#!/usr/bin/env node

// =====================================================
// 資料庫遷移腳本 (修復版)
// =====================================================

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

// 資料庫配置
const dbConfig = {
  host: process.env.DB_HOST || 'mysql.theaken.com',
  port: parseInt(process.env.DB_PORT || '33306'),
  user: process.env.DB_USER || 'AI_Platform',
  password: process.env.DB_PASSWORD || 'Aa123456',
  database: process.env.DB_NAME || 'db_AI_Platform',
  charset: 'utf8mb4',
  timezone: '+08:00',
};

async function runMigration() {
  let connection;
  
  try {
    console.log('🚀 開始資料庫遷移...');
    
    // 創建連接
    connection = await mysql.createConnection({
      ...dbConfig,
      multipleStatements: true
    });
    
    console.log('✅ 資料庫連接成功');
    
    // 讀取 SQL 文件
    const sqlFile = path.join(__dirname, '..', 'database-schema-simple.sql');
    const sqlContent = fs.readFileSync(sqlFile, 'utf8');
    
    console.log('📖 讀取 SQL 文件成功');
    
    // 處理 SQL 內容，正確分割語句
    console.log('⚡ 處理 SQL 語句...');
    
    // 先處理觸發器，因為它們包含分號
    const triggerRegex = /CREATE TRIGGER[\s\S]*?END;/g;
    const triggers = sqlContent.match(triggerRegex) || [];
    
    // 移除觸發器部分，處理其他語句
    let remainingSql = sqlContent.replace(triggerRegex, '');
    
    // 分割其他語句
    const otherStatements = remainingSql
      .split(';')
      .map(stmt => stmt.trim())
      .filter(stmt => stmt.length > 0 && !stmt.startsWith('--'));
    
    // 合併所有語句
    const allStatements = [...otherStatements, ...triggers];
    
    console.log(`📊 共找到 ${allStatements.length} 個語句`);
    
    // 執行語句
    for (let i = 0; i < allStatements.length; i++) {
      const statement = allStatements[i];
      if (statement.trim()) {
        try {
          // 特殊處理 USE 語句和觸發器
          if (statement.toUpperCase().startsWith('USE') || 
              statement.toUpperCase().startsWith('CREATE TRIGGER')) {
            await connection.query(statement + ';');
          } else {
            await connection.execute(statement + ';');
          }
          console.log(`✅ 執行語句 ${i + 1}/${allStatements.length}`);
        } catch (error) {
          console.error(`❌ 語句 ${i + 1} 執行失敗:`, error.message);
          console.error(`語句內容: ${statement.substring(0, 100)}...`);
          // 對於某些錯誤，我們可以繼續執行
          if (error.message.includes('already exists') || 
              error.message.includes('Duplicate entry') ||
              error.message.includes('Table') && error.message.includes('already exists')) {
            console.log('⚠️ 跳過已存在的項目');
            continue;
          }
          throw error;
        }
      }
    }
    
    console.log('✅ 資料庫結構創建成功！');
    
    // 驗證表是否創建成功
    console.log('🔍 驗證表結構...');
    const [tables] = await connection.execute('SHOW TABLES');
    console.log(`📊 共創建了 ${tables.length} 個表:`);
    
    tables.forEach((table, index) => {
      const tableName = Object.values(table)[0];
      console.log(`  ${index + 1}. ${tableName}`);
    });
    
    // 檢查視圖
    console.log('🔍 驗證視圖...');
    const [views] = await connection.execute('SHOW FULL TABLES WHERE Table_type = "VIEW"');
    console.log(`📈 共創建了 ${views.length} 個視圖:`);
    
    views.forEach((view, index) => {
      const viewName = Object.values(view)[0];
      console.log(`  ${index + 1}. ${viewName}`);
    });
    
    // 檢查觸發器
    console.log('🔍 驗證觸發器...');
    const [triggerList] = await connection.execute('SHOW TRIGGERS');
    console.log(`⚙️ 共創建了 ${triggerList.length} 個觸發器:`);
    
    triggerList.forEach((trigger, index) => {
      console.log(`  ${index + 1}. ${trigger.Trigger}`);
    });
    
    console.log('🎉 資料庫遷移完成！');
    
  } catch (error) {
    console.error('❌ 遷移失敗:', error.message);
    console.error('詳細錯誤:', error);
    process.exit(1);
  } finally {
    if (connection) {
      await connection.end();
      console.log('🔌 資料庫連接已關閉');
    }
  }
}

// 執行遷移
if (require.main === module) {
  runMigration().catch(console.error);
}

module.exports = { runMigration };