from datetime import datetime
from decimal import Decimal
from typing import Optional, List
from uuid import UUID, uuid4

class Payment:
    def __init__(self, id: UUID, user_id: UUID, amount: Decimal, 
                 currency: str, status: str, stripe_payment_id: Optional[str] = None):
        self.id = id or uuid4()
        self.user_id = user_id
        self.amount = amount
        self.currency = currency
        self.status = status
        self.stripe_payment_id = stripe_payment_id
        self.created_at = datetime.utcnow()

class PaymentCreate:
    def __init__(self, amount: Decimal, currency: str):
        self.amount = amount
        self.currency = currency

class PaymentResponse:
    def __init__(self, id: UUID, amount: Decimal, currency: str, 
                 status: str, created_at: datetime, client_secret: Optional[str] = None):
        self.id = id
        self.amount = amount
        self.currency = currency
        self.status = status
        self.created_at = created_at
        self.client_secret = client_secret

def create_payment(payment: PaymentCreate) -> PaymentResponse:
    """Create a new payment"""
    new_payment = Payment(
        id=uuid4(),
        user_id=uuid4(), # Placeholder
        amount=payment.amount,
        currency=payment.currency,
        status="pending"
    )
    
    return PaymentResponse(
        id=new_payment.id,
        amount=new_payment.amount,
        currency=new_payment.currency,
        status=new_payment.status,
        created_at=new_payment.created_at
    )

def get_payment(payment_id: UUID) -> Optional[PaymentResponse]:
    """Get payment by ID"""
    # Placeholder implementation
    return None

def list_payments(skip: int = 0, limit: int = 100) -> List[PaymentResponse]:
    """List payments with pagination"""
    # Placeholder implementation 
    return []