Api

class Api

import axios, { AxiosRequestConfig } from 'axios';
import queryString from 'query-string';
import { Store } from 'redux';
import { isNil, omitBy, flow } from 'lodash';

import { BASE_URL } from 'redux/constants';
import { showError } from 'redux/actions';
import { isIe } from 'helpers';

const processConfig = (config: AxiosRequestConfig): AxiosRequestConfig => {

  let _config = {
    ...config,
    withCredentials: true,
    paramsSerializer: flow((params) => omitBy(params, isNil), queryString.stringify),
  } as AxiosRequestConfig;

  if (isIe()) {
    _config.headers = {
      ..._config.headers,
      'Cache-Control': 'no-cache',
      'Pragma': 'no-cache',
    };
  }
  return _config;
};

class Api {
  static _instance: Api = new Api();

  store: Store<any> = null;

  static getInstance(): Api {
    return Api._instance;
  }

  constructor() {
    if (Api._instance) {
      throw new Error('Instantiation failed: use Api.getInstance() instead of new.');
    }
  }

  get(url: string, config?: AxiosRequestConfig) {
    return new Promise((resolve, reject) => {
      axios.get(this.getUrl(url), processConfig(config))
        .then(({data}) => resolve(data))
        .catch((error: any) => {
          this.store.dispatch(showError(error));
          return reject(error);
        });
    });
  }

  put(url: string, payload: any = {}, config?: AxiosRequestConfig) {
    return  new Promise((resolve, reject) => {
      axios.put(this.getUrl(url), payload, processConfig(config))
        .then(({data}) => resolve(data))
        .catch((error: any) => {
          this.store.dispatch(showError(error));
          return reject(error);
        });
    });
  }

  post(url: string, payload: any = {}, config?: AxiosRequestConfig) {
    return  new Promise((resolve, reject) => {
      axios.post(this.getUrl(url), payload, processConfig(config))
        .then(({data}) => resolve(data))
        .catch((error: any) => {
          this.store.dispatch(showError(error));
          return reject(error);
        });
    });
  }

  delete(url: string, config?: AxiosRequestConfig) {
    return new Promise((resolve, reject) => {
      axios.delete(this.getUrl(url), processConfig(config))
        .then(({data}) => resolve(data))
        .catch((error: any) => {
          this.store.dispatch(showError(error));
          return reject(error);
        });
    });
  }

  get CancelToken() {
    return axios.CancelToken;
  }

  private getUrl(url: string): string {
    return (!(url.includes('.json') || url.includes('' + BASE_URL)) ? BASE_URL : '') + url;
  }
}

export default Api.getInstance();