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

// 資料庫連接配置
const dbConfig = {
  host: 'mysql.theaken.com',
  port: 33306,
  user: 'AI_Platform',
  password: 'Aa123456',
  database: 'db_AI_Platform',
  charset: 'utf8mb4'
};

async function fixFavoritesDuplicates() {
  let connection;
  
  try {
    console.log('連接到資料庫...');
    connection = await mysql.createConnection(dbConfig);
    
    console.log('檢查重複的收藏記錄...');
    
    // 查找重複記錄
    const [duplicates] = await connection.execute(`
      SELECT user_id, app_id, COUNT(*) as count
      FROM user_favorites 
      GROUP BY user_id, app_id 
      HAVING COUNT(*) > 1
    `);
    
    if (duplicates.length === 0) {
      console.log('沒有發現重複的收藏記錄');
      return;
    }
    
    console.log(`發現 ${duplicates.length} 組重複記錄:`);
    
    for (const duplicate of duplicates) {
      console.log(`用戶 ${duplicate.user_id} 對應用 ${duplicate.app_id} 有 ${duplicate.count} 條記錄`);
      
      // 保留最早的記錄，刪除其他重複記錄
      const [records] = await connection.execute(`
        SELECT id, created_at
        FROM user_favorites 
        WHERE user_id = ? AND app_id = ?
        ORDER BY created_at ASC
      `, [duplicate.user_id, duplicate.app_id]);
      
      if (records.length > 1) {
        // 保留第一條記錄，刪除其他記錄
        const keepRecord = records[0];
        const deleteIds = records.slice(1).map(r => r.id);
        
        console.log(`保留記錄 ID: ${keepRecord.id} (創建時間: ${keepRecord.created_at})`);
        console.log(`刪除記錄 IDs: ${deleteIds.join(', ')}`);
        
        await connection.execute(`
          DELETE FROM user_favorites 
          WHERE id IN (${deleteIds.map(() => '?').join(',')})
        `, deleteIds);
        
        console.log(`已清理 ${deleteIds.length} 條重複記錄`);
      }
    }
    
    console.log('重複記錄清理完成！');
    
    // 驗證修復結果
    const [remainingDuplicates] = await connection.execute(`
      SELECT user_id, app_id, COUNT(*) as count
      FROM user_favorites 
      GROUP BY user_id, app_id 
      HAVING COUNT(*) > 1
    `);
    
    if (remainingDuplicates.length === 0) {
      console.log('✅ 所有重複記錄已成功清理');
    } else {
      console.log('❌ 仍有重複記錄存在:', remainingDuplicates);
    }
    
  } catch (error) {
    console.error('修復過程中發生錯誤:', error);
  } finally {
    if (connection) {
      await connection.end();
      console.log('資料庫連接已關閉');
    }
  }
}

// 執行修復
fixFavoritesDuplicates().catch(console.error);