import { API_URL } from '../constants/constants.js';

export const constructUrl = (path, params, host = API_URL) => {
  if (!(/^\//g).test(path)) {
    throw new Error(`Invalid path! Expecting a valid relative path (path needs to start with /)(${path})`);
  }

  let url = path;

  if (host) {
    url = `${host}${url}`;
  }

  if (params) {
    url = `${url}?${params}`;
  }

  return url;
};

/**
 * Formats data for a POST request.
 *
 * @param {Object} body - data to be passed to the POST endpoint
 * @param {Boolean} isTraditional - similar to jQuery's option `traditional` for $.ajax(),
 *                  this serializes data in a way that helps support legacy endpoints
 */
export const formatPostData = (body) => {
  const postData = new FormData();
  Object.keys(body).forEach(key => postData.append(key, body[key]));
  return postData;
};

const parseQueryParamsString = (queryParams) => {
  if (typeof queryParams !== 'string') {
    return null;
  }

  return queryParams;
};

const parseQueryParamsObject = (queryParams) => {
  if (queryParams === null || typeof queryParams !== 'object' || Array.isArray(queryParams)) {
    return null;
  }

  return Object
    .keys(queryParams)
    .map((key) => {
      const value = queryParams[key];
      return `${encodeURIComponent(key)}=${encodeURIComponent(value)}`;
    })
    .join('&');
};

const parseQueryParamsArray = (queryParams) => {
  if (!Array.isArray(queryParams)) {
    return null;
  }

  return queryParams
    .map((param) => {
      const [key, value] = param.split('=');
      return `${encodeURIComponent(key)}=${encodeURIComponent(value)}`;
    })
    .join('&');
};

export const parseQueryParams = queryParams => (
  parseQueryParamsString(queryParams) ||
  parseQueryParamsObject(queryParams) ||
  parseQueryParamsArray(queryParams) ||
  ''
);

export const request = (url, options) => {
  try {
    return fetch(url, options).catch((err) => console.error(err));
  } catch (error) {
    return Promise.reject(error);
  }
};

export const unwrapJson = (response) => response.json();

export const validateResponse = (response) => response;