added a router for logistics, now creating label

backend/app/routers/logistics.py

@@ -0,0 +1,67 @@
+from fastapi import APIRouter, HTTPException, Depends
+from sqlalchemy.orm import Session
+from datetime import datetime, timedelta
+from typing import List
+
+from app.models import Dewar as DewarModel, Slot as SlotModel, LogisticsEvent as LogisticsEventModel
+from app.schemas import LogisticsEventCreate, SlotCreate, Slot as SlotSchema
+from app.database import get_db
+
+router = APIRouter()
+
+@router.post("/scan-dewar")
+async def scan_dewar(event_data: LogisticsEventCreate, db: Session = Depends(get_db)):
+    dewar_qr_code = event_data.dewar_qr_code
+    location_qr_code = event_data.location_qr_code
+    transaction_type = event_data.transaction_type
+
+    dewar = db.query(DewarModel).filter(DewarModel.unique_id == dewar_qr_code).first()
+    if not dewar:
+        raise HTTPException(status_code=404, detail="Dewar not found")
+
+    if transaction_type == 'incoming':
+        slot = db.query(SlotModel).filter(SlotModel.id == location_qr_code).first()
+        if not slot or slot.occupied:
+            raise HTTPException(status_code=404, detail="Slot not found or already occupied")
+        slot.occupied = True
+        log_event(db, dewar.id, slot.id, 'incoming')
+
+    elif transaction_type == 'beamline':
+        log_event(db, dewar.id, None, 'beamline')
+
+    elif transaction_type == 'outgoing':
+        slot = db.query(SlotModel).filter(SlotModel.id == location_qr_code).first()
+        if not slot or not slot.occupied:
+            raise HTTPException(status_code=404, detail="Slot not found or not occupied")
+        slot.occupied = False
+        log_event(db, dewar.id, slot.id, 'outgoing')
+
+    elif transaction_type == 'release':
+        slot = db.query(SlotModel).filter(SlotModel.id == location_qr_code).first()
+        if not slot or not slot.occupied:
+            raise HTTPException(status_code=404, detail="Slot not found or not occupied")
+        slot.occupied = False
+        log_event(db, dewar.id, slot.id, 'released')
+
+    db.commit()
+    return {"message": "Status updated successfully"}
+
+def log_event(db: Session, dewar_id: int, slot_id: int, event_type: str):
+    new_event = LogisticsEventModel(dewar_id=dewar_id, slot_id=slot_id, event_type=event_type)
+    db.add(new_event)
+
+@router.get("/refill-status", response_model=List[SlotSchema])
+async def refill_status(db: Session = Depends(get_db)):
+    slots_needing_refill = db.query(SlotModel).filter(SlotModel.needs_refill == True).all()
+    result = []
+    current_time = datetime.utcnow()
+
+    for slot in slots_needing_refill:
+        time_until_next_refill = slot.last_refill + timedelta(hours=24) - current_time
+        result.append({
+            'slot_id': slot.id,
+            'needs_refill': slot.needs_refill,
+            'time_until_refill': str(time_until_next_refill)
+        })
+
+    return result