import pytest

from infrasynth.billing.invoice_generator import _build_invoice_pdf
from infrasynth.billing.models import BillingPlan, Invoice, PaymentGateway
from infrasynth.billing.services import BillingService

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 plan(gateway):
    return BillingPlan.objects.create(
        slug="pro",
        name="Pro",
        price_amount="49.00",
        price_currency="USD",
        interval="monthly",
        gateway=gateway,
    )


class TestBuildInvoicePdf:
    def test_generates_pdf_bytes(self, user, gateway, plan):
        subscription = BillingService().create_subscription(plan, user, gateway)
        invoice = Invoice.objects.create(
            subscription=subscription,
            user=user,
            gateway=gateway,
            invoice_number="INV-2026-000001",
            amount=49,
            currency="USD",
            status="open",
            line_items=[{"description": "Pro", "amount": 49.0, "quantity": 1}],
        )
        pdf_bytes = _build_invoice_pdf(invoice)
        assert pdf_bytes.startswith(b"%PDF")
        assert len(pdf_bytes) > 100

    def test_pdf_includes_tax(self, user, gateway, plan):
        subscription = BillingService().create_subscription(plan, user, gateway)
        invoice = Invoice.objects.create(
            subscription=subscription,
            user=user,
            gateway=gateway,
            invoice_number="INV-2026-000002",
            amount=100,
            tax_amount=19,
            tax_name="IVA",
            currency="USD",
            status="open",
            line_items=[{"description": "Plan", "amount": 100.0, "quantity": 1}],
        )
        pdf_bytes = _build_invoice_pdf(invoice)
        assert pdf_bytes.startswith(b"%PDF")


class TestGenerateInvoicePdfTask:
    def test_task_generates_and_attaches_pdf(self, user, gateway, plan, media_root):
        subscription = BillingService().create_subscription(plan, user, gateway)
        invoice = BillingService().generate_invoice(subscription)
        invoice.refresh_from_db()
        assert invoice.pdf_file_id is not None
        assert invoice.pdf_file.original_filename.startswith("invoice_")
        assert invoice.pdf_file.mime_type == "application/pdf"
        assert invoice.pdf_file.size_bytes > 100

    def test_task_missing_invoice_returns_none(self):
        from infrasynth.billing.invoice_generator import generate_invoice_pdf

        assert generate_invoice_pdf.run(999999) is None