Add duplicate detection, conflict handling, and fix pagination issues

- Add photo_conflicts table for files with same path but different content
- Implement SHA256-based duplicate detection in file scanner
- Add conflict detection methods to PhotoService
- Skip identical files with info logging, store conflicts with warnings
- Fix infinite scroll pagination race conditions with functional state updates
- Add scroll throttling to prevent rapid API calls
- Enhance PhotoThumbnail with comprehensive EXIF date/time display
- Add composite React keys to prevent duplicate rendering issues

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/app/api/photos/route.ts

@@ -15,11 +15,34 @@ export async function GET(request: NextRequest) {
       rating: searchParams.get('rating') ? parseInt(searchParams.get('rating')!) : undefined
     }
 
+    // Get photos with pagination
     const photos = photoService.getPhotos(options)
     
+    // Get total count for pagination metadata
+    const totalCountOptions = { ...options }
+    delete totalCountOptions.limit
+    delete totalCountOptions.offset
+    const totalPhotos = photoService.getPhotos(totalCountOptions)
+    const totalCount = totalPhotos.length
+    
+    // Calculate pagination metadata
+    const limit = options.limit || 20
+    const offset = options.offset || 0
+    const hasMore = (offset + photos.length) < totalCount
+    const currentPage = Math.floor(offset / limit) + 1
+    const totalPages = Math.ceil(totalCount / limit)
+    
     return NextResponse.json({
       photos,
-      count: photos.length
+      pagination: {
+        total: totalCount,
+        count: photos.length,
+        limit,
+        offset,
+        hasMore,
+        currentPage,
+        totalPages
+      }
     })
   } catch (error) {
     console.error('Error fetching photos:', error)

src/components/DirectoryModal.tsx

@@ -180,15 +180,20 @@ export default function DirectoryModal({ isOpen, onClose, onSave, onDirectoryLis
   }
 
   const modalContent = (
-    <div className="absolute inset-0 bg-black bg-opacity-50 z-[9999]" style={{ display: 'block', position: 'absolute', top: 0, left: 0, right: 0, bottom: 0, height: '100vh', width: '100vw' }}>
+    <div className="fixed inset-0 bg-black bg-opacity-50 z-[9999] flex items-center justify-center p-4">
       <div 
-        className="absolute top-1/2 left-1/2 transform -translate-x-1/2 -translate-y-1/2 bg-white dark:bg-gray-800 p-6 rounded-lg w-96 shadow-2xl"
+        className="bg-white dark:bg-gray-800 rounded-lg shadow-2xl w-full max-w-lg max-h-[90vh] flex flex-col"
         onClick={(e) => e.stopPropagation()}
       >
-        <h2 className="text-lg font-semibold mb-4 text-gray-900 dark:text-white">
+        {/* Header */}
+        <div className="p-6 pb-4 border-b border-gray-200 dark:border-gray-600">
+          <h2 className="text-lg font-semibold text-gray-900 dark:text-white">
             Select Directory to Scan
           </h2>
+        </div>
         
+        {/* Content Area - Scrollable */}
+        <div className="flex-1 p-6 min-h-0">
           <div className="relative">
             <input
               type="text"
@@ -212,8 +217,9 @@ export default function DirectoryModal({ isOpen, onClose, onSave, onDirectoryLis
               )}
             </div>
             
+            {/* Suggestions - Now with better scrolling */}
             {showSuggestions && suggestions.length > 0 && (
-            <div className="absolute top-full left-0 right-0 mt-1 bg-white dark:bg-gray-700 border border-gray-300 dark:border-gray-600 rounded shadow-lg max-h-48 overflow-y-auto z-10">
+              <div className="absolute top-full left-0 right-0 mt-1 bg-white dark:bg-gray-700 border border-gray-300 dark:border-gray-600 rounded shadow-lg max-h-64 overflow-y-auto z-10">
                 {suggestions.map((suggestion, index) => (
                   <div
                     key={index}
@@ -225,14 +231,25 @@ export default function DirectoryModal({ isOpen, onClose, onSave, onDirectoryLis
                         : 'hover:bg-gray-100 dark:hover:bg-gray-600'
                     }`}
                   >
+                    <div className="truncate" title={suggestion}>
                       {suggestion}
                     </div>
+                  </div>
                 ))}
               </div>
             )}
           </div>
+        </div>
         
