/**
 * bootstrap-multiselect.js
 * https://github.com/davidstutz/bootstrap-multiselect
 *
 * Copyright 2012, 2013 David Stutz
 *
 * Dual licensed under the BSD-3-Clause and the Apache License, Version 2.0.
 */
!function($) {

    "use strict";// jshint ;_;

    if (typeof ko !== 'undefined' && ko.bindingHandlers && !ko.bindingHandlers.multiselect) {
        ko.bindingHandlers.multiselect = {
            init: function(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {},
            update: function(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {

               var config = ko.utils.unwrapObservable(valueAccessor());
               var selectOptions = allBindingsAccessor().options;
               var ms = $(element).data('multiselect');

               if (!ms) {
                  $(element).multiselect(config);
               }
               else {
                  ms.updateOriginalOptions();
                  if (selectOptions && selectOptions().length !== ms.originalOptions.length) {
                     $(element).multiselect('rebuild');
                  }
               }
            }
        };
    }

    /**
     * Constructor to create a new multiselect using the given select.
     * 
     * @param {jQuery} select
     * @param {Object} options
     * @returns {Multiselect}
     */
    function Multiselect(select, options) {

        this.options = this.mergeOptions(options);
        this.$select = $(select);

        // Initialization.
        // We have to clone to create a new reference.
        this.originalOptions = this.$select.clone()[0].options;
        this.query = '';
        this.searchTimeout = null;

        this.options.multiple = this.$select.attr('multiple') === "multiple";
        this.options.onChange = $.proxy(this.options.onChange, this);
        this.options.onDropdownShow = $.proxy(this.options.onDropdownShow, this);
        this.options.onDropdownHide = $.proxy(this.options.onDropdownHide, this);

        // Build select all if enabled.
        this.buildContainer();
        this.buildButton();
        this.buildSelectAll();
        this.buildDropdown();
        this.buildDropdownOptions();
        this.buildFilter();
        
        this.updateButtonText();
        this.updateSelectAll();
        
        this.$select.hide().after(this.$container);
    };

    Multiselect.prototype = {

        defaults: {
            /**
             * Default text function will either print 'None selected' in case no
             * option is selected or a list of the selected options up to a length of 3 selected options.
             * 
             * @param {jQuery} options
             * @param {jQuery} select
             * @returns {String}
             */
            buttonText: function(options, select) {
                if (options.length === 0) {
                    return this.nonSelectedText + ' <b class="caret"></b>';
                }
                else {
                    if (options.length > this.numberDisplayed) {
                        return options.length + ' ' + this.nSelectedText + ' <b class="caret"></b>';
                    }
                    else {
                        var selected = '';
                        options.each(function() {
                            var label = ($(this).attr('label') !== undefined) ? $(this).attr('label') : $(this).html();

                            selected += label + ', ';
                        });
                        return selected.substr(0, selected.length - 2) + ' <b class="caret"></b>';
                    }
                }
            },
            /**
             * Updates the title of the button similar to the buttonText function.
             * @param {jQuery} options
             * @param {jQuery} select
             * @returns {@exp;selected@call;substr}
             */
            buttonTitle: function(options, select) {
                if (options.length === 0) {
                    return this.nonSelectedText;
                }
                else {
                    var selected = '';
                    options.each(function () {
                        selected += $(this).text() + ', ';
                    });
                    return selected.substr(0, selected.length - 2);
                }
            },
            /**
             * Create a label.
             * 
             * @param {jQuery} element
             * @returns {String}
             */
            label: function(element){
                return $(element).attr('label') || $(element).html();
            },
            /**
             * Triggered on change of the multiselect.
             * Not triggered when selecting/deselecting options manually.
             * 
             * @param {jQuery} option
             * @param {Boolean} checked
             */
            onChange : function(option, checked) {

            },
            /**
             * Triggered when the dropdown is shown.
             * 
             * @param {jQuery} event
             */
            onDropdownShow: function(event) {

