Reapply "feat(loyalty): EnakPoint & EnakCoin" (#32)

This reverts commit 4e24f9bbb0.

internal/service/customer_wallet_service.go

@@ -0,0 +1,91 @@
+package service
+
+import (
+	"context"
+	"errors"
+
+	"github.com/google/uuid"
+
+	"apskel-pos-be/internal/constants"
+	"apskel-pos-be/internal/contract"
+	"apskel-pos-be/internal/models"
+	"apskel-pos-be/internal/processor"
+	"apskel-pos-be/internal/repository"
+)
+
+// CustomerWalletService moves balance on the customer's own request: exchanging
+// EnakCoin into EnakPoint and sending either to another customer
+// (docs/prd-point-coin.md F4, F5).
+type CustomerWalletService interface {
+	PreviewExchange(ctx context.Context, customerID uuid.UUID, coins int64) *contract.Response
+	Exchange(ctx context.Context, customerID uuid.UUID, req *contract.ExchangeCoinsRequest, idempotencyKey string, info models.CustomerPinRequestInfo) *contract.Response
+	TransferRecipient(ctx context.Context, customerID uuid.UUID, phoneNumber string) *contract.Response
+	Transfer(ctx context.Context, customerID uuid.UUID, req *contract.TransferWalletRequest, idempotencyKey string, info models.CustomerPinRequestInfo) *contract.Response
+}
+
+type CustomerWalletServiceImpl struct {
+	exchanges *processor.WalletExchangeProcessor
+	transfers *processor.WalletTransferProcessor
+}
+
+func NewCustomerWalletService(exchanges *processor.WalletExchangeProcessor, transfers *processor.WalletTransferProcessor) *CustomerWalletServiceImpl {
+	return &CustomerWalletServiceImpl{exchanges: exchanges, transfers: transfers}
+}
+
+func (s *CustomerWalletServiceImpl) TransferRecipient(ctx context.Context, customerID uuid.UUID, phoneNumber string) *contract.Response {
+	recipient, err := s.transfers.Recipient(ctx, customerID, phoneNumber)
+	if err != nil {
+		return walletMoveErrorResponse(err)
+	}
+	return contract.BuildSuccessResponse(recipient)
+}
+
+func (s *CustomerWalletServiceImpl) Transfer(ctx context.Context, customerID uuid.UUID, req *contract.TransferWalletRequest, idempotencyKey string, info models.CustomerPinRequestInfo) *contract.Response {
+	result, err := s.transfers.Transfer(ctx, customerID, models.WalletTransfer{
+		Currency:       req.Currency,
+		Amount:         req.Amount,
+		RecipientPhone: req.RecipientPhone,
+	}, req.Pin, idempotencyKey, info)
+	if err != nil {
+		return walletMoveErrorResponse(err)
+	}
+	return contract.BuildSuccessResponse(result)
+}
+
+func (s *CustomerWalletServiceImpl) PreviewExchange(ctx context.Context, customerID uuid.UUID, coins int64) *contract.Response {
+	preview, err := s.exchanges.Preview(ctx, customerID, coins)
+	if err != nil {
+		return walletMoveErrorResponse(err)
+	}
+	return contract.BuildSuccessResponse(preview)
+}
+
+func (s *CustomerWalletServiceImpl) Exchange(ctx context.Context, customerID uuid.UUID, req *contract.ExchangeCoinsRequest, idempotencyKey string, info models.CustomerPinRequestInfo) *contract.Response {
+	result, err := s.exchanges.Exchange(ctx, customerID, req.Coins, req.Pin, idempotencyKey, info)
+	if err != nil {
+		return walletMoveErrorResponse(err)
+	}
+	return contract.BuildSuccessResponse(result)
+}
+
+// walletMoveErrorResponse keeps the PIN codes the apps act on, and tells a refused
+// request apart from a server failure.
+func walletMoveErrorResponse(err error) *contract.Response {
+	var pinErr *processor.PinError
+	if errors.As(err, &pinErr) {
+		return PinErrorResponse(err)
+	}
+	code := constants.InternalServerErrorCode
+	switch {
+	case errors.Is(err, repository.ErrWalletNotFound),
+		errors.Is(err, processor.ErrWalletRecipientNotFound):
+		code = constants.NotFoundErrorCode
+	case errors.Is(err, processor.ErrWalletMoveRejected),
+		errors.Is(err, processor.ErrWalletIdempotencyConflict),
+		errors.Is(err, processor.ErrWalletInvalidEntry):
+		code = constants.ValidationErrorCode
+	}
+	return contract.BuildErrorResponse([]*contract.ResponseError{
+		contract.NewResponseError(code, constants.WalletServiceEntity, err.Error()),
+	})
+}