#!/usr/bin/env node

import { readFileSync, writeFileSync, existsSync, copyFileSync } from 'fs';
import { fileURLToPath } from 'url';
import { dirname, join } from 'path';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

const TOKEN_PATH = join(__dirname, '../../../secrets/gmail/tokens.json');
const BACKUP_PATH = join(__dirname, '../../../secrets/gmail/tokens.json.backup');

async function migrateTokens() {
  console.log('\n🔄 Gmail Token Migration\n');

  if (!existsSync(TOKEN_PATH)) {
    console.log('❌ No token.json file found. Nothing to migrate.');
    console.log('   Run: npm run setup -- --account <account-id>');
    return;
  }

  // Read current token
  const content = readFileSync(TOKEN_PATH, 'utf8');
  const data = JSON.parse(content);

  // Check if already in new format
  if (data.accounts && data.defaultAccount) {
    console.log('✅ Token file is already in multi-account format.');
    console.log(`   Default account: ${data.defaultAccount}`);
    console.log(`   Accounts: ${Object.keys(data.accounts).join(', ')}`);
    return;
  }

  // Backup old token
  console.log('📦 Creating backup: token.json.backup');
  copyFileSync(TOKEN_PATH, BACKUP_PATH);

  // Migrate to new format
  const migratedConfig = {
    defaultAccount: 'default',
    accounts: {
      default: {
        ...data,
        email: data.email || 'unknown@gmail.com'
      }
    }
  };

  // Save migrated config
  writeFileSync(TOKEN_PATH, JSON.stringify(migratedConfig, null, 2), { mode: 0o600 });

  console.log('✅ Migration complete!');
  console.log(`   Default account: ${migratedConfig.defaultAccount}`);
  console.log('   Your existing authentication is preserved.\n');
  console.log('💡 Next steps:');
  console.log('   - Add second account: npm run setup -- --account work');
  console.log('   - List accounts: node scripts/manage-accounts.js --list');
  console.log('   - Set default: node scripts/manage-accounts.js --set-default <account-id>\n');
}

migrateTokens().catch(error => {
  console.error('❌ Migration failed:', error.message);
  process.exit(1);
});