import logging
from datetime import datetime
from flask import jsonify
from app.models.offer import Offer

# Configure logging
logger = logging.getLogger(__name__)

class OfferService:
    """
    Service class for handling offer-related operations.
    """

    @staticmethod
    def get_all_offers(filters=None):
        """
        Get all offers with optional filtering.

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

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

            # Extract filters
            id = filters.get('id')
            product_id = filters.get('product_id')
            start_date = filters.get('start_date')
            end_date = filters.get('end_date')

            # Extract pagination parameters
            page = int(filters.get('page', 1))
            limit = int(filters.get('limit', 20))

            # Ensure page and limit are valid
            if page < 1:
                page = 1
            if limit < 1 or limit > 100:
                limit = 20

            # 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 offers with optional filters and pagination
            offers, total_count = Offer.get_all_offers(
                id=id,
                product_id=product_id,
                start_date=start_date,
                end_date=end_date,
                page=page,
                limit=limit
            )

            # Convert offers to dictionary format
            offers_data = []
            for offer in offers:
                offers_data.append(offer.to_dict())

            # Calculate total pages
            total_pages = (total_count + limit - 1) // limit

            response_data = {
                'offers': offers_data,
                'count': len(offers_data),
                'pagination': {
                    'total_count': total_count,
                    'total_pages': total_pages,
                    'current_page': page,
                    'limit': limit,
                    'has_next': page < total_pages,
                    'has_prev': page > 1
                }
            }

            return response_data

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