import { observes } from 'ember-addons/ember-computed-decorators';

export default Ember.Component.extend({
  tagName: 'table',
  classNames: ['topic-list'],
  showTopicPostBadges: true,

  _init: function(){
    this.addObserver('hideCategory', this.rerender);
    this.addObserver('order', this.rerender);
    this.addObserver('ascending', this.rerender);
    this.refreshLastVisited();
  }.on('init'),

  toggleInTitle: function(){
    return !this.get('bulkSelectEnabled') && this.get('canBulkSelect');
  }.property('bulkSelectEnabled'),

  sortable: function(){
    return !!this.get('changeSort');
  }.property(),

  skipHeader: function() {
    return this.site.mobileView;
  }.property(),

  showLikes: function(){
    return this.get('order') === "likes";
  }.property('order'),

  showOpLikes: function(){
    return this.get('order') === "op_likes";
  }.property('order'),

  @observes('topics.[]')
  topicsAdded() {
    // special case so we don't keep scanning huge lists
    if (!this.get('lastVisitedTopic')) {
      this.refreshLastVisited();
    }
  },

  @observes('topics', 'order', 'ascending', 'category')
  lastVisitedTopicChanged() {
    this.refreshLastVisited();
  },

  _updateLastVisitedTopic(topics, order, ascending) {

    this.set('lastVisitedTopic', null);

    if (!this.get('highlightLastVisited')) {
      return;
    }

    if (order !== "default" && order !== "activity") {
      return;
    }

    if (!topics || topics.length === 1) {
      return;
    }

    if (ascending) {
      return;
    }

    let user = Discourse.User.current();
    if (!user || !user.previous_visit_at) {
      return;
    }

    let lastVisitedTopic, topic;

    let prevVisit = user.get('previousVisitAt');

    // this is more efficient cause we keep appending to list
    // work backwards
    let start = 0;
    while(topics[start] && topics[start].get('pinned')) {
      start++;
    }

    let i;
    for(i=topics.length-1;i>=start;i--){
      if (topics[i].get('bumpedAt') > prevVisit) {
        lastVisitedTopic = topics[i];
        break;
      }
      topic = topics[i];
    }

    if (!lastVisitedTopic || !topic) {
      return;
    }

    // end of list that was scanned
    if (topic.get('bumpedAt') > prevVisit) {
      return;
    }

    this.set('lastVisitedTopic', lastVisitedTopic);
  },

  refreshLastVisited() {
    this._updateLastVisitedTopic(this.get('topics'), this.get('order'), this.get('ascending'));
  },

  click(e) {
    var self = this;
    var onClick = function(sel, callback){
      var target = $(e.target).closest(sel);

      if(target.length === 1){
        callback.apply(self, [target]);
      }
    };

    onClick('button.bulk-select', function(){
      this.sendAction('toggleBulkSelect');
      this.rerender();
    });

    onClick('th.sortable', function(e2){
      this.sendAction('changeSort', e2.data('sort-order'));
      this.rerender();
    });
  }
});