prefetch history

apps/client/src/features/page-history/components/history-item.tsx

@@ -3,18 +3,40 @@ import { CustomAvatar } from "@/components/ui/custom-avatar.tsx";
 import { formattedDate } from "@/lib/time";
 import classes from "./history.module.css";
 import clsx from "clsx";
+import { IPageHistory } from "@/features/page-history/types/page.types";
+import { memo, useCallback } from "react";
 
 interface HistoryItemProps {
-  historyItem: any;
-  onSelect: (id: string) => void;
+  historyItem: IPageHistory;
+  index: number;
+  onSelect: (id: string, index: number) => void;
+  onHover?: (id: string) => void;
+  onHoverEnd?: () => void;
   isActive: boolean;
 }
 
-function HistoryItem({ historyItem, onSelect, isActive }: HistoryItemProps) {
+const HistoryItem = memo(function HistoryItem({
+  historyItem,
+  index,
+  onSelect,
+  onHover,
+  onHoverEnd,
+  isActive,
+}: HistoryItemProps) {
+  const handleClick = useCallback(() => {
+    onSelect(historyItem.id, index);
+  }, [onSelect, historyItem.id, index]);
+
+  const handleMouseEnter = useCallback(() => {
+    onHover?.(historyItem.id);
+  }, [onHover, historyItem.id]);
+
   return (
     <UnstyledButton
       p="xs"
-      onClick={() => onSelect(historyItem.id)}
+      onClick={handleClick}
+      onMouseEnter={handleMouseEnter}
+      onMouseLeave={onHoverEnd}
       className={clsx(classes.history, { [classes.active]: isActive })}
     >
       <Group wrap="nowrap">
@@ -27,11 +49,11 @@ function HistoryItem({ historyItem, onSelect, isActive }: HistoryItemProps) {
             <Group gap={4} wrap="nowrap">
               <CustomAvatar
                 size="sm"
-                avatarUrl={historyItem.lastUpdatedBy.avatarUrl}
-                name={historyItem.lastUpdatedBy.name}
+                avatarUrl={historyItem.lastUpdatedBy?.avatarUrl}
+                name={historyItem.lastUpdatedBy?.name}
               />
               <Text size="sm" c="dimmed" lineClamp={1}>
-                {historyItem.lastUpdatedBy.name}
+                {historyItem.lastUpdatedBy?.name}
               </Text>
             </Group>
           </div>
@@ -39,6 +61,6 @@ function HistoryItem({ historyItem, onSelect, isActive }: HistoryItemProps) {
       </Group>
     </UnstyledButton>
   );
-}
+});
 
 export default HistoryItem;

apps/client/src/features/page-history/components/history-list.tsx

@@ -2,6 +2,8 @@ import {
   usePageHistoryListQuery,
   usePageHistoryQuery,
 } from "@/features/page-history/queries/page-history-query";
+import { getPageHistoryById } from "@/features/page-history/services/page-history-service";
+import { queryClient } from "@/main";
 import HistoryItem from "@/features/page-history/components/history-item";
 import {
   activeHistoryIdAtom,
@@ -34,6 +36,8 @@ import {
   SpaceCaslSubject,
 } from "@/features/space/permissions/permissions.type.ts";
 
+const PREFETCH_DELAY_MS = 300;
+
 interface Props {
   pageId: string;
 }
@@ -58,6 +62,7 @@ function HistoryList({ pageId }: Props) {
   );
 
   const loadMoreRef = useRef<HTMLDivElement>(null);
+  const prefetchTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
 
   const [mainEditor] = useAtom(pageEditorAtom);
   const [mainEditorTitle] = useAtom(titleEditorAtom);
@@ -99,6 +104,35 @@ function HistoryList({ pageId }: Props) {
     }
   }, [activeHistoryData]);
 
+  const clearPrefetchTimeout = useCallback(() => {
+    if (prefetchTimeoutRef.current) {
+      clearTimeout(prefetchTimeoutRef.current);
+      prefetchTimeoutRef.current = null;
+    }
+  }, []);
+
+  const handleHover = useCallback((historyId: string) => {
+    clearPrefetchTimeout();
+    prefetchTimeoutRef.current = setTimeout(() => {
+      queryClient.prefetchQuery({
+        queryKey: ["page-history", historyId],
+        queryFn: () => getPageHistoryById(historyId),
+      });
+    }, PREFETCH_DELAY_MS);
+  }, [clearPrefetchTimeout]);
+
+  useEffect(() => {
+    return clearPrefetchTimeout;
+  }, [clearPrefetchTimeout]);
+
+  const handleSelect = useCallback(
+    (id: string, index: number) => {
+      setActiveHistoryId(id);
+      setActiveHistoryPrevId(historyItems[index + 1]?.id ?? "");
+    },
+    [historyItems, setActiveHistoryId, setActiveHistoryPrevId],
+  );
+
   useEffect(() => {
     if (historyItems.length > 0 && !activeHistoryId) {
       setActiveHistoryId(historyItems[0].id);
@@ -142,10 +176,10 @@ function HistoryList({ pageId }: Props) {
           <HistoryItem
             key={historyItem.id}
             historyItem={historyItem}
-            onSelect={(id) => {
-              setActiveHistoryId(id);
-              setActiveHistoryPrevId(historyItems[index + 1]?.id ?? "");
-            }}
+            index={index}
+            onSelect={handleSelect}
+            onHover={handleHover}
+            onHoverEnd={clearPrefetchTimeout}
             isActive={historyItem.id === activeHistoryId}
           />
         ))}