake = new FakeBindings();
        fake.Mapped[InputAction.MovementForward] = new List<KeyChord> { ChordW, ChordUp };
        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView row = controller.Rows.Single();
        Assert.Equal(2, row.Model.Current.Count);

        row.KeyButtons[0].OnRightClick!.Invoke();

        Assert.Single(row.Model.Current);
        Assert.DoesNotContain(ChordW, row.Model.Current);
    }

    [Fact]
    public void Capture_ConflictWithAnotherRow_AutoReassignsAndNotifies()
    {
        var snapshot = new RetailActionMapSnapshot(new[]
        {
            Row(0x4, 0x29, RetailActionClass.Movement),  // MovementForward
            Row(0x4, 0x2A, RetailActionClass.Movement),  // MovementBackup — will hold ChordA
        });
        var fake = new FakeBindings();
        fake.Mapped[InputAction.MovementBackup] = new List<KeyChord> { ChordA };
        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView forward = controller.Rows.Single(r => r.ActionId == 0x29u);
        KeyboardConfigController.RowView backup = controller.Rows.Single(r => r.ActionId == 0x2Au);

        forward.KeyButtons[0].OnClick!.Invoke();
        fake.Capture(ChordA); // steal MovementBackup's chord

        Assert.Contains(ChordA, forward.Model.Current);
        Assert.DoesNotContain(ChordA, backup.Model.Current);
        Assert.Contains(fake.Messages, m => m.Contains("reassigned"));
    }

    [Fact]
    public void Capture_ConflictWithNonBindableAcdreamAction_RefusesAndLeavesBoth()
    {
        var snapshot = new RetailActionMapSnapshot(new[] { Row(0x4, 0x29, RetailActionClass.Movement) });
        var fake = new FakeBindings();
        // AcdreamToggleAudioMute has no RetailActionIdentityTable row at all.
        var muteChord = new KeyChord(Silk.NET.Input.Key.M, ModifierMask.Ctrl);
        fake.Mapped[InputAction.AcdreamToggleAudioMute] = new List<KeyChord> { muteChord };
        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView forward = controller.Rows.Single();
        forward.KeyButtons[0].OnClick!.Invoke();
        fake.Capture(muteChord);

        Assert.DoesNotContain(muteChord, forward.Model.Current);
        Assert.Contains("cannot overwrite", fake.Messages);
        Assert.Equal(new[] { muteChord }, fake.Mapped[InputAction.AcdreamToggleAudioMute]);
    }

    [Fact]
    public void OkButton_AppliesCommitsSavesAndToggles()
    {
        var snapshot = new RetailActionMapSnapshot(new[] { Row(0x4, 0x29, RetailActionClass.Movement) });
        var fake = new FakeBindings();
        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView row = controller.Rows.Single();
        row.KeyButtons[0].OnClick!.Invoke();
        fake.Capture(ChordW);
        Assert.True(row.Model.Changed);

        UiButton ok = (UiButton)layout.FindElement(0x1000002Cu)!;
        ok.OnClick!.Invoke();

        Assert.False(row.Model.Changed); // Apply committed saved=current
        Assert.Equal(1, fake.SaveCalls);
        Assert.Equal(1, fake.ToggleCalls);
    }

    [Fact]
    public void CancelButton_RevertsUncommittedEditAndToggles()
    {
        var snapshot = new RetailActionMapSnapshot(new[] { Row(0x4, 0x29, RetailActionClass.Movement) });
        var fake = new FakeBindings();
        fake.Mapped[InputAction.MovementForward] = new List<KeyChord> { ChordW };
        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView row = controller.Rows.Single();
        row.KeyButtons[0].OnClick!.Invoke();
        fake.Capture(ChordUp); // now [Up] uncommitted (slot 0 replaced)

        UiButton cancel = (UiButton)layout.FindElement(0x1000002Du)!;
        cancel.OnClick!.Invoke();

        Assert.Equal(new[] { ChordW }, row.Model.Current); // reverted to Saved
        Assert.Equal(1, fake.ToggleCalls);
        Assert.Equal(0, fake.SaveCalls);
    }

    [Fact]
    public void DefaultsButton_RestoresDatDefaultLive_WithoutCommitting()
    {
        var snapshot = new RetailActionMapSnapshot(new[]
        {
            Row(0x4, 0x29, RetailActionClass.Movement, defaults:
                new[] { new RetailKeyChord(0x11, 0, 0, 3) }), // DIK_W
        });
        var fake = new FakeBindings();
        fake.Mapped[InputAction.MovementForward] = new List<KeyChord> { ChordUp };
        ImportedLayout layout = FixtureLoader.LoadKeyboardConfig();
        KeyboardConfigController controller = KeyboardConfigController.Bind(
            layout, snapshot, MakeTemplateResolver(), (_, _) => null, fake.ToBindings())!;

        KeyboardConfigController.RowView row = controller.Rows.Single();
        Assert.Equal(new[] { ChordUp }, row.Model.Current);

        UiButton defaultsButton = (UiButton)layout.FindElement(0x1000002Au)!;
        defaultsButton.OnClick!.Invoke();

        Assert.Equal(new[] { ChordW }, row.Model.Current);
        Assert.True(row.Model.Changed); // live but uncommitted, matching retail
    }

    [Fact]
    public void Bind_MissingWindowRoot_ReturnsNull()
    {
        ElementInfo empty = new() { Id = 0x99999999u, Type = 3 };
        ImportedLayout emptyLayout = LayoutImporter.Build(empty, NoTex, null);
        var snapshot = new RetailActionMapSnapshot(Array.Empty<RetailActionMapRow>());
        var fake = new FakeBindings();

        KeyboardConfigController? controller = KeyboardConfigController.Bind(
            emptyLayout, snapshot, (_, _) => null, (_, _) => null, fake.ToBindings());

        Assert.Null(controller);
    }
}