            },
            /**
             * Triggered when the dropdown is hidden.
             * 
             * @param {jQuery} event
             */
            onDropdownHide: function(event) {

            },
            buttonClass: 'btn btn-default',
            dropRight: false,
            selectedClass: 'active',
            buttonWidth: 'auto',
            buttonContainer: '<div class="btn-group" />',
            // Maximum height of the dropdown menu.
            // If maximum height is exceeded a scrollbar will be displayed.
            maxHeight: false,
            includeSelectAllOption: false,
            selectAllText: ' Select all',
            selectAllValue: 'multiselect-all',
            enableFiltering: false,
            enableCaseInsensitiveFiltering: false,
            filterPlaceholder: 'Search',
            // possible options: 'text', 'value', 'both'
            filterBehavior: 'text',
            preventInputChangeEvent: false,
            nonSelectedText: 'None selected',
            nSelectedText: 'selected',
            numberDisplayed: 3
        },

        templates: {
            button: '<button type="button" class="multiselect dropdown-toggle" data-toggle="dropdown"></button>',
            ul: '<ul class="multiselect-container dropdown-menu"></ul>',
            filter: '<div class="input-group"><span class="input-group-addon"><i class="glyphicon glyphicon-search"></i></span><input class="form-control multiselect-search" type="text"></div>',
            li: '<li><a href="javascript:void(0);"><label></label></a></li>',
            divider: '<li class="divider"></li>',
            liGroup: '<li><label class="multiselect-group"></label></li>'
        },

        constructor: Multiselect,

        /**
         * Builds the container of the multiselect.
         */
        buildContainer: function() {
            this.$container = $(this.options.buttonContainer);
            this.$container.on('show.bs.dropdown', this.options.onDropdownShow);
            this.$container.on('hide.bs.dropdown', this.options.onDropdownHide);
        },

        /**
         * Builds the button of the multiselect.
         */
        buildButton: function() {
            this.$button = $(this.templates.button).addClass(this.options.buttonClass);

            // Adopt active state.
            if (this.$select.prop('disabled')) {
                this.disable();
            }
            else {
                this.enable();
            }

            // Manually add button width if set.
            if (this.options.buttonWidth && this.options.buttonWidth != 'auto') {
                this.$button.css({
                    'width' : this.options.buttonWidth
                });
            }

            // Keep the tab index from the select.
            var tabindex = this.$select.attr('tabindex');
            if (tabindex) {
                this.$button.attr('tabindex', tabindex);
            }

            this.$container.prepend(this.$button);
        },

        /**
         * Builds the ul representing the dropdown menu.
         */
        buildDropdown: function() {

            // Build ul.
            this.$ul = $(this.templates.ul);

            if (this.options.dropRight) {
                this.$ul.addClass('pull-right');
            }

            // Set max height of dropdown menu to activate auto scrollbar.
            if (this.options.maxHeight) {
                // TODO: Add a class for this option to move the css declarations.
                this.$ul.css({
                    'max-height': this.options.maxHeight + 'px',
                    'overflow-y': 'auto',
                    'overflow-x': 'hidden'
                });
            }

            this.$container.append(this.$ul);
        },

        /**
         * Build the dropdown options and binds all nessecary events.
         * Uses createDivider and createOptionValue to create the necessary options.
         */
        buildDropdownOptions: function() {

            this.$select.children().each($.proxy(function(index, element) {
                
                // Support optgroups and options without a group simultaneously.
                var tag = $(element).prop('tagName')
                    .toLowerCase();

                if (tag === 'optgroup') {
                    this.createOptgroup(element);
                }
                else if (tag === 'option') {

                    if ($(element).data('role') === 'divider') {
                        this.createDivider();
                    }
                    else {
                        this.createOptionValue(element);
                    }

                }
                
                // Other illegal tags will be ignored.
            }, this));

            // Bind the change event on the dropdown elements.
            $('li input', this.$ul).on('change', $.proxy(function(event) {
                var checked = $(event.target).prop('checked') || false;
                var isSelectAllOption = $(event.target).val() === this.options.selectAllValue;

