import pytest
from datetime import date
from plants.models import Plant, PruningLog
from plants.utils.pruning import pruning_status, months_before


def test_months_before_same_year():
    d = date(2026, 5, 27)
    assert months_before(d, 1) == date(2026, 4, 1)
    assert months_before(d, 4) == date(2026, 1, 1)


def test_months_before_crosses_year():
    d = date(2026, 5, 27)
    assert months_before(d, 5) == date(2025, 12, 1)
    assert months_before(d, 12) == date(2025, 5, 1)


def test_months_before_january():
    d = date(2026, 1, 15)
    assert months_before(d, 1) == date(2025, 12, 1)
    assert months_before(d, 2) == date(2025, 11, 1)


@pytest.mark.django_db
def test_no_schedule():
    plant = Plant.objects.create(name='Fern', location='Office', pruning_months=[])
    assert pruning_status(plant) == 'no_schedule'


@pytest.mark.django_db
def test_due_this_month():
    today = date(2026, 5, 15)
    plant = Plant.objects.create(name='Rose', location='Garden', pruning_months=[5])
    assert pruning_status(plant, today) == 'due_this_month'


@pytest.mark.django_db
def test_due_this_month_already_logged():
    today = date(2026, 5, 15)
    plant = Plant.objects.create(name='Rose', location='Garden', pruning_months=[5])
    PruningLog.objects.create(plant=plant, pruned_on=date(2026, 5, 1))
    assert pruning_status(plant, today) == 'upcoming'


@pytest.mark.django_db
def test_overdue_when_past_month_not_logged():
    today = date(2026, 5, 15)
    plant = Plant.objects.create(name='Rose', location='Garden', pruning_months=[3])
    assert pruning_status(plant, today) == 'overdue'


@pytest.mark.django_db
def test_not_overdue_when_past_month_logged():
    today = date(2026, 5, 15)
    plant = Plant.objects.create(name='Rose', location='Garden', pruning_months=[3])
    PruningLog.objects.create(plant=plant, pruned_on=date(2026, 3, 10))
    assert pruning_status(plant, today) == 'upcoming'


@pytest.mark.django_db
def test_not_overdue_when_logged_after_scheduled_month():
    # Pruned in May clears a March schedule — the common real-world case
    today = date(2026, 5, 28)
    plant = Plant.objects.create(name='Rose', location='Garden', pruning_months=[3])
    PruningLog.objects.create(plant=plant, pruned_on=date(2026, 5, 28))
    assert pruning_status(plant, today) == 'upcoming'


@pytest.mark.django_db
def test_upcoming_future_month():
    today = date(2026, 5, 15)
    plant = Plant.objects.create(name='Rose', location='Garden', pruning_months=[8])
    assert pruning_status(plant, today) == 'upcoming'


@pytest.mark.django_db
def test_overdue_crosses_year_boundary():
    # Pruning month December, checked in January
    today = date(2026, 1, 10)
    plant = Plant.objects.create(name='Apple', location='Garden', pruning_months=[12])
    assert pruning_status(plant, today) == 'overdue'


@pytest.mark.django_db
def test_overdue_several_months_before_year_boundary():
    # Plant scheduled in August, checked in January — should be overdue
    today = date(2026, 1, 10)
    plant = Plant.objects.create(name='Oak', location='Garden', pruning_months=[8])
    assert pruning_status(plant, today) == 'overdue'