Fix bugs, convert thumbnail to png, add context menu

backend/app/services/thumbnails.py

@@ -0,0 +1,38 @@
+"""Thumbnail generation service."""
+
+import pymupdf
+from pathlib import Path
+
+from app.config import settings
+
+def generate_thumbnail(file_id: str) -> None:
+    """Generate a PNG thumbnail for the first page of a PDF."""
+    pdf_path = settings.PDF_STORAGE_PATH / f"{file_id}.pdf"
+    thumb_path = settings.THUMBNAILS_PATH / f"{file_id}.png"
+    
+    if not pdf_path.exists():
+        return
+        
+    try:
+        doc = pymupdf.open(pdf_path)
+        if len(doc) > 0:
+            page = doc[0]
+            # Zoom to approximately 600px width
+            rect = page.rect
+            zoom = 600.0 / rect.width if rect.width > 0 else 1.0
+            mat = pymupdf.Matrix(zoom, zoom)
+            
+            # Render pixmap
+            pix = page.get_pixmap(matrix=mat, alpha=False)
+            
+            # Save as PNG
+            pix.save(thumb_path, output="png")
+        doc.close()
+    except Exception as e:
+        print(f"Failed to generate thumbnail for {file_id}: {e}")
+
+def delete_thumbnail(file_id: str) -> None:
+    """Delete a thumbnail file."""
+    thumb_path = settings.THUMBNAILS_PATH / f"{file_id}.png"
+    if thumb_path.exists():
+        thumb_path.unlink()