import { getDNS, isLocalhost } from '@/utils/dns.ts';
import http from 'http';
import { UserApp } from './get-user-app.ts';
import { config, fileStore } from '../module/config.ts';
import path from 'path';
import fs from 'fs';
import { getContentType } from './get-content-type.ts';
import { createRefreshHtml } from './html/create-refresh-html.ts';

const api = config?.api || { host: 'kevisual.xiongxiao.me', path: '/api/router' };
const domain = config?.proxy?.domain || 'kevisual.xiongxiao.me';
const allowedOrigins = config?.proxy?.allowOrigin || [];

const noProxyUrl = ['/', '/favicon.ico'];
export const handleRequest = async (req: http.IncomingMessage, res: http.ServerResponse) => {
  if (req.url === '/favicon.ico') {
    res.writeHead(200, { 'Content-Type': 'image/x-icon' });
    res.write('proxy no favicon.ico\n');
    return;
  }
  if (req.url.startsWith('/api/proxy')) {
    return;
  }
  if (req.url.startsWith('/api')) {
    // 代理到 http://codeflow.xiongxiao.me/api
    const _u = new URL(req.url, `http://${api.host}`);
    // 设置代理请求的目标 URL 和请求头
    let header: any = {};
    if (req.headers?.['Authorization']) {
      header.authorization = req.headers['Authorization'];
    } else if (req.headers?.['authorization']) {
      header.authorization = req.headers['authorization'];
    }
    if (req.headers?.['Content-Type']) {
      header['Content-Type'] = req.headers?.['Content-Type'];
    }
    const options = {
      host: _u.hostname,
      path: req.url,
      method: req.method,
      headers: {
        ...header,
      },
    };
    if (_u.port) {
      // @ts-ignore
      options.port = _u.port;
    }
    // 创建代理请求
    const proxyReq = http.request(options, (proxyRes) => {
      // 将代理服务器的响应头和状态码返回给客户端
      res.writeHead(proxyRes.statusCode, proxyRes.headers);
      // 将代理响应流写入客户端响应
      proxyRes.pipe(res, { end: true });
    });
    // 处理代理请求的错误事件
    proxyReq.on('error', (err) => {
      console.error(`Proxy request error: ${err.message}`);
      res.writeHead(500, { 'Content-Type': 'text/plain' });
      res.write(`Proxy request error: ${err.message}`);
    });
    // 处理 POST 请求的请求体（传递数据到目标服务器）
    req.pipe(proxyReq, { end: true });
    return;
  }
  if (req.url.startsWith('/api')) {
    res.end('not catch api');
    return;
  }

  const dns = getDNS(req);
  // 配置可以跨域
  // 配置可以访问的域名 localhost, xiongxiao.me
  const _orings = allowedOrigins || [];
  const host = dns.hostName;
  if (
    _orings.some((item) => {
      return host.includes(item);
    })
  ) {
    res.setHeader('Access-Control-Allow-Origin', '*');
  }
  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');

  let user, app;
  let domainApp = false;
  if (isLocalhost(dns.hostName)) {
    // 本地开发环境 测试
    // user = 'root';
    // app = 'codeflow';
    // domainApp = true;
  } else {
    // 验证域名
    if (dns.hostName !== domain) {
      // redis获取域名对应的用户和应用
      domainApp = true;
      const data = await UserApp.getDomainApp(dns.hostName);
      if (!data) {
        res.writeHead(404, { 'Content-Type': 'text/plain' });
        res.write('Invalid domain\n');
        return res.end();
      }
      if (!data.user || !data.app) {
        res.writeHead(404, { 'Content-Type': 'text/plain' });
        res.write('Invalid domain config\n');
        return res.end();
      }
      user = data.user;
      app = data.app;
    }
  }
  // const url = req.url;
  const pathname = new URL(req.url, `http://${dns.hostName}`).pathname;
  const url = pathname;
  if (!domainApp && noProxyUrl.includes(url)) {
    res.write('No proxy for this URL\n');
    return res.end();
  }
  if (!domainApp) {
    // 原始url地址
    const urls = url.split('/');
    if (urls.length < 3) {
      console.log('urls errpr', urls);
      res.writeHead(404, { 'Content-Type': 'text/html' });
      res.write('Invalid Proxy URL\n');
      return res.end();
    }
    const [_, _user, _app] = urls;
    if (_app && urls.length === 3) {
      // 重定向到
      res.writeHead(302, { Location: `${url}/` });
      return res.end();
    }
    if (!_user || !_app) {
      res.write('Invalid URL\n');
      return res.end();
    }
    user = _user;
    app = _app;
  }

