import Axios, { AxiosResponse, AxiosRequestConfig, AxiosError } from 'axios';

export type ResponseDataExtractor<T> = <D>(response: AxiosResponse<T>) => D;

export interface ApiError {
  message: string;
  source: string;
  statusCode: number;
  status: string;
}

export class ApiClient<T> {
  constructor(
    protected baseUrl: string,
    protected headerProcessor: () => object,
    protected extractor: ResponseDataExtractor<T>,
    protected errorHandler: (error: ApiError) => void
  ) {
  }

  async get<D>(
    url: string,
    params?: object,
    apiOptions: ApiOptions = {}
  ): Promise<D> {
    const request: AxiosRequestConfig = {
      ...this.baseRequestOptions(apiOptions),
      method: 'get',
      url,
      params
    };

    return this.execute<D>(request);
  }
  // 仅仅适用于web端
  exportFile<D>(
    url: string,
    params?: object,
    apiOptions: ApiOptions = {},
    tokenKeyName?: string
  ): void {
    const request = {
      ...this.baseRequestOptions(apiOptions),
      method: 'get',
      url,
      params
    };
    // 参数拼接,默认为 gssToken
    const tokenKey = tokenKeyName || 'gssToken';
    const preWholeUrl = `${request.baseURL}${request.url}`;
    let tokenValue = (request.headers.hasOwnProperty('Authorization')) ? (request.headers as any).Authorization : void 0;
    if (!tokenValue) {
      return;
    }
    tokenValue = tokenValue.replace('Bearer ', '');
    const paramsUrl = this.encodeSearchParams({ ...request.params, [tokenKey]: tokenValue } || {});
    const finalUrl = `${preWholeUrl}?${paramsUrl}`;
    // 开始下载
    this.dynamicDownload(finalUrl);
  }

  // 获取请求地址和请求头
  getAllRequestData<D>(
    url: string,
    params?: object,
    apiOptions: ApiOptions = {},
    tokenKeyName?: string
  ): Promise<D> {
    const request = {
      ...this.baseRequestOptions(apiOptions),
      method: 'get',
      url,
      params
    };
    const tokenKey = tokenKeyName || 'gssToken';
    const preWholeUrl = `${request.baseURL}${request.url}`;
    let tokenValue = (request.headers.hasOwnProperty('Authorization')) ? (request.headers as any).Authorization : void 0;
    const paramsUrl = this.encodeSearchParams({ ...request.params, [tokenKey]: tokenValue } || {});
    const finalUrl = `${preWholeUrl}?${paramsUrl}`;
    return {
      wholeUrl: finalUrl,
      authorization: tokenValue
    } as any;
  }

  async delete<D>(
    url: string,
    params?: object,
    apiOptions: ApiOptions = {}
  ): Promise<D> {
    const request: AxiosRequestConfig = {
      ...this.baseRequestOptions(apiOptions),
      method: 'delete',
      url,
      params
    };

    return this.execute<D>(request);
  }

  async post<D>(
    url: string,
    data?: object | any[],
    params?: object,
    apiOptions: ApiOptions = {}
  ): Promise<D> {
    const request: AxiosRequestConfig = {
      ...this.baseRequestOptions(apiOptions),
      method: 'post',
      url,
      data,
      params
    };

    return this.execute<D>(request);
  }

  async put<D>(
    url: string,
    data?: object,
    params?: object,
    apiOptions: ApiOptions = {}
  ): Promise<D> {
    const request: AxiosRequestConfig = {
      ...this.baseRequestOptions(apiOptions),
      method: 'put',
      url,
      data,
      params
    };

    return this.execute<D>(request);
  }

  async patch<D>(
    url: string,
    params?: object,
    apiOptions: ApiOptions = {}
  ): Promise<D> {
    const request: AxiosRequestConfig = {
      ...this.baseRequestOptions(apiOptions),
      method: 'patch',
      url,
      params
    };

    return this.execute<D>(request);
  }


  async execute<D>(axiosOptions: AxiosRequestConfig): Promise<D> {
    try {
      const resp = await Axios.request(axiosOptions);
      // console.log('status code:==', resp.status);
      return this.extractor(resp);
    } catch (e) {
      const error = e as AxiosError;
      if (error.response) {
        // The request was made and the server responded with a status code
        // that falls out of the range of 2xx
        const message = JSON.stringify(error.response.data);
        // throw new Error(`HTTP Status: ${error.response.status}, ${message}`)
        const apiError: ApiError = {
          source: '',
          message: message,
          status: error.response.statusText,
          statusCode: error.response.status
        };
        // console.log(this.errorHandler)
        this.errorHandler(apiError);
        throw new Error(`HTTP Status: ${error.response.status}, ${message}`);
      } else if (error.request) {
        // The request was made but no response was received
        // `error.request` is an instance of XMLHttpRequest in the browser and an instance of
        // http.ClientRequest in node.js
        console.log(error.request);
        throw new Error(`网络没有响应, 请检查网络然后重试`);
      } else {
        // Something happened in setting up the request that triggered an Error
        console.log('Error', error.message);
        throw e;
      }
      // const error=e as ApiError;
      // if (error.response) {
      //   // The request was made and the server responded with a status code
      //   // that falls out of the range of 2xx
      //   const message = JSON.stringify(error.response.data);
      //   throw new Error(`HTTP Status: ${error.response.status}, ${message}`)
      // } else if (error.request) {
      //   // The request was made but no response was received
      //   // `error.request` is an instance of XMLHttpRequest in the browser and an instance of
      //   // http.ClientRequest in node.js
      //   console.log(error.request);
      //   throw new Error(`网络没有响应, 请检查网络然后重试`);
      // } else {
      //   // Something happened in setting up the request that triggered an Error
      //   console.log('Error', error.message);
      //   throw e;
      // }
    }
  }

  private dynamicDownload(url: string) {
    const link = document.createElement('iframe');
    link.style.display = 'none';
    link.src = url;
    document.body.appendChild(link);
    link.onload = function() {
      link.parentNode.removeChild(link);
    };
  }

  private encodeSearchParams(paramsObj: object): string {
    const paramsArr = Array.of();
    Object.keys(paramsObj).forEach(key => {
      let value = (paramsObj as any)[key];
      // 如果值为undefined, 则置空
      if (([undefined, 'undefined'] as any).includes(value)) {
        value = '';
      }
      // 针对需要编码的进行编码(比如中文)编码
      paramsArr.push([key, encodeURIComponent(value)].join('='));
    });
    return paramsArr.join('&');
  }

  private baseRequestOptions({ ignoreHeaders }: ApiOptions = {}) {
    const headers = ignoreHeaders ? {} : this.headerProcessor();
    const baseRequest = {
      baseURL: this.baseUrl,
      method: 'get',
      headers
    };

    return baseRequest;
  }
}

export interface ApiOptions {
  ignoreHeaders?: boolean;
}