using System.Numerics;
using DatReaderWriter;
using DatReaderWriter.DBObjs;
using DatReaderWriter.Enums;
using DatReaderWriter.Options;
using SysEnv = System.Environment;

string datDir = SysEnv.GetEnvironmentVariable("ACDREAM_DAT_DIR")
    ?? Path.Combine(SysEnv.GetFolderPath(SysEnv.SpecialFolder.UserProfile),
        "Documents", "Asheron's Call");

if (!Directory.Exists(datDir))
{
    Console.Error.WriteLine($"DAT directory not found: {datDir}");
    return 2;
}

using var dats = new DatCollection(datDir, DatAccessType.Read);
if (args.Length > 0 && string.Equals(args[0], "buildings", StringComparison.OrdinalIgnoreCase))
{
    uint landblockId = args.Length > 1 ? ParseHex(args[1]) : 0xA9B40000u;
    int radius = args.Length > 2 ? int.Parse(args[2], System.Globalization.CultureInfo.InvariantCulture) : 0;
    DumpBuildings(dats, landblockId, radius);
}
else if (args.Length > 0 && string.Equals(args[0], "portals", StringComparison.OrdinalIgnoreCase))
{
    var ids = args.Length == 1
        ? new uint[] { 0xA9B40171u }
        : args.Skip(1).Select(ParseHex).ToArray();
    foreach (var envCellId in ids)
        DumpCellPortals(dats, envCellId);
}
else
{
    var ids = args.Length == 0
        ? [0xA9B4013Fu]
        : args.Select(ParseHex).ToArray();

    foreach (var envCellId in ids)
    {
        DumpCell(dats, envCellId);
    }
}

return 0;

static uint ParseHex(string text)
{
    text = text.Trim();
    if (text.StartsWith("0x", StringComparison.OrdinalIgnoreCase))
        return Convert.ToUInt32(text[2..], 16);
    return Convert.ToUInt32(text, 16);
}

static void DumpCell(DatCollection dats, uint envCellId)
{
    Console.WriteLine($"=== EnvCell 0x{envCellId:X8} ===");
    var envCell = dats.Get<EnvCell>(envCellId);
    if (envCell is null)
    {
        Console.WriteLine("missing EnvCell");
        return;
    }

    var envId = 0x0D000000u | envCell.EnvironmentId;
    var environment = dats.Get<DatReaderWriter.DBObjs.Environment>(envId);
    if (environment is null)
    {
        Console.WriteLine($"missing Environment 0x{envId:X8}");
        return;
    }

    if (!environment.Cells.TryGetValue(envCell.CellStructure, out var cellStruct))
    {
        Console.WriteLine($"missing CellStruct {envCell.CellStructure}");
        return;
    }

    Console.WriteLine(
        $"environment=0x{envId:X8} cellStruct={envCell.CellStructure} " +
        $"surfaces={envCell.Surfaces.Count} verts={cellStruct.VertexArray.Vertices.Count} polys={cellStruct.Polygons.Count}");

    int posSides = 0;
    int negSides = 0;
    int skipped = 0;
    int likelyFloor = 0;
    int likelyCeiling = 0;

    foreach (var (polyId, poly) in cellStruct.Polygons.OrderBy(p => p.Key))
    {
        if (poly.VertexIds.Count < 3)
            continue;

        bool emitPos = !poly.Stippling.HasFlag(StipplingType.NoPos) && poly.PosSurface >= 0 && poly.PosSurface < envCell.Surfaces.Count;
        bool emitNeg =
            (poly.Stippling.HasFlag(StipplingType.Negative) ||
             poly.Stippling.HasFlag(StipplingType.Both) ||
             (!poly.Stippling.HasFlag(StipplingType.NoNeg) && poly.SidesType == CullMode.Clockwise))
            && poly.NegSurface >= 0
            && poly.NegSurface < envCell.Surfaces.Count;

        if (emitPos) posSides++;
        if (emitNeg) negSides++;
        if (!emitPos && !emitNeg) skipped++;

        var normal = ComputeNormal(cellStruct, poly);
        var uvRange = UvRange(cellStruct, poly);
        string planeHint = Math.Abs(normal.Z) > 0.9f
            ? normal.Z > 0 ? "floor/up" : "ceiling/down"
            : Math.Abs(normal.Z) > 0.15f ? "slope" : "wall";

