package wallet

import (
	"context"
	"strings"

	"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)
	GetBalances(ctx context.Context, userID int64, assetTypes []string) ([]ledger.AssetBalance, error)
	AdminCreditAsset(ctx context.Context, command ledger.AdminCreditAssetCommand) (ledger.AssetBalance, string, error)
}

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

// New 创建钱包服务。
func New(repository Repository) *Service {
	return &Service{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.SenderUserID == command.TargetUserID {
		return ledger.Receipt{}, xerr.New(xerr.InvalidArgument, "sender and target must be different")
	}
	if command.GiftCount <= 0 {
		return ledger.Receipt{}, xerr.New(xerr.InvalidArgument, "gift_count 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)
}

// GetBalances 返回用户多资产余额；鉴权范围由 gateway 或后台入口控制。
func (s *Service) GetBalances(ctx context.Context, userID int64, assetTypes []string) ([]ledger.AssetBalance, error) {
	if userID <= 0 {
		return nil, xerr.New(xerr.InvalidArgument, "user_id is required")
	}
	if s.repository == nil {
		return nil, xerr.New(xerr.Unavailable, "wallet repository is not configured")
	}
	normalized := make([]string, 0, len(assetTypes))
	for _, assetType := range assetTypes {
		assetType = strings.ToUpper(strings.TrimSpace(assetType))
		if assetType == "" {
			continue
		}
		if !ledger.ValidAssetType(assetType) {
			return nil, xerr.New(xerr.InvalidArgument, "asset_type is invalid")
		}
		normalized = append(normalized, assetType)
	}

	return s.repository.GetBalances(ctx, userID, normalized)
}

// AdminCreditAsset 执行后台手动入账；所有审计字段必须随交易一起落库。
func (s *Service) AdminCreditAsset(ctx context.Context, command ledger.AdminCreditAssetCommand) (ledger.AssetBalance, string, error) {
	if command.CommandID == "" || command.TargetUserID <= 0 || command.OperatorUserID <= 0 || command.Amount <= 0 {
		return ledger.AssetBalance{}, "", xerr.New(xerr.InvalidArgument, "admin credit command is incomplete")
	}
	command.AssetType = strings.ToUpper(strings.TrimSpace(command.AssetType))
	if !ledger.ValidAssetType(command.AssetType) {
		return ledger.AssetBalance{}, "", xerr.New(xerr.InvalidArgument, "asset_type is invalid")
	}
	if command.Reason == "" || command.EvidenceRef == "" {
		return ledger.AssetBalance{}, "", xerr.New(xerr.InvalidArgument, "reason and evidence_ref are required")
	}
	if s.repository == nil {
		return ledger.AssetBalance{}, "", xerr.New(xerr.Unavailable, "wallet repository is not configured")
	}

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