from flask import jsonify
from app.utils.logger import logger
from app.api.services.base_service import BaseService
from app.models.loan import Loan
from datetime import datetime


class LoanService(BaseService):
    @staticmethod
    def process_request(filters=None):
        """
        Process the get loans request.

        Args:
            filters (dict, optional): Filters for the loans query.

        Returns:
            dict: A standardized response with loans data.
        """
        try:
            if filters is None:
                filters = {}

            # Extract filters
            customer_id = filters.get('customer_id')
            account_id = filters.get('account_id')
            offer_id = filters.get('offer_id')
            status = filters.get('status')
            start_date = filters.get('start_date')
            end_date = filters.get('end_date')

            # Convert string dates to datetime objects if provided
            if start_date and isinstance(start_date, str):
                start_date = datetime.fromisoformat(start_date.replace('Z', '+00:00'))
            if end_date and isinstance(end_date, str):
                end_date = datetime.fromisoformat(end_date.replace('Z', '+00:00'))

            # Get loans with filters
            query = Loan.query

            if customer_id:
                query = query.filter(Loan.customer_id == customer_id)

            if account_id:
                query = query.filter(Loan.account_id == account_id)

            if offer_id:
                query = query.filter(Loan.offer_id == offer_id)

            if status:
                query = query.filter(Loan.status == status)

            if start_date:
                query = query.filter(Loan.created_at >= start_date)

            if end_date:
                query = query.filter(Loan.created_at <= end_date)

            # Order by created_at descending (newest first)
            query = query.order_by(Loan.created_at.desc())

            loans = query.all()

            # Convert loans to dictionary format
            loans_data = []
            for loan in loans:
                loans_data.append({
                    'id': loan.id,
                    'customer_id': loan.customer_id,
                    'account_id': loan.account_id,
                    'offer_id': loan.offer_id,
                    'principal_amount': loan.principal_amount,
                    'status': loan.status,
                    'created_at': loan.created_at.isoformat(),
                    'updated_at': loan.updated_at.isoformat()
                })

            response_data = {
                'loans': loans_data,
                'count': len(loans_data)
            }

            return response_data

        except Exception as e:
            logger.error(f"Error retrieving loans: {str(e)}", exc_info=True)
            return jsonify({
                'status': 'error',
                'message': f'Failed to retrieve loans: {str(e)}'
            }), 500