[client] Persist route selection (#2810)

client/internal/statemanager/manager.go

@@ -22,9 +22,28 @@ import (
 // State interface defines the methods that all state types must implement
 type State interface {
 	Name() string
+}
+
+// CleanableState interface extends State with cleanup capability
+type CleanableState interface {
+	State
 	Cleanup() error
 }
 
+// RawState wraps raw JSON data for unregistered states
+type RawState struct {
+	data json.RawMessage
+}
+
+func (r *RawState) Name() string {
+	return "" // This is a placeholder implementation
+}
+
+// MarshalJSON implements json.Marshaler to preserve the original JSON
+func (r *RawState) MarshalJSON() ([]byte, error) {
+	return r.data, nil
+}
+
 // Manager handles the persistence and management of various states
 type Manager struct {
 	mu     sync.Mutex
@@ -209,15 +228,15 @@ func (m *Manager) PersistState(ctx context.Context) error {
 	return nil
 }
 
-// loadState loads the existing state from the state file
-func (m *Manager) loadState() error {
+// loadStateFile reads and unmarshals the state file into a map of raw JSON messages
+func (m *Manager) loadStateFile() (map[string]json.RawMessage, error) {
 	data, err := os.ReadFile(m.filePath)
 	if err != nil {
 		if errors.Is(err, fs.ErrNotExist) {
 			log.Debug("state file does not exist")
-			return nil
+			return nil, nil // nolint:nilnil
 		}
-		return fmt.Errorf("read state file: %w", err)
+		return nil, fmt.Errorf("read state file: %w", err)
 	}
 
 	var rawStates map[string]json.RawMessage
@@ -228,37 +247,69 @@ func (m *Manager) loadState() error {
 		} else {
 			log.Info("State file deleted")
 		}
-		return fmt.Errorf("unmarshal states: %w", err)
+		return nil, fmt.Errorf("unmarshal states: %w", err)
 	}
 
-	var merr *multierror.Error
+	return rawStates, nil
+}
 
-	for name, rawState := range rawStates {
-		stateType, ok := m.stateTypes[name]
-		if !ok {
-			merr = multierror.Append(merr, fmt.Errorf("unknown state type: %s", name))
-			continue
-		}
+// loadSingleRawState unmarshals a raw state into a concrete state object
+func (m *Manager) loadSingleRawState(name string, rawState json.RawMessage) (State, error) {
+	stateType, ok := m.stateTypes[name]
+	if !ok {
+		return nil, fmt.Errorf("state %s not registered", name)
+	}
 
-		if string(rawState) == "null" {
-			continue
-		}
+	if string(rawState) == "null" {
+		return nil, nil //nolint:nilnil
+	}
 
-		statePtr := reflect.New(stateType).Interface().(State)
-		if err := json.Unmarshal(rawState, statePtr); err != nil {
-			merr = multierror.Append(merr, fmt.Errorf("unmarshal state %s: %w", name, err))
-			continue
-		}
+	statePtr := reflect.New(stateType).Interface().(State)
+	if err := json.Unmarshal(rawState, statePtr); err != nil {
+		return nil, fmt.Errorf("unmarshal state %s: %w", name, err)
+	}
 
-		m.states[name] = statePtr
+	return statePtr, nil
+}
+
+// LoadState loads a specific state from the state file
+func (m *Manager) LoadState(state State) error {
+	if m == nil {
+		return nil
+	}
+
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	rawStates, err := m.loadStateFile()
+	if err != nil {
+		return err
+	}
+	if rawStates == nil {
+		return nil
+	}
+
+	name := state.Name()
+	rawState, exists := rawStates[name]
+	if !exists {
+		return nil
+	}
+
+	loadedState, err := m.loadSingleRawState(name, rawState)
+	if err != nil {
+		return err
+	}
+
+	m.states[name] = loadedState
+	if loadedState != nil {
 		log.Debugf("loaded state: %s", name)
 	}
 
-	return nberrors.FormatErrorOrNil(merr)
+	return nil
 }
 
-// PerformCleanup retrieves all states from the state file for the registered states and calls Cleanup on them.
-// If the cleanup is successful, the state is marked for deletion.
+// PerformCleanup retrieves all states from the state file and calls Cleanup on registered states that support it.
+// Unregistered states are preserved in their original state.
 func (m *Manager) PerformCleanup() error {
 	if m == nil {
 		return nil
@@ -267,22 +318,53 @@ func (m *Manager) PerformCleanup() error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
-	if err := m.loadState(); err != nil {
+	// Load raw states from file
+	rawStates, err := m.loadStateFile()
+	if err != nil {
 		log.Warnf("Failed to load state during cleanup: %v", err)
+		return err
+	}
+	if rawStates == nil {
+		return nil
 	}
 
 	var merr *multierror.Error
-	for name, state := range m.states {
-		if state == nil {
-			// If no state was found in the state file, we don't mark the state dirty nor return an error
+
+	// Process each state in the file
+	for name, rawState := range rawStates {
+		// For unregistered states, preserve the raw JSON
+		if _, registered := m.stateTypes[name]; !registered {
+			m.states[name] = &RawState{data: rawState}
 			continue
 		}
 
+		// Load the registered state
+		loadedState, err := m.loadSingleRawState(name, rawState)
+		if err != nil {
+			merr = multierror.Append(merr, err)
+			continue
+		}
+
+		if loadedState == nil {
+			continue
+		}
+
+		// Check if state supports cleanup
+		cleanableState, isCleanable := loadedState.(CleanableState)
+		if !isCleanable {
+			// If it doesn't support cleanup, keep it as-is
+			m.states[name] = loadedState
+			continue
+		}
+
+		// Perform cleanup for cleanable states
 		log.Infof("client was not shut down properly, cleaning up %s", name)
-		if err := state.Cleanup(); err != nil {
+		if err := cleanableState.Cleanup(); err != nil {
 			merr = multierror.Append(merr, fmt.Errorf("cleanup state for %s: %w", name, err))
+			// On cleanup error, preserve the state
+			m.states[name] = loadedState
 		} else {
-			// mark for deletion on cleanup success
+			// Successfully cleaned up - mark for deletion
 			m.states[name] = nil
 			m.dirty[name] = struct{}{}
 		}