Enhance logging in client connection methods and state transitions

- Added detailed debug logging in Connect and ConnectAll methods to track connection attempts and client states.
- Improved error messages for connection state checks in the Client struct.
- Implemented validation logging for state transitions in StateManager to capture invalid transitions.

Author: Dumbris

internal/upstream/client.go

@@ -144,11 +144,32 @@ func (c *Client) onStateChange(oldState, newState ConnectionState, info Connecti
 
 // Connect establishes a connection to the upstream MCP server
 func (c *Client) Connect(ctx context.Context) error {
+	c.logger.Debug("Connect method called",
+		zap.String("server", c.config.Name),
+		zap.String("url", c.config.URL),
+		zap.String("command", c.config.Command),
+		zap.String("protocol", c.config.Protocol),
+		zap.Bool("enabled", c.config.Enabled),
+		zap.Bool("quarantined", c.config.Quarantined),
+		zap.String("current_state", c.stateManager.GetState().String()),
+		zap.Bool("is_connecting", c.stateManager.IsConnecting()),
+		zap.Bool("is_ready", c.stateManager.IsReady()))
+
 	// Check if already connecting or connected
 	if c.stateManager.IsConnecting() || c.stateManager.IsReady() {
-		return fmt.Errorf("connection already in progress or established")
+		errMsg := fmt.Sprintf("connection already in progress or established (state: %s)", c.stateManager.GetState().String())
+		c.logger.Debug("Connect aborted - already in progress or connected",
+			zap.String("server", c.config.Name),
+			zap.String("current_state", c.stateManager.GetState().String()))
+		return fmt.Errorf(errMsg)
 	}
 
+	c.logger.Info("Starting connection to upstream MCP server",
+		zap.String("server", c.config.Name),
+		zap.String("url", c.config.URL),
+		zap.String("command", c.config.Command),
+		zap.String("protocol", c.config.Protocol))
+
 	// Transition to connecting state
 	c.stateManager.TransitionTo(StateConnecting)
 

internal/upstream/manager.go

@@ -365,28 +365,68 @@ func (m *Manager) ConnectAll(ctx context.Context) error {
 	}
 	m.mu.RUnlock()
 
+	m.logger.Debug("ConnectAll starting",
+		zap.Int("total_clients", len(clients)))
+
 	var wg sync.WaitGroup
 	for id, client := range clients {
+		m.logger.Debug("Evaluating client for connection",
+			zap.String("id", id),
+			zap.String("name", client.config.Name),
+			zap.Bool("enabled", client.config.Enabled),
+			zap.Bool("is_connected", client.IsConnected()),
+			zap.Bool("is_connecting", client.IsConnecting()),
+			zap.String("current_state", client.GetState().String()),
+			zap.Bool("quarantined", client.config.Quarantined))
+
 		if !client.config.Enabled {
+			m.logger.Debug("Skipping disabled client",
+				zap.String("id", id),
+				zap.String("name", client.config.Name))
+
 			if client.IsConnected() {
 				m.logger.Info("Disconnecting disabled client", zap.String("id", id), zap.String("name", client.config.Name))
 				_ = client.Disconnect()
 			}
 			continue
 		}
 
+		// Check connection eligibility with detailed logging
+		if client.IsConnected() {
+			m.logger.Debug("Client already connected, skipping",
+				zap.String("id", id),
+				zap.String("name", client.config.Name))
+			continue
+		}
+
+		if client.IsConnecting() {
+			m.logger.Debug("Client already connecting, skipping",
+				zap.String("id", id),
+				zap.String("name", client.config.Name))
+			continue
+		}
+
+		m.logger.Info("Attempting to connect client",
+			zap.String("id", id),
+			zap.String("name", client.config.Name),
+			zap.String("url", client.config.URL),
+			zap.String("command", client.config.Command),
+			zap.String("protocol", client.config.Protocol))
+
 		wg.Add(1)
 		go func(id string, c *Client) {
 			defer wg.Done()
-			// Only connect if not already connected or trying to connect
-			if !c.IsConnected() && !c.IsConnecting() {
-				if err := c.Connect(ctx); err != nil {
-					m.logger.Error("Failed to connect to upstream server",
-						zap.String("id", id),
-						zap.String("name", c.config.Name),
-						zap.String("state", c.GetState().String()),
-						zap.Error(err))
-				}
+
+			if err := c.Connect(ctx); err != nil {
+				m.logger.Error("Failed to connect to upstream server",
+					zap.String("id", id),
+					zap.String("name", c.config.Name),
+					zap.String("state", c.GetState().String()),
+					zap.Error(err))
+			} else {
+				m.logger.Info("Successfully initiated connection to upstream server",
+					zap.String("id", id),
+					zap.String("name", c.config.Name))
 			}
 		}(id, client)
 	}

internal/upstream/state.go

@@ -108,6 +108,14 @@ func (sm *StateManager) GetConnectionInfo() ConnectionInfo {
 func (sm *StateManager) TransitionTo(newState ConnectionState) {
 	sm.mu.Lock()
 	oldState := sm.currentState
+
+	// Validate transition
+	if err := sm.ValidateTransition(oldState, newState); err != nil {
+		// For now, log the validation error but allow the transition
+		// In the future, we might want to be stricter
+		fmt.Printf("Invalid state transition: %v (from %s to %s)\n", err, oldState.String(), newState.String())
+	}
+
 	sm.currentState = newState
 
 	// Clear error on successful transitions