add '/roll N' command to games and game lobbies

Adds '/roll N' command which gets a random number between 1 and N and prints it as "$username rolled a die [1 - $N] and got $value." to the game creation lobby chat or just to the sender otherwise (so not to flood the main chat).

The roll handler uses a uniform distribution generator, however with an additional mt rng from std library instead of the built-in wesnoth rng as the uniform distribution generator can use only a specially formatted rng engine.

src/chat_command_handler.hpp

@@ -110,6 +110,8 @@ protected:
 			_("Add a nickname to your friends list."), _("<nickname>"));
 		register_command("remove", &chat_command_handler::do_remove,
 			_("Remove a nickname from your ignores or friends list."), _("<nickname>"));
+		register_command("roll", &chat_command_handler::do_network_send_req_arg,
+			_("Get a random number between 1 and N visible in the game setup lobby."), _("<N>"));
 		register_command("version", &chat_command_handler::do_version,
 			_("Display version information."));
 		register_command("info", &chat_command_handler::do_info,

src/chat_events.cpp

@@ -101,6 +101,9 @@ void chat_handler::send_command(const std::string& cmd, const std::string& args
 	else if (cmd == "report") {
 		data.add_child("query")["type"] = "report " + args;
 	}
+	else if (cmd == "roll") {
+		data.add_child("query")["type"] = "roll " + args;
+	}
 	else if (cmd == "join") {
 		data.add_child("room_join")["room"] = args;
 	}

src/server/wesnothd/server.cpp

@@ -211,7 +211,7 @@ const std::string help_msg =
 	" dul|deny_unregistered_login [yes|no], kick <mask> [<reason>],"
 	" k[ick]ban <mask> <time> <reason>, help, games, metrics,"
 	" netstats [all], [lobby]msg <message>, motd [<message>],"
-	" pm|privatemsg <nickname> <message>, requests, sample, searchlog <mask>,"
+	" pm|privatemsg <nickname> <message>, requests, roll <sides>, sample, searchlog <mask>,"
 	" signout, stats, status [<mask>], stopgame <nick> [<reason>], unban <ipmask>\n"
 	"Specific strings (those not in between <> like the command names)"
 	" are case insensitive.";
@@ -226,6 +226,7 @@ server::server(int port,
 	, ip_log_()
 	, failed_logins_()
 	, user_handler_(nullptr)
+	, die_(static_cast<unsigned>(std::time(nullptr)))
 #ifndef _WIN32
 	, input_path_()
 #endif
@@ -385,6 +386,7 @@ void server::setup_handlers()
 	SETUP_HANDLER("version", &server::version_handler);
 	SETUP_HANDLER("metrics", &server::metrics_handler);
 	SETUP_HANDLER("requests", &server::requests_handler);
+	SETUP_HANDLER("roll", &server::roll_handler);
 	SETUP_HANDLER("games", &server::games_handler);
 	SETUP_HANDLER("wml", &server::wml_handler);
 	SETUP_HANDLER("netstats", &server::netstats_handler);
@@ -1152,7 +1154,7 @@ void server::handle_query(socket_ptr socket, simple_wml::node& query)
 
 	const std::string& query_help_msg =
 		"Available commands are: adminmsg <msg>, help, games, metrics,"
-		" motd, netstats [all], requests, sample, stats, status, version, wml.";
+		" motd, netstats [all], requests, roll <sides>, sample, stats, status, version, wml.";
 
 	// Commands a player may issue.
 	if(command == "status") {
@@ -1167,6 +1169,7 @@ void server::handle_query(socket_ptr socket, simple_wml::node& query)
 		command == "netstats all" ||
 		command.compare(0, 7, "version") == 0 ||
 		command == "requests" ||
+		command.compare(0, 4, "roll") == 0 ||
 		command == "sample" ||
 		command == "stats" ||
 		command == "status " + player.name() ||
@@ -2131,6 +2134,49 @@ void server::requests_handler(const std::string& /*issuer_name*/,
 	metrics_.requests(*out);
 }
 
+void server::roll_handler(const std::string& issuer_name,
+		const std::string& /*query*/,
+		std::string& parameters,
+		std::ostringstream* out)
+{
+	assert(out != nullptr);
+	if(parameters.empty()) {
+		return;
+	}
+	
+	int N;
+	try {
+		N = std::stoi(parameters);
+	} catch(const std::invalid_argument&) {
+		*out << "The number of die sides must be a number!";
+		return;
+	} catch(const std::out_of_range&) {
+		*out << "The number of sides is too big for the die!";
+		return;
+	}
+
+	if(N < 1) {
+		*out << "The die cannot have less than 1 side!";
+		return;
+	}
+	std::uniform_int_distribution<int> dice_distro(1, N);
+	std::string value = std::to_string(dice_distro(die_));
+
+	*out << "You rolled a die [1 - " + parameters + "] and got a " + value + ".";
+
+	auto player_ptr = player_connections_.get<name_t>().find(issuer_name);
+	if(player_ptr == player_connections_.get<name_t>().end()) {
+		return;
+	}
+
+	auto g_ptr = player_ptr->get_game();
+	if(g_ptr && g_ptr->is_member(player_ptr->socket())) {
+		g_ptr->send_server_message_to_all(issuer_name + " rolled a die [1 - " + parameters + "] and got a " + value + ".", player_ptr->socket());
+	} else {
+		*out << " (The result is shown to others only in a game.)";
+	}
+}
+
 void server::games_handler(const std::string& /*issuer_name*/,
 		const std::string& /*query*/,
 		std::string& /*parameters*/,

src/server/wesnothd/server.hpp

@@ -27,6 +27,7 @@
 
 #include <boost/asio/signal_set.hpp>
 #include <boost/asio/steady_timer.hpp>
+#include <random>
 
 namespace wesnothd
 {
@@ -108,6 +109,8 @@ private:
 	std::unique_ptr<user_handler> user_handler_;
 	std::map<socket_ptr::element_type*, std::string> seeds_;
 
+	std::mt19937 die_;
+
 	player_connections player_connections_;
 	std::deque<std::shared_ptr<game>> games() {
 		std::deque<std::shared_ptr<game>> result;
@@ -207,6 +210,7 @@ private:
 	void stats_handler(const std::string &, const std::string &, std::string &, std::ostringstream *);
 	void metrics_handler(const std::string &, const std::string &, std::string &, std::ostringstream *);
 	void requests_handler(const std::string &, const std::string &, std::string &, std::ostringstream *);
+	void roll_handler(const std::string &, const std::string &, std::string &, std::ostringstream *);
 	void games_handler(const std::string &, const std::string &, std::string &, std::ostringstream *);
 	void wml_handler(const std::string &, const std::string &, std::string &, std::ostringstream *);
 	void netstats_handler(const std::string &, const std::string &, std::string &, std::ostringstream *);