-        <div className="flex gap-2 mt-4">
+        {/* Fixed Footer with Buttons */}
+        <div className="p-6 pt-4 border-t border-gray-200 dark:border-gray-600 bg-gray-50 dark:bg-gray-750 rounded-b-lg">
+          <div className="flex gap-2 justify-end">
+            <Button
+              onClick={handleClose}
+              variant="secondary"
+            >
+              Cancel
+            </Button>
             <Button
               onClick={handleSave}
               disabled={!isValid || isValidating}
@@ -240,12 +257,7 @@ export default function DirectoryModal({ isOpen, onClose, onSave, onDirectoryLis
             >
               Save
             </Button>
-          <Button
-            onClick={handleClose}
-            variant="secondary"
-          >
-            Cancel
-          </Button>
+          </div>
         </div>
       </div>
     </div>

src/components/PhotoGrid.tsx

@@ -22,21 +22,36 @@ export default function PhotoGrid({
 }: PhotoGridProps) {
   const [photos, setPhotos] = useState<Photo[]>([])
   const [loading, setLoading] = useState(true)
+  const [loadingMore, setLoadingMore] = useState(false)
   const [error, setError] = useState<string | null>(null)
   const [sortBy, setSortBy] = useState<SortOption>('created_at')
   const [sortOrder, setSortOrder] = useState<SortOrder>('DESC')
   const [searchTerm, setSearchTerm] = useState('')
   const [selectedPhoto, setSelectedPhoto] = useState<Photo | null>(null)
+  const [pagination, setPagination] = useState({
+    total: 0,
+    hasMore: false,
+    currentPage: 1,
+    limit: 20,
+    offset: 0
+  })
 
-  const fetchPhotos = async () => {
+  const fetchPhotos = async (reset = true) => {
     try {
+      if (reset) {
         setLoading(true)
+        setPhotos([])
+      } else {
+        setLoadingMore(true)
+      }
       setError(null)
       
+      const offset = reset ? 0 : pagination.offset
       const params = new URLSearchParams({
         sortBy,
         sortOrder,
-        limit: '100', // Load first 100 photos
+        limit: pagination.limit.toString(),
+        offset: offset.toString()
       })
       
       if (directoryPath) {
@@ -50,12 +65,42 @@ export default function PhotoGrid({
       }
       
       const data = await response.json()
+      
+      if (reset) {
         setPhotos(data.photos || [])
+      } else {
+        // Prevent duplicates by filtering out photos we already have using functional update
+        setPhotos(prev => {
+          const incomingPhotos = data.photos || []
+          const newPhotos = incomingPhotos.filter(newPhoto => 
+            !prev.some(existingPhoto => existingPhoto.id === newPhoto.id)
+          )
+          console.log(`[PHOTO GRID] Received ${incomingPhotos.length} photos, ${newPhotos.length} are new, ${incomingPhotos.length - newPhotos.length} were duplicates`)
+          return [...prev, ...newPhotos]
+        })
+      }
+      
+      setPagination({
+        total: data.pagination.total,
+        hasMore: data.pagination.hasMore,
+        currentPage: data.pagination.currentPage,
+        limit: data.pagination.limit,
+        offset: offset + (data.photos || []).length
+      })
+      
     } catch (error) {
       console.error('Error fetching photos:', error)
       setError('Failed to load photos')
     } finally {
       setLoading(false)
+      setLoadingMore(false)
+    }
+  }
+
+  const loadMorePhotos = () => {
+    if (!loadingMore && pagination.hasMore) {
+      console.log(`[PHOTO GRID] Loading more photos: offset=${pagination.offset}, current photos=${photos.length}`)
+      fetchPhotos(false)
     }
   }
 
