// BigBlueButton open source conferencing system - http://www.bigbluebutton.org/.
//
// Copyright (c) 2016 BigBlueButton Inc. and by respective authors (see below).
//
// This program is free software; you can redistribute it and/or modify it under the
// terms of the GNU Lesser General Public License as published by the Free Software
// Foundation; either version 3.0 of the License, or (at your option) any later
// version.
//
// BigBlueButton is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
// PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License along
// with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.

// Handles live updating and initial population of the previous meetings and active meetings lists on
// the landing page using custom Actioncable events.

var MEETINGS = {}
var WAITING = {}
var LOADING_DELAY = 1750 // milliseconds.

// Updates the previous meetings section.
var updatePreviousMeetings = function(){
  $("ul.previously-joined li").each(function(idx, li) {
    var previous_meeting = $(li);
    if(Object.keys(MEETINGS).indexOf(previous_meeting.text()) > -1){
      previous_meeting.remove()
    }
  });
}

// Ignore excess on either side of user_id.
var trimUserId = function(user_id){
  components = user_id.split('_')
  return components.sort(function (a, b) {return b.length - a.length;})[0]
}

// Finds a user by their user_id.
var findByUserId = function(users, user_id){
  for(i = 0; i < users.length; i++){
    if(trimUserId(users[i]['user_id']) == trimUserId(user_id)){
      return i
    }
  }
  return undefined
}

// Adds a user to a meeting.
var addUser = function(data){
  if(data['role'] == 'MODERATOR'){
    MEETINGS[data['meeting']]['moderators'].push({'name': data['user'], 'user_id': data['user_id']})
  } else {
    MEETINGS[data['meeting']]['participants'].push({'name':data['user'], 'user_id': data['user_id']})
  }
  updateMeetingText(MEETINGS[data['meeting']])
}

// Removes a user from a meeting.
var removeUser = function(data){
  user = findByUserId(MEETINGS[data['meeting']]['moderators'], data['user_id'])
  if(user == undefined){
    user = findByUserId(MEETINGS[data['meeting']]['participants'], data['user_id']);
    if(user == undefined){ return; }
    MEETINGS[data['meeting']]['participants'].splice(user, 1);
  } else {
    MEETINGS[data['meeting']]['moderators'].splice(user, 1);
  }
  updateMeetingText(MEETINGS[data['meeting']])
}

// Updates the display text for an active meeting.
var updateMeetingText = function(m){
  // If a meeting has a moderators property, it is running.
  var body;
  if(m.hasOwnProperty('moderators')){
    var list;
    if(m['moderators'].length + m['participants'].length == 0){
      list = '(empty)'
    } else {
      list = m['moderators'].map(function(x){ return x['name']; }).join('(mod), ') +
        (m['moderators'].length > 0 ? '(mod)' : '') +
        (m['participants'].length > 0 && m['moderators'].length != 0 ? ', ' : '') +
        (m['participants'].map(function(x){ return x['name']; }).join(', '))
    }
    body = '<a>' + m['name'] + '</a><i>: ' + list + '</i>'
  // Otherwise it hasn't started (users waiting the join).
  } else {
    body = '<a>' + m['name'] + '</a><i> (not yet started): ' +  m['users'].join(', ') + '</i>'
  }

  // If the item doesn't exist, add it and set up join meeting event.
  if($("li[id='" +  m['name'].replace(' ', '_') + "']").length == 0){
    var meeting_item = $("<li>" + body + "</li>")
    meeting_item.attr('id', m['name'].replace(' ', '_'))
    $('.actives').append(meeting_item);

    // Set up join on click.
    meeting_item.click(function(){
      joinMeeting(m['name']);
    });
  // Otherwise, just change the body.
  } else {
    $("li[id='" +  m['name'].replace(' ', '_') + "']").html(body)
  }
}

// Initially populates the active meetings when the page loads using the API.
var initialPopulate = function(){
  // Only populate on room resources.
  var chopped = window.location.href.split('/')
  if (!window.location.href.includes('rooms') || chopped[chopped.length - 2] == $('body').data('current-user')) { return; }
  
  $.post((window.location.href + '/statuses').replace('#', ''), {previously_joined: getPreviouslyJoined()})
    .done(function(data) {
      
      // Populate waiting meetings.
      Object.keys(data['waiting']).forEach(function(key) { 
        WAITING[key] = {'name': key, 'users': data['waiting'][key]}
        updateMeetingText(WAITING[key])
      })
      