                // Apply or unapply the configured selected class.
                if (this.options.selectedClass) {
                    if (checked) {
                        $(event.target).parents('li')
                            .addClass(this.options.selectedClass);
                    }
                    else {
                        $(event.target).parents('li')
                            .removeClass(this.options.selectedClass);
                    }
                }

                // Get the corresponding option.
                var value = $(event.target).val();
                var $option = this.getOptionByValue(value);

                var $optionsNotThis = $('option', this.$select).not($option);
                var $checkboxesNotThis = $('input', this.$container).not($(event.target));

                if (isSelectAllOption) {
                    if (this.$select[0][0].value === this.options.selectAllValue) {
                        var values = [];
                        var options = $('option[value!="' + this.options.selectAllValue + '"]', this.$select);
                        for (var i = 0; i < options.length; i++) {
                            // Additionally check whether the option is visible within the dropcown.
                            if (options[i].value !== this.options.selectAllValue && this.getInputByValue(options[i].value).is(':visible')) {
                                values.push(options[i].value);
                            }
                        }

                        if (checked) {
                            this.select(values);
                        }
                        else {
                            this.deselect(values);
                        }
                    }
                }

                if (checked) {
                    $option.prop('selected', true);

                    if (this.options.multiple) {
                        // Simply select additional option.
                        $option.prop('selected', true);
                    }
                    else {
                        // Unselect all other options and corresponding checkboxes.
                        if (this.options.selectedClass) {
                            $($checkboxesNotThis).parents('li').removeClass(this.options.selectedClass);
                        }

                        $($checkboxesNotThis).prop('checked', false);
                        $optionsNotThis.prop('selected', false);

                        // It's a single selection, so close.
                        this.$button.click();
                    }

                    if (this.options.selectedClass === "active") {
                        $optionsNotThis.parents("a").css("outline", "");
                    }
                }
                else {
                    // Unselect option.
                    $option.prop('selected', false);
                }

                this.$select.change();
                this.options.onChange($option, checked);
                
                this.updateButtonText();
                this.updateSelectAll();

                if(this.options.preventInputChangeEvent) {
                    return false;
                }
            }, this));

            $('li a', this.$ul).on('touchstart click', function(event) {
                event.stopPropagation();

                if (event.shiftKey) {
                    var checked = $(event.target).prop('checked') || false;

                    if (checked) {
                        var prev = $(event.target).parents('li:last')
                            .siblings('li[class="active"]:first');

                        var currentIdx = $(event.target).parents('li')
                            .index();
                        var prevIdx = prev.index();

                        if (currentIdx > prevIdx) {
                            $(event.target).parents("li:last").prevUntil(prev).each(
                                function() {
                                    $(this).find("input:first").prop("checked", true)
                                        .trigger("change");
                                }
                            );
                        }
                        else {
                            $(event.target).parents("li:last").nextUntil(prev).each(
                                function() {
                                    $(this).find("input:first").prop("checked", true)
                                        .trigger("change");
                                }
                            );
                        }
                    }
                }

                $(event.target).blur();
            });

            // Keyboard support.
            this.$container.on('keydown', $.proxy(function(event) {
                if ($('input[type="text"]', this.$container).is(':focus')) {
                    return;
                }
                if ((event.keyCode === 9 || event.keyCode === 27)
                        && this.$container.hasClass('open')) {
                    
                    // Close on tab or escape.
                    this.$button.click();
                }
                else {
                    var $items = $(this.$container).find("li:not(.divider):visible a");

                    if (!$items.length) {
                        return;
                    }

                    var index = $items.index($items.filter(':focus'));

                    // Navigation up.
                    if (event.keyCode === 38 && index > 0) {
                        index--;
                    }
                    // Navigate down.
                    else if (event.keyCode === 40 && index < $items.length - 1) {
                        index++;
                    }
                    else if (!~index) {
                        index = 0;
                    }

                    var $current = $items.eq(index);
                    $current.focus();

                    if (event.keyCode === 32 || event.keyCode === 13) {
                        var $checkbox = $current.find('input');

