Optimize torrent fetching

pkg/realdebrid/util.go

@@ -0,0 +1,14 @@
+package realdebrid
+
+func indexFromEnd(subIndex int, pageNumber int, pageSize int, totalElements int) int {
+	// Adjust pageNumber for 1-based index
+	adjustedPageNumber := pageNumber - 1
+
+	// Calculate the overall index in the array
+	overallIndex := (adjustedPageNumber * pageSize) + subIndex
+
+	// Calculate the index from the end
+	indexFromEnd := totalElements - 1 - overallIndex
+
+	return indexFromEnd
+}