acdream/tests/AcDream.App.Tests/Rendering/Walk/WalkLookInGateSweepTests.cs

using AcDream.App.Tests.Rendering;
using AcDream.App.Rendering.Walk;
using DatReaderWriter;
using DatReaderWriter.Options;
using System.Text;

namespace AcDream.App.Tests.Rendering.Walk;

/// <summary>
/// FW1 look-in gate adjudication sweep: with data joins proven correct,
/// the wrong-building punches must come from the sidedness gate's two
/// unvalidated inputs — the GfxObj portal-poly plane sign and the
/// BuildingPortal side-flag decode. This sweeps all combinations against
/// the street-outdoor fixture and reports which (if any) reproduces
/// retail's punch set {001a, 0022}. Diagnostic: always passes; the result
/// lands in the campaign record via the assert message when no arm matches.
/// </summary>
[Trait("Lane", "InstalledDat")]
public sealed class WalkLookInGateSweepTests
{
    private sealed class Recorder : IWalkEventSink
    {
        public readonly List<WalkEvent> Events = new();
        public void Emit(in WalkEvent walkEvent) => Events.Add(walkEvent);
    }

    [Fact(Skip = "FW1 near-win state (2026-08-30): with +Y-forward, alwaysDrawObjects, "
        + "the exact degrade rule and side mode 1, the street fixture matches retail "
        + "EXCEPT look-in flood depth (mine D[16e]/D[164]; retail D[16e,16a,16c]/"
        + "D[164,162,167,169]) - adjudicate the interior flood propagation next "
        + "(the doorway-still fixture tests it in isolation).")]
    public void Sweep_the_lookin_gate_decodes_against_the_street_fixture()
    {
        string? datDir = CornerFloodReplayTests.ResolveDatDir();
        if (datDir is null)
        {
            Assert.Fail("Lane=InstalledDat requires an installed retail DAT directory.");
        }
        IReadOnlyList<WalkOracleFrame> frames =
            WalkOracleTrace.Load("posed/holtburg-street-outdoor");
        WalkOracleFrame frame = frames[1];
        Assert.NotNull(frame.Pose);

        // Retail's ground truth for this frame: which buildings punched, and
        // which cells each punch listed.
        string expectedPunches = PunchSignature(
            frame.Events.Select(e => e.Kind == WalkOracleEventKind.Building
                ? ("BLD", e.CellId!.Value, Array.Empty<uint>())
                : e.Kind == WalkOracleEventKind.DrawCells
                    ? ("DC", 0u, e.Cells.ToArray())
                    : ("", 0u, Array.Empty<uint>())));

        var report = new StringBuilder();
        report.AppendLine($"RETAIL: {expectedPunches}");
        string? winner = null;

        foreach (bool flipPlanes in new[] { false, true })
        {
            foreach (int sideMode in new[] { 0, 1, 2, 3 })
            {
                // sideMode: 0 = (Flags & 0x2), 1 = inverted 0x2,
                //           2 = (Flags & 0x1), 3 = inverted 0x1.
                using var dats = new DatCollection(datDir!, DatAccessType.Read);
                WalkWorldDatAdapter.FlipGfxPolygonPlanes = flipPlanes;
                WalkWorldDatAdapter.BuildingSideMode = sideMode;
                try
                {
                    WalkLandscapeDatBuilder.BuiltWorld world =
                        WalkLandscapeDatBuilder.Build(dats, frame.Pose!.CellId);
                    var ctx = new WalkTraceReplayContext(frame.Pose, world.Cells)
                    {
                        Buildings = world.Buildings,
                    };
                    var walk = new RetailFrameWalk();
                    var recorder = new Recorder();
                    walk.WalkFrame(frame.Pose.CellId, null, world.Landscape, ctx, recorder);
                    string actual = PunchSignature(
                        recorder.Events.Select(e => e.Kind == WalkEventKind.Building
                            ? ("BLD", e.CellId, Array.Empty<uint>())
                            : e.Kind == WalkEventKind.DrawCells
                                ? ("DC", 0u, e.Cells.ToArray())
                                : ("", 0u, Array.Empty<uint>())));
                    string arm = $"flip={flipPlanes} side={sideMode}";
                    report.AppendLine($"{arm}: {actual}");
                    if (actual == expectedPunches)
                        winner ??= arm;
                }
                finally
                {
                    WalkWorldDatAdapter.FlipGfxPolygonPlanes = false;
                    WalkWorldDatAdapter.BuildingSideMode = 0;
                }
            }
        }

        Assert.True(
            winner is not null,
            $"no gate decode reproduces retail's punch pattern\n{report}");
    }

    private static string PunchSignature(
        IEnumerable<(string Kind, uint Id, uint[] Cells)> events)
    {
        var parts = new List<string>();
        foreach ((string kind, uint id, uint[] cells) in events)
        {
            if (kind == "BLD") parts.Add($"B{id:x8}");
            else if (kind == "DC")
                parts.Add($"D[{string.Join(',', cells.Select(c => (c & 0xFFFF).ToString("x3")))}]");
        }
        return string.Join("|", parts);
    }
}