import 'dotenv/config';
import { closeSync, existsSync, mkdirSync, openSync } from 'fs';
import { dirname, resolve } from 'path';
import { spawnSync } from 'child_process';
import Database from 'better-sqlite3';

const dbType = process.env.DB_TYPE || 'sqlite';
const dbPath = process.env.DATABASE_URL || './data/spanglish.db';
const BACKUP_DIR = resolve(process.cwd(), 'data', 'backups');

function parseArgs(): { output?: string } {
  const args = process.argv.slice(2);
  const result: { output?: string } = {};
  for (let i = 0; i < args.length; i++) {
    if (args[i] === '-o' || args[i] === '--output') {
      result.output = args[i + 1];
      i++;
    }
  }
  return result;
}

function getTimestamp(): string {
  const now = new Date();
  const y = now.getFullYear();
  const m = String(now.getMonth() + 1).padStart(2, '0');
  const d = String(now.getDate()).padStart(2, '0');
  const h = String(now.getHours()).padStart(2, '0');
  const min = String(now.getMinutes()).padStart(2, '0');
  const s = String(now.getSeconds()).padStart(2, '0');
  return `${y}-${m}-${d}-${h}${min}${s}`;
}

function exportSqlite(outputPath: string): void {
  const db = new Database(resolve(process.cwd(), dbPath), { readonly: true });
  try {
    db.backup(outputPath);
    console.log(`Exported to ${outputPath}`);
  } finally {
    db.close();
  }
}

function exportPostgres(outputPath: string): void {
  const connString = process.env.DATABASE_URL || 'postgresql://localhost:5432/spanglish';
  const outFd = openSync(outputPath, 'w');
  try {
    const result = spawnSync(
      'pg_dump',
      ['--clean', '--if-exists', connString],
      {
        stdio: ['ignore', outFd, 'pipe'],
        encoding: 'utf-8',
      }
    );

    if (result.error) {
      console.error('pg_dump failed. Ensure pg_dump is installed and in PATH.');
      console.error(result.error.message);
      process.exit(1);
    }

    if (result.status !== 0) {
      console.error('pg_dump failed:', result.stderr);
      process.exit(1);
    }

    console.log(`Exported to ${outputPath}`);
  } finally {
    closeSync(outFd);
  }
}

async function main() {
  const { output } = parseArgs();
  const ext = dbType === 'postgres' ? '.sql' : '.db';
  const defaultName = `spanglish-${getTimestamp()}${ext}`;

  const outputPath = output
    ? resolve(process.cwd(), output)
    : resolve(BACKUP_DIR, defaultName);

  const dir = dirname(outputPath);
  if (!existsSync(dir)) {
    mkdirSync(dir, { recursive: true });
  }

  console.log(`Database type: ${dbType}`);
  if (dbType === 'sqlite') {
    exportSqlite(outputPath);
  } else {
    exportPostgres(outputPath);
  }
  process.exit(0);
}

main().catch((err) => {
  console.error('Export failed:', err);
  process.exit(1);
});