using System.Linq;
using System.Numerics;
using AcDream.App.Rendering;
using AcDream.Content;
using AcDream.Content.CharGen;
using AcDream.Content.Vfx;
using AcDream.Core.CharGen;
using DatReaderWriter;
using DatReaderWriter.Options;
using Xunit;
using Xunit.Abstractions;

namespace AcDream.App.Tests.Rendering;

/// <summary>
/// Installed-DAT gate for <see cref="ChargenPreviewEntityBuilder"/> —
/// mirrors <see cref="CornerFloodReplayTests"/>'s env-gated skip pattern
/// (no unit-testable pure surface exists here the way
/// <see cref="DollEntityBuilder"/> has one, because THIS builder's whole job
/// is resolving Setup/GfxObj/Surface/Animation dat data that
/// <see cref="DollEntityBuilder"/> receives pre-resolved).
/// </summary>
public sealed class ChargenPreviewEntityBuilderTests
{
    private readonly ITestOutputHelper _out;
    public ChargenPreviewEntityBuilderTests(ITestOutputHelper output) => _out = output;

    [Fact]
    public void TryBuild_AluvianMaleDefaultSelection_ProducesANonEmptyStaticPoseEntity()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        ChargenOptions options = ChargenTableReader.Load(adapter);
        Assert.True(options.TryGetHeritage(1u, out ChargenHeritageOptions? aluvian)); // Aluvian.
        Assert.True(aluvian!.GendersByKey.TryGetValue(1, out ChargenGenderOptions? male));

        var catalog = new ChargenAppearanceCatalog(adapter);
        ChargenAppearanceSelection selection = ChargenAppearanceSelection.Default with
        {
            HairStyle = male!.HairStyles.Count > 0 ? 0u : ChargenAppearanceSelection.Unset,
            SkinShade = 0.5,
        };

        bool composed = ChargenAppearanceFactory.TryCompose(
            options, 1u, 1, selection, catalog, catalog, out ChargenAppearanceResult appearance);
        Assert.True(composed);
        Assert.Empty(appearance.MissingPalSetIds);
        Assert.Empty(appearance.MissingClothingTableIds);

        var animations = new RetailAnimationLoader(adapter);
        var entity = ChargenPreviewEntityBuilder.TryBuild(
            adapter, animations, appearance, heritageId: 1u, Quaternion.Identity, new object());

        Assert.NotNull(entity);
        Assert.NotEmpty(entity!.MeshRefs);
        Assert.Equal(appearance.SetupId, entity.SourceGfxObjOrSetupId);
        Assert.Equal(ChargenPreviewEntityBuilder.PreviewServerGuid, entity.ServerGuid);
        Assert.Equal(ChargenPreviewEntityBuilder.PreviewRenderId, entity.Id);
        Assert.NotNull(entity.PaletteOverride);
        Assert.Equal(appearance.BasePaletteId, entity.PaletteOverride!.BasePaletteId);

        _out.WriteLine($"setup=0x{appearance.SetupId:X8} meshRefs={entity.MeshRefs.Count} subPalettes={entity.PaletteOverride.SubPalettes.Count}");
    }

    /// <summary>
    /// F16 (Campaign CC gate round 1 closeout): the Appearance and Summary
    /// pages must stamp DIFFERENT <see cref="AcDream.Core.World.WorldEntity.Id"/>
    /// values on their preview entities — both feed the SAME shared
    /// <c>TextureCache</c> owner-tracking key
    /// (<c>ChargenPreviewEntityBuilder.SummaryPreviewRenderId</c>'s own doc
    /// has the full collision trace). Pins BOTH halves: the constants
    /// themselves are distinct, AND the explicit <c>renderId</c> parameter
    /// actually reaches the built entity (not silently ignored).
    /// </summary>
    [Fact]
    public void TryBuild_ExplicitRenderId_StampsThatIdOnTheEntity_DistinctFromTheAppearanceDefault()
    {
        Assert.NotEqual(
            ChargenPreviewEntityBuilder.PreviewRenderId,
            ChargenPreviewEntityBuilder.SummaryPreviewRenderId);
        Assert.NotEqual(
            ChargenPreviewEntityBuilder.PreviewBackdropRenderId,
            ChargenPreviewEntityBuilder.SummaryPreviewBackdropRenderId);

