#!/usr/bin/env node
/**
 * 构建前清理 .next/standalone，避免 Next.js build 时 EBUSY（目录被占用）
 * 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 standaloneDir = path.join(rootDir, '.next', 'standalone');

const RETRIES = 5;
const DELAY_MS = 2000;

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

async function main() {
  if (!fs.existsSync(standaloneDir)) {
    return;
  }

  for (let attempt = 1; attempt <= RETRIES; attempt++) {
    try {
      fs.rmSync(standaloneDir, { recursive: true, force: true, maxRetries: 3 });
      console.log('[clean-standalone] 已删除 .next/standalone');
      return;
    } 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 .next/standalone：目录被占用');
          console.error('  请先关闭：pnpm start、或占用该目录的其它程序（如资源管理器、杀毒）');
          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);
});