from flask import request, jsonify
from marshmallow import ValidationError
from app.api.enums.loan_status import LoanStatus
from app.models import Repayment
from app.models.customer import Customer
from app.models.loan import Loan
from app.utils.logger import logger
from app.api.schemas.repayment import RepaymentSchema
from app.api.services.base_service import BaseService
from app.api.enums import TransactionType 
from threading import Thread
from app.extensions import db

class RepaymentService(BaseService):
    TRANSACTION_TYPE = TransactionType.REPAYMENT 

    @staticmethod
    def process_request(data):
        """
        Process the Repayment request.

        Args:
            data (dict): The request data.

        Returns:
            dict: A standardized response.
        """
        try:
            with db.session.begin():
                validated_data = RepaymentService.validate_data(data, RepaymentSchema())
                customer_id =  validated_data.get('customerId')
                request_id =  validated_data.get('requestId')
                loan_id = validated_data.get('debtId')
                product_id = validated_data.get('productId')
                account_id = validated_data.get('accountId')
                customer = Customer.get_customer(customer_id) 
        
                if(RepaymentService.validate_account_ownership(account_id = account_id, customer_id = customer_id)):

                    # Save the repayment details  
                    repayment = Repayment.create_repayment(
                        customer_id = customer_id,
                        loan_id = loan_id,
                        product_id = product_id

                    )

                    if not repayment:
                        logger.error(f"Failed to save repayment details")
                        return jsonify({
                            "message": "Failed to save repayment details."
                        }), 400
                
                    
                    #Update Loan status
                    Loan.update_status(loan_id = loan_id, status = LoanStatus.REPAID)
                    
                    transaction = RepaymentService.log_transaction(validated_data = validated_data)

                    if not transaction:
                        logger.error(f"Failed to log transaction")
                        return jsonify({
                            "message": "Failed to log transaction."
                        }), 400   
                else: 
                    return jsonify({
                            "message": "Invalid Customer or Account"
                        }), 400
        


                # Simulated processing logic
                response_data = {
                    "customerId": customer_id,
                    "productId": product_id,
                    "debtId": loan_id,
                    "resultCode": "00",
                    "resultDescription": "Successful"
                }

                # return ResponseHelper.success(
                #     data=response_data,
                #     message="Repayment processed successfully"
                # )

                # Call Kafka in a background thread
                thread = Thread(target=RepaymentService.async_send_to_kafka, args=(response_data, request_id, "LOAN_REPAYMENT"))
                thread.start()

                db.session.commit()
                return response_data

        except ValidationError as err:

            logger.error(f"Validation Error: {getattr(err, 'messages', str(err))}")
            db.session.rollback() 

            return jsonify({
                "message": "Validation exception"
                }) , 422
        
        except  ValueError as err:
            logger.error(f"{getattr(err, 'messages', str(err))}")
            db.session.rollback() 

            return jsonify({
                "message": str(err)
                }) , 400

        except Exception as e:
            logger.error(f"An error occurred: {str(e)}", exc_info=True)
            db.session.rollback() 
            return jsonify({
                "message": "Internal Server Error"
                }) , 500