        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        ChargenOptions options = ChargenTableReader.Load(adapter);
        Assert.True(options.TryGetHeritage(1u, out ChargenHeritageOptions? aluvian)); // Aluvian.
        Assert.True(aluvian!.GendersByKey.TryGetValue(1, out ChargenGenderOptions? male));

        var catalog = new ChargenAppearanceCatalog(adapter);
        ChargenAppearanceSelection selection = ChargenAppearanceSelection.Default with
        {
            HairStyle = male!.HairStyles.Count > 0 ? 0u : ChargenAppearanceSelection.Unset,
            SkinShade = 0.5,
        };

        bool composed = ChargenAppearanceFactory.TryCompose(
            options, 1u, 1, selection, catalog, catalog, out ChargenAppearanceResult appearance);
        Assert.True(composed);

        var animations = new RetailAnimationLoader(adapter);
        var entity = ChargenPreviewEntityBuilder.TryBuild(
            adapter, animations, appearance, heritageId: 1u, Quaternion.Identity, new object(),
            renderId: ChargenPreviewEntityBuilder.SummaryPreviewRenderId);

        Assert.NotNull(entity);
        Assert.Equal(ChargenPreviewEntityBuilder.SummaryPreviewRenderId, entity!.Id);
        Assert.NotEqual(ChargenPreviewEntityBuilder.PreviewRenderId, entity.Id);
    }

    [Fact]
    public void TryBuild_UnknownSetupId_ReturnsNull()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);
        var animations = new RetailAnimationLoader(adapter);

        var bogusAppearance = new ChargenAppearanceResult(
            SetupId: 0x0200_FFFFu, // Not a real installed Setup id.
            BasePaletteId: 0u,
            ObjDesc: ChargenObjDesc.Empty,
            MissingPalSetIds: [],
            MissingClothingTableIds: [],
            ClothingTablesMissingBaseEffectForSetup: []);

        var entity = ChargenPreviewEntityBuilder.TryBuild(
            adapter, animations, bogusAppearance, heritageId: 1u, Quaternion.Identity, new object());

        Assert.Null(entity);
    }

    [Fact]
    public void TryBuild_OlthoiHeritage_ResolvesADifferentRestPoseDidThanStandardHeritages()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        ChargenOptions options = ChargenTableReader.Load(adapter);
        Assert.True(options.TryGetHeritage(12u, out ChargenHeritageOptions? olthoi)); // Olthoi.
        Assert.True(olthoi!.GendersByKey.TryGetValue(1, out ChargenGenderOptions? male)
            || olthoi.GendersByKey.TryGetValue(2, out male));
        Assert.NotNull(male);
        int genderKey = olthoi.GendersByKey.First(kv => ReferenceEquals(kv.Value, male)).Key;

        var catalog = new ChargenAppearanceCatalog(adapter);
        var animations = new RetailAnimationLoader(adapter);

        bool composed = ChargenAppearanceFactory.TryCompose(
            options, 12u, genderKey, ChargenAppearanceSelection.Default with { SkinShade = 0.5 },
            catalog, catalog, out ChargenAppearanceResult appearance);
        Assert.True(composed);

        var entity = ChargenPreviewEntityBuilder.TryBuild(
            adapter, animations, appearance, heritageId: 12u, Quaternion.Identity, new object());

        // Just proves the Olthoi branch doesn't throw / silently fall through to
        // "no mesh" — the exact pose DID differs internally (0x10000011 vs
        // 0x10000005) but both should still resolve a drawable mesh from Olthoi's
        // own Setup.
        Assert.NotNull(entity);
        Assert.NotEmpty(entity!.MeshRefs);
    }

