from decimal import Decimal

from django.contrib.auth import get_user_model
from django.db import IntegrityError, transaction
from django.test import TestCase

from apps.accounts.models import Customer
from apps.orders.models import ProcessingOrder
from apps.payments.gateways import get_gateway
from apps.payments.models import Payment
from apps.workflows.models import Workflow, WorkflowVersion

User = get_user_model()


class PaymentTests(TestCase):
    def setUp(self):
        self.user = User.objects.create_user(username="c", password="***")
        self.customer = Customer.objects.create(user=self.user)
        wf = Workflow.objects.create(name="W", slug="w-pay")
        version = WorkflowVersion.objects.create(workflow=wf, version=1)
        self.order = ProcessingOrder.objects.create(customer=self.customer, workflow_version=version)

    def test_mock_gateway_verify_returns_success(self):
        result = get_gateway().verify("AUTH-1", "1000")
        self.assertEqual(result["status"], "success")
        self.assertTrue(result["transaction_id"])

    def test_duplicate_gateway_transaction_rejected(self):
        Payment.objects.create(
            order=self.order, amount=Decimal("1000"), currency="IRR",
            gateway="mock", transaction_id="TXN-1", status="success",
        )
        with self.assertRaises(IntegrityError):
            with transaction.atomic():
                Payment.objects.create(
                    order=self.order, amount=Decimal("1000"), currency="IRR",
                    gateway="mock", transaction_id="TXN-1", status="success",
                )