import { spawn } from 'child_process';

export function triggerBackup(): void {
  runBackup().catch((e) => console.error('[backup] Fehler:', e));
}

async function runBackup(): Promise<void> {
  const sshUrl = process.env.BACKUP_SSH_URL;
  if (!sshUrl) return;

  const match = sshUrl.match(/^([^:]+):(.+)$/);
  if (!match) {
    console.error('[backup] BACKUP_SSH_URL muss das Format user@host:/pfad haben');
    return;
  }
  const [, sshHost, remotePath] = match;
  const rawKeyPath = process.env.BACKUP_SSH_KEY_PATH || '';
  const keyPath = rawKeyPath.startsWith('~')
    ? rawKeyPath.replace('~', process.env.HOME || '/root')
    : rawKeyPath;

  const ts = new Date().toISOString().replace('T', '_').replace(/:/g, '-').slice(0, 19);
  const filename = `sternwarte_${ts}.sql.gz`;

  const dbHost = process.env.DB_HOST || 'db';
  const dbPort = process.env.DB_PORT || '3306';
  const dbUser = process.env.DB_USER || '';
  const dbPass = process.env.DB_PASS || '';
  const dbName = process.env.DB_NAME || 'sternwarte';

  const sshOpts = [
    ...(keyPath ? ['-i', keyPath] : []),
    '-o', 'StrictHostKeyChecking=no',
    '-o', 'BatchMode=yes',
  ];

  const dumpBin = process.env.BACKUP_DUMP_CMD || 'mariadb-dump';

  await new Promise<void>((resolve, reject) => {
    const dump = spawn(dumpBin, [
      `-h${dbHost}`, `-P${dbPort}`, `-u${dbUser}`,
      '--skip-ssl',
      `--ignore-table=${dbName}.beos`,
      dbName,
    ], { env: { ...process.env, MYSQL_PWD: dbPass } });
    const gzip = spawn('gzip');
    const ssh = spawn('ssh', [...sshOpts, sshHost, `cat > ${remotePath}/${filename}`]);

    dump.stdout.pipe(gzip.stdin);
    gzip.stdout.pipe(ssh.stdin);

    let dumpErr = '';
    let sshErr = '';
    dump.stderr.on('data', (d: Buffer) => { dumpErr += d.toString(); });
    ssh.stderr.on('data', (d: Buffer) => { sshErr += d.toString(); });

    dump.on('error', reject);
    gzip.on('error', reject);
    ssh.on('error', reject);

    dump.on('close', (code) => { if (code !== 0) gzip.stdin.end(); });
    gzip.on('close', () => ssh.stdin.end());

    ssh.on('close', (code) => {
      if (code === 0) {
        resolve();
      } else {
        reject(new Error(`ssh exit ${code}${sshErr ? ': ' + sshErr.trim() : ''}${dumpErr ? ' | dump: ' + dumpErr.trim() : ''}`));
      }
    });
  });

  // Backups älter als 30 Tage löschen
  await new Promise<void>((resolve) => {
    const ssh = spawn('ssh', [
      ...sshOpts, sshHost,
      `find ${remotePath} -name 'sternwarte_*.sql.gz' -mtime +30 -delete`,
    ]);
    ssh.on('error', (e) => { console.error('[backup] Cleanup spawn-Fehler:', e.message); resolve(); });
    ssh.on('close', (code) => {
      if (code !== 0) console.error('[backup] Cleanup fehlgeschlagen (exit ' + code + ')');
      resolve();
    });
  });

  console.log(`[backup] ${filename} → ${sshHost}:${remotePath}`);
}