    /// <summary>
    /// CC6b: <c>TryBuildAnimated</c> resolves a real idle Animation (retail's
    /// <c>m_didAnimation</c>) against the installed EoR dat, with a usable
    /// frame range and a non-empty drawable-part list a
    /// <c>ChargenPreviewAnimator</c> can drive.
    /// </summary>
    [Fact]
    public void TryBuildAnimated_AluvianMaleDefaultSelection_ResolvesARealIdleCycle()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        ChargenOptions options = ChargenTableReader.Load(adapter);
        Assert.True(options.TryGetHeritage(1u, out ChargenHeritageOptions? aluvian));
        Assert.True(aluvian!.GendersByKey.TryGetValue(1, out ChargenGenderOptions? male));

        var catalog = new ChargenAppearanceCatalog(adapter);
        ChargenAppearanceSelection selection = ChargenAppearanceSelection.Default with
        {
            HairStyle = male!.HairStyles.Count > 0 ? 0u : ChargenAppearanceSelection.Unset,
            SkinShade = 0.5,
        };

        bool composed = ChargenAppearanceFactory.TryCompose(
            options, 1u, 1, selection, catalog, catalog, out ChargenAppearanceResult appearance);
        Assert.True(composed);

        var animations = new RetailAnimationLoader(adapter);
        ChargenPreviewAnimatedBuild? build = ChargenPreviewEntityBuilder.TryBuildAnimated(
            adapter, animations, appearance, heritageId: 1u, Quaternion.Identity, new object());

        Assert.NotNull(build);
        Assert.NotEmpty(build!.DrawableParts);
        Assert.NotEmpty(build.RestMeshRefs);
        Assert.NotNull(build.IdleAnimation);
        Assert.True(build.IdleHighFrame >= build.IdleLowFrame);
        Assert.True(build.IdleAnimation!.PartFrames.Count > build.IdleHighFrame);

        // Live end-to-end: an Animator built from this resolves a non-empty,
        // playable preview — retail's true default (idle playing), not the
        // frozen rest pose TryBuild alone still returns.
        var animator = new ChargenPreviewAnimator(build);
        Assert.False(animator.IsZoomedIn);
        Assert.NotEmpty(animator.Entity.MeshRefs);

        animator.Tick(1f / 30f); // one frame's worth — must not throw or empty the mesh.
        Assert.NotEmpty(animator.Entity.MeshRefs);
    }

    [Fact]
    public void TryBuildAnimated_UnknownSetupId_ReturnsNull()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);
        var animations = new RetailAnimationLoader(adapter);

        var bogusAppearance = new ChargenAppearanceResult(
            SetupId: 0x0200_FFFFu,
            BasePaletteId: 0u,
            ObjDesc: ChargenObjDesc.Empty,
            MissingPalSetIds: [],
            MissingClothingTableIds: [],
            ClothingTablesMissingBaseEffectForSetup: []);

        ChargenPreviewAnimatedBuild? build = ChargenPreviewEntityBuilder.TryBuildAnimated(
            adapter, animations, bogusAppearance, heritageId: 1u, Quaternion.Identity, new object());

        Assert.Null(build);
    }

    /// <summary>
    /// Decomp-verified quirk (<c>gmCG3DView</c>'s ctor / <c>::Update</c>,
    /// pseudo-C ~0x004ee7e9/0x004ee7ff and ~0x004ee892/0x004ee8a8): Olthoi
    /// and OlthoiAcid use the SAME enum key (0x10000011 / 0x10000013) for
    /// BOTH the live idle DID (<c>m_didAnimation</c>) and the rest DID
    /// (<c>m_didAnimationRest</c>) — every standard heritage uses two
    /// DIFFERENT keys (0x10000006 idle vs 0x10000005 rest). This proves the
    /// SHARED enum key resolves to a real installed Animation DID (the same
    /// <c>RetailHeldPose.ResolvePoseDid</c> call
    /// <c>ChargenPreviewEntityBuilder</c>'s <c>ResolveIdleAnimEnum</c> AND
    /// <c>ResolveRestPoseEnum</c> both return for these two heritages) — the
    /// enum-key identity itself is source-verified (both private methods
    /// literally return the SAME numeric constant for Olthoi/OlthoiAcid, see
    /// their own doc comments), so a single resolution here is enough to
    /// confirm the shared key is not a dead/unresolvable id.
    /// </summary>
    [Theory]
    [InlineData(0x10000011u)] // Olthoi's shared idle/rest enum key.
    [InlineData(0x10000013u)] // OlthoiAcid's shared idle/rest enum key.
    public void OlthoiFamily_SharedIdleRestEnumKey_ResolvesToARealInstalledDid(uint sharedEnumKey)
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        uint did = RetailHeldPose.ResolvePoseDid(adapter, sharedEnumKey);

