import { spawn } from "node:child_process";
import { createHash } from "node:crypto";
import { createReadStream } from "node:fs";
import { mkdir, readFile, readdir, writeFile } from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import readline from "node:readline";
import { Document, NodeIO } from "@gltf-transform/core";
import { projectRoot, readJson, sourceRootFor } from "./lib/recipe.mjs";
import {
  isTrekkerPathEligible,
  NativeCollisionPartAccumulator,
  normalizeNativeResourcePath,
  nativeResourceFile,
  renderMeshOmissions,
  transformNativeCollisionTriangle,
  triangleTileKey,
  TREKKER_WATER_FOLIAGE_EXCLUSION_MASK,
  validateNativeCollisionCounts,
} from "./lib/native-collision-assembly.mjs";
import {
  normalizedResourceKey,
  readAndValidateNativeCollisionInventory,
  sha256File,
  writeNativeCollisionInventoryManifest,
} from "./lib/native-collision-inventory.mjs";

const DEFAULT_RECIPE = "scripts/runewaker-pipeline/recipes/the-origin.json";
const MAX_TRIANGLES_PER_GLB = 90_000;
const DEFAULT_TILE_SIZE_METERS = 256;
const USAGE = `Assemble bounded collision chunks from serialized native Runewaker ROS collision.

Usage:
  node scripts/runewaker-pipeline/assemble-native-collision.mjs --recipe <recipe.json> --placement-manifest <wdb-placement-manifest.json> --output-root <directory> [options]

Required:
  --recipe <path>                 Dungeon recipe; supplies source root, WDB, and coordinate scale
  --placement-manifest <path>     Exact WDB placement matrices and resource list
  --output-root <path>             Output directory for the deterministic run and default inventory

Options:
  --source-root <path>             Override recipe source root
  --inventory-root <path>          Reuse inventory with native-collision-inventory.json SHA index
  --extractor <path>               Native Rune Engine collision extractor executable
  --collision-mode <mode>           complete (default) or respect-options (honor ruENTITYOPTION_COLLISION)
  --tile-size-meters <number>      Spatial tile size (default ${DEFAULT_TILE_SIZE_METERS})
  --report-output <path>           Copy the complete run report to a stable workspace file
  --help                           Show this help

Each collision GLB is limited to ${MAX_TRIANGLES_PER_GLB.toLocaleString()} triangles. No render-mesh fallback is used.`;

function parseArgs(argv) {
  const options = {};
  const valueOptions = new Set([
    "recipe", "placement-manifest", "output-root", "source-root", "inventory-root", "extractor", "collision-mode", "tile-size-meters", "report-output",
  ]);
  for (let index = 0; index < argv.length; index += 1) {
    const token = argv[index];
    if (token === "--help" || token === "-h") return { help: true };
    if (!token.startsWith("--")) throw new Error(`Unexpected positional argument: ${token}`);
    const name = token.slice(2);
    if (!valueOptions.has(name)) throw new Error(`Unknown option --${name}.`);
    if (options[name] !== undefined) throw new Error(`Option --${name} may only be supplied once.`);
    const value = argv[index + 1];
    if (!value || value.startsWith("--")) throw new Error(`Option --${name} requires a value.`);
    options[name] = value;
    index += 1;
  }
  if (!options.recipe) options.recipe = DEFAULT_RECIPE;
  if (options["collision-mode"] === undefined) options["collision-mode"] = "complete";
  if (!["complete", "respect-options"].includes(options["collision-mode"])) throw new Error("--collision-mode must be complete or respect-options.");
  for (const required of ["placement-manifest", "output-root"]) {
    if (!options[required]) throw new Error(`Missing required option --${required}.`);
  }
  return { help: false, ...options };
}

function resolveProjectPath(value) {
  return path.resolve(projectRoot, value);
}

function resolveWorkspaceOutput(value) {
  const output = resolveProjectPath(value);
  const relative = path.relative(projectRoot, output);
  if (path.isAbsolute(relative) || relative === ".." || relative.startsWith(`..${path.sep}`)) {
    throw new Error("--output-root must stay inside the HealerMan workspace.");
  }
  return output;
}

