Allow register new device when exceed user limit when user already exist (#181)

backend/server/internal/database/db.go

@@ -153,6 +153,19 @@ func (db *DB) DistinctUsers(ctx context.Context) (int64, error) {
 	return numDistinctUsers, nil
 }
 
+func (db *DB) UserAlreadyExist(ctx context.Context, userID string) (bool, error) {
+	var cnt int64
+	tx := db.WithContext(ctx).Table("devices").Where("user_id = ?", userID).Count(&cnt)
+	if tx.Error != nil {
+		return false, fmt.Errorf("tx.Error: %w", tx.Error)
+	}
+
+	if cnt > 0 {
+		return true, nil
+	}
+	return false, nil
+}
+
 func (db *DB) DumpRequestCreate(ctx context.Context, req *shared.DumpRequest) error {
 	tx := db.WithContext(ctx).Create(req)
 	if tx.Error != nil {

backend/server/internal/server/api_handlers.go

@@ -201,7 +201,17 @@ func (s *Server) apiDownloadHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) apiRegisterHandler(w http.ResponseWriter, r *http.Request) {
+	userId := getRequiredQueryParam(r, "user_id")
+	deviceId := getRequiredQueryParam(r, "device_id")
+	isIntegrationTestDevice := getOptionalQueryParam(r, "is_integration_test_device", false) == "true"
+
 	if getMaximumNumberOfAllowedUsers() < math.MaxInt {
+		userAlreadyExist, err := s.db.UserAlreadyExist(r.Context(), userId)
+		if err != nil {
+			panic(fmt.Errorf("db.UserAlreadyExist: %w", err))
+		}
+
+		if !userAlreadyExist {
 			numDistinctUsers, err := s.db.DistinctUsers(r.Context())
 			if err != nil {
 				panic(fmt.Errorf("db.DistinctUsers: %w", err))
@@ -210,9 +220,7 @@ func (s *Server) apiRegisterHandler(w http.ResponseWriter, r *http.Request) {
 				panic(fmt.Sprintf("Refusing to allow registration of new device since there are currently %d users and this server allows a max of %d users", numDistinctUsers, getMaximumNumberOfAllowedUsers()))
 			}
 		}
-	userId := getRequiredQueryParam(r, "user_id")
+	}
-	deviceId := getRequiredQueryParam(r, "device_id")
-	isIntegrationTestDevice := getOptionalQueryParam(r, "is_integration_test_device", false) == "true"
 
 	existingDevicesCount, err := s.db.CountDevicesForUser(r.Context(), userId)
 	checkGormError(err)