import yaml from 'js-yaml';
import { set, defaultsDeep } from 'lodash';
import { currentBackend } from '../backends/backend';
import { authenticate } from '../actions/auth';
import * as MediaProxy from '../valueObjects/MediaProxy';
import * as publishModes from '../constants/publishModes';

export const CONFIG_REQUEST = 'CONFIG_REQUEST';
export const CONFIG_SUCCESS = 'CONFIG_SUCCESS';
export const CONFIG_FAILURE = 'CONFIG_FAILURE';

const defaults = {
  publish_mode: publishModes.SIMPLE,
};

export function applyDefaults(config) {
  if (!('media_folder' in config)) {
    throw new Error('Error in configuration file: A `media_folder` wasn\'t found. Check your config.yml file.');
  }

  // Make sure there is a public folder
  set(defaults,
    'public_folder',
    config.media_folder.charAt(0) === '/' ? config.media_folder : `/${ config.media_folder }`);

  return defaultsDeep(config, defaults);
}

function parseConfig(data) {
  const config = yaml.safeLoad(data);
  if (typeof CMS_ENV === 'string' && config[CMS_ENV]) {
    // TODO: Add tests and refactor
    for (const key in config[CMS_ENV]) { // eslint-disable-line no-restricted-syntax
      if (config[CMS_ENV].hasOwnProperty(key)) { // eslint-disable-line no-prototype-builtins
        config[key] = config[CMS_ENV][key];
      }
    }
  }

  return config;
}


export function configLoaded(config) {
  return {
    type: CONFIG_SUCCESS,
    payload: config,
  };
}

export function configLoading() {
  return {
    type: CONFIG_REQUEST,
  };
}

export function configFailed(err) {
  return {
    type: CONFIG_FAILURE,
    error: 'Error loading config',
    payload: err,
  };
}

export function configDidLoad(config) {
  return (dispatch) => {
    MediaProxy.setConfig(config);
    dispatch(configLoaded(config));
  };
}

export function loadConfig() {
  if (window.CMS_CONFIG) {
    return configDidLoad(window.CMS_CONFIG);
  }
  return (dispatch) => {
    dispatch(configLoading());

    fetch('config.yml').then((response) => {
      if (response.status !== 200) {
        throw new Error(`Failed to load config.yml (${ response.status })`);
      }

      response
        .text()
        .then(parseConfig)
        .then(applyDefaults)
        .then((config) => {
          dispatch(configDidLoad(config));
          const backend = currentBackend(config);
          const user = backend && backend.currentUser();
          if (user) dispatch(authenticate(user));
        });
    }).catch((err) => {
      dispatch(configFailed(err));
    });
  };
}