"""
Coupon Service - Coupon Operations
This service handles ONLY coupon validation and redemption
NO payment provider interactions, NO subscription logic
"""

import structlog
from typing import Dict, Any, Optional, Tuple
from sqlalchemy.ext.asyncio import AsyncSession

from app.repositories.coupon_repository import CouponRepository

logger = structlog.get_logger()


class CouponService:
    """Service for handling coupon validation and redemption"""

    def __init__(self, db_session: AsyncSession):
        self.db_session = db_session
        self.coupon_repo = CouponRepository(db_session)

    async def validate_coupon_code(
        self,
        coupon_code: str,
        tenant_id: str
    ) -> Dict[str, Any]:
        """
        Validate a coupon code for a tenant

        Args:
            coupon_code: Coupon code to validate
            tenant_id: Tenant ID

        Returns:
            Dictionary with validation results
        """
        try:
            validation = await self.coupon_repo.validate_coupon(coupon_code, tenant_id)

            return {
                "valid": validation.valid,
                "error_message": validation.error_message,
                "discount_preview": validation.discount_preview,
                "coupon": {
                    "code": validation.coupon.code,
                    "discount_type": validation.coupon.discount_type.value,
                    "discount_value": validation.coupon.discount_value
                } if validation.coupon else None
            }

        except Exception as e:
            logger.error("Failed to validate coupon", error=str(e), coupon_code=coupon_code)
            return {
                "valid": False,
                "error_message": "Error al validar el cupón",
                "discount_preview": None,
                "coupon": None
            }

    async def redeem_coupon(
        self,
        coupon_code: str,
        tenant_id: str,
        base_trial_days: int = 0
    ) -> Tuple[bool, Optional[Dict[str, Any]], Optional[str]]:
        """
        Redeem a coupon for a tenant

        Args:
            coupon_code: Coupon code to redeem
            tenant_id: Tenant ID
            base_trial_days: Base trial days without coupon

        Returns:
            Tuple of (success, discount_applied, error_message)
        """
        try:
            success, redemption, error = await self.coupon_repo.redeem_coupon(
                coupon_code,
                tenant_id,
                base_trial_days
            )

            if success and redemption:
                return True, redemption.discount_applied, None
            else:
                return False, None, error

        except Exception as e:
            logger.error("Failed to redeem coupon", error=str(e), coupon_code=coupon_code)
            return False, None, f"Error al aplicar el cupón: {str(e)}"

    async def get_coupon_by_code(self, coupon_code: str) -> Optional[Any]:
        """
        Get coupon details by code

        Args:
            coupon_code: Coupon code to retrieve

        Returns:
            Coupon object or None
        """
        try:
            return await self.coupon_repo.get_coupon_by_code(coupon_code)
        except Exception as e:
            logger.error("Failed to get coupon by code", error=str(e), coupon_code=coupon_code)
            return None