  const userApp = new UserApp({ user, app });
  let isExist = await userApp.getExist();
  if (!isExist) {
    try {
      const { code, loading } = await userApp.setCacheData();
      if (loading || code === 20000) {
        res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' });

        res.end(createRefreshHtml(user, app));
        return;
      }
      res.writeHead(500, { 'Content-Type': 'text/html; charset=utf-8' });
      res.write('Not Found App\n');
      res.end();
      // 不存在就一定先返回loading状态。
      return;
    } catch (error) {
      console.error('setCacheData error', error);
      res.writeHead(500, { 'Content-Type': 'text/html; charset=utf-8' });
      res.write('Server Error\n');
      res.end();
      userApp.setLoaded('error', 'setCacheData error');
      return;
    }
  }
  const indexFile = isExist; // 已经必定存在了
  try {
    let appFileUrl: string;
    if (domainApp) {
      appFileUrl = (url + '').replace(`/`, '');
    } else {
      appFileUrl = (url + '').replace(`/${user}/${app}/`, '');
    }
    const appFile = await userApp.getFile(appFileUrl);
    if (!appFile) {
      const [indexFilePath, etag] = indexFile.split('||');
      const contentType = getContentType(indexFilePath);
      const isHTML = contentType.includes('html');
      const filePath = path.join(fileStore, indexFilePath);
      if (!userApp.fileCheck(filePath)) {
        res.writeHead(500, { 'Content-Type': 'text/html; charset=utf-8' });
        res.write('File expired, Not Found\n');
        res.end();
        await userApp.clearCacheData();
        return;
      }
      // 如果 content是 'application/octet-stream' 会下载文件, 添加文件后缀
      if (contentType === 'application/octet-stream') {
        // 提取文件名，只保留文件名而不是整个路径
        const fileName = path.basename(indexFilePath);
        res.setHeader('Content-Disposition', `attachment; filename=${fileName}`);
      }
      // 不存在的文件,返回indexFile的文件
      res.writeHead(200, { 'Content-Type': contentType, 'Cache-Control': isHTML ? 'no-cache' : 'public, max-age=3600' });

      const readStream = fs.createReadStream(filePath);
      readStream.pipe(res);

      return;
    } else {
      const [appFilePath, eTag] = appFile.split('||');
      // 检查 If-None-Match 头判断缓存是否有效
      if (req.headers['if-none-match'] === eTag) {
        res.statusCode = 304; // 内容未修改
        res.end();
        return;
      }
      const filePath = path.join(fileStore, appFilePath);
      let contentType = getContentType(filePath);
      const isHTML = contentType.includes('html');
      // 如果 content是 'application/octet-stream' 会下载文件, 添加文件后缀
      if (contentType === 'application/octet-stream') {
        // 提取文件名，只保留文件名而不是整个路径
        const fileName = path.basename(appFilePath);
        res.setHeader('Content-Disposition', `attachment; filename=${fileName}`);
      }

      res.writeHead(200, {
        'Content-Type': contentType,
        'Cache-Control': isHTML ? 'no-cache' : 'public, max-age=3600', // 设置缓存时间为 1 小时
        ETag: eTag,
      });
      if (!userApp.fileCheck(filePath)) {
        console.error('File expired', filePath);
        res.end('File expired\n');
        await userApp.clearCacheData();
        return;
      }
      const readStream = fs.createReadStream(filePath);
      readStream.pipe(res);

      return;
    }
  } catch (error) {
    console.error('getFile error', error);
  }
};