@@ -63,6 +108,31 @@ export default function PhotoGrid({
     fetchPhotos()
   }, [directoryPath, sortBy, sortOrder])
 
+  // Infinite scroll effect
+  useEffect(() => {
+    let scrollTimeout: NodeJS.Timeout | null = null
+    
+    const handleScroll = () => {
+      if (scrollTimeout) return // Prevent multiple calls
+      
+      scrollTimeout = setTimeout(() => {
+        if (
+          window.innerHeight + document.documentElement.scrollTop + 1000 >= 
+          document.documentElement.offsetHeight
+        ) {
+          loadMorePhotos()
+        }
+        scrollTimeout = null
+      }, 100) // 100ms throttle
+    }
+
+    window.addEventListener('scroll', handleScroll)
+    return () => {
+      window.removeEventListener('scroll', handleScroll)
+      if (scrollTimeout) clearTimeout(scrollTimeout)
+    }
+  }, [loadingMore, pagination.hasMore])
+
   // Filter photos based on search term
   const filteredPhotos = photos.filter(photo => {
     if (!searchTerm) return true
@@ -101,6 +171,8 @@ export default function PhotoGrid({
       setSortBy(newSortBy)
       setSortOrder('DESC') // Default to descending for new field
     }
+    // Reset pagination when sorting changes
+    setPagination(prev => ({ ...prev, currentPage: 1, hasMore: false, offset: 0 }))
   }
 
   // Grid classes based on thumbnail size - made thumbnails larger
@@ -159,7 +231,8 @@ export default function PhotoGrid({
             Photos {directoryPath && `in ${directoryPath.split('/').pop()}`}
           </h2>
           <span className="text-sm text-gray-500 dark:text-gray-400">
-            {filteredPhotos.length} photo{filteredPhotos.length !== 1 ? 's' : ''}
+            {filteredPhotos.length} of {pagination.total} photo{pagination.total !== 1 ? 's' : ''}
+            {pagination.hasMore && <span className="ml-1">• Loading more...</span>}
           </span>
         </div>
         
@@ -205,7 +278,7 @@ export default function PhotoGrid({
       <div className={`grid ${gridClasses[thumbnailSize]}`}>
         {filteredPhotos.map((photo) => (
           <PhotoThumbnail
-            key={photo.id}
+            key={`${photo.id}-${photo.filepath}`}
             photo={photo}
             size={thumbnailSize}
             showMetadata={showMetadata}
@@ -214,6 +287,33 @@ export default function PhotoGrid({
         ))}
       </div>
 
+      {/* Load More Button/Indicator */}
+      {pagination.hasMore && !loading && (
+        <div className="flex flex-col items-center justify-center py-8">
+          {loadingMore ? (
+            <>
+              <div className="animate-spin rounded-full h-8 w-8 border-4 border-blue-600 border-t-transparent mb-2"></div>
+              <p className="text-sm text-gray-600 dark:text-gray-400">Loading more photos...</p>
+            </>
+          ) : (
+            <button
+              onClick={loadMorePhotos}
+              className="px-6 py-3 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2"
+            >
+              Load More Photos
+            </button>
+          )}
+        </div>
+      )}
+
+      {/* End of Results */}
+      {!loading && !loadingMore && !pagination.hasMore && photos.length > 0 && (
+        <div className="flex flex-col items-center justify-center py-8 text-gray-500 dark:text-gray-400">
+          <p className="text-sm">You've reached the end of your photos</p>
+          <p className="text-xs mt-1">Showing all {pagination.total} photos</p>
+        </div>
+      )}
+      
       {/* Full Resolution Image Modal */}
       <ImageModal
         photo={selectedPhoto}

