import json
import logging
import uuid
from typing import Any

from app.models.order import Order, OrderStatus
from app.models.payment import Payment, PaymentMethod, PaymentStatus

logger = logging.getLogger(__name__)

class PaymentService:
    """
    Payment service for processing payments.
    
    This is a mock implementation that simulates payment processing for demonstration purposes.
    In a real-world application, this would integrate with actual payment providers.
    """

    @staticmethod
    async def process_payment(
        db_session,
        order: Order,
        payment_method: PaymentMethod,
        payment_details: dict[str, Any]
    ) -> dict[str, Any]:
        """
        Process a payment for an order.
        
        Args:
            db_session: Database session
            order: Order to be paid
            payment_method: Payment method to use
            payment_details: Additional payment details
            
        Returns:
            Dictionary with payment result details

        """
        # Mock payment processing
        # In a real application, this would call the payment provider's API

        # Create a mock transaction ID
        transaction_id = f"TRANS-{uuid.uuid4()}"

        # Simulate payment processing
        success = True
        error_message = None
        status = PaymentStatus.COMPLETED

        # For demonstration purposes, let's fail some payments randomly based on order ID
        if int(order.id.replace("-", ""), 16) % 10 == 0:
            success = False
            error_message = "Payment declined by the provider"
            status = PaymentStatus.FAILED

        # Create payment record
        payment = Payment(
            id=str(uuid.uuid4()),
            order_id=order.id,
            amount=order.total_amount,
            payment_method=payment_method,
            status=status,
            transaction_id=transaction_id if success else None,
            payment_details=json.dumps(payment_details),
            error_message=error_message,
        )

        db_session.add(payment)

        # Update order status based on payment result
        if success:
            order.status = OrderStatus.PROCESSING

        db_session.commit()

        # Return payment result
        return {
            "success": success,
            "payment_id": payment.id,
            "status": status,
            "transaction_id": transaction_id if success else None,
            "error_message": error_message,
            "redirect_url": None,  # In real payment flows, this might be a URL to redirect the user to
        }

    @staticmethod
    async def process_stripe_payment(
        db_session,
        order: Order,
        payment_details: dict[str, Any]
    ) -> dict[str, Any]:
        """
        Process a payment using Stripe.
        
        Args:
            db_session: Database session
            order: Order to be paid
            payment_details: Stripe payment details including token
            
        Returns:
            Dictionary with payment result details

        """
        logger.info(f"Processing Stripe payment for order {order.id}")

        # In a real application, this would use the Stripe API
        # Example code (not actually executed):
        # import stripe
        # stripe.api_key = settings.STRIPE_API_KEY
        # try:
        #     charge = stripe.Charge.create(
        #         amount=int(order.total_amount * 100),  # Amount in cents
        #         currency="usd",
        #         source=payment_details.get("token"),
        #         description=f"Payment for order {order.order_number}",
        #         metadata={"order_id": order.id}
        #     )
        #     transaction_id = charge.id
        #     success = True
        #     error_message = None
        # except stripe.error.CardError as e:
        #     transaction_id = None
        #     success = False
        #     error_message = e.error.message

        # Mock implementation
        return await PaymentService.process_payment(
            db_session, order, PaymentMethod.STRIPE, payment_details
        )

    @staticmethod
    async def process_paypal_payment(
        db_session,
        order: Order,
        payment_details: dict[str, Any]
    ) -> dict[str, Any]:
        """
        Process a payment using PayPal.
        
        Args:
            db_session: Database session
            order: Order to be paid
            payment_details: PayPal payment details
            
        Returns:
            Dictionary with payment result details and potentially a redirect URL

        """
        logger.info(f"Processing PayPal payment for order {order.id}")

        # In a real application, this would use the PayPal API
        # Mock implementation
        result = await PaymentService.process_payment(
            db_session, order, PaymentMethod.PAYPAL, payment_details
        )

        # PayPal often requires redirect to complete payment
        if result["success"]:
            result["redirect_url"] = f"https://www.paypal.com/checkout/mock-redirect?order_id={order.id}"

        return result

    @staticmethod
    async def verify_payment(
        db_session,
        payment_id: str
    ) -> Payment | None:
        """
        Verify the status of a payment.
        
        Args:
            db_session: Database session
            payment_id: ID of the payment to verify
            
        Returns:
            Updated payment object or None if not found

        """
        # Get the payment
        payment = db_session.query(Payment).filter(Payment.id == payment_id).first()
        if not payment:
            return None

        # In a real application, this would check with the payment provider's API
        # to get the current status of the payment

        # For mock implementation, we'll just return the payment as is
        return payment