// 发布：构建 → 对比线上差异 → 上传 → 备份线上目录 → 切换 → 线上验证
//   node scripts/deploy.mjs            正式发布
//   node scripts/deploy.mjs --dry-run  只构建并列出差异，不改服务器
import fs from 'node:fs';
import os from 'node:os';
import path from 'node:path';
import crypto from 'node:crypto';
import { spawnSync } from 'node:child_process';
import { fileURLToPath } from 'node:url';
import { build } from './build.mjs';

const ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
const DIST = path.join(ROOT, 'dist');
const dryRun = process.argv.includes('--dry-run');

function run(cmd, args, opts = {}) {
  const r = spawnSync(cmd, args, { encoding: 'utf8', maxBuffer: 64 << 20, ...opts });
  if (r.status !== 0) {
    throw new Error(`${cmd} ${args.slice(0, 2).join(' ')} 失败（退出码 ${r.status}）\n${r.stderr || ''}`);
  }
  return r.stdout;
}
const ssh = (host, script) => run('ssh', ['-o', 'BatchMode=yes', host, 'bash -s'], { input: `set -euo pipefail\n${script}` });

const sha256 = (file) => crypto.createHash('sha256').update(fs.readFileSync(file)).digest('hex');

function walk(dir) {
  return fs.readdirSync(dir, { withFileTypes: true }).flatMap((e) => {
    const p = path.join(dir, e.name);
    return e.isDirectory() ? walk(p) : [p];
  });
}

// 北京时间时间戳，用作备份目录名
function stamp() {
  const d = new Date(Date.now() + 8 * 3600e3).toISOString();
  return d.slice(0, 19).replace(/[-:]/g, '').replace('T', '-');
}

async function main() {
  const { cfg, apkFile, apkBytes, vars } = build();
  const { host, siteDir, publicUrl, keepBackups } = cfg.deploy;
  const live = `${siteDir}/public/app`;
  const deployDir = `${siteDir}/.deploy`; // 在 public/ 之外，不会被公网访问
  const ts = stamp();
  console.log(`构建完成：v${cfg.version}（${cfg.channel}） · ${apkFile} · ${vars.apkSize}`);

  // ---- 对比线上（APK 单独比较，download/ 里的其他旧包不参与） ----
  const local = new Map(
    walk(DIST)
      .filter((f) => !f.startsWith(path.join(DIST, 'download') + path.sep))
      .map((f) => [path.relative(DIST, f), sha256(f)]),
  );
  const remoteOut = ssh(host, `
    cd ${live}
    find . -type f ! -path './download/*' -exec sha256sum {} + | sed 's|  \\./|  |'
    echo "__APK__ $(sha256sum download/${apkFile} 2>/dev/null | cut -d' ' -f1)"
  `);
  const remote = new Map();
  let remoteApkSha = '';
  for (const line of remoteOut.trim().split('\n')) {
    if (line.startsWith('__APK__')) remoteApkSha = line.slice(8).trim();
    else if (line) {
      const [sum, file] = line.split(/\s{2}/);
      remote.set(file, sum);
    }
  }
  const added = [...local.keys()].filter((f) => !remote.has(f));
  const changed = [...local.keys()].filter((f) => remote.has(f) && remote.get(f) !== local.get(f));
  const removed = [...remote.keys()].filter((f) => !local.has(f));
  const localApkSha = sha256(path.join(DIST, 'download', apkFile));
  const uploadApk = remoteApkSha !== localApkSha;

  console.log('\n与线上的差异：');
  for (const f of added) console.log(`  + ${f}`);
  for (const f of changed) console.log(`  ~ ${f}`);
  for (const f of removed) console.log(`  - ${f}`);
  console.log(`  APK ${apkFile}：${uploadApk ? (remoteApkSha ? '线上不同，需上传' : '线上没有，需上传') : '线上已是同一文件，跳过上传'}`);
  if (!added.length && !changed.length && !removed.length && !uploadApk) {
    console.log('\n线上已经是最新，无需发布。');
    return;
  }
  if (dryRun) {
    console.log('\n--dry-run：未改动服务器。');
    return;
  }

  // ---- 上传 ----
  const tgz = path.join(os.tmpdir(), `douba-app-${ts}.tgz`);
  run('tar', ['czf', tgz, '-C', DIST, '--exclude=./download', '.']);
  const remoteTgz = `/tmp/douba-app-${ts}.tgz`;
  const remoteApk = `/tmp/douba-app-${ts}.apk`;
  console.log('\n上传站点文件…');
  run('scp', ['-q', '-o', 'BatchMode=yes', tgz, `${host}:${remoteTgz}`]);
  fs.rmSync(tgz);
  if (uploadApk) {
    console.log(`上传 ${apkFile}（${vars.apkSize}，需要一会儿）…`);
    run('scp', ['-q', '-o', 'BatchMode=yes', path.join(DIST, 'download', apkFile), `${host}:${remoteApk}`], { stdio: ['ignore', 'inherit', 'pipe'] });
  }

  // ---- 服务器端：组装新目录 → 备份旧目录 → 切换 ----
  // 新目录与线上同在一个分区，两次 mv 都是瞬间完成的重命名
  console.log('切换线上目录…');
  ssh(host, `
    stage=${deployDir}/stage-${ts}
    mkdir -p "$stage/download" ${deployDir}/backups
    tar xzf ${remoteTgz} -C "$stage"
    # 保留线上已有的 APK（硬链接，不占额外空间），旧版下载链接不会失效
    for f in ${live}/download/*.apk; do [ -e "$f" ] && ln "$f" "$stage/download/"; done
    ${uploadApk ? `mv -f ${remoteApk} "$stage/download/${apkFile}"` : ':'}
    [ "$(sha256sum "$stage/download/${apkFile}" | cut -d' ' -f1)" = "${localApkSha}" ] || { echo "APK 校验失败" >&2; exit 1; }
    chown -R root:root "$stage"
    find "$stage" -type d -exec chmod 755 {} +
    find "$stage" -type f -exec chmod 644 {} +
    mv ${live} ${deployDir}/backups/app-${ts}
    mv "$stage" ${live}
    rm -f ${remoteTgz}
    ls -1d ${deployDir}/backups/app-* | sort -r | tail -n +${keepBackups + 1} | xargs -r rm -rf
  `);

  // ---- 线上验证 ----
  console.log('验证线上…');
  const page = run('curl', ['-fsS', '-H', 'Cache-Control: no-cache', publicUrl]);
  if (!page.includes(`"softwareVersion": "${cfg.version}"`)) throw new Error(`${publicUrl} 返回的页面不是 v${cfg.version}`);
  const head = run('curl', ['-fsSI', `${publicUrl}/download/${apkFile}`]);
  const len = Number((/content-length:\s*(\d+)/i.exec(head) || [])[1]);
  if (len !== apkBytes) throw new Error(`APK 下载地址返回的大小 ${len} 与本地 ${apkBytes} 不一致`);

  console.log(`\n发布成功：${publicUrl}  （v${cfg.version}，备份 ${deployDir}/backups/app-${ts}）`);
  console.log('如需回滚：npm run rollback');
}

main().catch((e) => {
  console.error(`\n发布失败：${e.message}`);
  process.exit(1);
});