// 支持的请求类型
const VALID_REQ_TYPES = ['wx', 'axios', 'jsonp', 'custom'];

// 小程序中合法的请求方法
const WX_VALID_METHODS = ['OPTIONS', 'GET', 'HEAD', 'POST', 'PUT', 'DELETE', 'TRACE', 'CONNECT'];

// 默认请求头
const DEFAULT_HEADER = { 'Content-Type': 'application/x-www-form-urlencoded;charset=utf-8' };

// 错误信息
const ERROR_STRINGS = {
  noData: 'no data!',
  paramsType: 'the "params" must be an object!',
  middleware: 'middleware must be a function!',
  reqTypeAndCustomFetch: 'reqType or customFetch only!',

  reqTypeFn: reqType => `invalid reqType: "${reqType}", `
    + `support these reqTypes: ["${VALID_REQ_TYPES.join('", "')}"].`,
  unknownMethodFn: method => `unknown method: "${method}"!`,
  requiredBodyFn: apiName => `${apiName} must pass required body!`,
  requiredParamFn: (apiName, param) => `${apiName} must pass required param: "${param}"!`,
};

export {
  ERROR_STRINGS,
  DEFAULT_HEADER,
  VALID_REQ_TYPES,
  WX_VALID_METHODS,
};