Update app.py

app.py

@@ -17,6 +17,8 @@ from starlette.requests import Request
 import fitz  # PyMuPDF
 import google.generativeai as genai
 from PIL import Image
+from fastapi import Query
+
 
 # Azure Blob Storage
 try:
@@ -1328,4 +1330,42 @@ async def cleanup_batch(
         "batch_id": batch_id,
         "folder_path": f"{ROOT_FOLDER}/{batch_id}/",
         "container": container_name
-    })
+    })
+
+
+    # ============================================================
+# GENERATE DOWNLOAD URL FROM BLOB PATH (PERMANENT ACCESS)
+# ============================================================
+
+
+@app.get("/blob/download-url")
+def generate_download_url(
+    blob_name: str = Query(..., description="Blob path like POD/BATCH.../file.pdf"),
+    container: str = Query(AZURE_CONTAINER_NAME),
+    expiry_minutes: int = Query(60)
+):
+    """
+    Returns fresh SAS download URL.
+    This prevents expired links problem.
+    """
+
+    try:
+        sas_token = generate_blob_sas(
+            account_name=AZURE_STORAGE_ACCOUNT_NAME,
+            container_name=container,
+            blob_name=blob_name,
+            account_key=AZURE_STORAGE_ACCOUNT_KEY,
+            permission=BlobSasPermissions(read=True),
+            expiry=datetime.utcnow() + timedelta(minutes=expiry_minutes)
+        )
+
+        download_url = f"https://{AZURE_STORAGE_ACCOUNT_NAME}.blob.core.windows.net/{container}/{blob_name}?{sas_token}"
+
+        return {
+            "success": True,
+            "download_url": download_url,
+            "expires_in_minutes": expiry_minutes
+        }
+
+    except Exception as e:
+        return {"success": False, "error": str(e)}