[Change] Remove hybrid local/remote network model

Client architecture has been refactored to be fully
server-authoritative, remove the previous "hybrid" model that supported
both local and remote command execution, that was a stupid idea.

- Client now connects to server on startup.
- The local command processor and VFS have been removed from the
  Terminal class.
- All command processing is now handled by the server.
- The client is now just a thin client essentially

I'll in the future enable single player mode by running the server on
the local machine in a separate thread.

assets/scripts/bin/ssh.lua

@@ -0,0 +1,4 @@
+-- /bin/ssh - Connects to a remote host.
+local target = arg[1]
+if not target then return "ssh: missing operand" end
+return { action = "ssh", target = target }

client/src/client_network.cpp

@@ -1,9 +1,9 @@
 #include <cstdio>
 #include <cstring>
-#include <SDL3_net/SDL_net.h>
+#include <vector>
+#include "SDL3_net/SDL_net.h"
 
 #include "client_network.h"
-#include <SDL3/SDL_error.h>
 
 ClientNetwork::ClientNetwork(void) {
   if(!NET_Init()) {
@@ -55,9 +55,9 @@ bool ClientNetwork::connect(const char* host, int port) {
   return false;
 }
 
-void ClientNetwork::send_command(const char* command) {
+void ClientNetwork::send_command(const std::string& command) {
   if(!_socket) return;
-  NET_WriteToStreamSocket(_socket, command, strlen(command)+1);
+  NET_WriteToStreamSocket(_socket, command.c_str(), command.length()+1);
 }
 
 void ClientNetwork::disconnect(void) {
@@ -80,6 +80,7 @@ std::string ClientNetwork::receive_response(void) {
       return std::string(buffer);
     }
   }
+
   return ""; /* Return empty on timeout or error. */
 }
 

client/src/client_network.h

@@ -9,7 +9,7 @@ public:
   ~ClientNetwork(void);
 
   bool connect(const char* host, int port);
-  void send_command(const char* command);
+  void send_command(const std::string& data);
   void disconnect(void);
   std::string receive_response(void);
 

client/src/terminal.cpp

@@ -4,26 +4,26 @@
 #include <SDL3/SDL_events.h>
 
 #include "client_network.h"
-#include "command_processor.h"
 #include "gfx/txt_renderer.h"
-#include "vfs_manager.h"
-#include "vfs.h"
 #include "terminal.h"
 
 Terminal::Terminal(void) {
   /* Placeholder welcome message to history. */
   _history.push_back("Welcome to Bettola (local mode)");
+  _history.push_back("Connecting to server...");
 
   _network      = new ClientNetwork();
-  _is_remote    = false;
   _should_close = false;
-
-  /* Create local file system for the client. */
-  VFSManager vfs_manager;
-  _local_vfs = vfs_manager.create_vfs("local");
-  _local_cmd_processor = new CommandProcessor(_local_vfs);
-  _current_path  = get_full_path(_local_cmd_processor->get_current_dir());
   _scroll_offset = 0;
+
+  /* TODO: Move network to main.cpp, or better yet, a dedicatated game state file */
+  if(_network->connect("localhost", 8080)) {
+    _history.push_back("Connection successful.");
+    _prompt = _network->receive_response(); /* Get initial prompt from server. */
+  } else {
+    _history.push_back("Connection failed. Please restart.");
+    _prompt = "error>";
+  }
 }
 
 bool Terminal::close(void) {
@@ -41,52 +41,27 @@ void Terminal::_on_ret_press(void) {
   _input_buffer.clear(); /* Clear the input buffer immediately. */
 
   /* Add the command to history. */
-  _history.push_back(_current_path + "> " + command);
-
-  if(_is_remote) {
-    /* REMOTE STATE. */
-    _network->send_command(command.c_str());
+  _history.push_back(_prompt + "> " + command);
 
   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;
+    /* TODO: Window will close, and the OS will close the socket.
+     * server will detect the disconnection.
+     */
+    return;
   } 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);
-      }
+    return;
   }
+
+  _network->send_command(command);
+  std::string response = _network->receive_response();
+  /* Server sends back "output\nprompt". Split them. */
+  size_t last_newline = response.find_last_of('\n');
+  if(last_newline != std::string::npos) {
+    _prompt = response.substr(last_newline+1);
+    std::string output = response.substr(0, last_newline);
+    if(!output.empty()) { _history.push_back(output); }
   }
 
   /* TODO: Ugly hack. Refactor to pass window height
@@ -151,7 +126,7 @@ void Terminal::render(TextRenderer* renderer, int x, int y, int width, int heigh
   }
 
