import { createHash } from "node:crypto";
import { readFile, writeFile } from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { NodeIO } from "@gltf-transform/core";
import { ALL_EXTENSIONS } from "@gltf-transform/extensions";
import { Matrix4, Vector3 } from "three";
import { sourceAnchorSupportGeometry } from "./lib/source-anchor-support.mjs";

const projectRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..");
const workRoot = path.join(projectRoot, "runewaker-export-work");
const slug = process.argv[2] ?? "aeternal-circle";
const stageDungeon = path.join(workRoot, "source-anchor-support-correction-staged-v2", slug);
const supportName = "runewaker_source_anchor_support";
const io = new NodeIO().registerExtensions(ALL_EXTENSIONS);
const sha256 = (bytes) => createHash("sha256").update(bytes).digest("hex");
const relative = (file) => path.relative(projectRoot, file).replaceAll("\\", "/");

function include(bounds, point) {
  for (let axis = 0; axis < 3; axis += 1) {
    bounds.minimum[axis] = Math.min(bounds.minimum[axis], point[axis]);
    bounds.maximum[axis] = Math.max(bounds.maximum[axis], point[axis]);
  }
}

function emptyBounds() {
  return { minimum: [Infinity, Infinity, Infinity], maximum: [-Infinity, -Infinity, -Infinity] };
}

const recipe = JSON.parse(await readFile(path.join(projectRoot, "scripts/runewaker-pipeline/recipes", `${slug}.json`), "utf8"));
const stageReport = JSON.parse(await readFile(path.join(stageDungeon, "staging-report.json"), "utf8"));
const conversion = JSON.parse(await readFile(path.join(workRoot, slug, "converted/conversion-report.json"), "utf8"));
const sourceReportPath = path.join(stageDungeon, "native-primary-collision-report.json");
const sourceReport = JSON.parse(await readFile(sourceReportPath, "utf8"));
const meters = Number(recipe.coordinateSystem.metersPerSourceUnit);
const sourceBounds = sourceReport.nativeCollisionBounds;
const expectedNativeBounds = {
  minimum: [
    Number(sourceBounds.min[0]) * meters,
    Number(sourceBounds.min[1]) * meters,
    -Number(sourceBounds.max[2]) * meters,
  ],
  maximum: [
    Number(sourceBounds.max[0]) * meters,
    Number(sourceBounds.max[1]) * meters,
    -Number(sourceBounds.min[2]) * meters,
  ],
};
const convertedNativeBounds = emptyBounds();
let convertedNativeTriangles = 0;
for (const record of conversion.collision ?? []) {
  const stagedRecord = stageReport.staged.collision.find((item) => item.source === record.file);
  const file = path.join(stageDungeon, stagedRecord?.staged ?? record.file);
  const document = await io.read(file);
  for (const node of document.getRoot().listNodes()) {
    if (!node.getMesh() || node.getExtras()?.sourceChunk === supportName) continue;
    const matrix = new Matrix4().fromArray(Array.from(node.getWorldMatrix()));
    for (const primitive of node.getMesh().listPrimitives()) {
      const position = primitive.getAttribute("POSITION");
      const indices = primitive.getIndices();
      convertedNativeTriangles += (indices?.getCount() ?? position?.getCount() ?? 0) / 3;
      if (!position) continue;
      const values = position.getArray();
      for (let offset = 0; offset < values.length; offset += 3) {
        include(convertedNativeBounds, new Vector3().fromArray(values, offset).applyMatrix4(matrix).toArray());
      }
    }
  }
}

const placement = stageReport.source.primaryPlacement;
const sourcePoints = recipe.source.sourceAnchorSupport.points.map((point) => point.map(Number));
const omitted = new Set(stageReport.source.omittedNativeGroundedPointIndices);
const nativeXZ = {
  minX: convertedNativeBounds.minimum[0], maxX: convertedNativeBounds.maximum[0],
  minZ: convertedNativeBounds.minimum[2], maxZ: convertedNativeBounds.maximum[2],
};
const padRows = [];
const supportBounds = emptyBounds();
const coreSupportBounds = emptyBounds();
for (const [sourcePointIndex, sourcePoint] of sourcePoints.entries()) {
  if (omitted.has(sourcePointIndex)) continue;
  const geometry = sourceAnchorSupportGeometry([sourcePoint], placement, {
    halfExtent: Number(stageReport.source.halfExtentSourceUnits),
    thickness: Number(stageReport.source.thicknessSourceUnits),
    metersPerSourceUnit: meters,
  });
  const top = [];
  for (let vertex = 0; vertex < 4; vertex += 1) {
    top.push(geometry.positions.slice(vertex * 3, vertex * 3 + 3));
  }
  const box = emptyBounds();
  for (const point of geometry.positions.reduce((all, value, index) => {
    if (index % 3 === 0) all.push(geometry.positions.slice(index, index + 3));
    return all;
  }, [])) {
    include(box, point);
    include(supportBounds, point);
  }
  const overlapsNativeXZ = box.maximum[0] >= nativeXZ.minX && box.minimum[0] <= nativeXZ.maxX
    && box.maximum[2] >= nativeXZ.minZ && box.minimum[2] <= nativeXZ.maxZ;
  const yGapM = box.minimum[1] > convertedNativeBounds.maximum[1]
    ? box.minimum[1] - convertedNativeBounds.maximum[1]
    : box.maximum[1] < convertedNativeBounds.minimum[1]
      ? convertedNativeBounds.minimum[1] - box.maximum[1]
      : 0;
  if (overlapsNativeXZ) {
    for (const point of geometry.positions.reduce((all, value, index) => {
      if (index % 3 === 0) all.push(geometry.positions.slice(index, index + 3));
      return all;
    }, [])) include(coreSupportBounds, point);
  }
  padRows.push({ sourcePointIndex, sourcePoint, center: top.reduce((center, point) => center.map((value, axis) => value + point[axis] / top.length), [0, 0, 0]),
    bounds: box, overlapsNativeXZ, verticalGapToNativeBoundsM: yGapM });
}

