import {
  mergeConfig,
  dispatchRequest,
  jsonpRequest
} from "./utils"

export default class request {

  constructor(options) {
    // 请求公共地址
    this.baseUrl = options.baseUrl || "";
    // 公共文件上传请求地址
    this.fileUrl = options.fileUrl || "";
    // 超时时间
    this.timeout = options.timeout || 6000;
    // 服务器上传图片默认url
    this.defaultUploadUrl = options.defaultUploadUrl || "";
    // 默认请求头
    this.header = options.header || {};
    // 默认配置
    this.config = options.config || {
      isPrompt: true,
      load: true,
      isFactory: true,
      resend: 0
    };
  }

  // post请求
  post(url = '', data = {}, options = {}) {
    return this.request({
      method: "POST",
      data: data,
      url: url,
      ...options
    });
  }

  // get请求
  get(url = '', data = {}, options = {}) {
    return this.request({
      method: "GET",
      data: data,
      url: url,
      ...options
    });
  }

  // put请求
  put(url = '', data = {}, options = {}) {
    return this.request({
      method: "PUT",
      data: data,
      url: url,
      ...options
    });
  }

  // delete请求
  delete(url = '', data = {}, options = {}) {
    return this.request({
      method: "DELETE",
      data: data,
      url: url,
      ...options
    });
  }

  // jsonp请求(只限于H5使用)
  jsonp(url = '', data = {}, options = {}) {
    return this.request({
      method: "JSONP",
      data: data,
      url: url,
      ...options
    });
  }

  // 接口请求方法
  async request(data) {
    // 请求数据
    let requestInfo,
      // 是否运行过请求开始钩子
      runRequestStart = false;
    try {
      if (!data.url) {
        throw {
          errMsg: "【request】缺失数据url",
          statusCode: 0
        }
      }
      // 数据合并
      requestInfo = mergeConfig(this, data);
      // 代表之前运行到这里
      runRequestStart = true;
      // 请求前回调
      if (this.requestStart) {
        let requestStart = this.requestStart(requestInfo);
        if (typeof requestStart == "object") {
          let changekeys = ["data", "header", "isPrompt", "load", "isFactory"];
          changekeys.forEach(key => {
            requestInfo[key] = requestStart[key];
          });
        } else {
          throw {
            errMsg: "【request】请求开始拦截器未通过",
            statusCode: 0,
            data: requestInfo.data,
            method: requestInfo.method,
            header: requestInfo.header,
            url: requestInfo.url,
          }
        }
      }
      let requestResult = {};
      if (requestInfo.method == "JSONP") {
        requestResult = await jsonpRequest(requestInfo);
      } else {
        requestResult = await dispatchRequest(requestInfo);
      }
      // 是否用外部的数据处理方法
      if (requestInfo.isFactory && this.dataFactory) {
        // 数据处理
        let result = await this.dataFactory({
          ...requestInfo,
          response: requestResult
        });
        return Promise.resolve(result);
      } else {
        return Promise.resolve(requestResult);
      }
    } catch (err) {
      this.requestError && this.requestError(err);
      return Promise.reject(err);
    } finally {
      // 如果请求开始未运行到，请求结束也不运行
      if (runRequestStart) {
        this.requestEnd && this.requestEnd(requestInfo);
      }
    }
  }

}