Fix bugs, convert thumbnail to png, add context menu

backend/app/services/storage.py

@@ -0,0 +1,53 @@
+"""Document storage service."""
+
+import shutil
+import uuid
+import pymupdf
+from pathlib import Path
+from fastapi import UploadFile, HTTPException
+
+from app.config import settings
+
+def validate_pdf(filepath: Path) -> None:
+    """Validate PDF magic bytes and PyMuPDF openability."""
+    with open(filepath, "rb") as f:
+        header = f.read(5)
+        if header != b"%PDF-":
+            raise ValueError("Not a valid PDF file (missing magic bytes)")
+
+    try:
+        doc = pymupdf.open(filepath)
+        doc.close()
+    except Exception as e:
+        raise ValueError(f"Failed to open PDF with PyMuPDF: {e}")
+
+async def save_upload_file(upload_file: UploadFile) -> tuple[str, int, int]:
+    """Save an uploaded file to disk and validate it."""
+    file_id = str(uuid.uuid4())
+    filepath = settings.PDF_STORAGE_PATH / f"{file_id}.pdf"
+
+    try:
+        with open(filepath, "wb") as f:
+            shutil.copyfileobj(upload_file.file, f)
+    except Exception as e:
+        if filepath.exists():
+            filepath.unlink()
+        raise HTTPException(status_code=500, detail="Failed to save file")
+
+    page_count = 0
+    try:
+        doc = pymupdf.open(filepath)
+        page_count = len(doc)
+        doc.close()
+    except Exception as e:
+        filepath.unlink()
+        raise HTTPException(status_code=400, detail=f"Failed to open PDF with PyMuPDF: {e}")
+    
+    size = filepath.stat().st_size
+    return file_id, size, page_count
+
+def delete_pdf_file(file_id: str) -> None:
+    """Delete a PDF file from storage."""
+    filepath = settings.PDF_STORAGE_PATH / f"{file_id}.pdf"
+    if filepath.exists():
+        filepath.unlink()