const coreBounds = emptyBounds();
for (const point of [
  [convertedNativeBounds.minimum[0], convertedNativeBounds.minimum[1], convertedNativeBounds.minimum[2]],
  [convertedNativeBounds.maximum[0], convertedNativeBounds.maximum[1], convertedNativeBounds.maximum[2]],
  [coreSupportBounds.minimum[0], coreSupportBounds.minimum[1], coreSupportBounds.minimum[2]],
  [coreSupportBounds.maximum[0], coreSupportBounds.maximum[1], coreSupportBounds.maximum[2]],
]) {
  if (point.every(Number.isFinite)) include(coreBounds, point);
}
const gridWidth = Math.ceil((coreBounds.maximum[0] - coreBounds.minimum[0]) / Number(recipe.navigation.cellSize));
const gridDepth = Math.ceil((coreBounds.maximum[2] - coreBounds.minimum[2]) / Number(recipe.navigation.cellSize));
const overlapRows = padRows.filter((row) => row.overlapsNativeXZ);
const remoteRows = padRows.filter((row) => !row.overlapsNativeXZ);
const report = {
  schemaVersion: 1,
  slug,
  source: {
    primaryModel: recipe.source.model,
    primaryModelSha256: stageReport.source.sourceModelSha256,
    nativeCollisionReport: relative(sourceReportPath),
    nativeCollisionReportSha256: sha256(await readFile(sourceReportPath)),
    nativeCollisionTriangles: sourceReport.nativeCollisionTriangleCount,
    visualFallbackTriangles: sourceReport.renderMeshFallbackTriangleCount,
    nativeTriangleFlags: sourceReport.nativeTriangleFlagCounts,
    pathCollisionExclusionMask: sourceReport.pathCollisionPolicy.exclusionMask,
    convertedCollisionChunks: conversion.collision.map((record) => record.file),
  },
  boundsProof: {
    convertedCollisionExcludingSupport: convertedNativeBounds,
    expectedNativeCollisionBoundsAfterUnitsAndZBridge: expectedNativeBounds,
    comparisonMaximumErrorM: convertedNativeBounds.minimum.map((value, axis) => Math.max(
      Math.abs(value - expectedNativeBounds.minimum[axis]),
      Math.abs(convertedNativeBounds.maximum[axis] - expectedNativeBounds.maximum[axis]),
    )).reduce((max, value) => Math.max(max, value), 0),
    convertedNativeCollisionTriangles: convertedNativeTriangles,
    sourceQueryNativeTriangles: sourceReport.nativeCollisionTriangleCount,
    exactBoundsMatchToleranceM: 0.01,
    nativeCoreBounds: convertedNativeBounds,
    supportUnionBounds: supportBounds,
    nativeCorePlusXZOverlappingSupportBounds: coreBounds,
  },
  selection: {
    sourceAnchorPointCount: sourcePoints.length,
    omittedNativeGroundedPointIndices: [...omitted],
    retainedSupportCount: padRows.length,
    coreXzOverlapCount: overlapRows.length,
    isolatedRemoteCount: remoteRows.length,
    coreSupportSourcePointIndices: overlapRows.map((row) => row.sourcePointIndex),
    remoteSupportSourcePointIndices: remoteRows.map((row) => row.sourcePointIndex),
    remoteSupportClearanceM: Number(recipe.navigation.agentRadius ?? 0.36),
    remoteSupportTopInsetHalfExtentM: Number(stageReport.source.halfExtentSourceUnits) * meters - Number(recipe.navigation.agentRadius ?? 0.36),
  },
  predictedCoreRecastGrid: {
    cellSize: Number(recipe.navigation.cellSize),
    widthCells: gridWidth,
    depthCells: gridDepth,
    cellCount: gridWidth * gridDepth,
    recipeTileSize: recipe.navigation.tileSize ?? null,
  },
  padRows,
  conclusion: "This report only classifies source-grounded collision and support selection. It does not merge/bake any nav surfaces. Before staging, verify the bounds comparison and keep remote supports as separate explicit components with agent-radius inset; no route connectivity is inferred.",
};
const output = path.join(stageDungeon, "native-core-support-overlap.json");
await writeFile(output, `${JSON.stringify(report, null, 2)}\n`, "utf8");
console.log(JSON.stringify({
  report: relative(output),
  nativeCollisionTriangles: sourceReport.nativeCollisionTriangleCount,
  convertedNativeTriangles,
  boundsErrorM: report.boundsProof.comparisonMaximumErrorM,
  coreXzOverlapCount: overlapRows.length,
  isolatedRemoteCount: remoteRows.length,
  coreBounds,
  grid: report.predictedCoreRecastGrid,
}, null, 2));