Add MOTD command

Resolves #22.

command.go

@@ -29,6 +29,7 @@ const (
 	CommandBoard         = "board"         // Print current board state in human-readable form.
 	CommandPong          = "pong"          // Response to server ping.
 	CommandDisconnect    = "disconnect"    // Disconnect from server.
+	CommandMOTD          = "motd"          // Read (or write) the message of the day.
 	CommandBroadcast     = "broadcast"     // Send a message to all players.
 	CommandShutdown      = "shutdown"      // Prevent the creation of new matches.
 )

pkg/server/server.go

@@ -76,6 +76,8 @@ type server struct {
 	leaderboardCacheTime [12]time.Time
 	leaderboardCacheLock sync.Mutex
 
+	motd string
+
 	mailServer   string
 	passwordSalt string
 	resetSalt    string
@@ -413,7 +415,7 @@ func (s *server) handleConnection(conn net.Conn) {
 		commands:  commands,
 		Client:    newSocketClient(conn, commands, events, s.verbose),
 	}
-	s.sendHello(c)
+	s.sendWelcome(c)
 	s.handleClient(c)
 }
 
@@ -478,13 +480,21 @@ func (s *server) randomUsername() []byte {
 	}
 }
 
-func (s *server) sendHello(c *serverClient) {
+func (s *server) sendWelcome(c *serverClient) {
 	if c.json {
 		return
 	}
 	c.Write(s.welcome)
 }
 
+func (s *server) sendMOTD(c *serverClient) {
+	motd := s.motd
+	if motd == "" {
+		motd = fmt.Sprintf(gotext.GetD(c.language, "Connect with other players and stay up to date on the latest changes. Visit %s"), "bgammon.org/community")
+	}
+	c.sendNotice(motd)
+}
+
 func (s *server) gameByClient(c *serverClient) *serverGame {
 	s.gamesLock.RLock()
 	defer s.gamesLock.RUnlock()

pkg/server/server_command.go

@@ -12,6 +12,8 @@ import (
 	"github.com/leonelquinteros/gotext"
 )
 
+var clearBytes = []byte("clear")
+
 func (s *server) handleCommands() {
 	var cmd serverCommand
 COMMANDS:
@@ -214,7 +216,7 @@ COMMANDS:
 				}
 
 				// Send message of the day.
-				cmd.client.sendNotice(fmt.Sprintf(gotext.GetD(cmd.client.language, "Connect with other players and stay up to date on the latest changes. Visit %s"), "bgammon.org/community"))
+				s.sendMOTD(cmd.client)
 
 				// Rejoin match in progress.
 				s.gamesLock.RLock()
@@ -245,7 +247,7 @@ COMMANDS:
 		clientGame := s.gameByClient(cmd.client)
 		if clientGame != nil && clientGame.client1 != cmd.client && clientGame.client2 != cmd.client {
 			switch keyword {
-			case bgammon.CommandHelp, "h", bgammon.CommandJSON, bgammon.CommandList, "ls", bgammon.CommandBoard, "b", bgammon.CommandLeave, "l", bgammon.CommandReplay, bgammon.CommandSet, bgammon.CommandPong, bgammon.CommandDisconnect, bgammon.CommandBroadcast, bgammon.CommandShutdown:
+			case bgammon.CommandHelp, "h", bgammon.CommandJSON, bgammon.CommandList, "ls", bgammon.CommandBoard, "b", bgammon.CommandLeave, "l", bgammon.CommandReplay, bgammon.CommandSet, bgammon.CommandPong, bgammon.CommandDisconnect, bgammon.CommandMOTD, bgammon.CommandBroadcast, bgammon.CommandShutdown:
 				// These commands are allowed to be used by spectators.
 			default:
 				cmd.client.sendNotice(gotext.GetD(cmd.client.language, "Command ignored: You are spectating this match."))
@@ -1243,6 +1245,22 @@ COMMANDS:
 				clientGame.removeClient(cmd.client)
 			}
 			cmd.client.Terminate("Client disconnected")
+		case bgammon.CommandMOTD:
+			if len(params) == 0 {
+				cmd.client.sendNotice("Message of the day:")
+				s.sendMOTD(cmd.client)
+				continue
+			} else if !cmd.client.Admin() {
+				cmd.client.sendNotice("Access denied.")
+				continue
+			}
+
+			motd := bytes.Join(params, []byte(" "))
+			if bytes.Equal(bytes.ToLower(motd), clearBytes) {
+				motd = nil
+			}
+			s.motd = string(motd)
+			cmd.client.sendNotice("MOTD updated.")
 		case bgammon.CommandBroadcast:
 			if !cmd.client.Admin() {
 				cmd.client.sendNotice("Access denied.")