const fs = require('fs');
const path = require('path');

/**
 * 表别名修复脚本：修复 SQL 查询中的表别名问题
 */

class TableAliasFixer {
  constructor() {
    this.filesToFix = [
      'services/matchingService.js',
      'routes/matchingAdmin.js', 
      'routes/transfers.js',
      'routes/matching.js'
    ];
  }
  
  /**
   * 修复单个文件中的表别名问题
   * @param {string} filePath - 文件路径
   */
  async fixFile(filePath) {
    const fullPath = path.join(process.cwd(), filePath);
    
    if (!fs.existsSync(fullPath)) {
      console.log(`文件不存在: ${filePath}`);
      return;
    }
    
    console.log(`正在修复文件: ${filePath}`);
    
    let content = fs.readFileSync(fullPath, 'utf8');
    let originalContent = content;
    
    // 1. 修复 "FROM transfers WHERE source_type = 'allocation' oa" 的问题
    content = content.replace(
      /FROM transfers WHERE source_type = 'allocation' (\w+)/g,
      "FROM transfers $1 WHERE $1.source_type = 'allocation'"
    );
    
    // 2. 修复重复的 source_type 条件
    content = content.replace(
      /FROM transfers WHERE source_type = 'allocation' (\w+) AND \1\.source_type = 'allocation'/g,
      "FROM transfers $1 WHERE $1.source_type = 'allocation'"
    );
    
    // 3. 修复 "FROM transfers WHERE source_type = 'allocation'" 后面直接跟其他子句的情况
    content = content.replace(
      /FROM transfers WHERE source_type = 'allocation'\s+(JOIN|ORDER|GROUP|LIMIT)/g,
      "FROM transfers WHERE source_type = 'allocation' $1"
    );
    
    // 4. 修复子查询中的问题
    content = content.replace(
      /\(SELECT[^)]*FROM transfers WHERE source_type = 'allocation' (\w+)/g,
      (match, alias) => {
        return match.replace(
          `FROM transfers WHERE source_type = 'allocation' ${alias}`,
          `FROM transfers ${alias} WHERE ${alias}.source_type = 'allocation'`
        );
      }
    );
    
    // 5. 修复特定的查询模式
    content = this.fixSpecificPatterns(content, filePath);
    
    if (content !== originalContent) {
      fs.writeFileSync(fullPath, content);
      console.log(`✓ 已修复: ${filePath}`);
    } else {
      console.log(`- 无需修复: ${filePath}`);
    }
  }
  
  /**
   * 修复特定的查询模式
   * @param {string} content - 文件内容
   * @param {string} filePath - 文件路径
   * @returns {string} 修复后的内容
   */
  fixSpecificPatterns(content, filePath) {
    // 修复 SELECT 语句中的表别名问题
    content = content.replace(
      /SELECT ([^F]*?) FROM transfers WHERE source_type = 'allocation' (\w+)/g,
      "SELECT $1 FROM transfers $2 WHERE $2.source_type = 'allocation'"
    );
    
    // 修复 UPDATE 语句
    content = content.replace(
      /UPDATE transfers WHERE source_type = 'allocation' SET/g,
      "UPDATE transfers SET"
    );
    
    // 修复 WHERE 子句中的条件
    content = content.replace(
      /WHERE source_type = 'allocation' AND (\w+)\./g,
      "WHERE $1.source_type = 'allocation' AND $1."
    );
    
    return content;
  }
  
  /**
   * 执行所有文件的修复
   */
  async fixAllFiles() {
    console.log('开始修复表别名问题...');
    console.log('=' .repeat(60));
    
    for (const filePath of this.filesToFix) {
      try {
        await this.fixFile(filePath);
      } catch (error) {
        console.error(`修复文件 ${filePath} 失败:`, error.message);
      }
    }
    
    console.log('\n' + '=' .repeat(60));
    console.log('✓ 表别名修复完成！');
  }
}

async function main() {
  const fixer = new TableAliasFixer();
  await fixer.fixAllFiles();
}

// 如果直接运行此脚本
if (require.main === module) {
  main().catch(console.error);
}

module.exports = TableAliasFixer;