      // Add the meetings to the active meetings list.
      for(var i = 0; i < data['active'].length; i++){
        var meeting = data['active'][i]
        
        var name = meeting['name']
        var participants = meeting['participants']
        var moderators = meeting['moderators']
        
        // Create meeting.
        MEETINGS[name] = {'name': name, 'participants': participants, 'moderators': moderators}            
        updateMeetingText(MEETINGS[name])
      }
      
      // Remove from previous meetings if they are active.
      updatePreviousMeetings();
      $('.hidden-list').show();
      $('.active-spinner').hide();
    });
}

// Gets a list of known previously joined meetings.
var getPreviouslyJoined = function(){
  var joinedMeetings = localStorage.getItem('joinedRooms-' + $('body').data('current-user'));
  if (joinedMeetings == '' || joinedMeetings == null){ return []; }
  return joinedMeetings.split(',')
}

// Removes an active meeting.
var removeActiveMeeting = function(meeting){
  if(meeting){ $("li[id='" +  meeting['name'].replace(' ', '_') + "']").remove() }
}

// Directly join a meeting from active meetings.
var joinMeeting = function(meeting_name){
  if (meeting_name == undefined || meeting_name == null) { return; }
  Meeting.getInstance().setUserName(localStorage.getItem('lastJoinedName'));
  Meeting.getInstance().setMeetingId(meeting_name);

  var jqxhr = Meeting.getInstance().getJoinMeetingResponse();
  if (jqxhr) {
    jqxhr.done(function(data) {
      if (data.messageKey === 'wait_for_moderator') {
        waitForModerator(Meeting.getInstance().getURL());
      } else {
        $(location).attr("href", data.response.join_url);
      }
    });
    jqxhr.fail(function() {
      console.info("meeting join failed");
    });
  } else {
    $('.meeting-user-name').parent().addClass('has-error');
  }
}

// Only need to register for logged in users.
$(document).on('turbolinks:load', function(){
  if($('body').data('current-user')){
    MEETINGS = {}
    // Ensure actives is empty.
    $('.actives').empty();

    if(!App.messages){
      // Setup actioncable.
      App.messages = App.cable.subscriptions.create('RefreshMeetingsChannel', {
        received: function(data) {
          console.log('Recieved ' + data['method'] + ' action for ' + data['meeting'] + ' with room id ' + data['room'] + '.')
          if(data['room'] == $('body').data('current-user')){
            // Handle webhook event.
            if(data['method'] == 'create'){
              // Create an empty meeting.
              MEETINGS[data['meeting']] = {'name': data['meeting'],
                                          'participants': [],
                                          'moderators': []}
              updateMeetingText(MEETINGS[data['meeting']])
              updatePreviousMeetings();
              if (WAITING.hasOwnProperty(data['meeting'])){ delete WAITING[data['meeting']]; }
            } else if(data['method'] == 'destroy'){
              removeActiveMeeting(MEETINGS[data['meeting']])
              PreviousMeetings.uniqueAdd([data['meeting']])
              delete MEETINGS[data['meeting']]
            } else if(data['method'] == 'join'){
              addUser(data)
            } else if(data['method'] == 'leave'){
              removeUser(data)
            } else if(data['method'] == 'waiting'){
              // Handle waiting meeting.
              if(WAITING.hasOwnProperty(data['meeting'])){
                WAITING[data['meeting']]['users'].push(data['user'])
                updateMeetingText(WAITING[data['meeting']])
              } else {
                WAITING[data['meeting']] = {'name': data['meeting'],
                                            'users': [data['user']]}
                updateMeetingText(WAITING[data['meeting']])
              }
            } else if((data['method'] == 'no_longer_waiting') && (WAITING.hasOwnProperty(data['meeting']))){
                WAITING[data['meeting']]['users'].splice(WAITING[data['meeting']]['users'].indexOf(data['user']), 1)
                updateMeetingText(WAITING[data['meeting']])
                if(WAITING[data['meeting']]['users'].length == 0){
                  removeActiveMeeting(WAITING[data['meeting']])
                  delete WAITING[data['meeting']]
                }
            }
          }
        }
      });
    }

    console.log('Populating active meetings.');
    // Short delay to hide the previous meetings population.
    setTimeout(initialPopulate, LOADING_DELAY);
  }
});