function validatePlacementInputs(recipe, manifest) {
  if (manifest.dungeonId && manifest.dungeonId !== recipe.slug) {
    throw new Error(`Placement manifest dungeonId ${manifest.dungeonId} does not match recipe ${recipe.slug}.`);
  }
  if (!Array.isArray(manifest.staticPlacements) || manifest.staticPlacements.length === 0) {
    throw new Error("Placement manifest must contain staticPlacements.");
  }
  if (!Array.isArray(manifest.resources) || manifest.resources.length === 0) {
    throw new Error("Placement manifest must contain resources.");
  }
  if (Number(manifest.sourceDescriptorCount) !== manifest.staticPlacements.length) {
    throw new Error("Placement manifest static placement count does not match sourceDescriptorCount.");
  }
  if (!Number.isFinite(Number(recipe.coordinateSystem?.metersPerSourceUnit)) || Number(recipe.coordinateSystem.metersPerSourceUnit) <= 0) {
    throw new Error("Recipe must declare coordinateSystem.metersPerSourceUnit as a positive value.");
  }
  const placementResources = new Map();
  for (const placement of manifest.staticPlacements) {
    normalizeNativeResourcePath(placement.resource);
    if (!Array.isArray(placement.transform?.primaryLocalThreeMatrix) || placement.transform.primaryLocalThreeMatrix.length !== 16) {
      throw new Error(`Placement ${placement.guid ?? placement.id} lacks its exact 16-value primaryLocalThreeMatrix.`);
    }
    placementResources.set(normalizedResourceKey(placement.resource), placement.resource);
  }
  const manifestResources = new Set();
  for (const row of manifest.resources) {
    const key = normalizedResourceKey(row.resource);
    if (manifestResources.has(key)) throw new Error(`Duplicate resource row in placement manifest: ${row.resource}`);
    manifestResources.add(key);
  }
  for (const key of placementResources.keys()) {
    if (!manifestResources.has(key)) throw new Error(`Placed ROS resource is absent from placement manifest resource index: ${key}`);
  }
  const staticResources = [...placementResources.keys()].map((key) => manifest.resources.find((row) => normalizedResourceKey(row.resource) === key));
  return { staticPlacements: manifest.staticPlacements, resources: staticResources };
}

function runExtractor(extractor, resourceRoot, resource, reportFile, collisionMode) {
  return new Promise((resolve, reject) => {
    const child = spawn(extractor, [resourceRoot, resource, reportFile.replaceAll("\\", "/"), collisionMode], {
      windowsHide: true,
      stdio: ["ignore", "ignore", "pipe"],
    });
    let stderr = "";
    child.stderr.setEncoding("utf8");
    child.stderr.on("data", (part) => { stderr += part; });
    child.on("error", reject);
    child.on("close", (code) => {
      if (code !== 0) reject(new Error(`Native collision extractor failed for ${resource} (exit ${code}): ${stderr.trim()}`));
      else resolve();
    });
  });
}

async function extractInventory({ inventoryRoot, extractor, nativeExtractor, collisionMode, resourceRoot, expectedResources, placementManifestSha256, sourceWdbSha256 }) {
  await mkdir(inventoryRoot, { recursive: true });
  const rows = [];
  const ordered = [...expectedResources].sort((a, b) => normalizedResourceKey(a.resource).localeCompare(normalizedResourceKey(b.resource)));
  for (let index = 0; index < ordered.length; index += 1) {
    const resource = ordered[index].resource;
    const sourceFile = nativeResourceFile(resourceRoot, resource);
    const sourceBefore = await sha256File(sourceFile);
    const basename = path.basename(normalizeNativeResourcePath(resource)).replace(/[^a-zd._-]/gi, "_");
    const reportFile = path.join(inventoryRoot, `${String(index).padStart(4, "0")}-${basename}.json`);
    await runExtractor(extractor, resourceRoot, resource, reportFile, collisionMode);
    const sourceAfter = await sha256File(sourceFile);
    if (sourceBefore !== sourceAfter) throw new Error(`Source ROS changed during extraction: ${resource}`);
    const report = JSON.parse(await readFile(reportFile, "utf8"));
    if (normalizedResourceKey(report.sourceModel) !== normalizedResourceKey(resource)) {
      throw new Error(`Extractor report identity mismatch. Requested ${resource}, got ${report.sourceModel}.`);
    }
    if (report.collisionMode !== collisionMode) throw new Error(`Extractor collision mode mismatch for ${resource}.`);
    const triangleCount = Number(report.nativeCollisionTriangleCount);
    if (!Number.isSafeInteger(triangleCount) || triangleCount < 0) throw new Error(`Invalid native triangle count in report for ${resource}.`);
    const objFile = `${reportFile}.obj`;
    const flagsFile = `${reportFile}.flags.bin`;
    rows.push({ resource, report, reportFile, objFile, flagsFile, sourceResourceSha256: sourceBefore });
    if ((index + 1) % 25 === 0 || index + 1 === ordered.length) {
      console.log(`extracted ${index + 1}/${ordered.length} native ROS collision resources`);
    }
  }
  return writeNativeCollisionInventoryManifest({
    inventoryRoot,
    placementManifestSha256,
    sourceWdbSha256,
    nativeExtractor,
    collisionMode,
    resources: rows,
    sourceResourceRoot: resourceRoot,
  });
}

