[Add] Remote SSH sessions and window management.

This is the beginning of the remote session functionality. It allows
players to connect to different NPC systems via an 'ssh' command.

*Server*
- Can now manage a world of multiple NPC file systems that are
  identified by IP addresses.
- Implemented SSH command to allow connection to remote NPC systems.
  Each remote session is managed via a 'CommandProcessor'.
- 'exit' command causes the remote server to terminate the client
  connection

*Client*
- Terminal can enter a 'remote' state via the SSH command which sends
  subsequent commands to the server.
- the local 'exit' command will close the terminal window.
- Refactored UI object ownership to prevent memory leaks and ensure
  proper cleanup when a window is closed or the terminal application.

client/src/client_network.cpp

@@ -60,6 +60,13 @@ void ClientNetwork::send_command(const char* command) {
   NET_WriteToStreamSocket(_socket, command, strlen(command)+1);
 }
 
+void ClientNetwork::disconnect(void) {
+  if(_socket) {
+    NET_DestroyStreamSocket(_socket);
+    _socket = nullptr;
+  }
+}
+
 std::string ClientNetwork::receive_response(void) {
   if(!_socket) return "";
   char buffer[2048];

client/src/client_network.h

@@ -10,6 +10,7 @@ public:
 
   bool connect(const char* host, int port);
   void send_command(const char* command);
+  void disconnect(void);
   std::string receive_response(void);
 
 private:

client/src/main.cpp

@@ -88,6 +88,8 @@ int main(int argc, char** argv) {
       desktop->handle_event(&event);
     }
 
+    desktop->update();
+
     Uint32 current_time = SDL_GetTicks();
     if(current_time - last_blink_time > 500) { /* Every 500ms. */
       show_cursor = !show_cursor;
@@ -106,8 +108,6 @@ int main(int argc, char** argv) {
 
   /* Cleanup. */
   delete desktop;
-  delete term;
-  delete test_window;
   delete shape_renderer_instance;
   delete txt_render_instance;
   SDL_GL_DestroyContext(context);

client/src/terminal.cpp

@@ -14,15 +14,22 @@
 Terminal::Terminal(void) {
   /* Placeholder welcome message to history. */
   _history.push_back("Welcome to Bettola (local mode)");
-  _network = nullptr; /* No network connection for now. */
+
+  _network      = new ClientNetwork();
+  _is_remote    = false;
+  _should_close = false;
 
   /* Create local file system for the client. */
-  _local_vfs = vfs_manager::create_root_system();
+  _local_vfs = vfs_manager::create_root_system("local");
   _local_cmd_processor = new CommandProcessor(_local_vfs);
-  _current_path = get_full_path(_local_cmd_processor->get_current_dir());
+  _current_path  = get_full_path(_local_cmd_processor->get_current_dir());
   _scroll_offset = 0;
 }
 
+bool Terminal::close(void) {
+  return _should_close;
+}
+
 Terminal::~Terminal(void) {
   if(_network) {
     delete _network;
@@ -31,35 +38,57 @@ Terminal::~Terminal(void) {
 
 void Terminal::_on_ret_press(void) {
   std::string command = _input_buffer;
+  _input_buffer.clear(); /* Clear the input buffer immediately. */
+
   /* Add the command to history. */
   _history.push_back(_current_path + "> " + command);
 
-  std::string response;
-  /*
-   * All commands run locally for now.
-   * TODO: Remote commands.
-   */
-  if(command == "clear") {
-    _history.clear();
-  } else {
-    response = _local_cmd_processor->process_command(command);
-  }
+  if(_is_remote) {
+    /* REMOTE STATE. */
+    _network->send_command(command.c_str());
 
-  /* Check if the response is a new path for the prompt. */
-  if(response.rfind("/", 0) == 0) {
-    _current_path = response;
-  } else if(!response.empty()) {
-    /* Otherwise, it's command out. Split it by newline and add to history. */
-    std::stringstream ss(response);
-    std::string line;
-    while(std::getline(ss, line, '\n')) {
-      if(!line.empty()) {
-        _history.push_back(line);
+    if(command == "exit") {
+      /* Don't wait for a response, the server booted us. */
+      _is_remote = false;
+      _network->disconnect();
+      _current_path = get_full_path(_local_cmd_processor->get_current_dir());
+      _history.push_back("Connection closed.");
+    } else {
+      /* For all other commands, wait for a response. */
+      std::string response = _network->receive_response();
+      if(!response.empty()) { _history.push_back(response); }
+    }
+  } else {
+    /* LOCAL STATE! */
+    if(command.rfind("ssh ", 0) == 0) {
+      if(_network->connect("localhost", 8080)) {
+        _network->send_command(command.c_str());
+        std::string response = _network->receive_response();
+        if(response.rfind("CONNECTED ", 0) == 0) {
+          _is_remote = true;
+          std::string ip = response.substr(10);
+          _current_path = "root@" + ip;
+        } else {
+          _history.push_back(response);
+          _network->disconnect(); /* Disconnect on fialed ssh login. */
+        }
+      } else {
+        _history.push_back("Connection failed.");
+      }
+    } else if(command == "exit") {
+      _should_close = true;
+    } else if(command == "clear") {
+      _history.clear();
+    } else {
+      std::string response = _local_cmd_processor->process_command(command);
+      if(response.rfind("/", 0) == 0) {
+        _current_path = response;
+      } else if(!response.empty()) {
+        _history.push_back(response);
       }
     }
   }
 
