#!/usr/bin/env node
import { access, copyFile, mkdir, readFile, readdir, stat, writeFile } from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";

const projectRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..");
const shippingRoot = path.join(projectRoot, "public", "assets", "game", "dungeons");
const sharedRoot = path.join(projectRoot, "public", "assets", "game", "creatures", "shared");
const registryFile = path.join(projectRoot, "src", "game", "generated", "fivePlayerDungeonImports.json");

const exists = async (file) => access(file).then(() => true, () => false);
const readJson = async (file) => JSON.parse(await readFile(file, "utf8"));
const writeJson = (file, value) => writeFile(file, `${JSON.stringify(value, null, 2)}\n`);

const records = [];
for (const entry of await readdir(shippingRoot, { withFileTypes: true })) {
  if (!entry.isDirectory()) continue;
  const manifestFile = path.join(shippingRoot, entry.name, "dungeon-pack.json");
  if (!await exists(manifestFile)) continue;
  records.push({ manifestFile, manifest: await readJson(manifestFile) });
}

const referencesByChecksum = new Map();
for (const { manifest } of records) {
  for (const model of Object.values(manifest.creatureModels ?? {})) {
    if (!model.checksum || !model.url) continue;
    const references = referencesByChecksum.get(model.checksum) ?? [];
    references.push(model);
    referencesByChecksum.set(model.checksum, references);
  }
}

await mkdir(sharedRoot, { recursive: true });
let duplicateGroups = 0;
let relinkedModels = 0;
let createdSharedFiles = 0;

for (const [checksum, references] of referencesByChecksum) {
  const urls = [...new Set(references.map((model) => model.url))];
  if (urls.length <= 1) continue;
  const sharedUrl = `/assets/game/creatures/shared/${checksum}.glb`;
  const sharedFile = path.join(projectRoot, "public", sharedUrl.replace(/^\/+/, ""));
  const preferredUrl = urls.find((url) => url === sharedUrl) ?? urls[0];
  const sourceFile = path.join(projectRoot, "public", preferredUrl.replace(/^\/+/, ""));
  if (!await exists(sourceFile)) throw new Error(`Missing shared-creature source: ${preferredUrl}`);
  const sourceDetails = await stat(sourceFile);
  const expectedSize = Number(references[0].size ?? references[0].byteLength);
  if (Number.isFinite(expectedSize) && sourceDetails.size !== expectedSize) {
    throw new Error(`Size mismatch for shared-creature source: ${preferredUrl}`);
  }
  if (!await exists(sharedFile)) {
    await copyFile(sourceFile, sharedFile);
    createdSharedFiles += 1;
  }
  for (const model of references) {
    model.url = sharedUrl;
    relinkedModels += 1;
  }
  duplicateGroups += 1;
}

for (const { manifestFile, manifest } of records) await writeJson(manifestFile, manifest);
const imports = records.map(({ manifest }) => manifest).sort((left, right) => (
  left.slug.localeCompare(right.slug)
));
await writeJson(registryFile, {
  schemaVersion: 1,
  generatedAt: "deterministic",
  imports,
});

console.log(JSON.stringify({
  status: "green",
  duplicateGroups,
  relinkedModels,
  createdSharedFiles,
  sharedRoot: path.relative(projectRoot, sharedRoot).replaceAll("\\", "/"),
}, null, 2));