from datetime import timedelta from decimal import Decimal from django.contrib.auth import get_user_model from django.test import TestCase from django.utils import timezone from shop_management.models.data.customer import Customer from shop_management.models.data.customer_balance_payment import CustomerBalancePayment from shop_management.models.data.customer_payment import CustomerPayment from shop_management.models.data.inventory import InventoryBatch from shop_management.models.data.organization import Warehouse from shop_management.models.data.product import Product from shop_management.models.data.sale import Sale, SaleItem from shop_management.models.data.shop import Shop from shop_management.models.data.shop_account import Account from shop_management.models.data.utils import Currency, ExchangeRate, Unit from shop_management.services.inventory import receive_stock from shop_management.services.sales import post_sale, void_sale from shop_management.views.data.sale import SaleViewSet class CustomerCreditApplicationTests(TestCase): def setUp(self): self.user = get_user_model().objects.create_user( username="credit-seller", password="test", is_staff=True ) self.shop = Shop.objects.create(owner=self.user, name="Kabul") self.warehouse = Warehouse.objects.create( shop=self.shop, code="MAIN", name="Main" ) self.afn = Currency.objects.create(shop=self.shop, title="AFN") self.afn_account = Account.objects.create( shop=self.shop, name="AFN Cash", currency=self.afn ) self.customer = Customer.objects.create( shop=self.shop, name="Credit Customer" ) self.unit = Unit.objects.create(shop=self.shop, title="Each") self.product = Product.objects.create( shop=self.shop, name="Medicine", default_unit=self.unit, requires_batch=True, requires_expiry=True, ) self.batch = InventoryBatch.objects.create( product=self.product, batch_number="CREDIT", expiry_date=timezone.localdate() + timedelta(days=90), ) receive_stock( warehouse=self.warehouse, product=self.product, batch=self.batch, quantity=10, unit_cost=10, currency=self.afn, ) def create_credit(self, amount, currency, account): return CustomerBalancePayment.objects.create( customer=self.customer, account=account, amount=amount, currency=currency, settlement_currency=currency, settlement_amount=amount, unallocated_amount=amount, ) def create_draft_sale(self, total): sale = Sale.objects.create( shop=self.shop, warehouse=self.warehouse, currency=self.afn, customer=self.customer, sales_type=Sale.SalesType.CREDIT, invoice_date=timezone.localdate(), discount_type=Sale.DiscountType.FIXED, discount_value=0, received_amount=0, uses_inventory_engine=True, document_status=Sale.DocumentStatus.DRAFT, ) SaleItem.objects.create( sale=sale, product=self.product, unit=self.unit, quantity=1, sale_price=total, ) return sale def test_posting_sale_uses_existing_same_currency_credit_first(self): self.create_credit(Decimal("20.00"), self.afn, self.afn_account) sale = self.create_draft_sale(Decimal("27.00")) post_sale(sale.id, user=self.user) sale.refresh_from_db() self.assertEqual(sale.total_remained_amount["AFN"], Decimal("7.00")) self.assertEqual(self.customer.get_credit_by_currency(), {}) self.assertEqual(self.customer.get_total_owed_by_currency(), {"AFN": 7.0}) def test_posting_sale_converts_credit_before_creating_due(self): usd = Currency.objects.create(shop=self.shop, title="USD") usd_account = Account.objects.create( shop=self.shop, name="USD Cash", currency=usd ) ExchangeRate.objects.create( shop=self.shop, from_currency=usd, to_currency=self.afn, rate=Decimal("63.400000"), rate_date=timezone.localdate(), ) self.create_credit(Decimal("95.68"), usd, usd_account) sale = self.create_draft_sale(Decimal("9500.00")) post_sale(sale.id, user=self.user) sale.refresh_from_db() application = sale.credit_applications.get() self.assertEqual(application.source_amount, Decimal("95.68")) self.assertEqual(application.sale_amount, Decimal("6066.11")) self.assertEqual(application.exchange_rate, Decimal("63.400000")) self.assertEqual(sale.total_remained_amount["AFN"], Decimal("3433.89")) self.assertEqual(self.customer.get_credit_by_currency(), {}) self.assertEqual( self.customer.get_total_owed_by_currency(), {"AFN": 3433.89} ) def test_voiding_sale_restores_credit_applied_when_posted(self): self.create_credit(Decimal("20.00"), self.afn, self.afn_account) sale = self.create_draft_sale(Decimal("27.00")) post_sale(sale.id, user=self.user) self.assertEqual(self.customer.get_credit_by_currency(), {}) void_sale(sale.id, user=self.user, reason="Customer cancelled") self.assertEqual(self.customer.get_credit_by_currency(), {"AFN": 20.0}) self.assertEqual(self.customer.get_total_owed_by_currency(), {}) def test_cash_received_after_credit_only_allocates_remaining_due(self): self.create_credit(Decimal("20.00"), self.afn, self.afn_account) sale = self.create_draft_sale(Decimal("27.00")) SaleViewSet()._complete_engine_sale( sale, self.user, financial_account_id=self.afn_account.id, received_amount=Decimal("10.00"), ) sale.refresh_from_db() payment = CustomerPayment.objects.get(allocations__sale=sale) allocation = payment.allocations.get(sale=sale) self.assertEqual(allocation.allocated_amount, Decimal("7.00")) self.assertEqual(payment.unallocated_amount, Decimal("3.00")) self.assertEqual(sale.total_remained_amount["AFN"], Decimal("0.00")) self.assertEqual(self.customer.get_credit_by_currency(), {"AFN": 3.0}) def test_new_sale_applies_credit_to_oldest_unpaid_invoice_first(self): older_sale = self.create_draft_sale(Decimal("9500.00")) post_sale(older_sale.id, user=self.user) usd = Currency.objects.create(shop=self.shop, title="USD") usd_account = Account.objects.create( shop=self.shop, name="USD Cash", currency=usd ) ExchangeRate.objects.create( shop=self.shop, from_currency=usd, to_currency=self.afn, rate=Decimal("63.400000"), rate_date=timezone.localdate(), ) self.create_credit(Decimal("95.68"), usd, usd_account) newer_sale = self.create_draft_sale(Decimal("180.00")) post_sale(newer_sale.id, user=self.user) older_sale.refresh_from_db() newer_sale.refresh_from_db() self.assertEqual( older_sale.total_remained_amount["AFN"], Decimal("3433.89") ) self.assertEqual( newer_sale.total_remained_amount["AFN"], Decimal("180.00") ) self.assertEqual(self.customer.get_credit_by_currency(), {}) self.assertEqual( self.customer.get_total_owed_by_currency(), {"AFN": 3613.89} )