                        $checkbox.prop("checked", !$checkbox.prop("checked"));
                        $checkbox.change();
                    }

                    event.stopPropagation();
                    event.preventDefault();
                }
            }, this));
        },

        /**
         * Create an option using the given select option.
         * 
         * @param {jQuery} element
         */
        createOptionValue: function(element) {
            if ($(element).is(':selected')) {
                $(element).prop('selected', true);
            }

            // Support the label attribute on options.
            var label = this.options.label(element);
            var value = $(element).val();
            var inputType = this.options.multiple ? "checkbox" : "radio";

            var $li = $(this.templates.li);
            $('label', $li).addClass(inputType);
            $('label', $li).append('<input type="' + inputType + '" />');

            var selected = $(element).prop('selected') || false;
            var $checkbox = $('input', $li);
            $checkbox.val(value);

            if (value === this.options.selectAllValue) {
                $checkbox.parent().parent()
                    .addClass('multiselect-all');
            }

            $('label', $li).append(" " + label);

            this.$ul.append($li);

            if ($(element).is(':disabled')) {
                $checkbox.attr('disabled', 'disabled')
                    .prop('disabled', true)
                    .parents('li')
                    .addClass('disabled');
            }

            $checkbox.prop('checked', selected);

            if (selected && this.options.selectedClass) {
                $checkbox.parents('li')
                    .addClass(this.options.selectedClass);
            }
        },

        /**
         * Creates a divider using the given select option.
         * 
         * @param {jQuery} element
         */
        createDivider: function(element) {
            var $divider = $(this.templates.divider);
            this.$ul.append($divider);
        },

        /**
         * Creates an optgroup.
         * 
         * @param {jQuery} group
         */
        createOptgroup: function(group) {
            var groupName = $(group).prop('label');

            // Add a header for the group.
            var $li = $(this.templates.liGroup);
            $('label', $li).text(groupName);

            this.$ul.append($li);

            // Add the options of the group.
            $('option', group).each($.proxy(function(index, element) {
                this.createOptionValue(element);
            }, this));
        },

        /**
         * Build the selct all.
         * Checks if a select all ahs already been created.
         */
        buildSelectAll: function() {
            var alreadyHasSelectAll = this.hasSelectAll();
            
            // If options.includeSelectAllOption === true, add the include all checkbox.
            if (this.options.includeSelectAllOption && this.options.multiple && !alreadyHasSelectAll) {
                this.$select.prepend('<option value="' + this.options.selectAllValue + '">' + this.options.selectAllText + '</option>');
            }
        },

        /**
         * Builds the filter.
         */
        buildFilter: function() {

            // Build filter if filtering OR case insensitive filtering is enabled and the number of options exceeds (or equals) enableFilterLength.
            if (this.options.enableFiltering || this.options.enableCaseInsensitiveFiltering) {
                var enableFilterLength = Math.max(this.options.enableFiltering, this.options.enableCaseInsensitiveFiltering);

                if (this.$select.find('option').length >= enableFilterLength) {

                    this.$filter = $(this.templates.filter);
                    $('input', this.$filter).attr('placeholder', this.options.filterPlaceholder);
                    this.$ul.prepend(this.$filter);

                    this.$filter.val(this.query).on('click', function(event) {
                        event.stopPropagation();
                    }).on('input keydown', $.proxy(function(event) {
                        // This is useful to catch "keydown" events after the browser has updated the control.
                        clearTimeout(this.searchTimeout);

                        this.searchTimeout = this.asyncFunction($.proxy(function() {

                            if (this.query !== event.target.value) {
                                this.query = event.target.value;

                                $.each($('li', this.$ul), $.proxy(function(index, element) {
                                    var value = $('input', element).val();
                                    var text = $('label', element).text();

