feat: impl bearer auth middleware

apps/backend/internal/user/service.go

@@ -0,0 +1,32 @@
+package user
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+
+	"github.com/google/uuid"
+	"github.com/uptrace/bun"
+)
+
+type Service struct {
+	db *bun.DB
+}
+
+func NewService(db *bun.DB) *Service {
+	return &Service{
+		db: db,
+	}
+}
+
+func (s *Service) UserByID(ctx context.Context, id uuid.UUID) (*User, error) {
+	var user User
+	err := s.db.NewSelect().Model(&user).Where("id = ?", id).Scan(ctx)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, newNotFoundError(id)
+		}
+		return nil, err
+	}
+	return &user, nil
+}