import express from 'express';
import { loadConfig, isDevMode, getPort } from './config.js';
import { logInfo, logError } from './logger.js';
import router from './routes.js';
import { initializeAuth } from './auth.js';
import { initializeUserAgentUpdater } from './user-agent-updater.js';
import './sls-logger.js'; // 初始化阿里云日志服务
import { sanitizeForLog } from './log-sanitizer.js';

// ============================================================================
// 全局错误处理 - 必须在应用启动前注册
// ============================================================================

let isShuttingDown = false;

/**
 * 优雅关闭服务器
 */
function gracefulShutdown(reason, exitCode = 1) {
  if (isShuttingDown) {
    return;
  }
  isShuttingDown = true;

  console.error(`\n${'='.repeat(80)}`);
  console.error(`🛑 Server shutting down: ${reason}`);
  console.error(`${'='.repeat(80)}\n`);

  // 给正在处理的请求一些时间完成
  setTimeout(() => {
    process.exit(exitCode);
  }, 3000);
}

/**
 * 处理未捕获的 Promise Rejection
 */
process.on('unhandledRejection', (reason, promise) => {
  const errorInfo = {
    type: 'unhandledRejection',
    reason: reason instanceof Error ? reason.message : String(reason),
    stack: reason instanceof Error ? reason.stack : undefined,
    timestamp: new Date().toISOString()
  };

  console.error(`\n${'='.repeat(80)}`);
  console.error('⚠️  Unhandled Promise Rejection');
  console.error('='.repeat(80));
  console.error(`Time: ${errorInfo.timestamp}`);
  console.error(`Reason: ${errorInfo.reason}`);
  if (errorInfo.stack && isDevMode()) {
    console.error(`Stack: ${errorInfo.stack}`);
  }
  console.error('='.repeat(80) + '\n');

  logError('Unhandled Promise Rejection', sanitizeForLog(errorInfo));

  // 在生产环境中，unhandledRejection 可能表示严重问题，考虑退出
  // 但为了服务稳定性，这里只记录不退出
  // 如需更严格的处理，可取消下面的注释：
  // gracefulShutdown('Unhandled Promise Rejection', 1);
});

/**
 * 处理未捕获的异常
 */
process.on('uncaughtException', (error) => {
  const errorInfo = {
    type: 'uncaughtException',
    message: error.message,
    stack: error.stack,
    timestamp: new Date().toISOString()
  };

  console.error(`\n${'='.repeat(80)}`);
  console.error('💥 Uncaught Exception');
  console.error('='.repeat(80));
  console.error(`Time: ${errorInfo.timestamp}`);
  console.error(`Error: ${errorInfo.message}`);
  if (errorInfo.stack) {
    console.error(`Stack: ${errorInfo.stack}`);
  }
  console.error('='.repeat(80) + '\n');

  logError('Uncaught Exception', sanitizeForLog(errorInfo));

  // uncaughtException 后进程状态不确定，必须退出
  gracefulShutdown('Uncaught Exception', 1);
});

/**
 * 处理进程信号
 */
process.on('SIGTERM', () => {
  logInfo('Received SIGTERM signal');
  gracefulShutdown('SIGTERM', 0);
});

process.on('SIGINT', () => {
  logInfo('Received SIGINT signal');
  gracefulShutdown('SIGINT', 0);
});

// ============================================================================

const app = express();

app.use(express.json({ limit: '50mb' }));
app.use(express.urlencoded({ extended: true, limit: '50mb' }));

app.use((req, res, next) => {
  res.header('Access-Control-Allow-Origin', '*');
  res.header('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
  res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization, X-API-Key, anthropic-version');
  
  if (req.method === 'OPTIONS') {
    return res.sendStatus(200);
  }
  next();
});

app.use(router);

app.get('/', (req, res) => {
  res.json({
    name: 'droid2api',
    version: '1.0.0',
    description: 'OpenAI Compatible API Proxy',
    endpoints: [
      'GET /v1/models',
      'POST /v1/chat/completions',
      'POST /v1/responses',
      'POST /v1/messages',
      'POST /v1/messages/count_tokens'
    ]
  });
});

