import fs from "node:fs";
import path from "node:path";
import crypto from "node:crypto";
import { fileURLToPath } from "node:url";

const hash = (bytes) => crypto.createHash("sha256").update(bytes).digest("hex");

export function syncWebEngineRuntime(root) {
  const build = path.join(root, "build_web_blender6/bin");
  const wasm = fs.readFileSync(path.join(build, "web_engine.wasm"));
  const loader = fs.readFileSync(path.join(build, "web_engine.js"));
  if (!WebAssembly.validate(wasm) || !loader.length) throw new Error("compiled WebEngine artifacts are invalid");
  const manifestPath = path.join(root, "web/app/public/wasm-module-manifest.json");
  const original = fs.readFileSync(manifestPath, "utf8");
  const manifest = JSON.parse(original);
  const artifactHashes = { "web_engine.wasm": hash(wasm), "web_engine.js": hash(loader) };
  let bindings = 0;
  for (const module of manifest.modules ?? []) {
    for (const resource of Object.values(module.resources ?? {})) {
      for (const [name, digest] of Object.entries(artifactHashes)) {
        if (resource.url === `/vendor/blender/${name}`) {
          resource.sha256 = digest;
          bindings += 1;
        }
      }
    }
  }
  if (!bindings) throw new Error("runtime manifest has no compiled WebEngine binding");
  const changed = [];
  const write = (destination, data) => {
    if (fs.existsSync(destination) && fs.readFileSync(destination).equals(Buffer.from(data))) return;
    fs.mkdirSync(path.dirname(destination), { recursive: true });
    const temporary = `${destination}.tmp-${process.pid}`;
    fs.writeFileSync(temporary, data);
    fs.renameSync(temporary, destination);
    changed.push(path.relative(root, destination));
  };
  for (const directory of ["web/app/src/vendor/blender", "web/app/public/vendor/blender"]) {
    write(path.join(root, directory, "web_engine.js"), loader);
    write(path.join(root, directory, "web_engine.wasm"), wasm);
  }
  write(manifestPath, `${JSON.stringify(manifest, null, 2)}\n`);
  return { operation: "sync_compiled_runtime", status: "PASS", changed, bindings, artifactHashes };
}

if (process.argv[1] && path.resolve(process.argv[1]) === fileURLToPath(import.meta.url)) {
  console.log(JSON.stringify(syncWebEngineRuntime(path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../.."))));
}