src/components/PhotoThumbnail.tsx

@@ -69,6 +69,29 @@ export default function PhotoThumbnail({
     }
   }
 
+  const formatDateTime = (dateString: string) => {
+    try {
+      return new Date(dateString).toLocaleDateString(undefined, {
+        year: 'numeric',
+        month: 'short',
+        day: 'numeric',
+        hour: '2-digit',
+        minute: '2-digit'
+      })
+    } catch {
+      return 'Unknown'
+    }
+  }
+
+  // Get the best available date from EXIF data
+  const getBestDate = () => {
+    if (exif.date_time_original) return exif.date_time_original
+    if (exif.date_time_digitized) return exif.date_time_digitized
+    if (exif.date_time) return exif.date_time
+    if (photo.created_at) return photo.created_at
+    return null
+  }
+
   const formatFileSize = (bytes: number) => {
     if (bytes === 0) return '0 B'
     const k = 1024
@@ -156,11 +179,13 @@ export default function PhotoThumbnail({
                   </div>
                 )}
                 
-                {/* Date taken */}
-                {exif.date_time_original && (
+                {/* Date taken with time */}
+                {getBestDate() && (
                   <div className="flex items-center gap-1">
                     <IconCalendar className="w-3 h-3" />
-                    <span>{formatDate(exif.date_time_original)}</span>
+                    <span title={`Original: ${exif.date_time_original || 'N/A'}\nDigitized: ${exif.date_time_digitized || 'N/A'}\nModified: ${exif.date_time || 'N/A'}`}>
+                      {formatDateTime(getBestDate()!)}
+                    </span>
                   </div>
                 )}
               </div>
@@ -173,6 +198,21 @@ export default function PhotoThumbnail({
                 <div>{formatFileSize(photo.filesize)}</div>
               </div>
             </div>
+            
+            {/* Third row: Additional EXIF date info for large thumbnails */}
+            {size === 'large' && (exif.date_time_original || exif.date_time_digitized || exif.date_time) && (
+              <div className="text-gray-500 text-xs mt-1 space-y-0.5">
+                {exif.date_time_original && exif.date_time_original !== getBestDate() && (
+                  <div>📷 Taken: {formatDateTime(exif.date_time_original)}</div>
+                )}
+                {exif.date_time_digitized && exif.date_time_digitized !== getBestDate() && (
+                  <div>💾 Digitized: {formatDateTime(exif.date_time_digitized)}</div>
+                )}
+                {exif.date_time && exif.date_time !== getBestDate() && (
+                  <div>📝 Modified: {formatDateTime(exif.date_time)}</div>
+                )}
+              </div>
+            )}
           </div>
         </div>
       )}

src/lib/database.ts

@@ -134,6 +134,33 @@ function initializeTables(database: Database.Database) {
     )
   `)
 
+  // Create photo_conflicts table for files with same path but different content
+  database.exec(`
+    CREATE TABLE IF NOT EXISTS photo_conflicts (
+      id TEXT PRIMARY KEY,
+      filename TEXT NOT NULL,
+      filepath TEXT NOT NULL,
+      directory TEXT NOT NULL,
+      filesize INTEGER NOT NULL,
+      created_at DATETIME NOT NULL,
+      modified_at DATETIME NOT NULL,
+      width INTEGER,
+      height INTEGER,
+      format TEXT,
+      favorite BOOLEAN DEFAULT FALSE,
+      rating INTEGER CHECK (rating >= 0 AND rating <= 5),
+      description TEXT,
+      metadata TEXT, -- JSON string
+      thumbnail_blob BLOB, -- Cached thumbnail image data
+      thumbnail_size INTEGER, -- Size parameter used for cached thumbnail
+      thumbnail_generated_at DATETIME, -- When thumbnail was generated
+      indexed_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+      conflict_detected_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+      original_photo_id TEXT, -- Reference to the original photo record
+      conflict_reason TEXT -- Why this was flagged as a conflict
+    )
+  `)
+
   // Create indexes for better performance
   database.exec(`
     CREATE INDEX IF NOT EXISTS idx_photos_directory ON photos (directory);
@@ -152,6 +179,9 @@ function initializeTables(database: Database.Database) {
     CREATE INDEX IF NOT EXISTS idx_photo_hashes_hash_id ON photo_hashes (hash_id);
     CREATE INDEX IF NOT EXISTS idx_photos_thumbnail_size ON photos (thumbnail_size);
     CREATE INDEX IF NOT EXISTS idx_photos_thumbnail_generated_at ON photos (thumbnail_generated_at);
+    CREATE INDEX IF NOT EXISTS idx_photo_conflicts_filepath ON photo_conflicts (filepath);
+    CREATE INDEX IF NOT EXISTS idx_photo_conflicts_original_photo_id ON photo_conflicts (original_photo_id);
+    CREATE INDEX IF NOT EXISTS idx_photo_conflicts_detected_at ON photo_conflicts (conflict_detected_at);
   `)
 }
 

