const Router = require('@koa/router');
const ai = require('../controller/ai.controller');
const router = new Router({ prefix: '/ai' });
const request = require('../utils/request');
const util = require('../utils/util');
const qs = require('qs');
const bodyParser = require('koa-bodyparser');
const { chatStream } = require('../controller/ai.controller');

/**
 * 接口代理和大模型接入API接口
 */

// 流式chat
router.post('/stream', bodyParser(), chatStream);

// 接口转发(get)
router.get('/proxy', async (ctx) => handleProxy(ctx, 'get'));

// 接口转发(post)
router.post('/proxy', async (ctx) => handleProxy(ctx, 'post'));

// 接口转发(put)
router.put('/proxy', async (ctx) => handleProxy(ctx, 'put'));

// 接口转发(patch)
router.patch('/proxy', async (ctx) => handleProxy(ctx, 'patch'));

// 接口转发(delete)
router.delete('/proxy', async (ctx) => handleProxy(ctx, 'delete'));

const handleProxy = async (ctx, method) => {
  try {
    const {
      query,
      body,
      headers: { host, origin, proxyapi, ...headers },
    } = ctx.request;
    if (!proxyapi) {
      return util.fail(ctx, '接口请求地址不存在', 404);
    }

    let params = method === 'get' || method === 'delete' ? query : body;
    if (headers['content-type'] === 'application/x-www-form-urlencoded') {
      params = qs.stringify(params);
    } else {
      params = method === 'get' || method === 'delete' ? query : JSON.stringify(params || {});
    }
    let response = null;

    if (method === 'get' || method === 'delete') {
      response = await request[method](proxyapi, {
        params,
        headers,
      });
    } else {
      response = await request[method](proxyapi, params, {
        headers,
      });
    }

    const { status, statusText, data } = response;
    for (let key in response.headers) {
      ctx.set(key, response.headers[key]);
    }
    if (status === 200) {
      ctx.body = data;
    } else {
      if (status === 401 || status === 405) {
        return util.fail(ctx, '接口请求方法错误', status);
      }
      if (status === 404) {
        return util.fail(ctx, '接口请求地址不存在', status);
      }
      util.fail(ctx, data || statusText, 500);
    }
  } catch (error) {
    // 根据错误类型设置状态码和错误信息
    if (error.code === 'ECONNREFUSED' || error.code === 'ENOTFOUND') {
      // 服务地址不存在或无法连接
      ctx.status = 502; // Bad Gateway
      ctx.body = {
        message: '服务不可用或地址不存在',
        error: error.message,
      };
    } else if (error.response) {
      // 如果错误是来自后端接口的响应
      const { status, data } = error.response;
      ctx.status = status; // 设置状态码
      ctx.body = data; // 设置响应体
    } else if (error.request) {
      // 请求已发出，但没有收到响应
      ctx.status = 504; // Gateway Timeout
      ctx.body = {
        message: '请求超时，未收到响应',
        error: error.message,
      };
    } else {
      // 其他未知错误
      ctx.status = 500; // Internal Server Error
      ctx.body = {
        message: '服务器内部错误',
        error: error.message,
      };
    }
  }
};

module.exports = router;