        if (normal.Z > 0.9f) likelyFloor++;
        if (normal.Z < -0.9f) likelyCeiling++;

        var posSurf = SurfaceText(envCell, poly.PosSurface);
        var negSurf = SurfaceText(envCell, poly.NegSurface);
        Console.WriteLine(
            $"poly=0x{polyId:X4} pts={poly.VertexIds.Count} n=({normal.X:F3},{normal.Y:F3},{normal.Z:F3}) {planeHint,-12} " +
            $"stip={poly.Stippling} sides={poly.SidesType} pos={poly.PosSurface}->{posSurf} neg={poly.NegSurface}->{negSurf} " +
            $"emitPos={emitPos} emitNeg={emitNeg} posUv={poly.PosUVIndices?.Count ?? 0} negUv={poly.NegUVIndices?.Count ?? 0} " +
            $"uv=({uvRange.Min.X:F3},{uvRange.Min.Y:F3})..({uvRange.Max.X:F3},{uvRange.Max.Y:F3})");
    }

    Console.WriteLine(
        $"summary: posSides={posSides} negSides={negSides} skipped={skipped} " +
        $"likelyFloor={likelyFloor} likelyCeiling={likelyCeiling}");
    Console.WriteLine();
}

static void DumpCellPortals(DatCollection dats, uint envCellId)
{
    Console.WriteLine($"=== EnvCell 0x{envCellId:X8} portals ===");
    var envCell = dats.Get<EnvCell>(envCellId);
    if (envCell is null)
    {
        Console.WriteLine("missing EnvCell");
        return;
    }

    // Resolve cellStruct so we can replicate BuildLoadedCell's portal-polygon
    // vertex resolution and report what LoadedCell.PortalPolygons[i] would hold.
    var envId = 0x0D000000u | envCell.EnvironmentId;
    var environment = dats.Get<DatReaderWriter.DBObjs.Environment>(envId);
    DatReaderWriter.Types.CellStruct? cellStruct = null;
    if (environment is not null && environment.Cells.TryGetValue(envCell.CellStructure, out var cs))
        cellStruct = cs;

    uint lbPrefix = envCellId & 0xFFFF0000u;
    int exitCount = 0;
    int interiorCount = 0;
    for (int i = 0; i < envCell.CellPortals.Count; i++)
    {
        var portal = envCell.CellPortals[i];
        bool isExit = portal.OtherCellId == 0xFFFF;
        if (isExit) exitCount++; else interiorCount++;
        string dest = isExit
            ? "EXIT(outdoor)"
            : $"0x{(lbPrefix | (uint)portal.OtherCellId):X8}";

        // Replicate BuildLoadedCell (GameWindow.cs:5816-5838): look up the portal
        // polygon by portal.PolygonId, require >= 3 verts, resolve every VertexId.
        // If any vertex is missing the loader stores an EMPTY array, which the
        // PortalVisibilityBuilder's guard (poly.Length < 3) silently skips.
        string resolveText;
        if (cellStruct is null)
        {
            resolveText = "no-cellStruct";
        }
        else if (!cellStruct.Polygons.TryGetValue(portal.PolygonId, out var poly))
        {
            resolveText = $"polygon {portal.PolygonId} NOT in cellStruct.Polygons (keys=[{string.Join(",", cellStruct.Polygons.Keys.OrderBy(k => k))}])";
        }
        else
        {
            int vc = poly.VertexIds.Count;
            int resolved = 0;
            var missing = new List<int>();
            for (int vi = 0; vi < vc; vi++)
            {
                if (cellStruct.VertexArray.Vertices.ContainsKey((ushort)poly.VertexIds[vi]))
                    resolved++;
                else
                    missing.Add(poly.VertexIds[vi]);
            }
            bool wouldResolve = vc >= 3 && resolved == vc;
            resolveText =
                $"polyVerts={vc} resolved={resolved} BUILDER_SEES={(wouldResolve ? "OK" : "EMPTY/SKIPPED")} " +
                $"vids=[{string.Join(",", poly.VertexIds)}]" +
                (missing.Count > 0 ? $" MISSING=[{string.Join(",", missing)}]" : "");
        }