// 404 处理 - 捕获所有未匹配的路由
app.use((req, res, next) => {
  const errorInfo = {
    timestamp: new Date().toISOString(),
    method: req.method,
    url: req.originalUrl || req.url,
    path: req.path,
    query: req.query,
    params: req.params,
    body: req.body,
    headers: {
      'content-type': req.headers['content-type'],
      'user-agent': req.headers['user-agent'],
      'origin': req.headers['origin'],
      'referer': req.headers['referer']
    },
    ip: req.ip || req.connection.remoteAddress
  };

  const safeQuery = sanitizeForLog(errorInfo.query);
  const safeBody = sanitizeForLog(errorInfo.body);
  const safeHeaders = sanitizeForLog(errorInfo.headers);
  const safeIp = sanitizeForLog(errorInfo.ip);

  console.error('\n' + '='.repeat(80));
  console.error('❌ 非法请求地址');
  console.error('='.repeat(80));
  console.error(`时间: ${errorInfo.timestamp}`);
  console.error(`方法: ${errorInfo.method}`);
  console.error(`地址: ${errorInfo.url}`);
  console.error(`路径: ${errorInfo.path}`);
  
  if (Object.keys(errorInfo.query).length > 0) {
    console.error(`查询参数: ${JSON.stringify(safeQuery, null, 2)}`);
  }
  
  if (errorInfo.body && Object.keys(errorInfo.body).length > 0) {
    console.error(`请求体: ${JSON.stringify(safeBody, null, 2)}`);
  }
  
  console.error(`客户端IP: ${safeIp}`);
  console.error(`User-Agent: ${safeHeaders['user-agent'] || 'N/A'}`);
  
  if (safeHeaders.referer) {
    console.error(`来源: ${safeHeaders.referer}`);
  }
  
  console.error('='.repeat(80) + '\n');

  logError('Invalid request path', sanitizeForLog(errorInfo));

  res.status(404).json({
    error: 'Not Found',
    message: `路径 ${req.method} ${req.path} 不存在`,
    timestamp: errorInfo.timestamp,
    availableEndpoints: [
      'GET /v1/models',
      'POST /v1/chat/completions',
      'POST /v1/responses',
      'POST /v1/messages',
      'POST /v1/messages/count_tokens'
    ]
  });
});

// 错误处理中间件
app.use((err, req, res, next) => {
  logError('Unhandled error', err);
  res.status(500).json({
    error: 'Internal server error',
    message: isDevMode() ? err.message : undefined
  });
});

(async () => {
  try {
    loadConfig();
    logInfo('Configuration loaded successfully');
    logInfo(`Dev mode: ${isDevMode()}`);
    
    // Initialize User-Agent version updater
    initializeUserAgentUpdater();
    
    // Initialize auth system (load and setup API key if needed)
    // This won't throw error if no auth config is found - will use client auth
    await initializeAuth();
    
    const PORT = getPort();
  logInfo(`Starting server on port ${PORT}...`);
  
  const server = app.listen(PORT)
    .on('listening', () => {
      logInfo(`Server running on http://localhost:${PORT}`);
      logInfo('Available endpoints:');
      logInfo('  GET  /v1/models');
      logInfo('  POST /v1/chat/completions');
      logInfo('  POST /v1/responses');
      logInfo('  POST /v1/messages');
      logInfo('  POST /v1/messages/count_tokens');
    })
    .on('error', (err) => {
      if (err.code === 'EADDRINUSE') {
        console.error(`\n${'='.repeat(80)}`);
        console.error(`ERROR: Port ${PORT} is already in use!`);
        console.error('');
        console.error('Please choose one of the following options:');
        console.error(`  1. Stop the process using port ${PORT}:`);
        console.error(`     lsof -ti:${PORT} | xargs kill`);
        console.error('');
        console.error('  2. Change the port in config.json:');
        console.error('     Edit config.json and modify the "port" field');
        console.error(`${'='.repeat(80)}\n`);
        process.exit(1);
      } else {
        logError('Failed to start server', err);
        process.exit(1);
      }
    });
  } catch (error) {
    logError('Failed to start server', error);
    process.exit(1);
  }
})();