splitted user registration into user, consents & bankaccount creation

internal/services/bank_account_service.go

@@ -0,0 +1,53 @@
+package services
+
+import (
+	"GoMembership/internal/models"
+	"GoMembership/internal/repositories"
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"strconv"
+	"time"
+)
+
+type BankAccountService interface {
+	RegisterBankAccount(bankAccount *models.BankAccount) (int64, error)
+}
+
+type bankAccountService struct {
+	repo repositories.BankAccountRepository
+}
+
+func NewBankAccountService(repo repositories.BankAccountRepository) BankAccountService {
+	return &bankAccountService{repo}
+}
+
+func (service *bankAccountService) RegisterBankAccount(bankAccount *models.BankAccount) (int64, error) {
+	bankAccount.MandateDateSigned = time.Now()
+	ref, err := generateSEPAMandateReference(strconv.Itoa(bankAccount.UserID))
+	if err != nil {
+		return -1, err
+	}
+	bankAccount.MandateReference = ref
+
+	return service.repo.CreateBankAccount(bankAccount)
+}
+
+func generateUniqueID(length int) (string, error) {
+	bytes := make([]byte, length)
+	_, err := rand.Read(bytes)
+	if err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(bytes), nil
+}
+
+func generateSEPAMandateReference(userID string) (string, error) {
+	today := time.Now().Format("20060102") // Format YYYYMMDD
+	uniqueID, err := generateUniqueID(4)   // 4 Bytes = 8 Hex-Zeichen
+	if err != nil {
+		return "", err
+	}
+	mandateReference := fmt.Sprintf("%s-%s-%s", userID, today, uniqueID)
+	return mandateReference, nil
+}