import { ContentType, HttpMethod, interceptorsRequest, interceptorsResponse } from './fetch-utils'
import type { IReqConfig } from './fetch-utils'

/**
 * 发送请求
 */
async function sendRequest(url: string, headers: Headers, config: IReqConfig) {
  const res = await fetch(url, {
    body: JSON.stringify(config.params), // 设置参数
    headers,
    method: HttpMethod.post,
  })
  return res
}
const parseRes = async(res: Response) => {
  const contentType = res.headers.get('Content-Type')
  let resVal
  // 判定返回的内容类型，做不同的处理
  if (contentType) {
    if (contentType.includes('json'))
      resVal = await res.json()

    if (contentType.includes('text'))
      resVal = await res.text()

    if (contentType.includes('form'))
      resVal = await res.formData()

    if (contentType.includes('video'))
      resVal = await res.blob()
  } else {
    resVal = await res.text()
  }
  return resVal
}

const handleRes = async(res: Response) => {
  const parsedRes = await parseRes(res)
  // 如果res.ok，则请求成功
  if (res.ok)
    return parsedRes

  // 请求失败，返回解析之后的失败的数据
  throw parsedRes
}
const request = async(
  url: string,
  config: IReqConfig = {
    'params': {},
    'method': 'POST',
    'headers': {
      'Content-Type': ContentType.json,
      'token': '',
    },
    'token': '',
    'Content-Type': ContentType.json,
  },
) => {
  // 请求拦截
  const { reqUrl, headers } = interceptorsRequest(url, config)
  // 发送请求
  const promise: Response = await sendRequest(reqUrl, headers as Headers, config)
  // 处理请求结果(响应拦截)
  return interceptorsResponse(promise, handleRes)
}

export default request