import atexit
import calendar
from datetime import datetime

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

from common.common import CostDetail
from sink.model.o11ycost import O11yCost

engine = None

def s2ts(date: str):
    return calendar.timegm(datetime.strptime(date, "%Y-%m-%d").utctimetuple())

def write(database_url: str, cost_details: list[CostDetail]):
    # init engine
    global engine
    if engine is None:
        engine = create_engine(database_url)
    # init session
    Session = sessionmaker(bind=engine)
    session = Session()
    try:
        # write to db
        for cost_detail in cost_details:
            timestamp = s2ts(cost_detail.date)
            cloud_resource_cost = O11yCost(
                provider=cost_detail.provider,
                region=cost_detail.region,
                cloud_service=cost_detail.cloud_service,
                inner_cloud_service=cost_detail.inner_cloud_service,
                fixed_cost=cost_detail.fixed_cost,
                cost=cost_detail.cost,
                timestamp=timestamp,
            )
            session.merge(cloud_resource_cost)  # merge will update if exists
        session.commit()
    except Exception:
        session.rollback()
        raise
    finally:
        session.close()


def close():
    global engine
    if engine is not None:
        engine.dispose()
        engine = None


atexit.register(close)