from datetime import date
from pathlib import Path
import sys

sys.path.insert(0, str(Path(__file__).resolve().parent.parent))

from app.services.subscription_billing_calendar import (
    advance_billing_periods,
    billing_date_for_period,
    is_danish_bank_day,
    next_billing_date,
    prorated_30_day_factor,
    resolve_month_date,
    validate_billing_schedule,
)
import pytest
from app.services.subscription_agreement import agreement_status


def test_fixed_day_is_resolved_in_target_month():
    assert next_billing_date(date(2026, 1, 17), "monthly", "fixed_day", 5) == date(2026, 2, 5)


def test_first_bank_day_skips_weekend_and_new_year():
    assert resolve_month_date(2026, 1, "first_business_day", None) == date(2026, 1, 2)


def test_last_bank_day_skips_new_years_eve():
    assert resolve_month_date(2026, 12, "last_business_day", None) == date(2026, 12, 30)


def test_bank_holiday_after_ascension_is_closed():
    assert not is_danish_bank_day(date(2026, 5, 15))


def test_biweekly_keeps_exact_interval_even_with_month_schedule():
    assert next_billing_date(date(2026, 4, 1), "biweekly", "first_business_day", 1) == date(2026, 4, 15)


def test_short_intervals_are_forced_to_runnable_anchor_schedule():
    assert validate_billing_schedule("daily", "fixed_day", 17) == ("interval_anchor", 17)


def test_monthly_interval_anchor_is_rejected():
    with pytest.raises(ValueError, match="only valid"):
        validate_billing_schedule("monthly", "interval_anchor", 1)


def test_new_fixed_day_rules_cannot_use_day_29_to_31():
    with pytest.raises(ValueError, match="between 1 and 28"):
        validate_billing_schedule("quarterly", "fixed_day", 31)


def test_period_can_be_invoiced_two_months_in_advance():
    assert billing_date_for_period(date(2027, 1, 1), 2, "fixed_day", 1) == date(2026, 11, 1)


def test_first_invoice_uses_next_scheduled_day_when_period_started_later_in_month():
    # A subscription that begins on 31 August and invoices on day 1 must start
    # on 1 September, not retrospectively on 1 August.
    assert billing_date_for_period(date(2026, 8, 31), 0, "fixed_day", 1) == date(2026, 9, 1)


def test_three_monthly_periods_cover_a_quarter():
    assert advance_billing_periods(date(2027, 1, 1), "monthly", 3) == date(2027, 4, 1)


def test_short_opening_period_uses_30_day_basis():
    assert prorated_30_day_factor(date(2027, 1, 5), date(2027, 2, 1)) == 26 / 30


def test_agreement_status_prioritizes_failures_and_pending_changes():
    subscriptions = [{"status": "active"}, {"status": "paused"}]
    assert agreement_status(subscriptions, [{"status": "failed"}]) == "Kræver handling"
    assert agreement_status(subscriptions, [{"status": "pending"}]) == "Ændring afventer"
    assert agreement_status(subscriptions, []) == "Delvist pauseret"


def test_agreement_status_handles_partial_termination_and_closed():
    assert agreement_status([{"status": "active"}, {"status": "cancelled"}], []) == "Delvist opsagt"
    assert agreement_status([{"status": "expired"}, {"status": "cancelled"}], []) == "Afsluttet"