async function readObjTriangleSoup(file, expectedTriangles) {
  const positions = new Float32Array(expectedTriangles * 9);
  const reader = readline.createInterface({ input: createReadStream(file), crlfDelay: Infinity });
  let vertex = 0;
  let face = 0;
  for await (const line of reader) {
    if (line.startsWith("v ")) {
      const parts = line.trim().split(/\s+/);
      if (parts.length !== 4) throw new Error(`Malformed OBJ vertex in ${file}.`);
      const offset = vertex * 3;
      positions[offset] = Number(parts[1]);
      positions[offset + 1] = Number(parts[2]);
      positions[offset + 2] = Number(parts[3]);
      if (![positions[offset], positions[offset + 1], positions[offset + 2]].every(Number.isFinite)) {
        throw new Error(`Non-finite OBJ vertex in ${file}.`);
      }
      vertex += 1;
    } else if (line.startsWith("f ")) {
      const parts = line.trim().split(/\s+/).slice(1).map(Number);
      const expected = [face * 3 + 1, face * 3 + 2, face * 3 + 3];
      if (parts.length !== 3 || parts.some((value, index) => value !== expected[index])) {
        throw new Error(`Native collision OBJ is not a sequential triangle soup at face ${face + 1}: ${file}`);
      }
      face += 1;
    }
  }
  validateNativeCollisionCounts({
    triangleCount: expectedTriangles,
    flagBytes: expectedTriangles * 4,
    positionVertexCount: vertex,
  });
  if (face !== expectedTriangles) throw new Error(`${file} has ${face} faces, expected ${expectedTriangles}.`);
  return positions;
}

class TilePartWriter {
  constructor({ variant, tile, outputDirectory, rootExtras }) {
    this.variant = variant;
    this.tile = tile;
    this.outputDirectory = outputDirectory;
    this.rootExtras = rootExtras;
    this.partIndex = 0;
    this.accumulator = new NativeCollisionPartAccumulator(MAX_TRIANGLES_PER_GLB);
    this.files = [];
  }

  async add(points, flag) {
    const complete = this.accumulator.add(points, flag);
    if (complete) await this.writePart(complete);
  }

  async flush() {
    const part = this.accumulator.finish();
    if (part) await this.writePart(part);
  }

  async writePart(part) {
    const document = new Document();
    const { triangleCount, positions, sourceTriangleFlags: flags, flagCounts } = part;
    document.getRoot().setExtras({
      ...this.rootExtras,
      variant: this.variant,
      tile: this.tile,
      partIndex: this.partIndex,
      triangleCount,
      triangleFlagEncoding: "primitive.extras.sourceTriangleFlags maps one value to each consecutive triangle in POSITION order",
    });
    const buffer = document.createBuffer(`${this.variant}-${this.tile}-${this.partIndex}-buffer`);
    const scene = document.createScene(`${this.variant}-${this.tile}-${this.partIndex}-scene`);
    document.getRoot().setDefaultScene(scene);
    const positionAccessor = document.createAccessor(`${this.variant}-${this.tile}-${this.partIndex}-position`, buffer)
      .setType("VEC3")
      .setArray(positions);
    const primitive = document.createPrimitive()
      .setAttribute("POSITION", positionAccessor)
      .setExtras({ sourceTriangleFlags: flags, sourceTriangleFlagCounts: flagCounts });
    const mesh = document.createMesh(`${this.variant}-tile-${this.tile}-part-${this.partIndex}`).addPrimitive(primitive);
    scene.addChild(document.createNode(mesh.getName()).setMesh(mesh));
    const filename = `${this.variant}-tile-${this.tile.replace(":", "_")}-part-${String(this.partIndex).padStart(3, "0")}.glb`;
    const file = path.join(this.outputDirectory, filename);
    await new NodeIO().write(file, document);
    const bytes = await readFile(file);
    this.files.push({
      file,
      sha256: createHash("sha256").update(bytes).digest("hex"),
      byteLength: bytes.byteLength,
      tile: this.tile,
      partIndex: this.partIndex,
      triangles: triangleCount,
      flagCounts,
    });
    this.partIndex += 1;
  }
}

