#!/usr/bin/env node

/**
 * 数据库初始化脚本
 * 用于验证数据库连接和创建基础表结构
 */

const mysql = require('mysql2/promise');
const databaseConfig = require('../config/database');
const path = require('path');
const fs = require('fs');

class DatabaseInitializer {
  constructor() {
    this.connection = null;
  }

  /**
   * 创建数据库连接
   */
  async createConnection() {
    try {
      this.connection = await mysql.createConnection({
        host: databaseConfig.host,
        port: databaseConfig.port,
        user: databaseConfig.username,
        password: databaseConfig.password,
        database: databaseConfig.database,
        charset: 'utf8mb4',
        timezone: '+08:00'
      });

      console.log('✅ 数据库连接成功');
      return true;
    } catch (error) {
      console.error('❌ 数据库连接失败:', error.message);
      return false;
    }
  }

  /**
   * 验证数据库连接
   */
  async validateConnection() {
    try {
      const [rows] = await this.connection.execute('SELECT NOW() as current_time, VERSION() as mysql_version');
      console.log('📊 数据库信息:');
      console.log(`  当前时间: ${rows[0].current_time}`);
      console.log(`  MySQL版本: ${rows[0].mysql_version}`);
      return true;
    } catch (error) {
      console.error('❌ 数据库验证失败:', error.message);
      return false;
    }
  }

  /**
   * 检查表是否存在
   * @param {string} tableName - 表名
   */
  async checkTableExists(tableName) {
    try {
      const [rows] = await this.connection.execute(
        `SELECT COUNT(*) as count FROM information_schema.tables 
         WHERE table_schema = ? AND table_name = ?`,
        [databaseConfig.database, tableName]
      );
      return rows[0].count > 0;
    } catch (error) {
      console.error(`❌ 检查表 ${tableName} 存在失败:`, error.message);
      return false;
    }
  }

  /**
   * 执行SQL文件
   * @param {string} filePath - SQL文件路径
   */
  async executeSqlFile(filePath) {
    try {
      const sqlContent = fs.readFileSync(filePath, 'utf8');
      const statements = sqlContent.split(';').filter(stmt => stmt.trim());
      
      for (const statement of statements) {
        if (statement.trim()) {
          await this.connection.execute(statement);
        }
      }
      
      console.log(`✅ 成功执行SQL文件: ${path.basename(filePath)}`);
      return true;
    } catch (error) {
      console.error(`❌ 执行SQL文件失败:`, error.message);
      return false;
    }
  }

  /**
   * 关闭数据库连接
   */
  async closeConnection() {
    if (this.connection) {
      await this.connection.end();
      console.log('🔌 数据库连接已关闭');
    }
  }

  /**
   * 主初始化方法
   */
  async initialize() {
    console.log('🚀 开始数据库初始化...');
    console.log(`📋 环境: ${process.env.NODE_ENV || 'development'}`);
    console.log(`🗄️  数据库: ${databaseConfig.database}`);
    console.log(`🌐 主机: ${databaseConfig.host}:${databaseConfig.port}`);
    console.log('─'.repeat(50));

    // 创建连接
    const connected = await this.createConnection();
    if (!connected) {
      process.exit(1);
    }

    // 验证连接
    const validated = await this.validateConnection();
    if (!validated) {
      await this.closeConnection();
      process.exit(1);
    }

    console.log('✅ 数据库连接验证通过');
    console.log('─'.repeat(50));

    // 检查并创建uploads表
    const uploadsTableExists = await this.checkTableExists('uploads');
    if (!uploadsTableExists) {
      console.log('📁 创建uploads表...');
      await this.createUploadsTable();
    } else {
      console.log('✅ uploads表已存在');
    }

    console.log('📋 数据库初始化完成');
    console.log('✅ 所有检查通过，数据库连接正常');

    await this.closeConnection();
  }

  /**
   * 创建uploads表
   */
  async createUploadsTable() {
    const createTableSQL = `
      CREATE TABLE uploads (
        id BIGINT AUTO_INCREMENT PRIMARY KEY,
        user_id BIGINT UNSIGNED NOT NULL,
        original_name VARCHAR(255) NOT NULL,
        stored_name VARCHAR(255) NOT NULL,
        file_path VARCHAR(500) NOT NULL,
        file_size BIGINT NOT NULL,
        mime_type VARCHAR(100) NOT NULL,
        file_type ENUM('image', 'document', 'other') DEFAULT 'image',
        upload_type VARCHAR(50) NOT NULL COMMENT '上传类型: avatar, product, identification, etc',
        status ENUM('active', 'deleted') DEFAULT 'active',
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
        INDEX idx_user_id (user_id),
        INDEX idx_upload_type (upload_type),
        INDEX idx_created_at (created_at)
      ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='文件上传记录表'
    `;

    try {
      await this.connection.execute(createTableSQL);
      console.log('✅ uploads表创建成功');
      return true;
    } catch (error) {
      console.error('❌ 创建uploads表失败:', error.message);
      return false;
    }
  }
}

// 执行初始化
const initializer = new DatabaseInitializer();

// 处理命令行参数
const args = process.argv.slice(2);
if (args.includes('--help') || args.includes('-h')) {
  console.log(`
使用方法: node scripts/initDatabase.js [选项]

选项:
  --help, -h    显示帮助信息
  --check       只检查连接，不执行初始化
  
示例:
  node scripts/initDatabase.js          # 完整初始化
  node scripts/initDatabase.js --check  # 只检查连接
  `);
  process.exit(0);
}

initializer.initialize().catch(error => {
  console.error('❌ 初始化过程中发生错误:', error.message);
  process.exit(1);
});