from datetime import date
from decimal import Decimal

import pytest
from django.conf import settings

from finance.enums import PayrollPeriodStatus
from finance.models import PayrollAuditEvent, PayrollPeriod
from finance.payroll.carryovers import create_carryover
from finance.tasks import ensure_monthly_payroll_period, open_monthly_payroll_period

pytestmark = pytest.mark.django_db


def test_monthly_period_task_is_scheduled_for_first_day():
    task = settings.CELERY_BEAT_SCHEDULE["open-monthly-payroll-period"]

    assert task["task"] == "finance.tasks.open_monthly_payroll_period"
    assert task["schedule"].day_of_month == {1}
    assert task["schedule"].hour == {0}
    assert task["schedule"].minute == {5}


def test_ensure_monthly_payroll_period_opens_full_calendar_month():
    period, created = ensure_monthly_payroll_period(date(2026, 8, 1))

    assert created is True
    assert period.code == "2026-08"
    assert period.name == "Август 2026"
    assert period.date_from == date(2026, 8, 1)
    assert period.date_to == date(2026, 8, 31)
    assert period.pay_date is None
    assert period.currency == "RUB"
    assert period.status == PayrollPeriodStatus.OPEN
    assert period.created_by is None

    event = PayrollAuditEvent.objects.get(
        action="payroll.period_created",
        period=period,
    )
    assert event.actor is None
    assert event.metadata == {"channel": "automation", "schedule": "monthly"}


def test_ensure_monthly_payroll_period_is_idempotent():
    first, first_created = ensure_monthly_payroll_period(date(2028, 2, 1))
    second, second_created = ensure_monthly_payroll_period(date(2028, 2, 15))

    assert first_created is True
    assert second_created is False
    assert second.pk == first.pk
    assert first.date_to == date(2028, 2, 29)
    assert PayrollPeriod.objects.count() == 1
    assert (
        PayrollAuditEvent.objects.filter(
            action="payroll.period_created",
            period=first,
        ).count()
        == 1
    )


def test_monthly_task_uses_local_current_month(monkeypatch):
    monkeypatch.setattr("finance.tasks.timezone.localdate", lambda: date(2026, 9, 1))

    result = open_monthly_payroll_period()

    period = PayrollPeriod.objects.get(pk=result["period_id"])
    assert result == {"period_id": period.pk, "code": "2026-09", "created": True}
    assert period.date_from == date(2026, 9, 1)
    assert period.date_to == date(2026, 9, 30)


def test_monthly_period_opening_does_not_materialize_legacy_manual_carryover(
    user_factory,
):
    manager = user_factory(email="period.carryover.manager@example.test")
    employee = user_factory(email="period.carryover.employee@example.test")
    source = PayrollPeriod.objects.create(
        code="2026-07",
        name="Июль 2026",
        date_from=date(2026, 7, 1),
        date_to=date(2026, 7, 31),
        currency="RUB",
        status=PayrollPeriodStatus.CLOSED,
        created_by=manager,
    )
    carryover = create_carryover(
        source_period=source,
        employee=employee,
        direction="company_owes",
        amount=Decimal("700.00"),
        reason="Остаток июля",
        actor=manager,
    )
    assert carryover.target_period_id is None

    target, created = ensure_monthly_payroll_period(date(2026, 8, 1))

    assert created is True
    carryover.refresh_from_db()
    assert target.status == PayrollPeriodStatus.OPEN
    assert carryover.target_period_id is None
    assert carryover.generated_input_line_id is None