import datetime

from sqlalchemy import func

from calculators import Helper


class CalculatorMixin:
    date = None

    @classmethod
    def query_by_month(cls, query, year, month):
        last_month_year, last_month = Helper.get_last_month(year, month)
        query = query.filter(cls.date >= datetime.date(last_month_year, last_month, 26))
        query = query.filter(cls.date <= datetime.date(year, month, 25))
        return query

    def upsert(self, *args, **kwargs):
        result = self.get_by_key(*args, **kwargs)
        if not result:
            session = db.session
            session.add(self)
            session.commit()
        else:
            session = db.session
            self.id = result.id
            session.add(result)
            session.commit()

    @classmethod
    def get_last_date_from(cls, date):
        query = cls.query.filter(cls.date <= date)
        query = query.with_entities(func.max(cls.date))
        result = query.one_or_none()
        return result[0]