-  _input_buffer.clear();
   /* TODO: Ugly hack. Refactor to pass window height
    * We need the window height to know if we should
    * auto-scroll, but we don't have it here.

client/src/terminal.h

@@ -16,14 +16,17 @@ public:
   void handle_input(SDL_Event* event);
   void render(TextRenderer* renderer, int x, int y, int width, int height, bool show_cursor);
   void scroll(int amount, int content_height);
+  bool close(void);
 
 private:
   void _on_ret_press(void);
 
   std::string _input_buffer;
+  bool _should_close;
   std::vector<std::string> _history;
   int _scroll_offset;
   std::string _current_path;
+  bool _is_remote;
   vfs_node* _local_vfs;
   CommandProcessor* _local_cmd_processor;
   ClientNetwork* _network;

client/src/ui/desktop.cpp

@@ -4,14 +4,19 @@
 #include <SDL3/SDL_events.h>
 #include "gfx/shape_renderer.h"
 #include "gfx/txt_renderer.h"
+#include "terminal.h"
 #include "ui/ui_window.h"
 
 Desktop::Desktop(void) {
   _focused_window = nullptr;
 }
 
-/* Desktop won't own the windows, so doesn't delete them. */
-Desktop::~Desktop(void) {}
+/* Desktop owns UIWindow, make sure we delete them. */
+Desktop::~Desktop(void) {
+  for(auto win : _windows) {
+    delete win;
+  }
+}
 
 void Desktop::add_window(UIWindow* window) {
   _windows.push_back(window);
@@ -51,6 +56,20 @@ void Desktop::handle_event(SDL_Event* event) {
   }
 }
 
+void Desktop::update(void) {
+  _windows.erase(std::remove_if(_windows.begin(), _windows.end(),
+                                [](UIWindow* window) {
+                                  Terminal* term = window->get_content();
+                                  if(term && term->close()) {
+                                    /* Window owns the terminal content, delete window also deletes terminal. */
+                                    delete window;
+                                    return true; /* Remove from vector. */
+                                  }
+                                  return false;
+                                }),
+                              _windows.end());
+}
+
 void Desktop::render(ShapeRenderer* shape_renderer, TextRenderer* txt_renderer,
                      int screen_height, bool show_cursor) {
   for(auto win: _windows) {

client/src/ui/desktop.h

@@ -14,6 +14,7 @@ public:
 
   void add_window(UIWindow* window);
   void handle_event(SDL_Event* event);
+  void update(void);
   void render(ShapeRenderer* shape_renderer, TextRenderer* txt_renderer, int screen_height,
               bool show_cursor);
 

client/src/ui/ui_window.cpp

@@ -15,6 +15,12 @@ UIWindow::UIWindow(const char* title, int x, int y, int width, int height) {
   _is_focused   = false; /* Not focused by default? */
 }
 
+UIWindow::~UIWindow(void) {
+  if(_content) {
+    delete _content;
+  }
+}
+
 void UIWindow::set_content(Terminal* term) {
   _content = term;
 }

client/src/ui/ui_window.h

@@ -9,6 +9,7 @@
 class UIWindow {
 public:
   UIWindow(const char* title, int x, int y, int width, int height);
+  ~UIWindow(void);
 
   void render(ShapeRenderer* shape_renderer, TextRenderer* txt_renderer, int screen_height,
               bool show_cursor);

common/src/vfs_manager.cpp

@@ -10,7 +10,7 @@ vfs_node* new_node(std::string name, vfs_node_type type, vfs_node* parent) {
   return node;
 }
 
-vfs_node* vfs_manager::create_root_system(void) {
+vfs_node* vfs_manager::create_root_system(const std::string& system_type) {
   /* Rood directory. */
   vfs_node* root = new_node("/", DIR_NODE, nullptr);
 
@@ -33,5 +33,12 @@ vfs_node* vfs_manager::create_root_system(void) {
   ls_exe->content = "[executable]";
   bin->children["ls"] = ls_exe;
 