        // U.4c side-test validation (supersedes the earlier `retailTraversesAtCentroid`
        // column, which the characterization doc flagged UNRELIABLE). Builds the portal
        // plane EXACTLY as GameWindow.BuildLoadedCell (Cross(p1-p0,p2-p0), d=-dot(N,p0)),
        // derives the OLD centroid InsideSide, reads the dat PortalSide, and runs THREE
        // candidate side senses for a camera SWEPT from the cell centroid toward (and a
        // bit past) the portal plane:
        //   O = OLD centroid sense (CameraOnInteriorSide pre-fix)
        //   A = PortalSide, winding-corrected  (docs/research/2026-05-31-u4c-initcell-pseudocode.md)
        //   B = PortalSide, doc-§314 literal intuition (opposite polarity)
        // FINDING (2026-05-31): for the real Holtburg cottage cells, A is BYTE-IDENTICAL
        // to O at every pose (the PortalSide swap is a NO-OP for the flap), and B culls
        // true-interior poses (wrong polarity). No side-test sense fixes the flap — the
        // flap is the 3rd-person eye legitimately crossing the portal plane while still
        // rooted in the cell, which any plane-side test culls. See the BLOCKED report.
        string sideText = "no-cellStruct";
        if (cellStruct is not null && cellStruct.Polygons.TryGetValue(portal.PolygonId, out var sp)
            && sp.VertexIds.Count >= 3
            && TryGetOrigin(cellStruct, (ushort)sp.VertexIds[0], out var s0)
            && TryGetOrigin(cellStruct, (ushort)sp.VertexIds[1], out var s1)
            && TryGetOrigin(cellStruct, (ushort)sp.VertexIds[2], out var s2))
        {
            var n = Vector3.Cross(s1 - s0, s2 - s0);
            n = n.LengthSquared() > 0f ? Vector3.Normalize(n) : Vector3.Zero;
            float d = -Vector3.Dot(n, s0);
            // Cell centroid = AABB center over all cellStruct verts (matches BuildLoadedCell).
            var mn = new Vector3(float.MaxValue); var mx = new Vector3(float.MinValue);
            foreach (var v in cellStruct.VertexArray.Vertices.Values)
            { mn = Vector3.Min(mn, v.Origin); mx = Vector3.Max(mx, v.Origin); }
            var centroid = (mn + mx) * 0.5f;
            float centroidDot = Vector3.Dot(n, centroid) + d;
            int ourInsideSide = centroidDot >= 0 ? 0 : 1;                  // GameWindow.cs:5648
            bool portalSide = !portal.Flags.HasFlag(PortalFlags.PortalSide); // PortalInfo.cs:44 bool
            int datPortalSide = portalSide ? 0 : 1;                        // raw bit (0 = bool true)

            const float eps = 0.01f; // PortalVisibilityBuilder.PortalSideEpsilon
            // Nearest portal-polygon vertex = the plane-ward sweep anchor.
            var pnear = s0; float bestD = centroidDot;
            foreach (var vid in sp.VertexIds)
                if (TryGetOrigin(cellStruct, (ushort)vid, out var vv))
                {
                    float vd = Vector3.Dot(n, vv) + d;
                    if (Math.Abs(vd) < Math.Abs(bestD)) { bestD = vd; pnear = vv; }
                }

            static bool OldSense(int side, float dot, float e) => side == 0 ? dot >= -e : dot <= e;
            static bool SenseA(bool ps, float dot, float e) => ps ? dot < e : dot > -e;
            static bool SenseB(bool ps, float dot, float e) => ps ? dot > -e : dot < e;

