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

// 数据库配置
const dbConfig = {
  host: process.env.DB_HOST || '114.55.111.44',
  user: process.env.DB_USER || 'maov2',
  password: process.env.DB_PASSWORD || '5fYhw8z6T62b7heS',
  database: process.env.DB_NAME || 'maov2',
};

// 初始化数据库连接
async function initDB() {
  try {
    const connection = await mysql.createConnection(dbConfig);
    console.log('数据库连接成功');
    return connection;
  } catch (error) {
    console.error('数据库连接失败:', error);
    throw error;
  }
}

// 递归解析省市区数据
function parseRegionData(regions, parentCode = null, level = 1) {
  const result = [];
  let sortOrder = 1;

  for (const region of regions) {
    // 添加当前区域
    result.push({
      code: region.code,
      name: region.name,
      parent_code: parentCode,
      level: level,
      sort_order: sortOrder++
    });

    // 递归处理子区域
    if (region.children && region.children.length > 0) {
      const childrenData = parseRegionData(region.children, region.code, level + 1);
      result.push(...childrenData);
    }
  }

  return result;
}

// 导入省市区数据
async function importChinaRegions() {
  let connection;

  try {
    // 读取 JSON 数据文件
    const jsonFilePath = path.join(__dirname, 'pca-code.json');
    const jsonData = fs.readFileSync(jsonFilePath, 'utf8');
    const regionsData = JSON.parse(jsonData);

    console.log('成功读取省市区数据文件');

    // 解析数据
    const parsedData = parseRegionData(regionsData);
    console.log(`解析完成，共 ${parsedData.length} 条记录`);

    // 连接数据库
    connection = await initDB();

    // 清空现有数据
    await connection.execute('DELETE FROM china_regions');
    console.log('已清空现有数据');

    // 批量插入数据
    const batchSize = 100;
    let insertedCount = 0;

    for (let i = 0; i < parsedData.length; i += batchSize) {
      const batch = parsedData.slice(i, i + batchSize);
      const values = batch.map(item => [
        item.code,
        item.name,
        item.parent_code,
        item.level,
        item.sort_order
      ]);

      const placeholders = values.map(() => '(?, ?, ?, ?, ?)').join(', ');
      const flatValues = values.flat();

      await connection.execute(
        `INSERT INTO china_regions (code, name, parent_code, level, sort_order) VALUES ${placeholders}`,
        flatValues
      );

      insertedCount += batch.length;
      console.log(`已插入 ${insertedCount}/${parsedData.length} 条记录`);
    }

    // 统计导入结果
    const [provinceResult] = await connection.execute(
      'SELECT COUNT(*) as count FROM china_regions WHERE level = 1'
    );
    const [cityResult] = await connection.execute(
      'SELECT COUNT(*) as count FROM china_regions WHERE level = 2'
    );
    const [districtResult] = await connection.execute(
      'SELECT COUNT(*) as count FROM china_regions WHERE level = 3'
    );
    const [totalResult] = await connection.execute(
      'SELECT COUNT(*) as count FROM china_regions'
    );

    console.log('\n=== 导入完成 ===');
    console.log(`省份数量: ${provinceResult[0].count}`);
    console.log(`城市数量: ${cityResult[0].count}`);
    console.log(`区县数量: ${districtResult[0].count}`);
    console.log(`总记录数: ${totalResult[0].count}`);

  } catch (error) {
    console.error('导入失败:', error);
    throw error;
  } finally {
    if (connection) {
      await connection.end();
      console.log('数据库连接已关闭');
    }
  }
}

// 如果直接运行此脚本
if (require.main === module) {
  importChinaRegions()
    .then(() => {
      console.log('省市区数据导入成功！');
      process.exit(0);
    })
    .catch((error) => {
      console.error('导入过程中发生错误:', error);
      process.exit(1);
    });
}

module.exports = { importChinaRegions };