import { HttpError, ReferenceError, UnauthorizedError } from './errors';

export const serverPath = (document.documentElement.dataset.apiDomain || '') + '/api';

interface FetchParams {
  [key: string]: string | number | boolean;
}

export const handleFetch = async (path: string, init: RequestInit = {}, isJson = true): Promise<Response> => {
  const headers: Headers = new Headers(init.headers);

  if (isJson) {
    headers.append('Accept', 'application/json');
    headers.append('Content-Type', 'application/json');
  }

  const response = await fetch(`${serverPath}${path}`, {
    ...init,
    ...(init && init.body) && {
      body: init.body,
    },
    headers,
    credentials: 'include',
  });

  return handleResponse(response);
};

export const handleDelete = (path: string): Promise<Response> => {
  return handleFetch(path, { method: 'delete' }, false)
    .catch((error: HttpError) => {
      // Error code 3001 indicates the item is still referenced somewhere else
      if (error.errorCode === 3001) {
        throw new ReferenceError(
          'Er zijn nog bestaande verwijzingen naar dit item, verwijder deze eerst.',
          true,
          error,
        );
      }

      throw error;
    });
};

export const stringifyQuery = (path: string, params: FetchParams): string => {
  const qsParams = Object.keys(params).map((key) => key + '=' + encodeURIComponent(params[key])).join('&');
  return `${path}?${qsParams}`;
};

const handleResponse = async (response: Response): Promise<Response> => {
  // TODO: singletonFactory can return a 204 on /{itemName}/latest, we have to take that response into account
  if (!response.ok) {
    let errorCode;
    let message;

    if (response.body) {
      const res = await response.json();
      message = res.message;
      errorCode = res.errorCode;
    }

    if (response.status === 401) {
      throw new UnauthorizedError(`Deze gebruiker heeft geen toegang tot ${response.url}`, errorCode);
    }

    throw new HttpError(
      `De server geeft een fout terug. ${response.status}: ${message || response.statusText}`,
      response.status,
      errorCode,
    );
  }

  return response;
};