jfilter/frag-den-staat-app

import cache from 'react-native-modest-cache';

const userAgent = __DEV__ ? 'FragDenStaat App Development' : 'FragDenStaat App';

const headers = {
  Accept: 'application/json',
  'User-Agent': userAgent,
};

function getFromCacheOrFetch(url, additionalHeaders = {}) {
  return new Promise((resolve, reject) => {
    cache
      .get(url)
      .then(value => {
        if (value) {
          resolve(value);
        } else {
          fetch(encodeURI(url), {
            headers: Object.assign(headers, additionalHeaders),
          })
            .then(response => {
              if (!response.ok) {
                reject(response.status);
              }
              setTimeout(() => null, 0); // workaround for issue-6679
              return response;
            })
            .then(response => response.json())
            .then(response => {
              cache.set(url, response);
              resolve(response);
            })
            .catch(error => reject(error));
        }
      })
      .catch(error => reject(error));
  });
}

/**
 * Fetches data from the URL and dispatches action creators according to the state of the fetching process.
 *
 * @param      {Function}  buildUrl         Returns Url
 * @param      {Function}  dispatch        The dispatch
 * @param      {Function}  beforeFetch     The before fetch
 * @param      {Function}  onSuccessFetch  On success fetch
 * @param      {Function}  onErrorFetch    On error fetch
 */
function fetchAndDispatch(
  buildUrl,
  dispatch,
  beforeFetch,
  onSuccessFetch,
  onErrorFetch,
  additionalHeaders
) {
  dispatch(beforeFetch());
  const url = buildUrl();
  getFromCacheOrFetch(url, additionalHeaders)
    .then(onSuccessFetch)
    .catch(error => dispatch(onErrorFetch(error.message)));
}

function fetchMultipleAndDispatch(
  urls,
  dispatch,
  beforeFetch,
  onSuccessFetch,
  onErrorFetch
) {
  dispatch(beforeFetch());

  Promise.all(urls.map(getFromCacheOrFetch))
    .then(onSuccessFetch)
    .catch(error => dispatch(onErrorFetch(error.message)));
}

const clearCache = () => cache.flush();

export {
  fetchAndDispatch,
  fetchMultipleAndDispatch,
  getFromCacheOrFetch,
  clearCache,
};