import { CmsError, HttpError, ReferenceError, UnauthorizedError } from './errors';
import { stringify } from 'query-string';
import { getCmsSettings } from '../tools/settings';

export enum ErrorCode {
  Reference = 3001,
  Validation = 3012
}

export function getServerPath() {
  return (getCmsSettings().apiDomain || '') + '/api';
}

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

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

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

    return handleResponse(response);
  } catch (err) {
    // Known cases for 'TypeError: failed to fetch':
    // - invalid session token (most cases)
    if (err instanceof TypeError && err.message === 'Failed to fetch') {
      throw new CmsError(
        err.message,
        'Er ging iets mis. Mogelijk ben je niet meer ingelogd. Probeer deze pagina te verversen en probeer het opnieuw.<br> Blijf je dit bericht krijgen? Neem dan contact op met jouw contactpersoon voor dit CMS.'
      );
    }

    throw err;
  }
};

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 === ErrorCode.Reference) {
      throw new ReferenceError('', 'Er zijn nog bestaande verwijzingen naar dit item, verwijder deze eerst.', true, error);
    }

    throw error;
  });
};

export const stringifyQuery = (path: string, params: Object): string => {
  if (params) {
    const query = stringify(params, { sort: false });
    return `${path}?${query}`;
  }
  return `${path}`;
};

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 message;
    let friendlyMessage;
    let errorCode;

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

    if (response.status === 401) {
      if (message) {
        throw new UnauthorizedError(message, errorCode);
      }

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

    if (response.body) {
      throw new CmsError(message, friendlyMessage, response.status, errorCode);
    }

    throw new CmsError(message || response.statusText, undefined, response.status, errorCode);
  }

  return response;
};