                                    if (value !== this.options.selectAllValue && text) {
                                        // by default lets assume that element is not
                                        // interesting for this search
                                        var showElement = false;

                                        var filterCandidate = '';
                                        if ((this.options.filterBehavior === 'text' || this.options.filterBehavior === 'both')) {
                                            filterCandidate = text;
                                        }
                                        if ((this.options.filterBehavior === 'value' || this.options.filterBehavior === 'both')) {
                                            filterCandidate = value;
                                        }

                                        if (this.options.enableCaseInsensitiveFiltering && filterCandidate.toLowerCase().indexOf(this.query.toLowerCase()) > -1) {
                                            showElement = true;
                                        }
                                        else if (filterCandidate.indexOf(this.query) > -1) {
                                            showElement = true;
                                        }

                                        if (showElement) {
                                            $(element).show();
                                        }
                                        else {
                                            $(element).hide();
                                        }
                                    }
                                }, this));
                            }

                            // TODO: check whether select all option needs to be updated.
                        }, this), 300, this);
                    }, this));
                }
            }
        },

        /**
         * Unbinds the whole plugin.
         */
        destroy: function() {
            this.$container.remove();
            this.$select.show();
        },

        /**
         * Refreshs the multiselect based on the selected options of the select.
         */
        refresh: function() {
            $('option', this.$select).each($.proxy(function(index, element) {
                var $input = $('li input', this.$ul).filter(function() {
                    return $(this).val() === $(element).val();
                });

                if ($(element).is(':selected')) {
                    $input.prop('checked', true);

                    if (this.options.selectedClass) {
                        $input.parents('li')
                            .addClass(this.options.selectedClass);
                    }
                }
                else {
                    $input.prop('checked', false);

                    if (this.options.selectedClass) {
                        $input.parents('li')
                            .removeClass(this.options.selectedClass);
                    }
                }

                if ($(element).is(":disabled")) {
                    $input.attr('disabled', 'disabled')
                        .prop('disabled', true)
                        .parents('li')
                        .addClass('disabled');
                }
                else {
                    $input.prop('disabled', false)
                        .parents('li')
                        .removeClass('disabled');
                }
            }, this));

            this.updateButtonText();
            this.updateSelectAll();
        },

        /**
         * Select all options of the given values.
         * 
         * @param {Array} selectValues
         */
        select: function(selectValues) {
            if(selectValues && !$.isArray(selectValues)) {
                selectValues = [selectValues];
            }

            for (var i = 0; i < selectValues.length; i++) {
                var value = selectValues[i];

                var $option = this.getOptionByValue(value);
                var $checkbox = this.getInputByValue(value);

                if (this.options.selectedClass) {
                    $checkbox.parents('li')
                        .addClass(this.options.selectedClass);
                }

                $checkbox.prop('checked', true);
                $option.prop('selected', true);
            }

            this.updateButtonText();
        },

        /**
         * Deselects all options of the given values.
         * 
         * @param {Array} deselectValues
         */
        deselect: function(deselectValues) {
            if(deselectValues && !$.isArray(deselectValues)) {
                deselectValues = [deselectValues];
            }

            for (var i = 0; i < deselectValues.length; i++) {

                var value = deselectValues[i];

                var $option = this.getOptionByValue(value);
                var $checkbox = this.getInputByValue(value);

                if (this.options.selectedClass) {
                    $checkbox.parents('li')
                        .removeClass(this.options.selectedClass);
                }

                $checkbox.prop('checked', false);
                $option.prop('selected', false);
            }

            this.updateButtonText();
        },

        /**
         * Rebuild the plugin.
         * Rebuilds the dropdown, the filter and the select all option.
         */
        rebuild: function() {
            this.$ul.html('');

            // Remove select all option in select.
            $('option[value="' + this.options.selectAllValue + '"]', this.$select).remove();

