/**
 * pdf.js 解码 JBIG2 / JPEG2000 扫描页时会在 worker 里按 wasmUrl 取 wasm 运行时，
 * 这个目录不由打包器管理，所以每次 dev/build 前把 node_modules 里的文件同步到 public。
 */
import {
  copyFileSync,
  existsSync,
  mkdirSync,
  readdirSync,
  readFileSync,
} from "node:fs";
import { dirname, join, resolve } from "node:path";
import { fileURLToPath } from "node:url";

const frontend = resolve(dirname(fileURLToPath(import.meta.url)), "..");
const from = join(frontend, "node_modules/pdfjs-dist/wasm");
const to = join(frontend, "public/pdfjs-wasm");

mkdirSync(to, { recursive: true });
const files = readdirSync(from).filter((name) => !name.startsWith("LICENSE"));
let copied = 0;
for (const name of files) {
  const source = join(from, name);
  const dest = join(to, name);
  // 内容没变就不重写：dev server 在跑时改 public 里的同名文件会触发整页刷新并弹覆盖层
  if (existsSync(dest) && readFileSync(dest).equals(readFileSync(source))) continue;
  copyFileSync(source, dest);
  copied += 1;
}
console.log(
  copied
    ? `[pdfjs-wasm] 已同步 ${copied}/${files.length} 个文件 -> public/pdfjs-wasm`
    : "[pdfjs-wasm] public/pdfjs-wasm 已是最新",
);