+  if(system_type == "npc") {
+    vfs_node* npc_file = new_node("npc_system.txt", FILE_NODE, root);
+    npc_file->content = "This guy sucks nuts!";
+    root->children["npc_system.txt"] = npc_file;
+
+  }
+
   return root;
 }

common/src/vfs_manager.h

@@ -3,5 +3,5 @@
 #include "vfs.h"
 
 namespace vfs_manager {
-  vfs_node* create_root_system(void);
+  vfs_node* create_root_system(const std::string& system_type);
 }

server/src/main.cpp

@@ -1,16 +1,22 @@
 #include <cstdio>
+#include <map>
+#include <string>
 
+#include "vfs.h"
 #include "vfs_manager.h"
 #include "network_manager.h"
 
 int main(int argc, char** argv) {
   printf("=== Server starting ===\n");
 
-  vfs_node* root_vfs = vfs_manager::create_root_system();
-  printf("Virtual file system created. Root contains '%s' directory.\n",
-         root_vfs->children["home"]->name.c_str());
+  /* Create the world map of networks. */
+  std::map<std::string, vfs_node*> world_vfs;
+  world_vfs["8.8.8.8"] = vfs_manager::create_root_system("npc"); /* Basic npc system. */
+  world_vfs["10.0.2.15"] = vfs_manager::create_root_system("npc"); /* Another one. */
+  printf("Created world with %zu networks.\n", world_vfs.size());
 
-  NetworkManager* net_manager = new NetworkManager(root_vfs);
+  /* Network manager now managed the whole world. */
+  NetworkManager* net_manager = new NetworkManager(world_vfs);
   net_manager->start(); /* Our loop. */
 
   delete net_manager; /* Shouldn't get here. */

server/src/network_manager.cpp

@@ -1,13 +1,15 @@
 #include <cstdio>
 #include <cstring>
+#include <algorithm>
+#include <SDL_net.h>
 
-#include "SDL_net.h"
 #include "vfs.h"
+#include "command_processor.h"
 
 #include "network_manager.h"
 
-NetworkManager::NetworkManager(vfs_node* vfs_root) {
-  _vfs_root = vfs_root;
+NetworkManager::NetworkManager(std::map<std::string, vfs_node*> world_vfs) {
+  _world_vfs = world_vfs;
 
   if(!NET_Init()) {
     printf("Error: SDLNet_Init: %s\n", SDL_GetError());
@@ -45,7 +47,7 @@ void NetworkManager::_handle_new_connections(void) {
   if(NET_AcceptClient(_server_socket, &client_socket)) {
     if(client_socket) {
       Player* new_player = new Player(client_socket);
-      new_player->current_dir = _vfs_root;
+      new_player->cmd_processor = nullptr; /* Not connected to remote host yet. */
       _players.push_back(new_player);
       printf("Client connected. Total players: %zu\n", _players.size());
     }
@@ -63,72 +65,65 @@ void NetworkManager::_handle_client_activity(void) {
    * 0 if no data, and < 0 on error (disconnect).
    */
     int bytes_received = NET_ReadFromStreamSocket(player->socket, buffer, 512);
+    if(bytes_received > 0) {
+      printf("bytes_received: %d\n", bytes_received);
+    }
 
     if(bytes_received > 0) {
-      _process_command(player, buffer);
-    } else if(bytes_received < 0 ) {
+      /* _process_command returns true, the client wants to exit, boot it! */
+      if(_process_command(player, buffer)) {
+        _disconnect_client(player, i);
+      }
+    } else if(bytes_received < 0) {
+      /* Disconnect on error or if the client closes the connection. */
       _disconnect_client(player, i);
     }
   }
 }
 
-void NetworkManager::_process_command(Player* player, char* command) {
-  /* Remove trailing newline for command comparison. */
+bool NetworkManager::_process_command(Player* player, char* command) {
+  /* Create a clean std::string from the buffer. */
   std::string cmd_str = command;
-  if(!cmd_str.empty() && cmd_str.back() == '\n') {
-    cmd_str.pop_back();
-  }
-  if(strncmp(command, "cd ", 3) == 0) {
-    /* Handle 'cd' command. */
-    std::string target_dir_name = command + 3;
-    /* Remove trailing newline if it exists. */
-    if(!target_dir_name.empty() && target_dir_name.back() == '\n') {
-      target_dir_name.pop_back();
-    }
 