            // Important to distinguish between radios and checkboxes.
            this.options.multiple = this.$select.attr('multiple') === "multiple";

            this.buildSelectAll();
            this.buildDropdownOptions();
            this.buildFilter();
            
            this.updateButtonText();
            this.updateSelectAll();
        },

        /**
         * The provided data will be used to build the dropdown.
         * 
         * @param {Array} dataprovider
         */
        dataprovider: function(dataprovider) {
            var optionDOM = "";
            dataprovider.forEach(function (option) {
                optionDOM += '<option value="' + option.value + '">' + option.label + '</option>';
            });

            this.$select.html(optionDOM);
            this.rebuild();
        },

        /**
         * Enable the multiselect.
         */
        enable: function() {
            this.$select.prop('disabled', false);
            this.$button.prop('disabled', false)
                .removeClass('disabled');
        },

        /**
         * Disable the multiselect.
         */
        disable: function() {
            this.$select.prop('disabled', true);
            this.$button.prop('disabled', true)
                .addClass('disabled');
        },

        /**
         * Set the options.
         * 
         * @param {Array} options
         */
        setOptions: function(options) {
            this.options = this.mergeOptions(options);
        },

        /**
         * Merges the given options with the default options.
         * 
         * @param {Array} options
         * @returns {Array}
         */
        mergeOptions: function(options) {
            return $.extend({}, this.defaults, options);
        },
        
        /**
         * Checks whether a select all option is present.
         * 
         * @returns {Boolean}
         */
        hasSelectAll: function() {
            return this.$select[0][0] ? this.$select[0][0].value === this.options.selectAllValue : false;
        },
        
        /**
         * Updates the select all option based on the currently selected options.
         */
        updateSelectAll: function() {
            if (this.hasSelectAll()) {
                var selected = this.getSelected();
                
                if (selected.length === $('option', this.$select).length - 1) {
                    this.select(this.options.selectAllValue);
                }
                else {
                    this.deselect(this.options.selectAllValue);
                }
            }
        },
        
        /**
         * Update the button text and its title base don the currenty selected options.
         */
        updateButtonText: function() {
            var options = this.getSelected();
            
            // First update the displayed button text.
            $('button', this.$container).html(this.options.buttonText(options, this.$select));
            
            // Now update the title attribute of the button.
            $('button', this.$container).attr('title', this.options.buttonTitle(options, this.$select));

        },

        /**
         * Get all selected options.
         * 
         * @returns {jQUery}
         */
        getSelected: function() {
            return $('option[value!="' + this.options.selectAllValue + '"]:selected', this.$select).filter(function() {
                return $(this).prop('selected');
            });
        },

        /**
         * Gets a select option by its value.
         * 
         * @param {String} value
         * @returns {jQuery}
         */
        getOptionByValue: function(value) {
            return $('option', this.$select).filter(function() {
                return $(this).val() === value;
            });
        },

        /**
         * Get the input (radio/checkbox) by its value.
         * 
         * @param {String} value
         * @returns {jQuery}
         */
        getInputByValue: function(value) {
            return $('li input', this.$ul).filter(function() {
                return $(this).val() === value;
            });
        },

        /**
         * Used for knockout integration.
         */
        updateOriginalOptions: function() {
            this.originalOptions = this.$select.clone()[0].options;
        },

        asyncFunction: function(callback, timeout, self) {
            var args = Array.prototype.slice.call(arguments, 3);
            return setTimeout(function() {
                callback.apply(self || window, args);
            }, timeout);
        }
    };

    $.fn.multiselect = function(option, parameter) {
        return this.each(function() {
            var data = $(this).data('multiselect');
            var options = typeof option === 'object' && option;

            // Initialize the multiselect.
            if (!data) {
                $(this).data('multiselect', ( data = new Multiselect(this, options)));
            }

            // Call multiselect method.
            if (typeof option === 'string') {
                data[option](parameter);
            }
        });
    };

    $.fn.multiselect.Constructor = Multiselect;

    $(function() {
        $("select[data-role=multiselect]").multiselect();
    });

}(window.jQuery);