class VariantTileCollection {
  constructor({ variant, outputDirectory, rootExtras }) {
    this.variant = variant;
    this.outputDirectory = outputDirectory;
    this.rootExtras = rootExtras;
    this.tiles = new Map();
  }

  async add(points, flag, tileSize) {
    const tile = triangleTileKey(points, tileSize);
    let writer = this.tiles.get(tile);
    if (!writer) {
      writer = new TilePartWriter({ variant: this.variant, tile, outputDirectory: this.outputDirectory, rootExtras: this.rootExtras });
      this.tiles.set(tile, writer);
    }
    await writer.add(points, flag);
  }

  async finish() {
    for (const [tile, writer] of [...this.tiles.entries()].sort(([a], [b]) => a.localeCompare(b, undefined, { numeric: true }))) {
      await writer.flush();
    }
    return [...this.tiles.values()].flatMap((writer) => writer.files);
  }
}

function appendMapCount(map, key, amount = 1) {
  map.set(key, (map.get(key) ?? 0) + amount);
}

async function assemble({
  recipe,
  recipeSha256,
  placementManifest,
  placementManifestSha256,
  sourceWdbSha256,
  inventory,
  outputRoot,
  tileSizeMeters,
  collisionMode,
}) {
  const fingerprint = createHash("sha256")
    .update(`${recipeSha256}\n${placementManifestSha256}\n${sourceWdbSha256}\n${inventory.manifestSha256}\n${TREKKER_WATER_FOLIAGE_EXCLUSION_MASK}\n${tileSizeMeters}\n${collisionMode}`)
    .digest("hex");
  const runRoot = path.join(outputRoot, "runs", fingerprint.slice(0, 24));
  const allDirectory = path.join(runRoot, "collision-all");
  const pathDirectory = path.join(runRoot, "collision-trekker-filtered");
  await mkdir(allDirectory, { recursive: true });
  await mkdir(pathDirectory, { recursive: true });
  const meters = Number(recipe.coordinateSystem.metersPerSourceUnit);
  const rootExtras = {
    sourceManifestSha256: placementManifestSha256,
    sourceWdbSha256,
    nativeCollisionInventorySha256: inventory.manifestSha256,
    nativeCollisionMode: collisionMode,
    sourceCoordinateTransform: `pThree=S*pRunewaker; S=scale(${meters},${meters},-${meters}), then exact WDB primaryLocalThreeMatrix`,
    collisionSource: "serialized native IRuCollisionObject / CRuCollisionStructure only; render-mesh fallback excluded",
    trekkerWaterFoliageExclusionMask: TREKKER_WATER_FOLIAGE_EXCLUSION_MASK,
    maxTrianglesPerGlb: MAX_TRIANGLES_PER_GLB,
  };
  const all = new VariantTileCollection({ variant: "all-serialized-native", outputDirectory: allDirectory, rootExtras });
  const pathEligible = new VariantTileCollection({ variant: "trekker-water-foliage-excluded", outputDirectory: pathDirectory, rootExtras });
  const resources = inventory.resources;
  const perResource = new Map();
  const perPlacement = [];
  const overallFlags = new Map();
  let allTriangles = 0;
  let completeNativeTriangles = 0;
  let collisionOptionOmittedTriangles = 0;
  let eligibleTriangles = 0;
  let excludedTriangles = 0;
  let fallbackTriangles = 0;