   /* Draw current input line. */
-  std::string line_to_render = _current_path + "> " + _input_buffer;
+  std::string line_to_render = _prompt + "> " + _input_buffer;
   if(show_cursor) {
     line_to_render += "_";
   }

client/src/terminal.h

@@ -5,8 +5,6 @@
 
 #include "gfx/txt_renderer.h"
 #include "client_network.h"
-#include "vfs_manager.h"
-#include "command_processor.h"
 
 class Terminal {
 public:
@@ -25,9 +23,6 @@ private:
   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;
+  std::string _prompt;
   ClientNetwork* _network;
 };

common/src/lua_processor.cpp

@@ -1,5 +1,7 @@
 #include "lua_processor.h"
 #include <sol/forward.hpp>
+#include <sol/object.hpp>
+#include <sol/protected_function_result.hpp>
 #include "vfs.h"
 
 LuaProcessor::LuaProcessor(void) {
@@ -27,7 +29,13 @@ sol::object LuaProcessor::execute(const std::string& script, vfs_node* current_d
     }
     _lua["arg"] = arg_table;
 
-    return _lua.script(script);
+    sol::protected_function_result result = _lua.safe_script(script);
+    if(result.valid()) {
+      return result;
+    } else {
+      sol::error err = result;
+      return sol::make_object(_lua, err.what());
+    }
 
   } catch(const sol::error& e) {
     /* Return the error message as a string in a sol::object. */

common/src/vfs_manager.cpp

@@ -75,7 +75,7 @@ vfs_node* VFSManager::create_vfs(const std::string& system_type) {
   user->children["readme.txt"] = readme;
 
   /* Link to the shared directories from the template. */
-  root->children["bin"] = _vfs_root->children["bin"];
+  root->children["bin"] = copy_vfs_node(_vfs_root->children["bin"], root);
 
   if(system_type == "npc") {
     vfs_node* npc_file = new_node("npc_system.txt", FILE_NODE, root);

server/src/main.cpp

@@ -1,24 +1,11 @@
 #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");
 
-  VFSManager vfs_manager;
-
-  /* Create the world map of networks. */
-  std::map<std::string, vfs_node*> world_vfs;
-  world_vfs["8.8.8.8"] = vfs_manager.create_vfs("npc"); /* Basic npc system. */
-  world_vfs["10.0.2.15"] = vfs_manager.create_vfs("npc"); /* Another one. */
-  printf("Created world with %zu networks.\n", world_vfs.size());
-
-  /* Network manager now managed the whole world. */
-  NetworkManager* net_manager = new NetworkManager(world_vfs);
+  NetworkManager* net_manager = new NetworkManager();
   net_manager->start(); /* Our loop. */
 
   delete net_manager; /* Shouldn't get here. */

server/src/network_manager.cpp

@@ -1,15 +1,26 @@
 #include <cstdio>
 #include <cstring>
-#include <algorithm>
-#include <SDL3_net/SDL_net.h>
 
+#include "SDL3_net/SDL_net.h"
 #include "vfs.h"
+#include "vfs_manager.h"
 #include "command_processor.h"
 
 #include "network_manager.h"
 
-NetworkManager::NetworkManager(std::map<std::string, vfs_node*> world_vfs) {
-  _world_vfs = world_vfs;
+/* Send a length-prefixed string. */
+void send_response_string(NET_StreamSocket* socket, const std::string& data) {
+  if(!socket) return;
+  NET_WriteToStreamSocket(socket, data.c_str(), data.length()+1);
+}
+
+NetworkManager::NetworkManager(void) {
+  /* The VFSManager for the world's NPC's.
+   * Player VSManagers will be created on a per-player basis.
+   */
+  _world_vfs["8.8.8.8"]   = _npc_vfs_manager.create_vfs("npc");
+  _world_vfs["10.0.2.15"] = _npc_vfs_manager.create_vfs("npc");
+  printf("Created world with %zu networks.\n", _world_vfs.size());
 
   if(!NET_Init()) {
     printf("Error: SDLNet_Init: %s\n", SDL_GetError());
@@ -24,6 +35,9 @@ NetworkManager::NetworkManager(std::map<std::string, vfs_node*> world_vfs) {
 }
 
 NetworkManager::~NetworkManager(void) {
+  for(auto player : _players) {
+    delete player;
+  }
   NET_DestroyServer(_server_socket);
   NET_Quit();
 }
@@ -47,83 +61,80 @@ 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->cmd_processor = nullptr; /* Not connected to remote host yet. */
       _players.push_back(new_player);
       printf("Client connected. Total players: %zu\n", _players.size());
+
+      /* Send the initial prompt to the new client. */
+      std::string prompt = get_full_path(new_player->cmd_processor->get_current_dir());
+      send_response_string(client_socket, prompt);
     }
   }
 }
 
 void NetworkManager::_handle_client_activity(void) {
-  char buffer [512];
-
   /* Iterate backwards so we can safely remove disconnected clients. */
   for(int i = _players.size()-1; i >= 0; --i) {
     Player* player = _players[i];
+    NET_StreamSocket* sock_array[1] = { player->socket };
 
