api command reference doc added

app/routers.py

@@ -318,6 +318,30 @@ async def reset_measurement(unit_id: str, db: Session = Depends(get_db)):
         raise HTTPException(status_code=502, detail=str(e))
 
 
+@router.get("/{unit_id}/measurement-state")
+async def get_measurement_state(unit_id: str, db: Session = Depends(get_db)):
+    """Get current measurement state (Start/Stop)."""
+    cfg = db.query(NL43Config).filter_by(unit_id=unit_id).first()
+    if not cfg:
+        raise HTTPException(status_code=404, detail="NL43 config not found")
+
+    if not cfg.tcp_enabled:
+        raise HTTPException(status_code=403, detail="TCP communication is disabled for this device")
+
+    client = NL43Client(cfg.host, cfg.tcp_port, ftp_username=cfg.ftp_username, ftp_password=cfg.ftp_password)
+    try:
+        state = await client.get_measurement_state()
+        is_measuring = state == "Start"
+        return {
+            "status": "ok",
+            "measurement_state": state,
+            "is_measuring": is_measuring
+        }
+    except Exception as e:
+        logger.error(f"Failed to get measurement state for {unit_id}: {e}")
+        raise HTTPException(status_code=502, detail=str(e))
+
+
 @router.post("/{unit_id}/sleep")
 async def sleep_device(unit_id: str, db: Session = Depends(get_db)):
     """Put the device into sleep mode for battery conservation."""