  for (let placementOrdinal = 0; placementOrdinal < placementManifest.staticPlacements.length; placementOrdinal += 1) {
    const placement = placementManifest.staticPlacements[placementOrdinal];
    const key = normalizedResourceKey(placement.resource);
    const native = resources.get(key);
    if (!native) throw new Error(`No hash-validated native collision inventory for ${placement.resource}.`);
    const report = native.report;
    const triangleCount = Number(report.nativeCollisionTriangleCount);
    const completeNativeCount = Number(report.completeNativeCollisionTriangleCount ?? triangleCount);
    const collisionOptionOmittedCount = Number(report.nativeTrianglesOmittedByCollisionOptions ?? Math.max(0, completeNativeCount - triangleCount));
    const fallbackCount = Number(report.renderMeshFallbackTriangleCount ?? 0);
    const flagBuffer = await readFile(native.flagsFile);
    const positions = await readObjTriangleSoup(native.objFile, triangleCount);
    validateNativeCollisionCounts({ triangleCount, flagBytes: flagBuffer.byteLength, positionVertexCount: positions.length / 3 });
    const matrix = placement.transform.primaryLocalThreeMatrix.map(Number);
    if (matrix.some((value) => !Number.isFinite(value))) throw new Error(`Non-finite matrix in placement ${placement.guid ?? placement.id}.`);
    let placementEligible = 0;
    let placementExcluded = 0;
    const placementFlags = new Map();
    for (let triangleIndex = 0; triangleIndex < triangleCount; triangleIndex += 1) {
      const flag = flagBuffer.readUInt32LE(triangleIndex * 4);
      appendMapCount(placementFlags, flag);
      appendMapCount(overallFlags, flag);
      const offset = triangleIndex * 9;
      const sourceTriangle = [
        positions.subarray(offset, offset + 3),
        positions.subarray(offset + 3, offset + 6),
        positions.subarray(offset + 6, offset + 9),
      ];
      const worldTriangle = transformNativeCollisionTriangle(sourceTriangle, matrix, meters);
      await all.add(worldTriangle, flag, tileSizeMeters);
      if (isTrekkerPathEligible(flag)) {
        await pathEligible.add(worldTriangle, flag, tileSizeMeters);
        placementEligible += 1;
      } else {
        placementExcluded += 1;
      }
    }
    allTriangles += triangleCount;
    completeNativeTriangles += completeNativeCount;
    collisionOptionOmittedTriangles += collisionOptionOmittedCount;
    eligibleTriangles += placementEligible;
    excludedTriangles += placementExcluded;
    fallbackTriangles += fallbackCount;
    let totals = perResource.get(key);
    if (!totals) {
      totals = {
        resource: placement.resource,
        placementCount: 0,
        nativeTriangles: 0,
        completeNativeTriangles: 0,
        collisionOptionOmittedTriangles: 0,
        disabledCollisionOptionEntityCount: Number(report.disabledCollisionOptionEntityCount ?? 0),
        entityNodesSkippedByCollisionOptionGates: Number(report.entityNodesSkippedByCollisionOptionGates ?? 0),
        trekkerFilteredTriangles: 0,
        engineVisualFallbackTriangles: 0,
        sourceReport: native.row.report,
      };
      perResource.set(key, totals);
    }
    totals.placementCount += 1;
    totals.nativeTriangles += triangleCount;
    totals.completeNativeTriangles += completeNativeCount;
    totals.collisionOptionOmittedTriangles += collisionOptionOmittedCount;
    totals.trekkerFilteredTriangles += placementEligible;
    totals.engineVisualFallbackTriangles += fallbackCount;
    perPlacement.push({
      ordinal: placementOrdinal,
      id: placement.id,
      guid: placement.guid,
      resource: placement.resource,
      sourceMatrix: "manifest.staticPlacements[].transform.primaryLocalThreeMatrix (column-major)",
      nativeSerializedTriangles: triangleCount,
      completeNativeSerializedTriangles: completeNativeCount,
      collisionOptionOmittedTriangles: collisionOptionOmittedCount,
      trekkerEligibleTriangles: placementEligible,
      maskExcludedTriangles: placementExcluded,
      engineVisualFallbackTriangles: fallbackCount,
      triangleFlagCounts: Object.fromEntries([...placementFlags.entries()].sort((a, b) => a[0] - b[0]).map(([flag, count]) => [String(flag), count])),
      renderableSubmeshesWithoutSerializedCollision: renderMeshOmissions(report),
    });
  }