src/lib/file-scanner.ts

@@ -131,16 +131,58 @@ async function processPhotoFile(
   let photoData: any = null
   
   try {
-    // Check if photo already exists
-    const existingPhoto = photoService.getPhotoByPath(filePath)
-    if (existingPhoto) {
+    stats = await stat(filePath)
+    
+    // Compute SHA256 hash first for conflict detection
+    console.log(`[FILE SCANNER] Computing SHA256 hash for: ${filename}`)
+    const sha256Hash = await computeFileHash(filePath)
+    console.log(`[FILE SCANNER] Computed hash for ${filename}: ${sha256Hash}`)
+    
+    // Check for conflicts with existing photos
+    const conflictCheck = photoService.checkForPhotoConflict(filePath, sha256Hash)
+    
+    if (conflictCheck.isDuplicate) {
+      console.info(`[FILE SCANNER] Skipping duplicate file (same path, same content): ${filename}`)
       result.photosSkipped++
       return
     }
     
-    stats = await stat(filePath)
+    if (conflictCheck.hasConflict && conflictCheck.existingPhoto) {
+      console.warn(`[FILE SCANNER] CONFLICT DETECTED: File ${filename} has same path but different content than existing photo`)
       
-    // Create basic photo record
+      // Create basic photo record for the conflicting file
+      photoData = {
+        filename,
+        filepath: filePath,
+        directory: basePath,
+        filesize: stats.size,
+        created_at: stats.birthtime.toISOString(),
+        modified_at: stats.mtime.toISOString(),
+        favorite: false,
+        metadata: JSON.stringify({
+          extension: extname(filename).toLowerCase(),
+          scanned_at: new Date().toISOString()
+        })
+      }
+      
+      // Try to extract image metadata (width, height, format)
+      try {
+        const metadata = await extractImageMetadata(filePath)
+        Object.assign(photoData, metadata)
+      } catch (metadataError) {
+        console.warn(`[FILE SCANNER] Could not extract metadata for ${filePath}:`, metadataError)
+      }
+      
+      // Store in conflicts table
+      const conflictReason = `File has same path as existing photo but different SHA256 hash. Original hash: ${conflictCheck.existingPhoto.id}, New hash: ${sha256Hash}`
+      const conflictId = photoService.createPhotoConflict(photoData, conflictCheck.existingPhoto.id, conflictReason)
+      console.warn(`[FILE SCANNER] Stored conflict record with ID: ${conflictId}`)
+      
+      result.errors++
+      return
+    }
+    
+    // Create basic photo record for new file
     photoData = {
       filename,
       filepath: filePath,
@@ -177,12 +219,8 @@ async function processPhotoFile(
     result.photosAdded++
     console.log(`[FILE SCANNER] Successfully added photo: ${filename}`)
     
-    // Compute and store SHA256 hash
+    // Store SHA256 hash
     try {
-      console.log(`[FILE SCANNER] Computing SHA256 hash for: ${filename}`)
-      const sha256Hash = await computeFileHash(filePath)
-      console.log(`[FILE SCANNER] Computed hash for ${filename}: ${sha256Hash}`)
-      
       // Create or update hash record
       const hashRecord = photoService.createOrUpdateImageHash(sha256Hash)
       