            bool oAll = true, aAll = true, bAll = true;
            var trace = new List<string>();
            foreach (float t in new[] { 0f, 0.25f, 0.5f, 0.75f, 1.0f, 1.15f, 1.3f })
            {
                var cam = Vector3.Lerp(centroid, pnear, t);
                float dot = Vector3.Dot(n, cam) + d;
                bool os = OldSense(ourInsideSide, dot, eps);
                bool a = SenseA(portalSide, dot, eps);
                bool b = SenseB(portalSide, dot, eps);
                if (!os) oAll = false; if (!a) aAll = false; if (!b) bAll = false;
                trace.Add($"t{t:F2}:D={dot:F2}/O={(os ? "T" : "x")}/A={(a ? "T" : "x")}/B={(b ? "T" : "x")}");
            }
            sideText =
                $"N=({n.X:F2},{n.Y:F2},{n.Z:F2}) d={d:F2} centroidDot={centroidDot:F3} " +
                $"ourInsideSide={ourInsideSide} datPortalSide={datPortalSide} " +
                $"sweepTraversesAll[OLD={oAll} A={aAll} B={bAll}] [{string.Join(" ", trace)}]";
        }

        Console.WriteLine(
            $"  portal[{i}] other=0x{portal.OtherCellId:X4} -> {dest} " +
            $"flags={portal.Flags} polyId={portal.PolygonId} | {resolveText}");
        Console.WriteLine($"           SIDES: {sideText}");
    }

    // U.4c H3 check: local AABB over all cellStruct verts. If the cell's AABB extends
    // PAST one of its own portal planes, a camera eye in that region is in this cell's
    // AABB (so an AABB-based FindCameraCell keeps rooting here) yet geometrically on the
    // neighbour's side of the portal (so the per-frame side test culls that portal) →
    // the flap's stale-root region.
    if (cellStruct is not null && cellStruct.VertexArray.Vertices.Count > 0)
    {
        var mn = new Vector3(float.MaxValue); var mx = new Vector3(float.MinValue);
        foreach (var v in cellStruct.VertexArray.Vertices.Values)
        { mn = Vector3.Min(mn, v.Origin); mx = Vector3.Max(mx, v.Origin); }
        Console.WriteLine($"  localAABB: min=({mn.X:F2},{mn.Y:F2},{mn.Z:F2}) max=({mx.X:F2},{mx.Y:F2},{mx.Z:F2})");
    }

    Console.WriteLine(
        $"summary: cell=0x{envCellId:X8} portals={envCell.CellPortals.Count} " +
        $"exits(0xFFFF)={exitCount} interior={interiorCount} " +
        $"numCellPortals={envCell.CellPortals.Count} seenOutside={(envCell.Flags.HasFlag(EnvCellFlags.SeenOutside) ? "Y" : "n")}");
    Console.WriteLine();
}

static void DumpBuildings(DatCollection dats, uint centerLandblockId, int radius)
{
    int centerX = (int)((centerLandblockId >> 24) & 0xFFu);
    int centerY = (int)((centerLandblockId >> 16) & 0xFFu);
    int totalRegistryBuildings = 0;
    int totalShellEntities = 0;

    for (int dy = -radius; dy <= radius; dy++)
    for (int dx = -radius; dx <= radius; dx++)
    {
        int x = centerX + dx;
        int y = centerY + dy;
        if (x < 0 || x > 255 || y < 0 || y > 255)
            continue;

        uint landblockId = ((uint)x << 24) | ((uint)y << 16);
        var info = dats.Get<LandBlockInfo>(landblockId | 0xFFFEu);
        if (info is null)
            continue;

        var (registryBuildings, shellEntities) = DumpLandblockBuildings(info, landblockId);
        totalRegistryBuildings += registryBuildings;
        totalShellEntities += shellEntities;
    }

    Console.WriteLine(
        $"radius-summary center=0x{(centerLandblockId & 0xFFFF0000u):X8} radius={radius} " +
        $"registryBuildings={totalRegistryBuildings} shellEntities={totalShellEntities}");
}

static (int RegistryBuildings, int ShellEntities) DumpLandblockBuildings(LandBlockInfo info, uint landblockId)
{
    uint lbPrefix = landblockId & 0xFFFF0000u;
    uint stabIdBase = 0xC0000000u
        | (((landblockId >> 24) & 0xFFu) << 16)
        | (((landblockId >> 16) & 0xFFu) << 8);
    uint nextEntityId = stabIdBase + 1u;

    int supportedObjects = 0;
    foreach (var obj in info.Objects)
    {
        if (!IsSupported(obj.Id))
            continue;
        supportedObjects++;
        nextEntityId++;
    }