  const allFiles = await all.finish();
  const eligibleFiles = await pathEligible.finish();
  const verifyFileCaps = (files, variant) => {
    for (const file of files) {
      if (file.triangles > MAX_TRIANGLES_PER_GLB) throw new Error(`${variant} output exceeds the ${MAX_TRIANGLES_PER_GLB}-triangle GLB limit.`);
    }
  };
  verifyFileCaps(allFiles, "All-source");
  verifyFileCaps(eligibleFiles, "Trekker-filtered");
  const sumFiles = (files) => files.reduce((sum, row) => sum + row.triangles, 0);
  if (sumFiles(allFiles) !== allTriangles || sumFiles(eligibleFiles) !== eligibleTriangles) {
    throw new Error("Written collision chunk triangle totals do not match source inventory assembly totals.");
  }
  const relativeFiles = (files) => files.map((row) => ({
    ...row,
    file: path.relative(projectRoot, row.file).split(path.sep).join("/"),
  }));
  const report = {
    schemaVersion: 1,
    purpose: "Repeatable static WDB source collision extraction and placement assembly; diagnostic assets only until reviewed and integrated.",
    source: {
      recipe: path.relative(projectRoot, path.resolve(projectRoot, recipe.file)).split(path.sep).join("/"),
      recipeSha256,
      placementManifest: placementManifest.file,
      placementManifestSha256,
      sourceWdb: recipe.source.wdb,
      sourceWdbSha256,
      nativeCollisionInventory: path.relative(projectRoot, inventory.manifestPath).split(path.sep).join("/"),
      nativeCollisionInventorySha256: inventory.manifestSha256,
      nativeExtractor: inventory.inventory.nativeExtractor ?? null,
      sourceRosHashPolicy: "Each source ROS SHA-256 is captured before and after native extraction and revalidated against the inventory when assembled.",
    },
    nativeExtractorPolicy: {
      query: collisionMode === "respect-options"
        ? "CRuEntity::QueryCollision with ignoreCollisionFlag=false; serialized collision traversal skips any node and subtree where ruENTITYOPTION_COLLISION is false"
        : "Complete serialized collision-option audit with ignoreCollisionFlag=true; disabled entities are included",
      collisionMode,
      renderMeshFallbackUsed: false,
      renderMeshFallbackTrianglesReportedButNotAssembled: fallbackTriangles,
      absentSerializedCollision: "reported and omitted; there is no visual-triangle fallback",
    },
    placement: {
      dungeonId: recipe.slug,
      uniqueResourceCount: inventory.resources.size,
      staticPlacementCount: placementManifest.staticPlacements.length,
      dynamicPlacementCountExcludedFromThisAssembly: placementManifest.dynamicPlacements?.length ?? 0,
      sourceBridge: `(x,y,z) -> (${meters}*x,${meters}*y,-${meters}*z), then primaryLocalThreeMatrix`,
      matrixStorage: "column-major affine matrix from exact WDB placement manifest",
      winding: "source-to-Three Z reflection reverses winding; swap vertices 1 and 2 exactly once after full point transform",
      metersPerSourceUnit: meters,
    },
    trekkerPathPolicy: {
      excludedFlagMask: TREKKER_WATER_FOLIAGE_EXCLUSION_MASK,
      excludedBits: { water: 0x00200000, foliage: 0x00800000 },
      sourceEvidence: "Rune Engine RuFusion_Trekker.cpp::IsPathClear and ::FindRestingHeight use m_exclusionMask=0x00A00000; RuWorld_Base.h defines WATER=0x00200000 and FOLIAGE=0x00800000.",
      flagSidecar: "Little-endian uint32 per serialized source triangle in the native query output order.",
    },
    limits: {
      maxTrianglesPerGlb: MAX_TRIANGLES_PER_GLB,
      spatialTileSizeMeters: tileSizeMeters,
      outputs: "Collision GLBs are non-indexed position-only triangle soups. Primitive extras preserve the exact source triangle flags in triangle order.",
      noFallback: "Resources/submeshes with no serialized collision are listed in per-placement omissions and omitted from output GLBs.",
    },
    totals: {
      nativeSerializedTriangles: allTriangles,
      completeNativeSerializedTriangles: completeNativeTriangles,
      collisionOptionOmittedTriangles,
      trekkerEligibleTriangles: eligibleTriangles,
      excludedByWaterFoliageMask: excludedTriangles,
      engineVisualFallbackTrianglesReported: fallbackTriangles,
      allSourceChunkCount: allFiles.length,
      trekkerFilteredChunkCount: eligibleFiles.length,
      sourceTriangleFlagCounts: Object.fromEntries([...overallFlags.entries()].sort((a, b) => a[0] - b[0]).map(([flag, count]) => [String(flag), count])),
    },
    collisionAssets: {
      allSerializedSource: relativeFiles(allFiles),
      trekkerFiltered: relativeFiles(eligibleFiles),
    },
    perResource: [...perResource.values()].sort((a, b) => a.resource.localeCompare(b.resource)),
    perPlacement,
  };
  const reportPath = path.join(runRoot, "native-collision-assembly-report.json");
  await writeFile(reportPath, `${JSON.stringify(report, null, 2)}\n`, "utf8");
  return { reportPath, report, runRoot };
}

