webapp/app/services/slot_snapshot_service.py

# app/services/slot_snapshot_service.py
from sqlalchemy.orm import Session
from app.models.slot_snapshot import VasSlotSnapshot
from app.schemas.slot_snapshot import SlotSnapshotCreate
from datetime import datetime

class SlotSnapshotService:
    def __init__(self, db: Session): self.db = db

    def create(self, data: SlotSnapshotCreate):
        rec = VasSlotSnapshot(**data.dict())
        self.db.add(rec); self.db.commit(); self.db.refresh(rec); return rec

    def latest_for(self, country:str, city:str, visa_type:str):
        return self.db.query(VasSlotSnapshot).filter_by(country=country, city=city, visa_type=visa_type).order_by(VasSlotSnapshot.snapshot_at.desc()).first()