using System;
using System.Collections.Generic;
using System.Numerics;
using AcDream.App.Rendering;
using AcDream.App.Rendering.Vfx;
using AcDream.Core.Vfx;
using AcDream.Core.World;
using DatReaderWriter.Types;
using Xunit;
using DatPhysicsScript = DatReaderWriter.DBObjs.PhysicsScript;

namespace AcDream.App.Tests.Rendering;

/// <summary>
/// Production sky default-script lifecycle per
/// <c>GameSky::CreateDeletePhysicsObjects @0x005073C0</c>: a slot keeps its
/// running script while (gfx id, properties) are unchanged — across day-group
/// swaps included — and a mismatch or window exit stops it. Research:
/// <c>docs/research/2026-08-23-sky-default-script-port.md</c>.
/// </summary>
public sealed class SkyPesFrameControllerTests
{
    private const uint AuroraSetup = 0x02000714u;
    private const uint AuroraScript = 0x330007DBu;

    private sealed class Harness
    {
        public readonly List<uint> ResolvedScriptIds = [];
        public readonly List<string> Diagnostics = [];
        public readonly PhysicsScriptRunner Runner;
        public readonly SkyPesFrameController Controller;

        public Harness()
        {
            var registry = new EmitterDescRegistry();
            var system = new ParticleSystem(registry, new Random(42));
            var poses = new EntityEffectPoseRegistry();
            var sink = new ParticleHookSink(system, poses);
            Runner = new PhysicsScriptRunner(
                id =>
                {
                    ResolvedScriptIds.Add(id);
                    var script = new DatPhysicsScript();
                    script.ScriptData.Add(new PhysicsScriptData
                    {
                        StartTime = 0.0,
                        Hook = new SoundHook(),
                    });
                    return script;
                },
                sink);
            Controller = new SkyPesFrameController(
                Runner,
                sink,
                poses,
                effects: null,
                Diagnostics.Add);
        }
    }

    private static SkyObjectData Carrier(
        uint gfxObjId = AuroraSetup,
        uint scriptId = AuroraScript,
        uint pesColumn = AuroraScript,
        uint properties = 0u,
        float begin = 0f,
        float end = 0f) => new()
    {
        GfxObjId = gfxObjId,
        DefaultScriptId = scriptId,
        PesObjectId = pesColumn,
        Properties = properties,
        BeginTime = begin,
        EndTime = end,
    };

    private static DayGroupData Group(params SkyObjectData[] objects) => new()
    {
        Name = "Test",
        SkyObjects = objects,
    };

    [Fact]
    public void PlaysOncePerSlotAndPersistsAcrossEquivalentDayGroups()
    {
        var h = new Harness();

        h.Controller.Update(0.1f, Group(Carrier()), Vector3.Zero);
        Assert.Equal([AuroraScript], h.ResolvedScriptIds);
        Assert.Equal(1, h.Runner.ActiveScriptCount);

        // A different DayGroupData instance with the SAME slot identity is
        // retail's midnight day-group swap keeping the aurora carrier: the
        // running script must survive, not restart. The runner caches
        // resolved scripts, so the replay probe is ActiveScriptCount —
        // PlayDirect stacks one scheduled script per play.
        h.Controller.Update(0.9f, Group(Carrier()), Vector3.One * 10f);
        Assert.Equal(1, h.Runner.ActiveScriptCount);
    }

    [Fact]
    public void SlotIdentityChangeStopsTheOldScriptAndPlaysTheNew()
    {
        var h = new Harness();
        h.Controller.Update(0.1f, Group(Carrier()), Vector3.Zero);

        h.Controller.Update(
            0.1f,
            Group(Carrier(gfxObjId: 0x02000589u, scriptId: 0x3300042Cu, pesColumn: 0x3300042Cu)),
            Vector3.Zero);

        Assert.Equal([AuroraScript, 0x3300042Cu], h.ResolvedScriptIds);
        Assert.Equal(1, h.Runner.ActiveScriptCount);
    }

    [Fact]
    public void LeavingTheVisibilityWindowStopsTheScriptAndReentryReplays()
    {
        var h = new Harness();
        SkyObjectData windowed() => Carrier(begin: 0.2f, end: 0.4f);

        h.Controller.Update(0.3f, Group(windowed()), Vector3.Zero);
        Assert.Equal(1, h.Runner.ActiveScriptCount);

        h.Controller.Update(0.5f, Group(windowed()), Vector3.Zero);
        Assert.Equal(0, h.Runner.ActiveScriptCount);

        // Re-entry replays (the runner's script cache absorbs the resolver
        // call; the fresh scheduled script is the observable).
        h.Controller.Update(0.25f, Group(windowed()), Vector3.Zero);
        Assert.Equal(1, h.Runner.ActiveScriptCount);
    }

    [Fact]
    public void SetupDefaultScriptIsTheSourceAndAMismatchedPesColumnLogsOnce()
    {
        var h = new Harness();
        var group = Group(Carrier(scriptId: AuroraScript, pesColumn: 0x33000999u));

        h.Controller.Update(0.1f, group, Vector3.Zero);
        h.Controller.Update(0.2f, group, Vector3.Zero);

        Assert.Equal([AuroraScript], h.ResolvedScriptIds);
        string diagnostic = Assert.Single(h.Diagnostics);
        Assert.Contains("0x330007DB", diagnostic, StringComparison.Ordinal);
        Assert.Contains("0x33000999", diagnostic, StringComparison.Ordinal);
    }

    [Fact]
    public void CarriersWithoutADefaultScriptNeverPlay()
    {
        var h = new Harness();
        h.Controller.Update(
            0.1f,
            Group(Carrier(gfxObjId: 0x010015F0u, scriptId: 0u, pesColumn: 0u)),
            Vector3.Zero);

        Assert.Empty(h.ResolvedScriptIds);
        Assert.Equal(0, h.Runner.ActiveScriptCount);
    }

    [Fact]
    public void NullDayGroupStopsEverything()
    {
        var h = new Harness();
        h.Controller.Update(0.1f, Group(Carrier()), Vector3.Zero);
        Assert.Equal(1, h.Runner.ActiveScriptCount);

        h.Controller.Update(0.1f, null, Vector3.Zero);
        Assert.Equal(0, h.Runner.ActiveScriptCount);
    }
}