async function main() {
  const options = parseArgs(process.argv.slice(2));
  if (options.help) {
    console.log(USAGE);
    return;
  }
  const recipeFile = resolveProjectPath(options.recipe);
  const recipe = await readJson(recipeFile);
  recipe.file = recipeFile;
  const placementManifestFile = resolveProjectPath(options["placement-manifest"]);
  const placementManifestBytes = await readFile(placementManifestFile);
  const placementManifest = JSON.parse(placementManifestBytes.toString("utf8"));
  placementManifest.file = path.relative(projectRoot, placementManifestFile).split(path.sep).join("/");
  const { resources } = validatePlacementInputs(recipe, placementManifest);
  const recipeSha256 = await sha256File(recipeFile);
  const placementManifestSha256 = createHash("sha256").update(placementManifestBytes).digest("hex");
  const sourceRoot = options["source-root"]
    ? resolveProjectPath(options["source-root"])
    : sourceRootFor(recipe);
  const resourceRoot = path.resolve(sourceRoot, recipe.source.resourceRoot);
  const sourceWdbFile = path.resolve(sourceRoot, recipe.source.wdb);
  const sourceWdbSha256 = await sha256File(sourceWdbFile);
  const outputRoot = resolveWorkspaceOutput(options["output-root"]);
  const tileSizeMeters = Number(options["tile-size-meters"] ?? DEFAULT_TILE_SIZE_METERS);
  if (!Number.isFinite(tileSizeMeters) || tileSizeMeters <= 0) throw new Error("--tile-size-meters must be a finite positive number.");
  const extractor = options.extractor
    ? resolveProjectPath(options.extractor)
    : path.join(path.dirname(fileURLToPath(import.meta.url)), "native", "bin", "native-collision-audit.exe");
  const extractorSource = path.join(path.dirname(fileURLToPath(import.meta.url)), "native", "native-collision-audit.cpp");
  if (!await import("node:fs/promises").then(({ access }) => access(extractor).then(() => true).catch(() => false))) {
    throw new Error(`Native collision extractor not found at ${extractor}; build it with scripts/runewaker-pipeline/build-native-collision-audit.ps1 or pass --extractor.`);
  }
  const extractorPath = path.relative(projectRoot, extractor).split(path.sep).join("/");
  const extractorSourcePath = path.relative(projectRoot, extractorSource).split(path.sep).join("/");
  const nativeExtractor = {
    executable: path.isAbsolute(extractorPath) || extractorPath.startsWith("..") ? extractor : extractorPath,
    executableSha256: await sha256File(extractor),
    source: extractorSourcePath,
    sourceSha256: await sha256File(extractorSource),
    collisionMode: options["collision-mode"],
  };

