_.extend($.fn.typeahead.Constructor.prototype, {
    render: function (items) {
        var that = this;

        items = $(items).map(function (i, item) {
            i = $(that.options.item)
                .attr('data-value', item[that.options.display])
                .attr('data-id', item.id);
            i.find('a').html(that.highlighter(item));
            return i[0];
        });

        items.first().addClass('active');
        this.$menu.html(items);
        return this;
    },
    select: function () {
        var val = this.$menu.find('.active').attr('data-value'),
            id = this.$menu.find('.active').attr('data-id');
        this.$element
            .val(this.updater(val, id))
            .change();
        return this.hide()
    }
});

return function (element, options) {
    var getSource = function () {
        var users = app.userCollection.filter(function (model) {
            if (options && options.excludeCurrentUser) {
                return model.id !== app.currentUser.id;
            }
        });
        return _.map(users, function (user) {
            return {
                id: user.get('id'),
                full_name: user.get('first_name') + ' ' + user.get('last_name')
            };
        });
    };

    element.typeahead({
        minLength: 3,
        source: getSource,
        display: 'full_name',
        sorter: function (items) {

            var beginswith = [],
                caseSensitive = [],
                caseInsensitive = [],
                item,
                itemDisplayed;

            while (item = items.shift()) {
                itemDisplayed = item[this.options.display];
                if (!itemDisplayed.toLowerCase().indexOf(this.query.toLowerCase())) {
                    beginswith.push(item);
                } else if (~itemDisplayed.indexOf(this.query)) {
                    caseSensitive.push(item);
                } else {
                    caseInsensitive.push(item);
                }
            }

            return beginswith.concat(caseSensitive, caseInsensitive);
        },
        highlighter: function (item) {
            var query = this.query.replace(/[\-\[\]{}()*+?.,\\\^$|#\s]/g, '\\$&');

            return item[this.options.display].replace(new RegExp('(' + query + ')', 'ig'), function ($1, match) {
                return '<strong>' + match + '</strong>';
            });
        },
        matcher: function (item) {
            var value = item[this.options.display];

            return {
                value: ~value.toLowerCase().indexOf(this.query.toLowerCase()),
                id: item.id
            };
        },
        updater: function (item, userId) {
            options.hiddenInputElement.val(userId);
            return item;
        }
    });
};