from decimal import Decimal

from django.db.models import Sum

from finance.models import PayrollOffCyclePayment


def period_payment_summary(period, rows):
    extra = PayrollOffCyclePayment.objects.filter(
        paid_on__range=(period.date_from, period.date_to),
        currency=period.currency,
        voided_at__isnull=True,
    ).aggregate(total=Sum("amount"))["total"] or Decimal("0.00")
    payroll = sum((Decimal(row["payment_total"]) for row in rows), Decimal("0.00"))
    return {
        "payroll_recorded": str(payroll),
        "outside_period": str(extra),
        "total_recorded": str(payroll + extra),
    }


def period_settlements(period):
    # A live projection beside immutable historical amounts.
    from finance.off_cycle.services import statement_settlement

    return (
        {
            statement.employee_id: {
                key: str(value) if isinstance(value, Decimal) else value
                for key, value in statement_settlement(statement).items()
            }
            for statement in period.current_run.statements.filter(
                off_cycle_payments__isnull=False,
            )
            .select_related("payment_confirmation")
            .distinct()
        }
        if period.current_run_id
        else {}
    )