// =====================================================
// 終極連線清理腳本
// =====================================================

const mysql = require('mysql2/promise');

async function ultimateKill() {
  console.log('💀 執行終極連線清理腳本...');
  
  let connection = null;
  
  try {
    // 建立連線
    connection = await mysql.createConnection({
      host: process.env.DB_HOST || '122.100.99.161',
      port: parseInt(process.env.DB_PORT || '43306'),
      user: process.env.DB_USER || 'A999',
      password: process.env.DB_PASSWORD || '1023',
      database: process.env.DB_NAME || 'db_AI_Platform',
      charset: 'utf8mb4',
      timezone: '+08:00',
    });

    console.log('✅ 已連接到資料庫');

    // 獲取所有連線
    const [connections] = await connection.execute(`
      SELECT ID, USER, HOST, DB, COMMAND, TIME, STATE, INFO
      FROM information_schema.PROCESSLIST 
      WHERE USER = ?
      ORDER BY TIME DESC
    `, [process.env.DB_USER || 'A999']);

    console.log(`🔍 找到 ${connections.length} 個連線需要清理`);

    // 顯示連線詳情
    connections.forEach((conn, index) => {
      console.log(`${index + 1}. ID: ${conn.ID}, 用戶: ${conn.USER}, 時間: ${conn.TIME}s, 狀態: ${conn.STATE}`);
    });

    // 殺死所有連線（除了當前連線）
    let killedCount = 0;
    for (const conn of connections) {
      if (conn.ID !== connection.threadId) {
        try {
          await connection.execute(`KILL ${conn.ID}`);
          console.log(`💀 已殺死連線 ${conn.ID}`);
          killedCount++;
        } catch (error) {
          console.log(`⚠️ 無法殺死連線 ${conn.ID}: ${error.message}`);
        }
      }
    }

    console.log(`✅ 已殺死 ${killedCount} 個連線`);

    // 等待連線關閉
    console.log('⏳ 等待連線完全關閉...');
    await new Promise(resolve => setTimeout(resolve, 3000));

    // 檢查最終狀態
    const [finalConnections] = await connection.execute(`
      SELECT COUNT(*) as count FROM information_schema.PROCESSLIST 
      WHERE USER = ?
    `, [process.env.DB_USER || 'A999']);

    const remainingConnections = finalConnections[0].count;
    console.log(`📊 清理後剩餘連線: ${remainingConnections}`);

    if (remainingConnections <= 1) {
      console.log('🎉 連線清理成功！');
    } else {
      console.warn(`⚠️ 仍有 ${remainingConnections - 1} 個連線未清理`);
    }

  } catch (error) {
    console.error('❌ 終極清理失敗:', error);
  } finally {
    if (connection) {
      await connection.end();
      console.log('🔌 連線已關閉');
    }
  }
}

// 執行清理
ultimateKill().then(() => {
  console.log('✅ 腳本執行完成');
  process.exit(0);
}).catch((error) => {
  console.error('❌ 腳本執行失敗:', error);
  process.exit(1);
});