import axios, { AxiosInstance, AxiosRequestConfig, AxiosResponse, InternalAxiosRequestConfig, AxiosHeaders } from 'axios';
import { BASE_URL } from './constants'
// 创建 axios 实例
const request: AxiosInstance = axios.create({
  baseURL: BASE_URL, // 设置基础URL
  timeout: 10000, // 请求超时时间
  headers: {
    'Content-Type': 'application/json',
  },
});

// 请求拦截器
request.interceptors.request.use(
  (config: InternalAxiosRequestConfig) => {
    // 从 localStorage 获取 token
    const token = localStorage.getItem('token') || 'mock-token';
    if (token && config.headers) {
      (config.headers as AxiosHeaders).set('Authorization', `Bearer ${token}`);
    }
    return config;
  },
  (error) => {
    return Promise.reject(error);
  }
);

// 响应拦截器
request.interceptors.response.use(
  (response: AxiosResponse) => {
    // 直接返回响应数据
    return response.data;
  },
  (error) => {
    if (error.response) {
      switch (error.response.status) {
        case 401:
          // 未授权，清除 token 并跳转到登录页
          localStorage.removeItem('token');
          window.location.href = '/login';
          break;
        case 403:
          // 权限不足
          console.error('没有权限访问该资源');
          break;
        case 404:
          // 资源不存在
          console.error('请求的资源不存在');
          break;
        case 500:
          // 服务器错误
          console.error('服务器错误');
          break;
        default:
          console.error('请求失败:', error.response.data.message || '未知错误');
      }
    } else if (error.request) {
      // 请求已发出但没有收到响应
      console.error('网络错误，请检查您的网络连接');
    } else {
      // 请求配置出错
      console.error('请求配置错误:', error.message);
    }
    return Promise.reject(error);
  }
);

// 封装 GET 请求
export const get = <T>(url: string, config?: AxiosRequestConfig): Promise<T> => {
  return request.get(url, config);
};

// 封装 POST 请求
export const post = <T>(url: string, data?: any, config?: AxiosRequestConfig): Promise<T> => {
  return request.post(url, data, config);
};

// 封装 PUT 请求
export const put = <T>(url: string, data?: any, config?: AxiosRequestConfig): Promise<T> => {
  return request.put(url, data, config);
};

// 封装 DELETE 请求
export const del = <T>(url: string, config?: AxiosRequestConfig): Promise<T> => {
  return request.delete(url, config);
};

// 封装流式数据请求
export const stream = async <T>({
  url,
  method = 'POST',
  data,
  onMessage,
  onError,
  onComplete,
}: {
  url: string;
  method?: 'GET' | 'POST';
  data?: any;
  onMessage: (data: T) => void;
  onError?: (error: any) => void;
  onComplete?: () => void;
}) => {
  try {
    const config: AxiosRequestConfig = {
      url,
      method,
      data,
      responseType: 'stream',
      headers: {
        'Accept': 'text/event-stream',
        'Cache-Control': 'no-cache',
        'Connection': 'keep-alive',
      },
      onDownloadProgress: (progressEvent: any) => {
        const responseText = progressEvent.event?.target?.responseText;
        if (!responseText) return;

        // 处理接收到的数据
        const lines: string[] = responseText.split('\n');
        lines.forEach((line: string) => {
          if (line.startsWith('data: ')) {
            try {
              const data = JSON.parse(line.slice(6));
              onMessage(data);
            } catch (e) {
              console.warn('Failed to parse stream data:', e);
            }
          }
        });
      },
    };

    const response = await request(config);
    onComplete?.();
    return response;
  } catch (error) {
    onError?.(error);
    throw error;
  }
};

// 封装文件下载流请求
export const downloadStream = async (
  url: string,
  filename: string,
  config?: AxiosRequestConfig
) => {
  try {
    const response = await request({
      url,
      method: 'GET',
      responseType: 'blob',
      ...config,
    });

    // 创建下载链接
    const blob = new Blob([response.data], { type: response.headers['content-type'] });
    const downloadUrl = window.URL.createObjectURL(blob);
    const link = document.createElement('a');
    link.href = downloadUrl;
    link.download = filename;
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
    window.URL.revokeObjectURL(downloadUrl);

    return response;
  } catch (error) {
    console.error('文件下载失败:', error);
    throw error;
  }
};

// 导出 request 实例
export default request;