Add auto-reconnection and improved connection handling

- Add automatic reconnection thread with retry logic
- Add IsConnected() method for thread-safe connection state checking
- Improve connection state management with is_reconnecting_ flag
- Add re-advertisement logic in ROSTopic on send/queue failures
- Refactor code organization with helper functions
- Improve error handling and logging
- Add thread-safe connection checks in SendMessage methods
- Better handling of connection failures and recovery

Author: stex2005

include/client/socket_websocket_connection.h

@@ -26,25 +26,30 @@ namespace rosbridge2cpp{
       SocketWebSocketConnection() = default;
 
       ~SocketWebSocketConnection() {
-        std::cout << "WebSocket Connection Destructor called" << std::endl;
+        std::cout << "[WebSocketConnection] Destructor called" << std::endl;
         if (is_connected_) {
           Disconnect();
         }
         terminate_receiver_thread_ = true;
+        terminate_reconnect_thread_ = true;
         if (receiver_thread_set_up_) {
-          std::cout << "Thread is set up: Calling .join() on it" << std::endl;
           receiver_thread_.join();
-          std::cout << "join() in Connection Destructor done" << std::endl;
         } else {
-          std::cout << "receiverThread hasn't been set up. Skipping join() on it" << std::endl;
+          std::cout << "[WebSocketConnection] receiverThread hasn't been set up. Skipping join() on it" << std::endl;
+        }
+        if (reconnect_thread_set_up_) {
+          reconnect_thread_.join();
         }
       }
 
       bool Init(std::string p_ip_addr, int p_port);
       bool SendMessage(std::string data);
       bool SendMessage(const uint8_t *data, unsigned int length);
       std::string GetLastSentMessage() const;
+      bool IsConnected() const;
       int ReceiverThreadFunction();
+      void ReconnectThreadFunction();
+      bool AttemptReconnect();
       void RegisterIncomingMessageCallback(std::function<void(json&)> fun);
       void RegisterIncomingMessageCallback(std::function<void(bson_t&)> fun);
       void RegisterErrorCallback(std::function<void(TransportError)> fun);
@@ -69,19 +74,34 @@ namespace rosbridge2cpp{
       bool terminate_receiver_thread_ = false;
       bool receiver_thread_set_up_ = false;
       bool is_connected_ = false;
+      bool is_reconnecting_ = false;
       bool callback_function_defined_ = false;
       bool bson_only_mode_ = false;
+      bool auto_reconnect_ = true;
+      bool terminate_reconnect_thread_ = false;
+      std::thread reconnect_thread_;
+      bool reconnect_thread_set_up_ = false;
 
       std::function<void(json&)> incoming_message_callback_;
       std::function<void(bson_t&)> incoming_message_callback_bson_;
       std::function<void(TransportError)> error_callback_ = nullptr;
 
-      std::mutex connection_mutex_;
+      mutable std::mutex connection_mutex_;
       std::condition_variable connection_cv_;
 
       mutable std::string last_sent_message_;
       mutable std::mutex last_message_mutex_;
 
+      // Reconnection state tracking
+      mutable std::mutex reconnect_mutex_;
+      bool last_send_failed_logged_ = false;
+      
+      // Helper functions
+      void RegisterWebSocketHandlers();
+      void SetupASIOThread();
+      bool IsConnectedOrReconnecting() const;
+      
+      // WebSocket event handlers
       void on_open(connection_hdl hdl);
       void on_close(connection_hdl hdl);
       void on_fail(connection_hdl hdl);