/*
 * Copyright 2012 Igor Kalnitsky <igor@kalnitsky.org>
 *
 * This file is part of Listbox.js.
 *
 * Listbox.js 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 of
 * the License, or (at your option) any later version.
 *
 * Listbox.js 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 Listbox.js.  If not, see <http://www.gnu.org/licenses/>.
 */

(function ($) {

    /**
    * A listbox class.
    *
    * Receive an elements as first argument, and options as a second.
    */
    function Listbox() {
        this._init.apply(this, arguments);
    }

    Listbox.prototype = {
        //
        // CSS classes used by plugin
        //

        MAIN_CLASS: 'lbjs',
        LIST_CLASS: 'lbjs-list',
        LIST_ITEM_CLASS: 'lbjs-item',
        SEARCHBAR_CLASS: 'lbjs-searchbar',

        //
        // A plugin internal methods
        //

        _init: function () {
            this._parent = arguments[0];
            this._settings = arguments[1];

            // create new flexible element
            this._createListbox();
            // hide parent element
            this._parent.css('display', 'none');
            // select first element by default
            this._setItem(this._list.children().first());
        },

        _createListbox: function () {
            this._listbox = $('<div>')
                .addClass(this.MAIN_CLASS)
                .insertAfter(this._parent);

            if (this._settings['class'] !== null)
                this._listbox.addClass(this._settings['class']);

            this._createSearchbar();
            this._createList();
        },

        _createSearchbar: function () {
            if (!this._settings['searchbar'])
                return;

            // searchbar wrapper is needed for properly stretch
            // the seacrhbar over the listbox width
            var searchbarWrapper = $('<div>')
                .addClass(this.SEARCHBAR_CLASS + '-wrapper')
                .appendTo(this._listbox);

            var searchbar = $('<input>')
                .addClass(this.SEARCHBAR_CLASS)
                .appendTo(searchbarWrapper)
                .attr('placeholder', 'search...');

            // set filter handler
            var instance = this;
            searchbar.keyup(function () {
                var searchQuery = $(this).val().toLowerCase();

                if (searchQuery !== '') {
                    // hide list items which not matched search query
                    instance._list.children().each(function (index) {
                        var text = $(this).text().toLowerCase();

                        if (text.search('^' + searchQuery) != -1) {
                            $(this).css('display', 'block');
                        } else {
                            $(this).css('display', 'none');

                            // remove selection from hidden elements to
                            // protect against implicitly influence
                            instance._unselectItem($(this));
                        }
                    });
                } else {
                    // make visible all list items
                    instance._list.children().each(function () {
                        $(this).css('display', 'block')
                    });
                }

                // select first visible element if none select yet
                var isItemSelect = instance._list.children('[selected]').length > 0;
                if (!instance._settings['multiselect'] && !isItemSelect)
                    instance._setItem(instance._list.children(':visible').first());
            });

            // save for using in _resizeListToListbox()
            this._searchbarWrapper = searchbarWrapper;
        },

        _createList: function () {
            // create container
            this._list = $('<div>')
                .addClass(this.LIST_CLASS)
                .appendTo(this._listbox);

            this._resizeListToListbox();

            // create items
            var instance = this;
            this._parent.children().each(function () {
                var item = $('<input type=checkbox />')
                    .addClass(instance.LIST_ITEM_CLASS)
                    .appendTo(instance._list)
                    .after('<a class="searchLink" itcID=' + $(this).val() + ' itcType=' + $(this).attr('itcType') + ' href="#"><span>' + $(this).text() + '</span> </a>' + '<br />')
                    .attr('ID', $(this).val())
                    .attr('itcType', $(this).attr('itcType'))
                    .click(function () {
                        instance._settings['multiselect']
                            ? instance._toggleItem($(this))
                            : instance._setItem($(this));
                    });

                if ($(this).attr('disabled'))
                    item.attr('disabled', '');
            });

        },

        _selectItem: function (item) {
//            if (item.attr('checked'))
//                return;

//            item.attr('checked', 'checked');

//            // make changes in real list
//            var selectItem = this._parent.children().get(item.index());
//            $(selectItem).attr('checked', 'checked');
        },

        _unselectItem: function (item) {
//            item.removeAttr('checked');

//            // make changes in real list
//            var selectItem = this._parent.children().get(item.index());
//            $(selectItem).removeAttr('checked');
        },

        // this function used by singleselect listbox
        _setItem: function (item) {
            if (item.attr('disabled'))
                return;

            var options = this._parent.children('[selected]');

            this._list.children('[selected]').each(function (index) {
                $(this).removeAttr('selected');
                $(options.get(index)).removeAttr('selected');
            });

            this._selectItem(item);
        },

        // this function used by multiselect listbox
        _toggleItem: function (item) {
            item.attr('selected')
                ? this._unselectItem(item)
                : this._selectItem(item);
        },

        _resizeListToListbox: function () {
            var listHeight = this._listbox.height();

            if (this._settings['searchbar'])
                listHeight -= this._searchbarWrapper.outerHeight(true);

            this._list.height(listHeight);
        }
    }


    /**
    * jQuery plugin definition.
    */
    $.fn.listbox = function (options) {
        var settings = $.extend({
            'class': null,
            'searchbar': true,
            'multiselect': false
        }, options);

        return this.each(function () {
            new Listbox($(this), settings)
        });
    }
})(jQuery);