fix interest

api.saladeaula.digital/app/routes/orders/checkout.py

@@ -12,7 +12,7 @@ from aws_lambda_powertools.event_handler.exceptions import (
     NotFoundError,
 )
 from layercake.dateutils import now, ttl
-from layercake.dynamodb import DynamoDBPersistenceLayer, KeyPair
+from layercake.dynamodb import DynamoDBPersistenceLayer, KeyPair, SortKey
 from layercake.extra_types import CnpjStr, CpfStr, CreditCard, NameStr
 from pydantic import (
     UUID4,
@@ -26,7 +26,7 @@ from pydantic import (
 
 from api_gateway import JSONResponse
 from boto3clients import dynamodb_client
-from config import ORDER_TABLE
+from config import DUE_DAYS, ORDER_TABLE
 from routes.enrollments.enroll import Enrollment
 
 router = Router()
@@ -135,24 +135,29 @@ class Checkout(BaseModel):
 def checkout(payload: Checkout):
     now_ = now()
     order_id = payload.id
+    org_id = payload.org_id
     address = payload.address
     credit_card = payload.credit_card
     items = payload.items
     enrollments = payload.enrollments
     coupon = payload.coupon
-    subtotal = _sum_items(items)
     payment_method = payload.payment_method
+    installments = payload.installments
+    subtotal = _sum_items(items)
     due_date = (
-        _calc_due_date(now_, 3)
+        _calc_due_date(now_, _get_due_days(org_id) if org_id else DUE_DAYS)
         if payment_method == 'BANK_SLIP'
         else now_ + timedelta(hours=1)
     )
     discount = (
-        _apply_discount(subtotal, coupon.amount, coupon.type) * -1
-        if coupon
-        else Decimal('0')
+        _apply_discount(subtotal, coupon.amount, coupon.type) * -1 if coupon else 0
+    )
+    total = subtotal + discount if subtotal > 0 else 0
+    interest_amount = (
+        _calc_interest(total, installments) - total
+        if payment_method == 'CREDIT_CARD' and installments
+        else 0
     )
-    total = subtotal + discount if subtotal > Decimal('0') else Decimal('0')
 
     with dyn.transact_writer() as transact:
         transact.put(
@@ -161,14 +166,21 @@ def checkout(payload: Checkout):
                 'sk': '0',
                 'status': 'PENDING',
                 'subtotal': subtotal,
-                'total': total,
+                'total': total + interest_amount,
                 'discount': discount,
                 'due_date': due_date,
                 # Post-migration (orders): rename `create_date` to `created_at`
                 'create_date': now_,
             }
             | ({'coupon': coupon.code} if coupon else {})
-            | ({'installments': payload.installments} if payload.installments else {})
+            | (
+                {
+                    'installments': payload.installments,
+                    'interest_amount': interest_amount,
+                }
+                if payload.installments
+                else {}
+            )
             | payload.model_dump()
         )
 
@@ -293,3 +305,17 @@ def _calc_due_date(
             business_days -= 1
 
     return current_dt
+
+
+def _get_due_days(
+    org_id: str | UUID4,
+    default: int = DUE_DAYS,
+) -> int:
+    return dyn.collection.get_item(
+        KeyPair(
+            pk=str(org_id),
+            sk=SortKey('METADATA#PAYMENT_POLICY', path_spec='due_days'),
+        ),
+        raise_on_error=False,
+        default=default,
+    )