let $T = Telerik.Web.UI;

if ($T && $T.RadGrid) {
    $T.RadGrid.prototype._initializeAriaSupport = function() {
        var wrapper = this.get_element();
        var isLightweight = this._renderMode === Telerik.Web.UI.RenderMode.Lite;
        var clientSettings = this.ClientSettings;

        var i;
        var j;
        var length;
        var row;
        var cell;
        var headers;
        var atleastOneEditRow = false;

        var initHeader = function (header) {
            header.setAttribute('role', 'columnheader');

            if (!header.parentNode.getAttribute('role')) {
                header.parentNode.setAttribute('role', 'row');
            }

            var sortLink = header.getElementsByTagName('a')[0];

            if (sortLink) {
                var sortInput = header.getElementsByTagName('input')[0];

                if (sortInput) {
                    if (sortInput.className.indexOf('rgSortAsc') > -1) {
                        header.setAttribute('aria-sort', 'ascending');
                    } else if (sortInput.className.indexOf('rgSortDesc') > -1) {
                        header.setAttribute('aria-sort', 'descending');
                    }
                } else {
                    header.setAttribute('aria-sort', 'none');
                }
            }
        };

        if (wrapper.querySelectorAll) {
            headers = wrapper.querySelectorAll('th.rgHeader');

            for (i = 0, length = headers.length; i < length; i++) {
                initHeader(headers[i]);
            }
        } else {
            headers = wrapper.getElementsByTagName('th');

            for (i = 0, length = headers.length; i < length; i++) {
                var header = headers[i];

                if (header.className.indexOf('rgHeader') > -1) {
                    initHeader(header);
                }
            }
        }

        var cells = wrapper.getElementsByTagName('td');

        for (i = 0, length = cells.length; i < length; i++) {
            cell = cells[i];
            row = cell.parentNode;
            var rowClass = row.className;

            if (cell.className.indexOf('rgExpandCol') > -1 || cell.className.indexOf('rgGroupCol') > -1) {
                cell.setAttribute('role', 'gridcell');
                row.setAttribute('role', 'row');

                if (rowClass.indexOf('rgGroupHeader') > -1 || row.id) {
                    // mark expanded states of group and parent items
                    var expButton = cell.getElementsByTagName(isLightweight ? 'button' : 'input')[0];

                    if (expButton) {
                        if (!isLightweight) {
                            expButton.setAttribute('role', 'button');
                        }

                        if (expButton.className.indexOf('rgCollapse') > -1) {
                            cell.setAttribute('aria-expanded', 'true');
                            expButton.setAttribute('aria-expanded', 'true');
                        } else if (expButton.className.indexOf('rgExpand') > -1) {
                            cell.setAttribute('aria-expanded', 'false');
                            expButton.setAttribute('aria-expanded', 'false');
                        }
                    }

                    // mark group headers
                    if (rowClass.indexOf('rgGroupHeader') > -1 && !row.getAttribute('role')) {
                        row.setAttribute('role', 'row');
                    }
                }
            } else if (rowClass.indexOf('rgRow') > -1 || rowClass.indexOf('rgAltRow') > -1 || rowClass.indexOf('rgFooter') > -1) {
                cell.setAttribute('role', 'gridcell');

                // mark data rows
                if (!row.getAttribute('role')) {
                    row.setAttribute('role', 'row');

                    if (rowClass.indexOf('rgSelectedRow') > -1) {
                        row.setAttribute('aria-selected', 'true');
                        row.tabIndex = 1;
                    }
                }
            } else if (cell.className.indexOf('rgCommandCell') > -1 && !row.getAttribute('role')) {
                // mark command item
                cell.setAttribute('role', 'presentation');
                row.setAttribute('role', 'presentation');
            } else if (row.className.indexOf('rgPager') > -1 && !row.getAttribute('role')) {
                // mark pager
                row.setAttribute('role', 'presentation');
                var divs = row.getElementsByTagName('div');
                var pagerBtn = row.querySelector('.rgPager .RadComboBox .rcbInner button');

                if (pagerBtn) {
                    var pagerComboInput = $telerik.findElement(pagerBtn.parentNode, 'PageSizeComboBox_Input');

                    pagerBtn.value = pagerComboInput.title;
                    pagerComboInput.setAttribute('aria-label', pagerComboInput.title);
                }

                for (var di = 0; di < divs.length; di++) {
                    var div = divs[di];

                    if (div.className && div.className.indexOf('rgWrap') > -1) {
                        var inputs = div.getElementsByTagName('input');

                        for (j = 0; j < inputs.length; j++) {
                            var inp = inputs[j];
                            var className = inp.className;