  let inventoryRoot;
  let inventory;
  if (options["inventory-root"]) {
    inventoryRoot = resolveProjectPath(options["inventory-root"]);
  } else {
    // Immutable inventory roots keep separate source revisions from overwriting one another.
    const currentSourceHashes = [];
    for (const row of [...resources].sort((a, b) => normalizedResourceKey(a.resource).localeCompare(normalizedResourceKey(b.resource)))) {
      currentSourceHashes.push(`${normalizedResourceKey(row.resource)}:${await sha256File(nativeResourceFile(resourceRoot, row.resource))}`);
    }
    const inventoryKey = createHash("sha256")
      .update(`${placementManifestSha256}\n${sourceWdbSha256}\n${currentSourceHashes.join("\n")}\n${nativeExtractor.executableSha256}\n${nativeExtractor.sourceSha256}\n${options["collision-mode"]}`)
      .digest("hex").slice(0, 24);
    inventoryRoot = path.join(outputRoot, "inventories", inventoryKey);
    await mkdir(path.dirname(inventoryRoot), { recursive: true });
    const existing = await readdir(inventoryRoot).catch(() => []);
    if (existing.includes("native-collision-inventory.json")) {
      inventory = await readAndValidateNativeCollisionInventory({
        inventoryRoot,
        placementManifestSha256,
        sourceWdbSha256,
        collisionMode: options["collision-mode"],
        nativeExtractor,
        expectedResources: resources.map((row) => row.resource),
        sourceResourceRoot: resourceRoot,
      });
      console.log(`reusing SHA-validated collision inventory: ${inventoryRoot}`);
    }
  }

  if (!inventory) {
    if (options["inventory-root"]) {
      inventory = await readAndValidateNativeCollisionInventory({
        inventoryRoot,
        placementManifestSha256,
        sourceWdbSha256,
        collisionMode: options["collision-mode"],
        nativeExtractor,
        expectedResources: resources.map((row) => row.resource),
        sourceResourceRoot: resourceRoot,
      });
    } else {
      await mkdir(inventoryRoot, { recursive: true });
      const existing = await readdir(inventoryRoot);
      if (existing.length > 0) throw new Error(`Inventory root is non-empty but has no valid manifest: ${inventoryRoot}`);
      await extractInventory({
        inventoryRoot, extractor, nativeExtractor, collisionMode: options["collision-mode"],
        resourceRoot, expectedResources: resources, placementManifestSha256, sourceWdbSha256,
      });
      inventory = await readAndValidateNativeCollisionInventory({
        inventoryRoot,
        placementManifestSha256,
        sourceWdbSha256,
        collisionMode: options["collision-mode"],
        nativeExtractor,
        expectedResources: resources.map((row) => row.resource),
        sourceResourceRoot: resourceRoot,
      });
    }
  }

  const result = await assemble({
    recipe, recipeSha256, placementManifest, placementManifestSha256, sourceWdbSha256,
    inventory, outputRoot, tileSizeMeters, collisionMode: options["collision-mode"],
  });
  if (options["report-output"]) {
    const reportOutput = resolveWorkspaceOutput(options["report-output"]);
    await mkdir(path.dirname(reportOutput), { recursive: true });
    await writeFile(reportOutput, `${JSON.stringify(result.report, null, 2)}\n`, "utf8");
  }
  console.log(JSON.stringify({
    report: path.relative(projectRoot, result.reportPath).split(path.sep).join("/"),
    inventory: path.relative(projectRoot, inventory.manifestPath).split(path.sep).join("/"),
    nativeResources: inventory.resources.size,
    staticPlacements: placementManifest.staticPlacements.length,
    collisionMode: options["collision-mode"],
    nativeTriangles: result.report.totals.nativeSerializedTriangles,
    completeNativeTriangles: result.report.totals.completeNativeSerializedTriangles,
    disabledSubtreeNativeTriangles: result.report.totals.collisionOptionOmittedTriangles,
    trekkerEligibleTriangles: result.report.totals.trekkerEligibleTriangles,
    waterFoliageExcludedTriangles: result.report.totals.excludedByWaterFoliageMask,
    chunkCounts: {
      all: result.report.totals.allSourceChunkCount,
      trekkerFiltered: result.report.totals.trekkerFilteredChunkCount,
      maximumTrianglesPerChunk: MAX_TRIANGLES_PER_GLB,
    },
    runRoot: path.relative(projectRoot, result.runRoot).split(path.sep).join("/"),
  }, null, 2));
}

main().catch((error) => {
  console.error(error.stack ?? error.message);
  process.exitCode = 1;
});