import _ from 'lodash';
import Captions from '/imports/api/captions';
import Users from '/imports/api/users';
import Auth from '/imports/ui/services/auth';
import { makeCall } from '/imports/ui/services/api';
import { Meteor } from 'meteor/meteor';
import { Session } from 'meteor/session';

const CAPTIONS_CONFIG = Meteor.settings.public.captions;
const CAPTIONS_TOKEN = '_cc_';
const LINE_BREAK = '\n';
const ROLE_MODERATOR = Meteor.settings.public.user.role_moderator;

const getActiveCaptions = () => {
  const activeCaptions = Session.get('activeCaptions');
  if (!activeCaptions) return '';
  return activeCaptions;
};

const getCaptions = locale => Captions.findOne({
  meetingId: Auth.meetingID,
  locale,
});

const getCaptionsData = () => {
  const activeCaptions = getActiveCaptions();
  let locale = '';
  let revs = 0;
  let data = '';
  if (activeCaptions) {
    const captions = getCaptions(activeCaptions);
    if (!_.isEmpty(captions)) {
      locale = activeCaptions;
      revs = captions.revs; // eslint-disable-line prefer-destructuring
      data = captions.data; // eslint-disable-line prefer-destructuring
    }
  }

  return { locale, revs, data };
};

const getAvailableLocales = () => {
  const { meetingID } = Auth;
  const locales = [];
  Captions.find({ meetingId: meetingID },
    { sort: { locale: 1 } },
    { fields: { ownerId: 1, locale: 1, name: 1 } })
    .forEach((caption) => {
      if (caption.ownerId === '') {
        locales.push({
          locale: caption.locale,
          name: caption.name,
        });
      }
    });
  return locales;
};

const getOwnedLocales = () => {
  const { meetingID } = Auth;
  const locales = [];
  Captions.find({ meetingId: meetingID },
    { fields: { ownerId: 1, locale: 1, name: 1 } })
    .forEach((caption) => {
      if (caption.ownerId !== '') {
        locales.push({
          locale: caption.locale,
          name: caption.name,
        });
      }
    });
  return locales;
};

const takeOwnership = (locale) => {
  makeCall('takeOwnership', locale);
};

const appendText = (text, locale) => {
  if (typeof text !== 'string' || text.length === 0) return;

  const formattedText = `${text.trim().replace(/^\w/, (c) => c.toUpperCase())}\n\n`;
  makeCall('appendText', formattedText, locale);
};

const canIOwnThisPad = (ownerId) => {
  const { userID } = Auth;
  if (!CAPTIONS_CONFIG.takeOwnership) return false;
  if (ownerId === '') return false;
  return ownerId !== userID;
};

const getSpeechRecognitionAPI = () => window.SpeechRecognition || window.webkitSpeechRecognition;

const canIDictateThisPad = (ownerId) => {
  const { userID } = Auth;
  if (!CAPTIONS_CONFIG.enableDictation) return false;
  if (ownerId === '') return false;
  const SpeechRecognitionAPI = getSpeechRecognitionAPI();
  if (!SpeechRecognitionAPI) return false;
  return ownerId === userID;
};

const setActiveCaptions = (locale) => {
  Session.set('activeCaptions', locale);
};

const setCaptionsSettings = (settings) => {
  Session.set('captionsSettings', settings);
};

const getCaptionsSettings = () => {
  const settings = Session.get('captionsSettings');
  if (!settings) {
    const {
      backgroundColor, fontColor, fontFamily, fontSize,
    } = CAPTIONS_CONFIG;
    return {
      backgroundColor, fontColor, fontFamily, fontSize,
    };
  }
  return settings;
};

const isCaptionsEnabled = () => {
  const captions = Captions.findOne({ meetingId: Auth.meetingID });
  return CAPTIONS_CONFIG.enabled && captions;
};

const isCaptionsAvailable = () => {
  if (isCaptionsEnabled) {
    const ownedLocales = getOwnedLocales();
    return (ownedLocales.length > 0);
  }
  return false;
};

const isCaptionsActive = () => {
  const enabled = isCaptionsEnabled();
  const activated = getActiveCaptions() !== '';
  return (enabled && activated);
};

const deactivateCaptions = () => {
  setActiveCaptions('');
};

const activateCaptions = (locale, settings) => {
  setCaptionsSettings(settings);
  setActiveCaptions(locale);
};

const formatCaptionsText = (text) => {
  const splitText = text.split(LINE_BREAK);
  const filteredText = splitText.filter((line, index) => {
    const lastLine = index === (splitText.length - 1);
    const emptyLine = line.length === 0;
    return (!emptyLine || lastLine);
  });
  while (filteredText.length > CAPTIONS_CONFIG.lines) filteredText.shift();
  return filteredText.join(LINE_BREAK);
};

const amIModerator = () => Users.findOne({ userId: Auth.userID },
  { fields: { role: 1 } }).role === ROLE_MODERATOR;

const initSpeechRecognition = (locale) => {
  const SpeechRecognitionAPI = getSpeechRecognitionAPI();
  let recognition = null;
  if (SpeechRecognitionAPI) {
    recognition = new SpeechRecognitionAPI();
    recognition.continuous = true;
    recognition.interimResults = true;
    recognition.lang = locale;
  }

  return recognition;
};

export default {
  CAPTIONS_TOKEN,
  getCaptionsData,
  getAvailableLocales,
  getOwnedLocales,
  takeOwnership,
  appendText,
  getCaptions,
  canIOwnThisPad,
  canIDictateThisPad,
  getCaptionsSettings,
  isCaptionsEnabled,
  isCaptionsAvailable,
  isCaptionsActive,
  deactivateCaptions,
  activateCaptions,
  formatCaptionsText,
  amIModerator,
  initSpeechRecognition,
};