using System;
using System.IO;
using DatReaderWriter;
using DatReaderWriter.DBObjs;
using DatReaderWriter.Options;
using Xunit;
using Xunit.Abstractions;
using Env = System.Environment;

namespace AcDream.Core.Tests.Physics;

/// <summary>
/// #137 corridor-seam inspection (2026-07-05, Facility Hub). Live probe
/// evidence (launch-175-verify2.log:42858): crossing corridor cells
/// 0x8A02016E → 0x8A02017A at world x≈85.25 records a wall hit with normal
/// (−1,0,0) — pointing straight back against the movement — after which the
/// stale sliding normal wedges all forward motion (ok=False hit=no, offset
/// projected to zero). Question this dump answers: does cell 0x8A02017A's
/// PHYSICS polygon set contain a portal-spanning polygon at its entry plane
/// (normal ≈ ±X at the portal's local X) — i.e., are portal-sealing polys in
/// our collision set where retail filters them?
/// </summary>
public class Issue137CorridorSeamInspectionTests
{
    private readonly ITestOutputHelper _out;
    public Issue137CorridorSeamInspectionTests(ITestOutputHelper output) => _out = output;

    [Theory]
    [InlineData(0x8A02016Eu)]
    [InlineData(0x8A02017Au)]
    public void CorridorCell_PhysicsPolysAndPortals_DatInspection(uint envCellId)
    {
        var datDir = Env.GetEnvironmentVariable("ACDREAM_DAT_DIR")
            ?? Path.Combine(Env.GetFolderPath(Env.SpecialFolder.UserProfile),
                            "Documents", "Asheron's Call");
        if (!Directory.Exists(datDir))
        {
            _out.WriteLine($"SKIP: dat directory not found at {datDir}");
            return;
        }

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

        var envCell = dats.Get<EnvCell>(envCellId);
        Assert.NotNull(envCell);
        _out.WriteLine($"=== EnvCell 0x{envCellId:X8} ===");
        _out.WriteLine($"  pos=({envCell!.Position.Origin.X:F2},{envCell.Position.Origin.Y:F2},{envCell.Position.Origin.Z:F2}) " +
                       $"rot=({envCell.Position.Orientation.X:F3},{envCell.Position.Orientation.Y:F3},{envCell.Position.Orientation.Z:F3},{envCell.Position.Orientation.W:F3})");
        _out.WriteLine($"  EnvironmentId=0x{envCell.EnvironmentId:X4} CellStructure={envCell.CellStructure}");
        _out.WriteLine($"  CellPortals={envCell.CellPortals.Count}");
        foreach (var p in envCell.CellPortals)
            _out.WriteLine($"    portal poly={p.PolygonId} other=0x{p.OtherCellId:X4} flags={p.Flags}");

        var environment = dats.Get<DatReaderWriter.DBObjs.Environment>(0x0D000000u | envCell.EnvironmentId);
        Assert.NotNull(environment);
        Assert.True(environment!.Cells.TryGetValue(envCell.CellStructure, out var cs));

        _out.WriteLine($"  PhysicsPolygons={cs!.PhysicsPolygons.Count} (portal-relevant normals below)");
        foreach (var (id, poly) in cs.PhysicsPolygons)
        {
            // Compute the face normal from the vertex fan (same math as
            // PhysicsDataCache.ResolvePolygons).
            var verts = poly.VertexIds;
            if (verts.Count < 3) continue;
            if (!cs.VertexArray.Vertices.TryGetValue((ushort)verts[0], out var v0)) continue;
            if (!cs.VertexArray.Vertices.TryGetValue((ushort)verts[1], out var v1)) continue;
            if (!cs.VertexArray.Vertices.TryGetValue((ushort)verts[2], out var v2)) continue;
            var n = System.Numerics.Vector3.Normalize(System.Numerics.Vector3.Cross(
                v1.Origin - v0.Origin, v2.Origin - v0.Origin));

            // Only print near-horizontal-normal polys (walls) — the seam wall
            // candidates; floors/ceilings are noise here.
            if (MathF.Abs(n.Z) > 0.3f) continue;
            _out.WriteLine($"    poly {id}: n=({n.X:F2},{n.Y:F2},{n.Z:F2}) v0=({v0.Origin.X:F2},{v0.Origin.Y:F2},{v0.Origin.Z:F2}) verts={verts.Count} sides={poly.SidesType} stip={poly.Stippling}");
        }

        // The portal polygons live in the VISUAL polygon set — print their
        // ids so overlap with the physics set (same id space?) is visible.
        _out.WriteLine($"  VisualPolygons={cs.Polygons.Count}");
        foreach (var p in envCell.CellPortals)
        {
            if (cs.Polygons.TryGetValue((ushort)p.PolygonId, out var vp))
            {
                _out.WriteLine($"    portal-poly {p.PolygonId} IS in the visual set (verts={vp.VertexIds.Count})");
                bool inPhysics = cs.PhysicsPolygons.ContainsKey((ushort)p.PolygonId);
                _out.WriteLine($"    portal-poly {p.PolygonId} in PHYSICS set: {inPhysics}");
            }
        }
    }
}