                            if (inp.type == 'submit' && className
                                && (className.indexOf('PagePrev') > -1
                                    || className.indexOf('PageFirst') > -1
                                    || className.indexOf('PageNext') > -1
                                    || className.indexOf('PageLast') > -1
                                    || className.indexOf('PagerButton') > -1)) {
                                inp.setAttribute('role', 'button');
                            }
                        }
                    }
                }
            } else if (row.className.indexOf('rgEditRow') > -1 && !row.getAttribute('role')) {
                // mark edit row
                row.setAttribute('role', 'row');
                row.removeAttribute('aria-readonly');
                atleastOneEditRow = true;
            } else if (!row.id) {
                // mark rows with no IDs in grid tables
                var table = row.parentNode.tagName.toLowerCase() === 'table' ? row.parentNode : row.parentNode.parentNode;

                if (table && table.className.indexOf('rgMasterTable') > -1 || table.className.indexOf('rgDetailTable') > -1) {
                    if (!row.getAttribute('role')) {
                        row.setAttribute('role', 'presentation');
                    }
                }
            }
        }

        if (this._groupPanel) {
            this._groupPanel.get_element().setAttribute('role', 'presentation');
        }

        //static headers
        var $dataTables;
        var $masterTableDataDiv;
        if (this.ClientSettings.Scrolling && this.ClientSettings.Scrolling.UseStaticHeaders) {
            $dataTables = $telerik.$(wrapper).find('.rgDataDiv>table.rgMasterTable, table.rgDetailTable');

            let $dataDivWrapper = $telerik.$(wrapper).find(".rgDataDiv");
            $dataDivWrapper.attr("tabIndex", 0);

            var $layoutTableElements = $telerik.$(wrapper).find('table[id$=Pager], table[id$=Header],table[id$=Footer]');
            $layoutTableElements.removeAttr('summary');
            //$layoutTableElements.find('caption').remove();
            $layoutTableElements.find('th:empty').remove();
            $layoutTableElements.find('thead:empty').remove();
            $layoutTableElements.attr('role', 'presentation');

            $masterTableDataDiv = $telerik.$(wrapper).find('.rgDataDiv>table.rgMasterTable');

            var mainDataTableTbodyId = "";
            var headerTableTHeadId = "";
            var footerTableTbodyId = "";

            var $mainDataTableTbody = $masterTableDataDiv.find('tbody');
            if ($mainDataTableTbody.length > 0) {
                mainDataTableTbodyId = $mainDataTableTbody.parent()[0].id + '_tbody';
                $mainDataTableTbody.attr('id', mainDataTableTbodyId);
            }

            var $headerTableThead = $telerik.$(wrapper).find('table[id$=Header]>thead');
            if ($headerTableThead.length > 0) {
                headerTableTHeadId = $headerTableThead.parent()[0].id + '_thead';
                $headerTableThead.attr('id', headerTableTHeadId);
            }

            var $footerTableTbody = $telerik.$(wrapper).find('table[id$=Footer]>tbody');
            if ($footerTableTbody.length > 0) {
                footerTableTbodyId = $footerTableTbody.parent()[0].id + '_tbody';
                $footerTableTbody.attr('id', footerTableTbodyId);
            }

            $masterTableDataDiv.attr('aria-owns', headerTableTHeadId + ' ' + mainDataTableTbodyId + ' ' + footerTableTbodyId);

            var $topPagerTable = $telerik.$(wrapper).find('table[id$=TopPager]');
            $topPagerTable.attr('role', 'toolbar');
        }
        else {
            $dataTables = $telerik.$(wrapper).find('table.rgMasterTable, table.rgDetailTable');
            $masterTableDataDiv = $telerik.$(wrapper).find('table.rgMasterTable');
        }


        var that = this;
        $dataTables.each(function () {
            this.setAttribute('role', 'grid');
            if (clientSettings.Selecting.AllowRowSelect && that.get_allowMultiRowSelection()) {
                this.setAttribute('aria-multiselectable', 'true');
            }
        });

        if (this._detailTables.length) {
            $masterTableDataDiv.attr('role', 'treegrid');
        }


        //headercontextfilter
        if (this._getHeaderContextMenu()) {
            var $headerContextMenuButtons = $telerik.$(wrapper).find('.rgOptions');
            $headerContextMenuButtons.each(function () {
                this.setAttribute('aria-label', 'Column Menu');
            })
            var contextMenu = this._getHeaderContextMenu();

            var filterMenuItem = contextMenu.findItemByValue("FilterMenuParent");
            if (filterMenuItem && filterMenuItem.get_element()) {
                var $filterMenuElement = $telerik.$(filterMenuItem.get_element());
                //filter function comboboxes 
                $filterMenuElement.find('input[id$="FirstCond_Input"]').attr('aria-label', 'First Condition Filter Function');
                $filterMenuElement.find('input[id$="SecondCond_Input"]').attr('aria-label', 'Second Condition Filter Function');
                //filter value inputs - textbox, numerictextbox, datepickers
                $filterMenuElement.find('input[id$="FirstCond"], input[id$="FirstCond_dateInput"]').attr('aria-label', 'First Condition Filter Value');
                $filterMenuElement.find('input[id$="SecondCond"], input[id$="SecondCond_dateInput"]').attr('aria-label', 'Second Condition Filter Value');
            }

            var filterListItem = contextMenu.findItemByValue("FilterList");
            if (filterListItem && filterListItem.get_element()) {
                var $filterListElement = $telerik.$(filterListItem.get_element());
                $filterListElement.find('input[id$="filterCheckListSearch"]').attr('aria-label', 'Filter Checklist Search');
            }
        }
    }
}