package user

import (
	"context"
	"errors"
	"strconv"

	"go.uber.org/zap"
)

// RedeemItemCard 积分兑换道具卡
func (s *service) RedeemItemCard(ctx context.Context, userID int64, cardID int64, quantity int) (ledgerID int64, err error) {
	if quantity <= 0 {
		quantity = 1
	}

	// 1. 查卡
	tpl, err := s.readDB.SystemItemCards.WithContext(ctx).Where(s.readDB.SystemItemCards.ID.Eq(cardID), s.readDB.SystemItemCards.Status.Eq(1)).First()
	if err != nil {
		return 0, errors.New("item card not found")
	}

	// 2. 算分
	ptsPerUnit, _ := s.CentsToPoints(ctx, tpl.Price)
	needPoints := ptsPerUnit * int64(quantity)
	if needPoints <= 0 {
		needPoints = 1
	}

	// 3. 扣分 (调用现有 Service)
	ledgerID, err = s.ConsumePointsFor(ctx, userID, needPoints, "system_item_cards", strconv.FormatInt(cardID, 10), "redeem item card", "redeem_item_card")
	if err != nil {
		return 0, err
	}

	// 4. 发卡 (如果失败，执行退分)
	if err := s.AddItemCard(ctx, userID, cardID, quantity); err != nil {
		s.logger.Error("failed to add item card after point consumption",
			zap.Int64("user_id", userID),
			zap.Int64("card_id", cardID),
			zap.Int64("ledger_id", ledgerID),
			zap.Error(err),
		)
		// 自动退分
		_, _ = s.RefundPoints(ctx, userID, needPoints, strconv.FormatInt(ledgerID, 10), "refund: grant item card failed")
		return ledgerID, errors.New("failed to grant item card: " + err.Error())
	}

	return ledgerID, nil
}