import responseHandler from './responseHandler';
import getEnvelopeBody from './getEnvelopeBody';
import { appendQueryParameters } from './location';
import parseJSON from '../json/parseJson';
import type { NetworkResponse, RequestOptions, SerializableObject } from '../types';

const rnoContent = (method: string): boolean => /^(?:GET|HEAD)$/i.test(method);

export default function fetchAdaptor<R>(
  options: RequestOptions,
): Promise<NetworkResponse<R>> {
  const method = options.method || 'GET';
  const hasContent = !rnoContent(method);
  let url = options.url || window.location.href;
  let requestInit: RequestInit;

  if (options.envelope) {
    url = appendQueryParameters(url, { envelope: 'request' });
    requestInit = {
      method: 'POST',
      headers: {},
      credentials: 'same-origin',
      body: getEnvelopeBody(method, options.headers || {}, options.data),
    };
  } else {
    requestInit = {
      method,
      headers: options.headers || {},
      credentials: 'same-origin',
    };

    if (options.data) {
      if (!hasContent) {
        url = appendQueryParameters(url, options.data as SerializableObject);
      } else {
        requestInit.body = JSON.stringify(options.data);
        requestInit.headers = {
          ...requestInit.headers,
          'Content-Type': 'application/json',
        };
      }
    }
  }

  return fetch(url, requestInit)
    .then((res) => Promise.all([res, res.text()]))
    .then(([res, body]) => responseHandler<R>(res.status, parseJSON(body)));
}