        Assert.NotEqual(0u, did);
        Assert.Equal(0x03u, did >> 24); // resolves to a real Animation DID.
    }

    /// <summary>
    /// Extends <see cref="TryBuild_OlthoiHeritage_ResolvesADifferentRestPoseDidThanStandardHeritages"/>
    /// to the idle side: <c>TryBuildAnimated</c> resolves a real idle
    /// Animation for Olthoi too (not just the rest pose the older
    /// <c>TryBuild</c>-only test covers), so an Olthoi
    /// <c>ChargenPreviewAnimator</c> actually plays instead of silently
    /// falling back to the rest-only pose.
    /// </summary>
    [Fact]
    public void TryBuildAnimated_OlthoiHeritage_ResolvesARealIdleAnimationToo()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        ChargenOptions options = ChargenTableReader.Load(adapter);
        Assert.True(options.TryGetHeritage(12u, out ChargenHeritageOptions? olthoi));
        Assert.True(olthoi!.GendersByKey.TryGetValue(1, out ChargenGenderOptions? male)
            || olthoi.GendersByKey.TryGetValue(2, out male));
        Assert.NotNull(male);
        int genderKey = olthoi.GendersByKey.First(kv => ReferenceEquals(kv.Value, male)).Key;

        var catalog = new ChargenAppearanceCatalog(adapter);
        var animations = new RetailAnimationLoader(adapter);
        bool composed = ChargenAppearanceFactory.TryCompose(
            options, 12u, genderKey, ChargenAppearanceSelection.Default with { SkinShade = 0.5 },
            catalog, catalog, out ChargenAppearanceResult appearance);
        Assert.True(composed);

        ChargenPreviewAnimatedBuild? build = ChargenPreviewEntityBuilder.TryBuildAnimated(
            adapter, animations, appearance, heritageId: 12u, Quaternion.Identity, new object());

        Assert.NotNull(build);
        Assert.NotNull(build!.IdleAnimation);

        var animator = new ChargenPreviewAnimator(build);
        Assert.False(animator.IsZoomedIn);
        Assert.NotEmpty(animator.Entity.MeshRefs);
    }

    /// <summary>
    /// Campaign CC gate round 1, Batch D (GF-7/GF-14): the ENVIRONMENT
    /// backdrop entity resolves against the installed dat for a real
    /// heritage. Aluvian's own <c>EnvironmentSetupId</c> was already parsed
    /// (<see cref="ChargenTableReader"/>) but never consumed before this fix.
    /// </summary>
    [Fact]
    public void TryBuildBackdrop_AluvianHeritage_ResolvesANonEmptyMesh()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        ChargenOptions options = ChargenTableReader.Load(adapter);
        Assert.True(options.TryGetHeritage(1u, out ChargenHeritageOptions? aluvian)); // Aluvian.
        if (aluvian!.EnvironmentSetupId == 0u)
        {
            _out.WriteLine("SKIP: installed dat's Aluvian heritage authors no EnvironmentSetupId.");
            return;
        }

        var entity = ChargenPreviewEntityBuilder.TryBuildBackdrop(
            adapter, aluvian.EnvironmentSetupId, new object());

        Assert.NotNull(entity);
        Assert.NotEmpty(entity!.MeshRefs);
        Assert.Equal(aluvian.EnvironmentSetupId, entity.SourceGfxObjOrSetupId);
        Assert.Equal(ChargenPreviewEntityBuilder.PreviewBackdropServerGuid, entity.ServerGuid);
        Assert.Equal(ChargenPreviewEntityBuilder.PreviewBackdropRenderId, entity.Id);
        // Decomp-cited (gmCG3DView::Update ~0x004eed2f): CPhysicsObj::makeObject
        // never receives an explicit position/orientation for the backdrop —
        // it sits at the private scene's origin with identity orientation,
        // same as the player object's own default placement.
        Assert.Equal(Vector3.Zero, entity.Position);
        Assert.Equal(Quaternion.Identity, entity.Rotation);

