feat: Implement notification system with Apprise integration and credential checks

app/api/diagnostic.py

@@ -49,3 +49,52 @@ async def diagnostic_settings(request: Request, current_user: dict = Depends(get
         "settings": safe_settings,
         "message": "Full settings have been dumped to application logs"
     }
+
+@router.post("/diagnostic/test-notification")
+@require_login
+async def test_notification(request: Request):
+    # Add request_time to request.state
+    import datetime
+    request.state.request_time = datetime.datetime.utcnow().isoformat()
+    """
+    Send a test notification through all configured notification channels
+    """
+    from app.utils.notification import send_notification
+    
+    try:
+        notification_urls = getattr(settings, 'notification_urls', [])
+        if not notification_urls:
+            return {
+                "status": "warning",
+                "message": "No notification services configured. Add notification URLs to your configuration."
+            }
+        
+        # Send a test notification
+        hostname = settings.external_hostname or "Document Processor"
+        result = send_notification(
+            title=f"Test Notification from {hostname}",
+            message=f"This is a test notification sent at {request.state.request_time}. If you're receiving this, notifications are working!",
+            notification_type="success",
+            tags=["test", "notification", "diagnostic"]
+        )
+        
+        if result:
+            logger.info("Test notification sent successfully")
+            return {
+                "status": "success",
+                "message": f"Test notification sent successfully to {len(notification_urls)} service(s)",
+                "services_count": len(notification_urls)
+            }
+        else:
+            logger.warning("Test notification send attempt returned False")
+            return {
+                "status": "error",
+                "message": "Failed to send test notification. Check application logs for details."
+            }
+    
+    except Exception as e:
+        logger.exception(f"Error sending test notification: {e}")
+        return {
+            "status": "error",
+            "message": f"Error sending notification: {str(e)}"
+        }