-    if(target_dir_name == "..") {
-      if(player->current_dir->parent) {
-        player->current_dir = player->current_dir->parent;
-      }
-    } else if(player->current_dir->children.count(target_dir_name)) {
-      vfs_node* target_node = player->current_dir->children[target_dir_name];
-      if(target_node->type == DIR_NODE) {
-        player->current_dir = target_node;
-      } else {
-        /* It's a file, not a directory. */
-        NET_WriteToStreamSocket(player->socket, "cd: not a directory\n", 22);
-        return;
-      }
+  if(cmd_str == "exit") {
+    /* Client is disconnecting, no response needed. */
+    return true; /* Disconnect signal. */
+  } else if(strncmp(cmd_str.c_str(), "ssh ", 4) == 0) {
+    std::string target = cmd_str.substr(4);
+    std::string target_ip = target;
+    size_t at_pos = target.find('@');
+    if(at_pos != std::string::npos) {
+      target_ip = target.substr(at_pos + 1);
     }
-    /* On successful cd, send back the new path for the prompt. */
-    std::string new_path = get_full_path(player->current_dir);
-    NET_WriteToStreamSocket(player->socket, new_path.c_str(), new_path.length()+1);
-  } else if(cmd_str == "ls") {
-    std::string response = "";
-    if(player->current_dir && player->current_dir->type == DIR_NODE) {
-      for(auto const& [name, node] : player->current_dir->children) {
-        response += name;
-        if(node->type == DIR_NODE) {
-          response += "/";
-        }
-        response += "  ";
-      }
+    if(_world_vfs.count(target_ip)) {
+      /* Create new command processor for the player's session on the target VFS. */
+      if(player->cmd_processor) { delete player->cmd_processor; }
+      player->cmd_processor = new CommandProcessor(_world_vfs[target_ip]);
+      std::string response = "CONNECTED " + target_ip;
+      NET_WriteToStreamSocket(player->socket, response.c_str(), response.length()+1);
+    } else {
+      NET_WriteToStreamSocket(player->socket, "ssh: Could not resolve hostname\n", 32);
     }
-    /* NET_WriteToStreamSocket is essentially the new send function in SDL3. */
-    NET_WriteToStreamSocket(player->socket, response.c_str(), response.length()+1);
-  } else if(cmd_str == "clear") {
-    /* Send an empty reply to unblock. */
-    NET_WriteToStreamSocket(player->socket, "", 1);
   } else {
-    /* Unknown command. */
-    std::string response = "Unknown command: " + cmd_str + "\n";
-    NET_WriteToStreamSocket(player->socket, response.c_str(), response.length()+1);
+    /* If not ssh command, and we have a command processor, process it. */
+    if(player->cmd_processor) {
+      std::string response = player->cmd_processor->process_command(cmd_str);
+      printf("OK: cmd_processor exits. Processing command '%s'\n", cmd_str.c_str());
+      NET_WriteToStreamSocket(player->socket, response.c_str(), response.length()+1);
+    } else {
+      printf("ERROR: cmd_processor is null. Cannot process command '%s'\n", cmd_str.c_str());
+      NET_WriteToStreamSocket(player->socket, "Error: Not in a remote session.\n", 32);
+    }
   }
+  return false; /* Don't disconnect. */
 }
 
 void NetworkManager::_disconnect_client(Player* player, int index) {
-  printf("Client disconnected.\n");
   NET_DestroyStreamSocket(player->socket);
-  _players.erase(_players.begin() + index);
+  /* If we have a valid index, remove the player. Otherwise, find them. */
+  if(index != -1) {
+    _players.erase(_players.begin() + index);
+  }
+  if(player->cmd_processor) { delete player->cmd_processor; }
   delete player;
 }

server/src/network_manager.h

@@ -1,14 +1,15 @@
 #pragma once
 
 #include <vector>
-#include <SDL3/SDL.h>
+#include <map>
+#include <string>
 
 #include "SDL_net.h"
 #include "player.h"
 
 class NetworkManager {
 public:
-  NetworkManager(vfs_node* vfs_root);
+  NetworkManager(std::map<std::string, vfs_node*> world_vfs);
   ~NetworkManager(void);
 
   void start(void);
@@ -16,10 +17,10 @@ public:
 private:
   void _handle_new_connections(void);
   void _handle_client_activity(void);
-  void _process_command(Player* player, char* command);
+  bool _process_command(Player* player, char* command);
   void _disconnect_client(Player* player, int index);
 
   NET_Server* _server_socket;
   std::vector<Player*> _players;
-  vfs_node* _vfs_root;
+  std::map<std::string, vfs_node*> _world_vfs;
 };

server/src/player.cpp

@@ -3,5 +3,5 @@
 
 Player::Player(NET_StreamSocket* new_socket) {
   socket = new_socket;
-  current_dir = nullptr; /* Will set to VFS root on connection. */
+  cmd_processor = nullptr;
 }

server/src/player.h

@@ -1,13 +1,15 @@
 #pragma once
 
 #include <SDL_net.h>
+
 #include "vfs.h"
+#include "command_processor.h"
 
 class Player {
 public:
   Player(NET_StreamSocket* socket);
 
   NET_StreamSocket* socket;
-  vfs_node* current_dir;
+  CommandProcessor* cmd_processor; /* Manages the VFS state for the remote session. */
 private:
 };