import pytest

from infrasynth.billing.models import App, PaymentGateway, Plan
from infrasynth.billing.services import BillingService
from infrasynth.shared.enums import InvoiceStatus, MonetizationModel, SubscriptionStatus

pytestmark = pytest.mark.django_db


@pytest.fixture
def gateway():
    return PaymentGateway.objects.create(
        slug="fake",
        display_name="Fake",
        gateway_class="tests.helpers.FakeGateway",
        is_active=True,
    )


@pytest.fixture
def app():
    return App.objects.create(slug="messenger", name="Messenger", monetization=MonetizationModel.SUBSCRIPTION)


@pytest.fixture
def plan(app, gateway):
    return Plan.objects.create(
        app=app,
        slug="pro",
        name="Pro",
        price_amount=4900,
        price_currency="USD",
        interval="monthly",
        gateway=gateway,
        external_id="price_123",
    )


class TestCreateCheckoutSession:
    def test_returns_session_and_gateway(self, user, tenant, plan):
        result, gateway = BillingService().create_checkout_session(
            plan, tenant, user, success_url="https://x/success", cancel_url="https://x/cancel"
        )
        assert result.session_id == "cs_fake_123"
        assert result.checkout_url == "https://checkout.example.com/cs_fake_123"
        assert result.client_secret == "secret_123"
        assert gateway.slug == "fake"

    def test_no_gateway_raises(self, tenant, plan, gateway):
        plan.gateway = None
        plan.save(update_fields=["gateway"])
        gateway.is_active = False
        gateway.save(update_fields=["is_active"])
        with pytest.raises(ValueError, match="No active payment gateway"):
            BillingService().create_checkout_session(plan, tenant)

    def test_gateway_failure_propagates(self, tenant, plan):
        plan.gateway.config = {"create_should_fail": True}
        plan.gateway.save(update_fields=["config"])
        with pytest.raises(ValueError, match="Fake gateway failure"):
            BillingService().create_checkout_session(plan, tenant)


class TestCreateSubscription:
    def test_creates_active_subscription(self, tenant, plan, gateway):
        subscription = BillingService().create_subscription(plan, tenant, gateway, external_id="sub_1")
        assert subscription.tenant_id == tenant.id
        assert subscription.plan_id == plan.id
        assert subscription.gateway_id == gateway.slug
        assert subscription.external_id == "sub_1"
        assert subscription.status == SubscriptionStatus.ACTIVE
        assert subscription.current_period_start is not None
        assert subscription.current_period_end is not None
        assert subscription.entitlement_id is not None

    def test_creates_entitlement(self, tenant, plan, gateway):
        subscription = BillingService().create_subscription(plan, tenant, gateway)
        entitlement = subscription.entitlement
        assert entitlement.app_id == plan.app_id
        assert entitlement.status == "active"

    def test_trial_subscription(self, tenant, plan, gateway):
        plan.trial_days = 14
        plan.save(update_fields=["trial_days"])
        subscription = BillingService().create_subscription(plan, tenant, gateway)
        assert subscription.status == SubscriptionStatus.TRIALING
        assert subscription.trial_end is not None
        assert subscription.entitlement.status == "trialing"

    def test_emits_subscription_created_signal(self, tenant, plan, gateway):
        from infrasynth.billing.signals import subscription_created

        sent = []
        receiver = lambda **kw: sent.append(kw)  # noqa: E731
        subscription_created.connect(receiver, weak=False)
        BillingService().create_subscription(plan, tenant, gateway)
        assert sent
        assert sent[0]["tenant_id"] == str(tenant.pk)
        assert sent[0]["plan_slug"] == "pro"
        assert sent[0]["app_slug"] == "messenger"
        assert sent[0]["gateway"] == "fake"
        subscription_created.disconnect(receiver)


class TestCancelSubscription:
    def test_cancels_local_and_gateway(self, tenant, plan, gateway):
        subscription = BillingService().create_subscription(plan, tenant, gateway, external_id="sub_1")
        assert BillingService().cancel_subscription(subscription) is True
        subscription.refresh_from_db()
        assert subscription.status == SubscriptionStatus.CANCELLED
        assert subscription.cancelled_at is not None
        assert subscription.cancel_at_period_end is False

    def test_emits_cancelled_signal(self, tenant, plan, gateway):
        from infrasynth.billing.signals import subscription_cancelled

        subscription = BillingService().create_subscription(plan, tenant, gateway)
        sent = []
        receiver = lambda **kw: sent.append(kw)  # noqa: E731
        subscription_cancelled.connect(receiver, weak=False)
        BillingService().cancel_subscription(subscription)
        assert sent
        assert sent[0]["reason"] == "user_requested"
        assert sent[0]["plan_slug"] == "pro"
        subscription_cancelled.disconnect(receiver)


class TestSyncSubscription:
    def test_syncs_fields_from_gateway(self, tenant, plan, gateway):
        subscription = BillingService().create_subscription(plan, tenant, gateway, external_id="sub_1")
        data = BillingService().sync_subscription(subscription)
        assert data["status"] == "active"
        subscription.refresh_from_db()
        assert subscription.status == SubscriptionStatus.ACTIVE
        assert subscription.metadata.get("synced") is True

