/**
 * 数据库迁移执行脚本
 * 用法: node database/migrate.js [migration_file]
 * 示例: node database/migrate.js 002_add_merchant_cover_image.sql
 */

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

const colors = {
  reset: '\x1b[0m',
  green: '\x1b[32m',
  yellow: '\x1b[33m',
  red: '\x1b[31m',
  cyan: '\x1b[36m',
  bold: '\x1b[1m',
};

function log(msg, color = '') {
  console.log(color ? `${color}${msg}${colors.reset}` : msg);
}

function loadEnv() {
  const envPaths = [
    path.resolve(__dirname, '../apps/server/.env.local'),
    path.resolve(__dirname, '../apps/server/.env'),
  ];

  let envFile = null;
  for (const p of envPaths) {
    if (fs.existsSync(p)) { envFile = p; break; }
  }

  if (!envFile) {
    log('错误: 未找到 .env.local 或 .env 文件', colors.red);
    process.exit(1);
  }

  const env = {};
  for (const line of fs.readFileSync(envFile, 'utf-8').split('\n')) {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith('#')) continue;
    const i = trimmed.indexOf('=');
    if (i === -1) continue;
    env[trimmed.slice(0, i).trim()] = trimmed.slice(i + 1).trim();
  }

  return {
    host: env.DB_HOST || 'localhost',
    port: parseInt(env.DB_PORT || '3306', 10),
    user: env.DB_USERNAME || 'root',
    password: env.DB_PASSWORD || '',
    database: env.DB_DATABASE || 'rent_platform',
  };
}

async function runSqlFile(conn, filePath) {
  let raw = fs.readFileSync(filePath, 'utf-8');

  // 移除注释行
  raw = raw.replace(/--.*$/gm, '');
  // 移除 USE 语句（已在代码中处理）
  raw = raw.replace(/USE\s+\S+\s*;/gi, '');

  // 按 ; 分割，过滤空语句
  const stmts = raw
    .split(';')
    .map((s) => s.trim())
    .filter((s) => s.length > 0);

  let ok = 0;
  let skip = 0;
  let errors = [];

  for (const stmt of stmts) {
    try {
      await conn.execute(stmt);
      ok++;
    } catch (err) {
      if (err.code === 'ER_DUP_FIELDNAME' || err.code === 'ER_DUP_KEYNAME') {
        skip++;
        log(`  ⚠ 跳过: ${err.message.slice(0, 80)}`, colors.yellow);
      } else {
        errors.push({ code: err.code, message: err.message, stmt: stmt.slice(0, 100) });
      }
    }
  }

  return { ok, skip, errors };
}

async function main() {
  const args = process.argv.slice(2);

  if (args.length === 0) {
    log('');
    log('用法: node database/migrate.js <migration_file>', colors.cyan);
    log('示例: node database/migrate.js 002_add_merchant_cover_image.sql', colors.cyan);
    log('');
    log('可用的迁移文件:', colors.yellow);
    const migrationsDir = path.resolve(__dirname, 'migrations');
    const files = fs.readdirSync(migrationsDir).filter(f => f.endsWith('.sql'));
    files.forEach(f => log(`  - ${f}`, colors.cyan));
    log('');
    process.exit(0);
  }

  const migrationFile = args[0];
  const migrationPath = path.resolve(__dirname, 'migrations', migrationFile);

  if (!fs.existsSync(migrationPath)) {
    log(`错误: 迁移文件不存在: ${migrationPath}`, colors.red);
    process.exit(1);
  }

  const config = loadEnv();

  log('');
  log('==========================================', colors.cyan);
  log('  数据库迁移执行', colors.bold + colors.cyan);
  log('==========================================', colors.cyan);
  log(`  主机:     ${config.host}:${config.port}`);
  log(`  用户:     ${config.user}`);
  log(`  数据库:   ${config.database}`);
  log(`  迁移文件: ${migrationFile}`);
  log('==========================================', colors.cyan);
  log('');

  let conn;
  try {
    conn = await mysql.createConnection({
      host: config.host,
      port: config.port,
      user: config.user,
      password: config.password,
      database: config.database,
    });
    log('✓ 数据库连接成功', colors.green);
  } catch (err) {
    log(`连接失败: ${err.message}`, colors.red);
    log('请检查 apps/server/.env.local 中的数据库配置', colors.red);
    process.exit(1);
  }

  log('');
  log('执行迁移...', colors.yellow);

  const result = await runSqlFile(conn, migrationPath);

  log('');
  if (result.errors.length > 0) {
    log('==========================================', colors.red);
    log(`  ✗ 迁移失败`, colors.bold + colors.red);
    log('==========================================', colors.red);
    log('');
    log('错误详情:', colors.red);
    result.errors.forEach((err, i) => {
      log(`  ${i + 1}. [${err.code}] ${err.message}`, colors.red);
      log(`     SQL: ${err.stmt}...`, colors.yellow);
    });
    log('');
  } else {
    log('==========================================', colors.green);
    log('  ✓ 迁移完成!', colors.bold + colors.green);
    log('==========================================', colors.green);
    log('');
    log(`  成功: ${result.ok} 条语句`, colors.green);
    if (result.skip > 0) {
      log(`  跳过: ${result.skip} 条语句 (已存在)`, colors.yellow);
    }
    log('');
  }

  await conn.end();

  if (result.errors.length > 0) {
    process.exit(1);
  }
}

main().catch((err) => {
  log(`\n迁移失败: ${err.message}`, colors.red);
  console.error(err);
  process.exit(1);
});