potential fix for not jumping to reading position sometimes

backend/src/main/java/com/storycove/entity/Story.java

@@ -307,10 +307,11 @@ public class Story {
         this.isRead = true;
         this.lastReadAt = LocalDateTime.now();
         // Set reading position to the end of content if available
-        if (contentPlain != null) {
-            this.readingPosition = contentPlain.length();
-        } else if (contentHtml != null) {
+        // ALWAYS use contentHtml for consistency (frontend uses contentHtml for position tracking)
+        if (contentHtml != null) {
             this.readingPosition = contentHtml.length();
+        } else if (contentPlain != null) {
+            this.readingPosition = contentPlain.length();
         }
     }
     

frontend/src/app/stories/[id]/page.tsx

@@ -238,17 +238,20 @@ export default function StoryReadingPage() {
   // Auto-scroll to saved reading position or URL hash when story content is loaded
   useEffect(() => {
     if (story && sanitizedContent && !hasScrolledToPosition) {
-      // Use a small delay to ensure content is rendered
-      const timeout = setTimeout(() => {
+      let cancelled = false;
+
+      const performScroll = () => {
+        if (cancelled) return;
+
         debug.log('Initializing reading position tracking, saved position:', story.readingPosition);
-        
+
         // Check if there's a hash in the URL (for TOC navigation)
         const hash = window.location.hash.substring(1);
         if (hash && hash.startsWith('heading-')) {
           debug.log('Auto-scrolling to heading from URL hash:', hash);
           const element = document.getElementById(hash);
           if (element) {
-            element.scrollIntoView({ 
+            element.scrollIntoView({
               behavior: 'smooth',
               block: 'start'
             });
@@ -256,7 +259,7 @@ export default function StoryReadingPage() {
             return;
           }
         }
-        
+
         // Otherwise, use saved reading position
         if (story.readingPosition && story.readingPosition > 0) {
           debug.log('Auto-scrolling to saved position:', story.readingPosition);
@@ -269,9 +272,57 @@ export default function StoryReadingPage() {
           setReadingPercentage(0);
           setHasScrolledToPosition(true);
         }
-      }, 500);
-      
-      return () => clearTimeout(timeout);
+      };
+
+      // Wait for images to load before scrolling so scrollHeight is accurate
+      const waitForImagesAndScroll = () => {
+        if (!contentRef.current) {
+          // Content not in DOM yet, use a small delay
+          setTimeout(performScroll, 500);
+          return;
+        }
+
+        const images = contentRef.current.querySelectorAll('img');
+        const unloadedImages = Array.from(images).filter(img => !img.complete);
+
+        if (unloadedImages.length === 0) {
+          // No pending images, scroll after a brief delay for layout
+          debug.log('No pending images, scrolling immediately');
+          setTimeout(performScroll, 100);
+          return;
+        }
+
+        debug.log(`Waiting for ${unloadedImages.length} images to load before scrolling`);
+        let loadedCount = 0;
+
+        // Fallback timeout in case images take too long
+        const fallbackTimeout = setTimeout(() => {
+          debug.log('Image load timeout reached, scrolling anyway');
+          performScroll();
+        }, 5000);
+
+        const onImageReady = () => {
+          loadedCount++;
+          if (loadedCount >= unloadedImages.length) {
+            clearTimeout(fallbackTimeout);
+            // Small delay after last image loads for layout to settle
+            setTimeout(performScroll, 50);
+          }
+        };
+
+        unloadedImages.forEach(img => {
+          img.addEventListener('load', onImageReady, { once: true });
+          img.addEventListener('error', onImageReady, { once: true });
+        });
+      };
+
+      // Small delay to ensure content is in the DOM
+      const timeout = setTimeout(waitForImagesAndScroll, 100);
+
+      return () => {
+        cancelled = true;
+        clearTimeout(timeout);
+      };
     }
   }, [story, sanitizedContent, scrollToCharacterPosition, calculateReadingPercentage, hasScrolledToPosition]);
 

frontend/src/components/collections/CollectionReadingView.tsx

@@ -39,8 +39,8 @@ export default function CollectionReadingView({
       (scrolled - contentTop + windowHeight * 0.3) / contentHeight
     ));
     
-    // Convert to character position in the plain text content
-    const textLength = story.contentPlain?.length || story.contentHtml?.length || 0;
+    // Convert to character position (ALWAYS use contentHtml for consistency with backend)
+    const textLength = story.contentHtml?.length || 0;
     return Math.floor(scrollRatio * textLength);
   }, [story]);
 
@@ -48,7 +48,7 @@ export default function CollectionReadingView({
   const calculateReadingPercentage = useCallback((currentPosition: number): number => {
     if (!story) return 0;
 
-    const totalLength = story.contentPlain?.length || story.contentHtml?.length || 0;
+    const totalLength = story.contentHtml?.length || 0;
     if (totalLength === 0) return 0;
 
     return Math.round((currentPosition / totalLength) * 100);
@@ -58,7 +58,7 @@ export default function CollectionReadingView({
   const scrollToCharacterPosition = useCallback((position: number) => {
     if (!contentRef.current || !story || hasScrolledToPosition) return;
 
-    const textLength = story.contentPlain?.length || story.contentHtml?.length || 0;
+    const textLength = story.contentHtml?.length || 0;
     if (textLength === 0 || position === 0) return;
 
     const ratio = position / textLength;
@@ -109,7 +109,11 @@ export default function CollectionReadingView({
   // Auto-scroll to saved reading position when story content is loaded
   useEffect(() => {
     if (story && !hasScrolledToPosition) {
-      const timeout = setTimeout(() => {
+      let cancelled = false;
+
+      const performScroll = () => {
+        if (cancelled) return;
+
         console.log('Collection view - initializing reading position tracking, saved position:', story.readingPosition);
         if (story.readingPosition && story.readingPosition > 0) {
           console.log('Collection view - auto-scrolling to saved position:', story.readingPosition);
@@ -121,9 +125,51 @@ export default function CollectionReadingView({
           setReadingPercentage(0);
           setHasScrolledToPosition(true);
         }
-      }, 500);
-      
-      return () => clearTimeout(timeout);
+      };
+
+      // Wait for images to load before scrolling so scrollHeight is accurate
+      const waitForImagesAndScroll = () => {
+        if (!contentRef.current) {
+          setTimeout(performScroll, 500);
+          return;
+        }
+
+        const images = contentRef.current.querySelectorAll('img');
+        const unloadedImages = Array.from(images).filter(img => !img.complete);
+
+        if (unloadedImages.length === 0) {
+          setTimeout(performScroll, 100);
+          return;
+        }
+
+        console.log(`Collection view - waiting for ${unloadedImages.length} images to load before scrolling`);
+        let loadedCount = 0;
+
+        const fallbackTimeout = setTimeout(() => {
+          console.log('Collection view - image load timeout reached, scrolling anyway');
+          performScroll();
+        }, 5000);
+
+        const onImageReady = () => {
+          loadedCount++;
+          if (loadedCount >= unloadedImages.length) {
+            clearTimeout(fallbackTimeout);
+            setTimeout(performScroll, 50);
+          }
+        };
+
+        unloadedImages.forEach(img => {
+          img.addEventListener('load', onImageReady, { once: true });
+          img.addEventListener('error', onImageReady, { once: true });
+        });
+      };
+
+      const timeout = setTimeout(waitForImagesAndScroll, 100);
+
+      return () => {
+        cancelled = true;
+        clearTimeout(timeout);
+      };
     }
   }, [story, scrollToCharacterPosition, calculateReadingPercentage, hasScrolledToPosition]);