    def test_without_gateway_returns_empty(self, tenant, plan):
        subscription = BillingService().create_subscription(plan, tenant, None, external_id="")
        assert BillingService().sync_subscription(subscription) == {}


class TestGenerateInvoice:
    def test_creates_invoice_and_pdf(self, tenant, plan, gateway, media_root):
        subscription = BillingService().create_subscription(plan, tenant, gateway, external_id="sub_1")
        invoice = BillingService().generate_invoice(subscription)
        invoice.refresh_from_db()
        assert invoice.status == InvoiceStatus.OPEN
        assert invoice.amount == 4900
        assert invoice.currency == "USD"
        assert invoice.invoice_number.startswith("INV-")
        assert invoice.due_date is not None
        assert invoice.subscription_id == subscription.id
        assert invoice.tenant_id == tenant.id

    def test_invoice_numbers_are_sequential(self, tenant, plan, gateway):
        service = BillingService()
        subscription = service.create_subscription(plan, tenant, gateway)
        first = service.generate_invoice(subscription)
        second = service.generate_invoice(subscription)
        assert first.invoice_number != second.invoice_number
        assert first.invoice_number < second.invoice_number

    def test_tax_applied(self, tenant, plan, gateway, settings):
        settings.INFRASYNTH_BILLING = {
            **settings.INFRASYNTH_BILLING,
            "TAX_PERCENTAGE": 19,
            "TAX_NAME": "IVA",
        }
        subscription = BillingService().create_subscription(plan, tenant, gateway)
        invoice = BillingService().generate_invoice(subscription)
        assert invoice.tax_amount == 931  # 19% of 4900 minor units
        assert invoice.tax_name == "IVA"

    def test_custom_line_items(self, tenant, plan, gateway):
        subscription = BillingService().create_subscription(plan, tenant, gateway)
        invoice = BillingService().generate_invoice(
            subscription,
            amount=9900,
            line_items=[{"description": "Extra", "amount": 9900, "quantity": 1}],
        )
        assert invoice.amount == 9900
        assert invoice.line_items[0]["description"] == "Extra"

    def test_emits_invoice_generated_signal(self, tenant, plan, gateway):
        from infrasynth.billing.signals import invoice_generated

        subscription = BillingService().create_subscription(plan, tenant, gateway)
        sent = []
        receiver = lambda **kw: sent.append(kw)  # noqa: E731
        invoice_generated.connect(receiver, weak=False)
        invoice = BillingService().generate_invoice(subscription)
        assert sent
        assert sent[0]["invoice_id"] == invoice.id
        assert sent[0]["amount"] == 4900
        assert sent[0]["tenant_id"] == str(tenant.pk)
        invoice_generated.disconnect(receiver)


class TestProcessWebhookEvent:
    def test_paid_event_reinstates_entitlement(self, tenant, plan, gateway):
        from infrasynth.billing.models import PaymentTransaction
        from infrasynth.shared.enums import EntitlementStatus

        subscription = BillingService().create_subscription(plan, tenant, gateway, external_id="sub_1")
        entitlement = subscription.entitlement
        entitlement.status = EntitlementStatus.PAST_DUE
        entitlement.save(update_fields=["status"])
        tenant.status = "suspended"
        tenant.save(update_fields=["status"])

        result = BillingService().process_webhook_event(
            gateway,
            "invoice.paid",
            {
                "metadata": {"tenant_id": str(tenant.pk)},
                "amount": 4900,
                "currency": "usd",
                "id": "evt_1",
            },
            event_id="evt_1",
        )
        assert result["action"] == "reinstated"
        entitlement.refresh_from_db()
        tenant.refresh_from_db()
        assert entitlement.status == EntitlementStatus.ACTIVE
        assert tenant.status == "active"
        assert PaymentTransaction.objects.filter(tenant=tenant).count() == 1

    def test_duplicate_event_is_idempotent(self, tenant, plan, gateway):
        from infrasynth.billing.models import PaymentTransaction

        BillingService().create_subscription(plan, tenant, gateway, external_id="sub_1")
        payload = {"metadata": {"tenant_id": str(tenant.pk)}, "amount": 100, "id": "evt_dup"}
        first = BillingService().process_webhook_event(gateway, "invoice.paid", payload, event_id="evt_dup")
        second = BillingService().process_webhook_event(gateway, "invoice.paid", payload, event_id="evt_dup")
        assert first["status"] == "processed"
        assert second["status"] == "duplicate"
        assert PaymentTransaction.objects.filter(tenant=tenant).count() == 1

    def test_failed_event_marks_past_due(self, tenant, plan, gateway):
        from infrasynth.shared.enums import EntitlementStatus

        subscription = BillingService().create_subscription(plan, tenant, gateway, external_id="sub_1")
        BillingService().process_webhook_event(
            gateway,
            "invoice.payment_failed",
            {"metadata": {"tenant_id": str(tenant.pk)}, "amount": 4900, "id": "evt_fail"},
            event_id="evt_fail",
        )
        subscription.entitlement.refresh_from_db()
        assert subscription.entitlement.status == EntitlementStatus.PAST_DUE