package wallet

import (
	"context"

	"hyapp/pkg/xerr"
	"hyapp/services/wallet-service/internal/domain/ledger"
)

// Repository 隔离账务存储，扣费必须由 repository 保证余额和幂等。
type Repository interface {
	DebitGift(ctx context.Context, command ledger.DebitGiftCommand) (ledger.Receipt, error)
}

// Config 保存钱包底座配置。
type Config struct {
	Currency          string
	IdempotencyTTLSec int64
}

// Service 承载钱包账务用例。
type Service struct {
	cfg        Config
	repository Repository
}

// New 创建钱包服务。
func New(cfg Config, repository Repository) *Service {
	return &Service{cfg: cfg, repository: repository}
}

// DebitGift 校验送礼扣费命令，并交给 repository 做原子落账和幂等。
func (s *Service) DebitGift(ctx context.Context, command ledger.DebitGiftCommand) (ledger.Receipt, error) {
	if command.CommandID == "" || command.RoomID == "" || command.SenderUserID <= 0 || command.TargetUserID <= 0 || command.GiftID == "" {
		return ledger.Receipt{}, xerr.New(xerr.InvalidArgument, "billing command is incomplete")
	}
	if command.GiftCount <= 0 || command.GiftUnitValue <= 0 {
		return ledger.Receipt{}, xerr.New(xerr.InvalidArgument, "gift_count and gift_unit_value must be positive")
	}
	if s.repository == nil {
		return ledger.Receipt{}, xerr.New(xerr.Unavailable, "wallet repository is not configured")
	}

	return s.repository.DebitGift(ctx, command)
}