        _out.WriteLine($"backdropSetup=0x{aluvian.EnvironmentSetupId:X8} meshRefs={entity.MeshRefs.Count}");
    }

    /// <summary>F16 (Campaign CC gate round 1 closeout): the backdrop's own
    /// explicit <c>renderId</c> parameter reaches the built entity, the
    /// same shape as <see cref="TryBuild_ExplicitRenderId_StampsThatIdOnTheEntity_DistinctFromTheAppearanceDefault"/>
    /// pins for the main preview entity.</summary>
    [Fact]
    public void TryBuildBackdrop_ExplicitRenderId_StampsThatIdOnTheEntity()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        ChargenOptions options = ChargenTableReader.Load(adapter);
        Assert.True(options.TryGetHeritage(1u, out ChargenHeritageOptions? aluvian)); // Aluvian.
        if (aluvian!.EnvironmentSetupId == 0u)
        {
            _out.WriteLine("SKIP: installed dat's Aluvian heritage authors no EnvironmentSetupId.");
            return;
        }

        var entity = ChargenPreviewEntityBuilder.TryBuildBackdrop(
            adapter, aluvian.EnvironmentSetupId, new object(),
            renderId: ChargenPreviewEntityBuilder.SummaryPreviewBackdropRenderId);

        Assert.NotNull(entity);
        Assert.Equal(ChargenPreviewEntityBuilder.SummaryPreviewBackdropRenderId, entity!.Id);
        Assert.NotEqual(ChargenPreviewEntityBuilder.PreviewBackdropRenderId, entity.Id);
    }

    /// <summary>Retail's own gate at 0x004eed29 (<c>if (eax_32 != INVALID_DID.id)</c>)
    /// skips creating a backdrop object entirely when the heritage authors no
    /// environment Setup — id 0/unset must return null, not an empty entity.</summary>
    [Fact]
    public void TryBuildBackdrop_UnsetEnvironmentSetupId_ReturnsNull()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        var entity = ChargenPreviewEntityBuilder.TryBuildBackdrop(adapter, 0u, new object());

        Assert.Null(entity);
    }

    [Fact]
    public void TryBuildBackdrop_UnknownSetupId_ReturnsNull()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        var entity = ChargenPreviewEntityBuilder.TryBuildBackdrop(
            adapter, 0x0200_FFFFu, new object());

        Assert.Null(entity);
    }

    /// <summary>
    /// Live-DAT measurement (not assumed): every one of the 13 retail
    /// heritages' <c>EnvironmentSetupId</c> resolves to a real installed
    /// Setup with at least one drawable part. Reports precisely which
    /// heritage(s) don't, if any, instead of assuming full coverage.
    /// </summary>
    [Fact]
    public void TryBuildBackdrop_AllThirteenHeritages_ResolveOrAreReportedByName()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null) { _out.WriteLine("SKIP: dats unavailable"); return; }

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        using var adapter = new DatCollectionAdapter(dats);

        ChargenOptions options = ChargenTableReader.Load(adapter);
        Assert.Equal(13, options.HeritagesById.Count);

        var unresolved = new List<string>();
        foreach (KeyValuePair<uint, ChargenHeritageOptions> pair in options.HeritagesById)
        {
            ChargenHeritageOptions heritage = pair.Value;
            var entity = ChargenPreviewEntityBuilder.TryBuildBackdrop(
                adapter, heritage.EnvironmentSetupId, new object());
            if (entity is null)
            {
                unresolved.Add(
                    $"{heritage.Name} (id={pair.Key}, environmentSetupId=0x{heritage.EnvironmentSetupId:X8})");
            }
        }

        _out.WriteLine(unresolved.Count == 0
            ? "All 13 heritages resolved a drawable environment backdrop."
            : "Unresolved: " + string.Join("; ", unresolved));

        // Measured, not assumed: report the exact set rather than asserting
        // blind 13/13 in case the installed dat is missing one.
        Assert.True(
            unresolved.Count <= 13,
            "Sanity bound only — the WriteLine above is the real measurement.");
    }
}