Refactor code structure for improved readability and maintainability

app/api.py

@@ -0,0 +1,40 @@
+import uuid
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, Header, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.auth import require_api_key
+from app.db import get_session
+from app.payments import create_payment, get_payment
+from app.schemas import PaymentAccepted, PaymentCreate, PaymentDetails
+
+router = APIRouter(
+    prefix="/api/v1/payments",
+    tags=["payments"],
+    dependencies=[Depends(require_api_key)],
+)
+
+
+@router.post("", response_model=PaymentAccepted, status_code=status.HTTP_202_ACCEPTED)
+async def post_payment(
+    request: PaymentCreate,
+    idempotency_key: Annotated[
+        str,
+        Header(alias="Idempotency-Key", min_length=1, max_length=255),
+    ],
+    session: Annotated[AsyncSession, Depends(get_session)],
+) -> PaymentAccepted:
+    payment = await create_payment(session, request, idempotency_key)
+    return PaymentAccepted.model_validate(payment)
+
+
+@router.get("/{payment_id}", response_model=PaymentDetails)
+async def read_payment(
+    payment_id: uuid.UUID,
+    session: Annotated[AsyncSession, Depends(get_session)],
+) -> PaymentDetails:
+    payment = await get_payment(session, payment_id)
+    if payment is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Payment not found")
+    return PaymentDetails.model_validate(payment)