refactor: implement packet parsing heuristics and introduce device-level state caching to throttle database writes and vitals updates

fiveparaminte-main/routers/dashboard.py

@@ -3,8 +3,9 @@ import json
 import logging
 import socket
 from typing import List
+from datetime import datetime, timezone
 
-from fastapi import APIRouter, Depends, HTTPException, WebSocket, WebSocketDisconnect
+from fastapi import APIRouter, Depends, HTTPException, WebSocket, WebSocketDisconnect, Request
 from fastapi.responses import HTMLResponse
 from sqlalchemy.orm import Session
 from database import get_db
@@ -69,27 +70,50 @@ def health_check():
     return {"status": "ok", "service": "Patient Monitor Vital Signs Forwarder"}
 
 @router.get("/status")
-def get_system_status(db: Session = Depends(get_db)):
+def get_system_status(request: Request, db: Session = Depends(get_db)):
     total_devices = db.query(Device).count()
     active_devices = db.query(Device).filter(Device.status == "active").count()
     total_readings = db.query(VitalReading).count()
     pending_transmissions = db.query(VitalReading).filter(VitalReading.transmitted == False).count()
+    active_ports = getattr(request.app.state, "active_ports", [])
     
     return {
         "total_devices": total_devices,
         "active_devices": active_devices,
         "total_readings_stored": total_readings,
-        "pending_transmissions": pending_transmissions
+        "pending_transmissions": pending_transmissions,
+        "active_ports": active_ports
     }
 
 @router.get("/devices")
 def list_devices(db: Session = Depends(get_db)):
     devices = db.query(Device).all()
+    now = datetime.now(timezone.utc)
+    updated = False
+    for device in devices:
+        last_seen = device.last_seen
+        if last_seen.tzinfo is None:
+            last_seen = last_seen.replace(tzinfo=timezone.utc)
+        
+        # If not seen for more than 15 seconds, mark offline
+        if (now - last_seen).total_seconds() > 15.0:
+            if device.status != "offline":
+                device.status = "offline"
+                updated = True
+        else:
+            if device.status != "active":
+                device.status = "active"
+                updated = True
+    if updated:
+        db.commit()
     return devices
 
 @router.get("/latest-readings")
-def get_latest_readings(limit: int = 10, db: Session = Depends(get_db)):
-    readings = db.query(VitalReading).order_by(VitalReading.timestamp.desc()).limit(limit).all()
+def get_latest_readings(device_id: str = None, limit: int = 10, db: Session = Depends(get_db)):
+    query = db.query(VitalReading)
+    if device_id:
+        query = query.filter(VitalReading.device_id == device_id)
+    readings = query.order_by(VitalReading.timestamp.desc()).limit(limit).all()
     return readings
 
 @router.get("/readings")