add create user method

internal/app/server.go

@@ -2,21 +2,28 @@ package app
 
 import (
 	"context"
+	"errors"
 
 	"git.3crabs.ru/save_my_money/smm_core/internal/services/category"
+	"git.3crabs.ru/save_my_money/smm_core/internal/services/user"
 	proto "git.3crabs.ru/save_my_money/smm_core/proto"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 type Server struct {
 	proto.UnsafeSmmCoreServer
 	categoryService *category.CategoryService
+	userService     *user.UserService
 }
 
 func NewServer(
 	categoryService *category.CategoryService,
+	userService *user.UserService,
 ) proto.SmmCoreServer {
 	return &Server{
 		categoryService: categoryService,
+		userService:     userService,
 	}
 }
 
@@ -24,6 +31,25 @@ func (s *Server) Ping(_ context.Context, _ *proto.PingReq) (*proto.PingRsp, erro
 	return &proto.PingRsp{}, nil
 }
 
+func (s *Server) AddUser(ctx context.Context, req *proto.CreateUserReq) (*proto.User, error) {
+	res, err := s.userService.AddUser(
+		ctx,
+		&user.UserEntity{
+			Username: req.Username,
+		},
+	)
+	if err != nil {
+		if errors.Is(err, &user.UsernameAlreadyExistsErr{}) {
+			return nil, status.Error(codes.AlreadyExists, "Пользователь с таким username уже существует")
+		}
+		return nil, err
+	}
+	return &proto.User{
+		Id:       int32(res.Id),
+		Username: res.Username,
+	}, nil
+}
+
 func (s *Server) AddCategory(ctx context.Context, req *proto.CreateCategoryReq) (*proto.Category, error) {
 	res, err := s.categoryService.AddCategory(
 		ctx,