Fix board date sorting on downloads page

The sort comparator had several issues causing date sorting to
produce unexpected results:

1. Exact tag match promotion ran before the sort type switch for
   all sort modes, overriding date and alphabetical sorts. Tag
   match promotion now only applies to the default (downloads)
   sort.

2. The tag match only checked item 'a' and returned -2, not
   comparing 'b'. Both items are now compared symmetrically.

3. Date and download count comparators used ternary conditional
   returns instead of subtraction, never returning 0 for equal
   values. Changed to use arithmetic subtraction for proper
   three-way comparison.

4. The filterResults tag-match DOM reordering also ignored the
   current sort selection. Now respects the active sort choice.

Fixes #1760

Author: makermelissa-piclaw

assets/javascript/downloads.js

@@ -350,8 +350,10 @@ function filterResults() {
     } else {
       download.style.display = 'block';
       board_count++;
-      // exact tag match re-order
-      if (downloadsSearch.searchTerm !== null && downloadsSearch.searchTerm !== undefined) {
+      // exact tag match re-order only for default (downloads) sort
+      var currentSort = document.querySelector("input[name='sort-by']:checked");
+      var currentSortValue = currentSort ? currentSort.value : 'downloads';
+      if (currentSortValue === 'downloads' && downloadsSearch.searchTerm !== null && downloadsSearch.searchTerm !== undefined) {
         let searched = downloadsSearch.searchTerm.toLowerCase();
         let tags = download.dataset.tags?.split(",") || [];
         if (searched !== "" && tags.indexOf(searched) >= 0) {
@@ -376,28 +378,30 @@ function handleSortResults(event) {
   Array.prototype.slice.call(downloads.children)
     .map(function (download) { return downloads.removeChild(download); })
     .sort(function (a, b) {
-      // exact tag match re-order
-      if (searched !== undefined && searched !== "" &&
-          a.dataset.tags.split(",").indexOf(searched) >= 0){
-
-        return -2;
+      // exact tag match re-order only for default (downloads) sort
+      if (sortType === 'downloads' && searched !== undefined && searched !== "") {
+        var aMatch = a.dataset.tags.split(",").indexOf(searched) >= 0;
+        var bMatch = b.dataset.tags.split(",").indexOf(searched) >= 0;
+        if (aMatch !== bMatch) {
+          return aMatch ? -1 : 1;
+        }
       }
       switch(sortType) {
         case 'alpha-asc':
           return a.dataset.name.localeCompare(b.dataset.name);
         case 'alpha-desc':
           return b.dataset.name.localeCompare(a.dataset.name);
         case 'date-asc':
-          dateA = new Date(a.dataset.date)
-          dateB = new Date(b.dataset.date)
-          return dateA.getTime() < dateB.getTime() ? -1 : 1;
+          var dateA = new Date(a.dataset.date);
+          var dateB = new Date(b.dataset.date);
+          return dateA.getTime() - dateB.getTime();
         case 'date-desc':
-          dateA = new Date(a.dataset.date)
-          dateB = new Date(b.dataset.date)
-          return dateA.getTime() < dateB.getTime() ? 1 : -1;
+          var dateA = new Date(a.dataset.date);
+          var dateB = new Date(b.dataset.date);
+          return dateB.getTime() - dateA.getTime();
         default:
           // sort by download count is the default
-          return parseInt(a.dataset.downloads, 10) < parseInt(b.dataset.downloads, 10) ? 1 : -1;
+          return parseInt(b.dataset.downloads, 10) - parseInt(a.dataset.downloads, 10);
       }
     })
     .forEach(function (download) { downloads.appendChild(download); });