implement $next on proxy server

src/ChatCommands.cc

@@ -758,8 +758,13 @@ static void server_command_warp(shared_ptr<ServerState>, shared_ptr<Lobby> l,
 
 static void proxy_command_warp(shared_ptr<ServerState>,
     ProxyServer::LinkedSession& session, const std::u16string& args) {
+  if (!session.is_in_game) {
+    send_text_message(session.client_channel, u"$C6You must be in a\ngame to use this\ncommand");
+    return;
+  }
   uint32_t area = stoul(encode_sjis(args), nullptr, 0);
   send_warp(session.client_channel, session.lobby_client_id, area);
+  session.area = area;
 }
 
 static void server_command_next(shared_ptr<ServerState>, shared_ptr<Lobby> l,
@@ -768,7 +773,7 @@ static void server_command_next(shared_ptr<ServerState>, shared_ptr<Lobby> l,
   check_cheats_enabled(l);
 
   if (!l->episode || (l->episode > 3)) {
-    return;
+    throw runtime_error("invalid episode number");
   }
 
   uint8_t new_area = c->area + 1;
@@ -781,6 +786,17 @@ static void server_command_next(shared_ptr<ServerState>, shared_ptr<Lobby> l,
   send_warp(c, new_area);
 }
 
+static void proxy_command_next(shared_ptr<ServerState>,
+    ProxyServer::LinkedSession& session, const std::u16string&) {
+  if (!session.is_in_game) {
+    send_text_message(session.client_channel, u"$C6You must be in a\ngame to use this\ncommand");
+    return;
+  }
+
+  session.area++;
+  send_warp(session.client_channel, session.lobby_client_id, session.area);
+}
+
 static void server_command_what(shared_ptr<ServerState>, shared_ptr<Lobby> l,
     shared_ptr<Client> c, const std::u16string&) {
   check_is_game(l, true);
@@ -972,8 +988,7 @@ static const unordered_map<u16string, ChatCommandDefinition> chat_commands({
     {u"$li",       {server_command_lobby_info,         proxy_command_lobby_info,      u"Usage:\nli"}},
     {u"$maxlevel", {server_command_max_level,          nullptr,                       u"Usage:\nmax_level <level>"}},
     {u"$minlevel", {server_command_min_level,          nullptr,                       u"Usage:\nmin_level <level>"}},
-    // TODO: implement this on proxy server
-    {u"$next",     {server_command_next,               nullptr,                       u"Usage:\nnext"}},
+    {u"$next",     {server_command_next,               proxy_command_next,            u"Usage:\nnext"}},
     {u"$password", {server_command_password,           nullptr,                       u"Usage:\nlock [password]\nomit password to\nunlock game"}},
     {u"$persist",  {server_command_persist,            nullptr,                       u"Usage:\npersist"}},
     {u"$proxygc",  {server_command_proxygc,            proxy_command_proxygc,         u"Usage:\nproxygc <gc#>"}},

src/ProxyCommands.cc

@@ -1045,6 +1045,7 @@ static HandlerResult S_65_67_68(shared_ptr<ServerState>,
   if (command == 0x67) {
     session.clear_lobby_players(12);
     session.is_in_game = false;
+    session.area = 0x0F;
 
     // This command can cause the client to no longer send D6 responses when
     // 1A/D5 large message boxes are closed. newserv keeps track of this
@@ -1117,6 +1118,7 @@ static HandlerResult S_64(shared_ptr<ServerState>,
   }
 
   session.clear_lobby_players(4);
+  session.area = 0;
   session.is_in_game = true;
 
   bool modified = false;
@@ -1181,6 +1183,7 @@ static HandlerResult S_66_69(shared_ptr<ServerState>,
 
 static HandlerResult C_98(shared_ptr<ServerState>,
     ProxyServer::LinkedSession& session, uint16_t, uint32_t, string&) {
+  session.area = 0x0F;
   session.is_in_game = false;
   return HandlerResult::Type::FORWARD;
 }
@@ -1281,7 +1284,11 @@ static HandlerResult C_6x(shared_ptr<ServerState> s,
   }
 
   if (!data.empty()) {
-    if (data[0] == 0x2F || data[0] == 0x4B || data[0] == 0x4C) {
+    if (data[0] == 0x21) {
+      const auto& cmd = check_size_t<G_InterLevelWarp_6x21>(data);
+      session.area = cmd.area;
+
+    } else if (data[0] == 0x2F || data[0] == 0x4B || data[0] == 0x4C) {
       if (session.infinite_hp) {
         send_player_stats_change(session.client_channel,
             session.lobby_client_id, PlayerStatsChange::ADD_HP, 2550);

src/ProxyServer.hh

@@ -86,6 +86,7 @@ public:
     std::vector<LobbyPlayer> lobby_players;
     size_t lobby_client_id;
     size_t leader_client_id;
+    uint16_t area;
     bool is_in_game;
 
     std::shared_ptr<PSOBBMultiKeyDetectorEncryption> detector_crypt;