#!/usr/bin/env node
/**
 * 构建前清理 .next/standalone、.next/static、.next/cache
 * - 避免 Next.js build 时 EBUSY（目录被占用）
 * - 避免混入 next dev 的 Turbopack 产物，导致打包后加载 chunk 500 / Failed to load chunk
 * 若曾运行 pnpm start，请先 Ctrl+C 停掉再 build
 */

const fs = require('fs');
const path = require('path');

const rootDir = path.join(__dirname, '..');
const nextDir = path.join(rootDir, '.next');
const dirsToClean = [
  path.join(nextDir, 'standalone'),
  path.join(nextDir, 'static'),
  path.join(nextDir, 'cache'),
];

const RETRIES = 5;
const DELAY_MS = 2000;

function sleep(ms) {
  return new Promise((r) => setTimeout(r, ms));
}

function removeDir(dirPath) {
  if (!fs.existsSync(dirPath)) return true;
  try {
    fs.rmSync(dirPath, { recursive: true, force: true, maxRetries: 3 });
    return true;
  } catch (e) {
    throw e;
  }
}

async function main() {
  for (const dirPath of dirsToClean) {
    if (!fs.existsSync(dirPath)) continue;
    for (let attempt = 1; attempt <= RETRIES; attempt++) {
      try {
        removeDir(dirPath);
        const name = path.relative(nextDir, dirPath) || dirPath;
        console.log('[clean-standalone] 已删除 .next/' + name);
        break;
      } catch (e) {
        if (e.code === 'EBUSY' || e.code === 'EPERM' || e.code === 'ENOTEMPTY') {
          if (attempt < RETRIES) {
            console.warn('[clean-standalone] 目录被占用，%ds 后重试 (%d/%d)...', DELAY_MS / 1000, attempt, RETRIES);
            await sleep(DELAY_MS);
          } else {
            console.error('[clean-standalone] 无法删除:', dirPath);
            console.error('  请先关闭：pnpm start / next dev、或占用该目录的其它程序');
            console.error('  然后重新执行：pnpm build');
            process.exit(1);
          }
        } else {
          throw e;
        }
      }
    }
  }
}

main().catch((e) => {
  console.error(e);
  process.exit(1);
});