(function ($) {
    $.fn.select2tree = function (options) {
        var defaults = {
            language: "zh-CN",
            minimumResultsForSearch: -1
            /*theme: "bootstrap"*/
        };
        var opts = $.extend(defaults, options);
        opts.templateResult = function (data, container) {
            if (data.element) {
                //insert span element and add 'parent' property
                var $wrapper = $("<span style=\"margin-right:6px;\"></span><span>" + data.text + "</span>");
                var $element = $(data.element);
                $(container).attr("val", $element.val());
                if ($element.attr("parent")) {
                    $(container).attr("parent", $element.attr("parent"));
                }
                return $wrapper;
            } else {
                return data.text;
            }
        };
        var $that = $(this);
        $that.select2(opts).on("select2:open", function () {
            open();
        });

        function moveOption(parentId, index) {
            index = index || 0;
            if (parentId !== undefined) {
                $(".select2-results__options li[parent='" + parentId + "']").insertAfter(".select2-results__options li[val='" + parentId + "']");
                $(".select2-results__options li[parent='" + parentId + "']").each(function () {
                    $(this).attr('level', index);
                    moveOption($(this).attr("val"), index + 1);
                });
            } else {
                $(".select2-results__options li:not([parent])").appendTo(".select2-results__options ul");
                $(".select2-results__options li:not([parent])").each(function () {
                    $(this).attr('level', index);
                    moveOption($(this).attr("val"), index + 1);
                });
            }
        }

        //deal switch action
        function switchAction(parentId, open, isAll) {
            if (!parentId || $(".select2-results__options li[parent='" + parentId + "']").length <= 0) {
                return;
            }
            if (isAll && $(".select2-results__options li[val='" + parentId + "'][level='1']").length > 0) {
                return;
            }
            if (open) {
                $(".select2-results__options li[val='" + parentId + "'] span[class]:eq(0)").removeClass("fa-plus-square").addClass("fa-minus-square");
            } else {
                $(".select2-results__options li[val='" + parentId + "'] span[class]:eq(0)").addClass("fa-plus-square").removeClass("fa-minus-square");
            }
            $(".select2-results__options li[parent='" + parentId + "']").each(function () {
                var $that = $(this);
                open ? $that.slideDown() : $that.slideUp();
                if (!open) {
                    switchAction($that.attr("val"), open, isAll);
                }
            });
        }

        function open() {
            setTimeout(function () {
                moveOption();

                $(".select2-results__options li").each(function () {
                    var $this = $(this);
                    $this.find("span:eq(0)").addClass('far fa-square');
                    if ($this.attr("parent")) {
                        $(this).siblings("li[val='" + $this.attr("parent") + "']").find("span:eq(0)")
                            .removeClass("fa-square").addClass("fa-plus-square switch").css({ "cursor": "pointer" });
                    }
                    if (!$this.attr("style")) {
                        var level = Number($this.attr("level")) || 0;
                        var paddingLeft = (level + 1) * 7 + (Number($this.css("paddingLeft").replace("px", "")) || 0);
                        $("li[parent='" + $this.attr("parent") + "']").css("display", "none").css("padding-left", paddingLeft + "px");
                    }
                });

                $(".select2-results__options li[level='0']").each(function () {
                    var $this = $(this);
                    var root = $this.attr("val");
                    switchAction(root, true, true);
                });

                openCurrent();

                //override mousedown for collapse/expand
                $(".switch").off("mousedown").on("mousedown", function (event) {
                    var isOpen = $(this).hasClass("fa-plus-square");
                    switchAction($(this).parent().attr("val"), isOpen);
                    if (isOpen) {
                        openCurrent();
                    }
                    event.stopPropagation();
                    event.preventDefault();
                });

                //override mouseup to nothing
                $(".switch").off("mouseup").on("mouseup", function () {
                    return false;
                });
            }, 100);
        }

        function openCurrent() {
            var id = $that.val();
            var $cur = $(".select2-results__options li[val='" + id + "']").find("span:eq(0)");
            if (id && $cur.length) {
                if ($cur.hasClass('fa-square')) {
                    $cur.removeClass("fa-square").addClass("fa-check-square");
                }
                openParent($cur.parent().attr("parent"), true);
            }
        }

        function openParent(parentId) {
            var $this = $(".select2-results__options li[val='" + parentId + "']");
            if (!parentId || $this.length <= 0) {
                return;
            }
            $this.find("span[class]:eq(0)").removeClass("fa-plus-square").addClass("fa-minus-square");
            $(".select2-results__options li[parent='" + parentId + "']").each(function () {
                $(this).slideDown();
            });
            openParent($this.attr("parent"));
        }
    };
})(jQuery);