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);

        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}");
    }

    [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);

        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);

        // 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);
    }
}