@@ -191,8 +229,8 @@ async function processPhotoFile(
       console.log(`[FILE SCANNER] Associated photo with hash: ${associated}`)
       
     } catch (hashError) {
-      console.error(`[FILE SCANNER] Error computing hash for ${filePath}:`, hashError)
-      // Continue processing even if hash computation fails
+      console.error(`[FILE SCANNER] Error storing hash for ${filePath}:`, hashError)
+      // Continue processing even if hash storage fails
     }
     
     // Log progress every 100 files

src/lib/photo-service.ts

@@ -426,6 +426,85 @@ export class PhotoService {
       return result.changes > 0
     }
   }
+
+  // Conflict detection and handling methods
+  checkForPhotoConflict(filepath: string, sha256Hash: string): { hasConflict: boolean, existingPhoto?: Photo, isDuplicate: boolean } {
+    const existingPhoto = this.getPhotoByPath(filepath)
+    
+    if (!existingPhoto) {
+      return { hasConflict: false, isDuplicate: false }
+    }
+
+    // Get the hash of the existing photo
+    const getPhotoHash = this.db.prepare(`
+      SELECT ih.sha256_hash 
+      FROM photo_hashes ph 
+      JOIN image_hashes ih ON ph.hash_id = ih.id 
+      WHERE ph.photo_id = ?
+    `)
+    const existingHashRow = getPhotoHash.get(existingPhoto.id) as { sha256_hash: string } | null
+    
+    if (!existingHashRow) {
+      // Existing photo has no hash, assume it's different content
+      return { hasConflict: true, existingPhoto, isDuplicate: false }
+    }
+
+    const existingHash = existingHashRow.sha256_hash
+    if (existingHash === sha256Hash) {
+      // Same file, same content - it's a duplicate
+      return { hasConflict: false, existingPhoto, isDuplicate: true }
+    } else {
+      // Same path, different content - it's a conflict
+      return { hasConflict: true, existingPhoto, isDuplicate: false }
+    }
+  }
+
+  createPhotoConflict(
+    photoData: Omit<Photo, 'id' | 'indexed_at' | 'thumbnail_blob' | 'thumbnail_size' | 'thumbnail_generated_at'>,
+    originalPhotoId: string,
+    conflictReason: string
+  ): string {
+    const id = randomUUID()
+    const insertConflict = this.db.prepare(`
+      INSERT INTO photo_conflicts (
+        id, filename, filepath, directory, filesize, created_at, modified_at,
+        width, height, format, favorite, rating, description, metadata,
+        original_photo_id, conflict_reason
+      ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+    `)
+
+    try {
+      const params = [
+        id, // string
+        photoData.filename, // string
+        photoData.filepath, // string
+        photoData.directory, // string
+        photoData.filesize, // number
+        photoData.created_at, // string
+        photoData.modified_at, // string
+        photoData.width || null, // number or null
+        photoData.height || null, // number or null  
+        photoData.format || null, // string or null
+        photoData.favorite || false, // boolean
+        photoData.rating || null, // number or null
+        photoData.description || null, // string or null
+        photoData.metadata || null, // string (JSON) or null
+        originalPhotoId, // string
+        conflictReason // string
+      ]
+
+      insertConflict.run(...params)
+      return id
+    } catch (error) {
+      console.error('Error creating photo conflict:', error)
+      throw new Error('Failed to create photo conflict record')
+    }
+  }
+
+  getPhotoConflicts(): Array<Photo & { original_photo_id: string, conflict_reason: string, conflict_detected_at: string }> {
+    const selectConflicts = this.db.prepare('SELECT * FROM photo_conflicts ORDER BY conflict_detected_at DESC')
+    return selectConflicts.all() as Array<Photo & { original_photo_id: string, conflict_reason: string, conflict_detected_at: string }>
+  }
 }
 
 export const photoService = new PhotoService()