"""Unit tests: BillingService — activation, payment events, plan changes."""
import pytest
from unittest.mock import AsyncMock, MagicMock, patch
from datetime import datetime, timezone


@pytest.mark.asyncio
async def test_activate_unpaid_session_raises(db_session):
    from app.services.billing_service import BillingService
    svc = BillingService(db_session)
    mock_session = MagicMock()
    mock_session.payment_status = "unpaid"
    with patch("app.services.billing_service.get_checkout_session",
               new_callable=AsyncMock, return_value=mock_session):
        with pytest.raises(ValueError, match="Payment not completed"):
            await svc.activate_from_session("cs_fake", "hash123")


@pytest.mark.asyncio
async def test_payment_succeeded_resets_tokens(db_session, test_author):
    from app.services.billing_service import BillingService
    from app.models.client_access import ClientAccess
    from sqlalchemy import select

    # Set tokens_used to non-zero
    result = await db_session.execute(
        select(ClientAccess).where(ClientAccess.author_id == test_author.id)
    )
    access = result.scalar_one_or_none()
    if access:
        access.tokens_used = 250_000
        access.stripe_subscription_id = "sub_test_reset"
        await db_session.commit()

        svc = BillingService(db_session)
        await svc.handle_payment_succeeded("sub_test_reset")

        await db_session.refresh(access)
        assert access.tokens_used == 0


@pytest.mark.asyncio
async def test_payment_failed_sets_grace_period(db_session, test_author):
    from app.services.billing_service import BillingService
    from app.models.user import User
    from sqlalchemy import select

    test_author.stripe_subscription_id = "sub_grace_test"
    await db_session.commit()

    svc = BillingService(db_session)
    await svc.handle_payment_failed("sub_grace_test", grace_days=7)

    result = await db_session.execute(
        select(User).where(User.id == test_author.id)
    )
    user = result.scalar_one_or_none()
    if user:
        assert user.payment_grace_until is not None
        assert user.payment_grace_until > datetime.now(timezone.utc)


@pytest.mark.asyncio
async def test_subscription_cancelled_revokes_access(db_session, test_author):
    from app.services.billing_service import BillingService
    from app.models.client_access import ClientAccess
    from sqlalchemy import select

    result = await db_session.execute(
        select(ClientAccess).where(ClientAccess.author_id == test_author.id)
    )
    access = result.scalar_one_or_none()
    if access:
        access.stripe_subscription_id = "sub_cancel_test"
        await db_session.commit()

        svc = BillingService(db_session)
        await svc.handle_subscription_cancelled("sub_cancel_test")

        await db_session.refresh(access)
        assert access.is_revoked is True