-  /* NET_ReadFromStreamSocket returns > 0 if data was received.
-   * 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 returns true, the client wants to exit, boot it! */
-      if(_process_command(player, buffer)) {
+    /* Timeout of 0 for non-blocking check. */
+    int ready = NET_WaitUntilInputAvailable((void**)sock_array, 1, 0);
+    if(ready == -1) {
+      /* An error occured on the socket. */
+      fprintf(stderr, "[SERVER] Socket error, disconnecting client.\n");
       _disconnect_client(player, i);
+      continue;
     }
-    } else if(bytes_received < 0) {
-      /* Disconnect on error or if the client closes the connection. */
+
+    if(ready > 0) {
+      /* Socket has data. If processing fails, disconnect the client. */
+      fprintf(stderr, "[SERVER] Socket has data, processing command...\n");
+
+      if(!_process_command(player)) {
+        fprintf(stderr, "[SERVER] _process_command failed, disconnecting client.\n");
         _disconnect_client(player, i);
       }
     }
   }
-
-bool NetworkManager::_process_command(Player* player, char* command) {
-  /* Create a clean std::string from the buffer. */
-  std::string cmd_str = command;
-
-  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);
 }
-    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);
+
+bool NetworkManager::_process_command(Player* player) {
+  /* Read the length-prefixed command from the client. */
+  char buffer[2048];
+  memset(buffer, 0, sizeof(buffer));
+
+  int bytes_received = NET_ReadFromStreamSocket(player->socket, buffer, sizeof(buffer)-1);
+  if(bytes_received <= 0) {
+    return false; /* Error or disconnect. */
   }
-  } else {
-    /* If not ssh command, and we have a command processor, process it. */
+
+  std::string cmd_str(buffer);
+  fprintf(stderr, "[SERVER] Received command: \"%s\"\n", cmd_str.c_str());
+
+  /* Process the command. */
+  std::string response;
+
   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);
+    response = player->cmd_processor->process_command(cmd_str);
   } 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);
+    response = "Error: No command processor available for this player.";
   }
-  }
-  return false; /* Don't disconnect. */
+
+  /* Get the new prompt. Append it to response with a known separator. */
+  std::string new_prompt = get_full_path(player->cmd_processor->get_current_dir());
+  std::string final_response = response + "\n" + new_prompt;
+
+  send_response_string(player->socket, final_response);
+  return true;
 }
 
 void NetworkManager::_disconnect_client(Player* player, int index) {
+  fprintf(stderr, "[SERVER] Disconnecting client.\n");
   NET_DestroyStreamSocket(player->socket);
   /* 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;
+  printf("Client disconnected. Total players: %zu\n", _players.size());
 }

server/src/network_manager.h

@@ -6,10 +6,11 @@
 
 #include <SDL3_net/SDL_net.h>
 #include "player.h"
+#include "vfs_manager.h"
 
 class NetworkManager {
 public:
-  NetworkManager(std::map<std::string, vfs_node*> world_vfs);
+  NetworkManager();
   ~NetworkManager(void);
 
   void start(void);
@@ -17,10 +18,11 @@ public:
 private:
   void _handle_new_connections(void);
   void _handle_client_activity(void);
-  bool _process_command(Player* player, char* command);
+  bool _process_command(Player* player);
   void _disconnect_client(Player* player, int index);
 
   NET_Server* _server_socket;
   std::vector<Player*> _players;
-  std::map<std::string, vfs_node*> _world_vfs;
+  std::map<std::string, vfs_node*> _world_vfs; /* For NPC's. */
+  VFSManager _npc_vfs_manager;
 };

server/src/player.cpp

@@ -1,7 +1,15 @@
 #include "player.h"
-#include <SDL3_net/SDL_net.h>
+#include "command_processor.h"
 
-Player::Player(NET_StreamSocket* new_socket) {
-  socket = new_socket;
-  cmd_processor = nullptr;
+Player::Player(NET_StreamSocket* new_socket) :
+    socket(new_socket),
+    vfs_root(vfs_manager.create_vfs("player")),
+    cmd_processor(new CommandProcessor(vfs_root)) {}
+
+Player::~Player(void) {
+  if(cmd_processor) {
+    delete cmd_processor;
+  }
+
+  /* TODO: The VFSManager should handle deleting the vfs_root. */
 }

server/src/player.h

@@ -3,13 +3,17 @@
 #include <SDL3_net/SDL_net.h>
 
 #include "vfs.h"
+#include "vfs_manager.h"
 #include "command_processor.h"
 
 class Player {
 public:
   Player(NET_StreamSocket* socket);
+  ~Player(void);
 
   NET_StreamSocket* socket;
+  VFSManager vfs_manager;
+  vfs_node* vfs_root;
   CommandProcessor* cmd_processor; /* Manages the VFS state for the remote session. */
 private:
 };