import mysql from 'mysql2/promise';
import dotenv from 'dotenv';

dotenv.config();

const dbConfig = {
  host: process.env.DB_HOST || 'mysql.theaken.com',
  port: parseInt(process.env.DB_PORT) || 33306,
  user: process.env.DB_USER || 'A102',
  password: process.env.DB_PASSWORD || 'Bb123456',
  database: process.env.DB_NAME || 'db_A102'
};

async function testConnection() {
  let connection;

  try {
    console.log('\n╔═══════════════════════════════════════╗');
    console.log('║  Database Connection Test            ║');
    console.log('╚═══════════════════════════════════════╝\n');

    console.log('📡 Attempting to connect to database...');
    console.log(`   Host: ${dbConfig.host}`);
    console.log(`   Port: ${dbConfig.port}`);
    console.log(`   Database: ${dbConfig.database}`);
    console.log(`   User: ${dbConfig.user}\n`);

    connection = await mysql.createConnection(dbConfig);

    console.log('✅ Connection successful!\n');

    // 測試基本查詢
    console.log('🔍 Testing basic queries...\n');

    // 1. 檢查資料庫版本
    const [versionResult] = await connection.execute('SELECT VERSION() as version');
    console.log(`   MySQL Version: ${versionResult[0].version}`);

    // 2. 列出所有資料表
    const [tables] = await connection.execute('SHOW TABLES');
    console.log(`   Tables found: ${tables.length}`);

    if (tables.length > 0) {
      console.log('\n📊 Available tables:');
      tables.forEach((table, index) => {
        const tableName = Object.values(table)[0];
        console.log(`   ${index + 1}. ${tableName}`);
      });

      // 3. 檢查每個資料表的記錄數
      console.log('\n📈 Table statistics:');
      for (const table of tables) {
        const tableName = Object.values(table)[0];
        const [countResult] = await connection.execute(`SELECT COUNT(*) as count FROM \`${tableName}\``);
        console.log(`   ${tableName}: ${countResult[0].count} rows`);
      }
    } else {
      console.log('\n⚠️  No tables found. Run "npm run db:init" to initialize the database.');
    }

    console.log('\n✅ All tests passed!\n');

  } catch (error) {
    console.error('\n❌ Connection failed!');
    console.error(`   Error: ${error.message}`);
    if (error.code) {
      console.error(`   Error Code: ${error.code}`);
    }
    if (error.errno) {
      console.error(`   Error Number: ${error.errno}`);
    }

    console.log('\n💡 Troubleshooting tips:');
    console.log('   1. Check if MySQL server is running');
    console.log('   2. Verify host and port in .env file');
    console.log('   3. Confirm database credentials');
    console.log('   4. Check firewall settings');
    console.log('   5. Ensure database exists\n');

    process.exit(1);
  } finally {
    if (connection) {
      await connection.end();
      console.log('🔌 Connection closed\n');
    }
  }
}

testConnection();