add init functions

internal/user/service.go

@@ -3,6 +3,8 @@ package user
 import "fmt"
 
 type Service struct {
+	initialized bool
+
 	store UserCRUD
 }
 
@@ -15,18 +17,48 @@ func NewService(store UserCRUD) (*Service, error) {
 	}, nil
 }
 
+func (s *Service) isInitialized() bool {
+	return s.initialized
+}
+
+func (s *Service) Init() error {
+	if s.isInitialized() {
+		return nil
+	}
+
+	err := s.store.init()
+	if err != nil {
+		return fmt.Errorf("failed to initialize user store: %w", err)
+	}
+
+	s.initialized = true
+	return nil
+}
+
 func (s *Service) Create(user *User) error {
+	if !s.isInitialized() {
+		return fmt.Errorf("user service is not initialized")
+	}
 	return s.store.Create(user)
 }
 
 func (s *Service) GetBy(by, value string) (*User, error) {
+	if !s.isInitialized() {
+		return nil, fmt.Errorf("user service is not initialized")
+	}
 	return s.store.GetBy(by, value)
 }
 
 func (s *Service) Update(user *User) error {
+	if !s.isInitialized() {
+		return fmt.Errorf("user service is not initialized")
+	}
 	return s.store.Update(user)
 }
 
 func (s *Service) Delete(id int64) error {
+	if !s.isInitialized() {
+		return fmt.Errorf("user service is not initialized")
+	}
 	return s.store.Delete(id)
 }