    Console.WriteLine(
        $"=== Landblock 0x{lbPrefix:X8} info=0x{(lbPrefix | 0xFFFEu):X8} " +
        $"objects={info.Objects.Count} supportedObjects={supportedObjects} buildings={info.Buildings.Count} ===");

    int registryBuildingId = 1;
    int shellEntities = 0;
    foreach (var (building, zeroBased) in info.Buildings.Select((b, i) => (b, i)))
    {
        if (!IsSupported(building.ModelId))
            continue;

        uint shellEntityId = nextEntityId++;
        shellEntities++;

        var portalCells = building.Portals
            .Where(p => p.OtherCellId != 0xFFFF)
            .Select(p => lbPrefix | (uint)p.OtherCellId)
            .Distinct()
            .OrderBy(id => id)
            .ToArray();
        string registryText = portalCells.Length == 0
            ? "none"
            : $"0x{registryBuildingId++:X}";
        string portalText = portalCells.Length == 0
            ? "[]"
            : "[" + string.Join(",", portalCells.Select(id => $"0x{id:X8}")) + "]";

        Console.WriteLine(
            $"buildingOrdinal={zeroBased + 1} registryId={registryText} shellEntity=0x{shellEntityId:X8} " +
            $"model=0x{building.ModelId:X8} pos=({building.Frame.Origin.X:F2},{building.Frame.Origin.Y:F2},{building.Frame.Origin.Z:F2}) " +
            $"portalCells={portalText}");
    }

    Console.WriteLine();
    return (registryBuildingId - 1, shellEntities);
}

static bool IsSupported(uint id)
{
    uint type = id & 0xFF000000u;
    return type == 0x01000000u || type == 0x02000000u;
}

static string SurfaceText(EnvCell envCell, short index)
{
    if (index < 0) return "none";
    if (index >= envCell.Surfaces.Count) return "out-of-range";
    return $"0x{(0x08000000u | envCell.Surfaces[index]):X8}";
}

static Vector3 ComputeNormal(DatReaderWriter.Types.CellStruct cellStruct, DatReaderWriter.Types.Polygon poly)
{
    if (poly.VertexIds.Count < 3) return Vector3.Zero;
    if (!TryGetOrigin(cellStruct, (ushort)poly.VertexIds[0], out var a) ||
        !TryGetOrigin(cellStruct, (ushort)poly.VertexIds[1], out var b) ||
        !TryGetOrigin(cellStruct, (ushort)poly.VertexIds[2], out var c))
    {
        return Vector3.Zero;
    }

    var n = Vector3.Cross(b - a, c - a);
    return n.LengthSquared() > 0f ? Vector3.Normalize(n) : Vector3.Zero;
}

static bool TryGetOrigin(DatReaderWriter.Types.CellStruct cellStruct, ushort id, out Vector3 origin)
{
    if (cellStruct.VertexArray.Vertices.TryGetValue(id, out var vertex))
    {
        origin = vertex.Origin;
        return true;
    }

    origin = Vector3.Zero;
    return false;
}

static (Vector2 Min, Vector2 Max) UvRange(DatReaderWriter.Types.CellStruct cellStruct, DatReaderWriter.Types.Polygon poly)
{
    var min = new Vector2(float.MaxValue, float.MaxValue);
    var max = new Vector2(float.MinValue, float.MinValue);
    bool any = false;
    for (int i = 0; i < poly.VertexIds.Count; i++)
    {
        if (!cellStruct.VertexArray.Vertices.TryGetValue((ushort)poly.VertexIds[i], out var vertex))
            continue;

        ushort uvIdx = 0;
        if (poly.PosUVIndices is not null && i < poly.PosUVIndices.Count)
            uvIdx = poly.PosUVIndices[i];
        if (uvIdx >= vertex.UVs.Count)
            uvIdx = 0;
        if (vertex.UVs.Count == 0)
            continue;

        var uv = new Vector2(vertex.UVs[uvIdx].U, vertex.UVs[uvIdx].V);
        min = Vector2.Min(min, uv);
        max = Vector2.Max(max, uv);
        any = true;
    }

    return any ? (min, max) : (Vector2.Zero, Vector2.Zero);
}