Telnet GO AHEAD (#226)

# Changes
* Negotiates whether to send IAC GO AHEAD with client.
* If enabled, sends GO AHEAD at end of in-game prompts. 
  * Note: Does not send anywhere else.
* A little bit of code and comment cleanup

Author: Volte6

internal/connections/clientsettings.go

@@ -3,11 +3,12 @@ package connections
 type ClientSettings struct {
 	Display DisplaySettings
 	Discord DiscordSettings
-	Client  ClientType
+	Client  ClientType // Client data provided by `Core.Hello` GMCP command
 	// Enabled GMCP Modules
-	GMCPModules map[string]int
+	GMCPModules map[string]int // Enabled GMCP Modules (if any)
 	// Is MSP enabled?
-	MSPEnabled bool
+	MSPEnabled        bool // Do they accept sound in their client?
+	SendTelnetGoAhead bool // Defaults false, should we send a IAC GA after prompts?
 }
 
 type DisplaySettings struct {

internal/events/eventtypes.go

@@ -58,15 +58,15 @@ type Message struct {
 
 func (m Message) Type() string { return `Message` }
 
-// Messages that are intended to reach all users on the system
+// Special commands that only the webclient is equipped to handle
 type WebClientCommand struct {
 	ConnectionId uint64
 	Text         string
 }
 
 func (b WebClientCommand) Type() string { return `WebClientCommand` }
 
-// Messages that are intended to reach all users on the system
+// GMCP Commands from clients to server
 type GMCPIn struct {
 	ConnectionId uint64
 	Command      string
@@ -75,7 +75,7 @@ type GMCPIn struct {
 
 func (b GMCPIn) Type() string { return `GMCP` }
 
-// Messages that are intended to reach all users on the system
+// GMCP Commands from server to client
 type GMCPOut struct {
 	ConnectionId uint64
 	UserId       int
@@ -91,7 +91,7 @@ type System struct {
 
 func (s System) Type() string { return `System` }
 
-// Messages that are intended to reach all users on the system
+// Payloads describing sound/music to play
 type MSP struct {
 	UserId    int
 	SoundType string // SOUND or MUSIC

internal/inputhandlers/term_iac.go

@@ -187,6 +187,16 @@ func TelnetIACHandler(clientInput *connections.ClientInput, sharedState map[stri
 			continue
 		}
 
+		if ok, _ := term.Matches(iacCmd, term.TelnetDontSuppressGoAhead); ok {
+			slog.Info("Received", "type", "IAC (TelnetDontSuppressGoAhead)")
+
+			cs := connections.GetClientSettings(clientInput.ConnectionId)
+			cs.SendTelnetGoAhead = true
+			connections.OverwriteClientSettings(clientInput.ConnectionId, cs)
+
+			continue
+		}
+
 		// Is it a screen size report?
 		if ok, payload := term.Matches(iacCmd, term.TelnetScreenSizeResponse); ok {
 

internal/term/term.go

@@ -48,8 +48,9 @@ var (
 	//
 	// GENERAL SETUP
 	//
-	// // Suppress Go Ahead
-	TelnetSuppressGoAhead = TerminalCommand{[]byte{TELNET_IAC, TELNET_WILL, TELNET_OPT_SUP_GO_AHD}, []byte{}}
+	// // Do/Don't Suppress Go Ahead
+	TelnetSuppressGoAhead     = TerminalCommand{[]byte{TELNET_IAC, TELNET_WILL, TELNET_OPT_SUP_GO_AHD}, []byte{}}
+	TelnetDontSuppressGoAhead = TerminalCommand{[]byte{TELNET_IAC, TELNET_DONT, TELNET_OPT_SUP_GO_AHD}, []byte{}}
 	// // Echo On
 	TelnetEchoOn = TerminalCommand{[]byte{TELNET_IAC, TELNET_WILL, TELNET_OPT_ECHO}, []byte{}}
 	// // Echo Off
@@ -76,6 +77,8 @@ var (
 	TelnetAcceptedChangeCharset = TerminalCommand{[]byte{TELNET_IAC, TELNET_SB, 2}, []byte{TELNET_IAC, TELNET_SE}}
 	// Client rejectected change
 	TelnetRejectedChangeCharset = TerminalCommand{[]byte{TELNET_IAC, TELNET_SB, 3, TELNET_IAC, TELNET_SE}, []byte{}}
+	// Go Ahead
+	TelnetGoAhead = TerminalCommand{[]byte{TELNET_IAC, TELNET_GA}, []byte{}}
 
 	///////////////////////////
 	// ANSI COMMANDS

internal/users/userrecord.go

@@ -290,36 +290,34 @@ func (u *UserRecord) GetConnectTime() time.Time {
 	return u.connectionTime
 }
 
-func (u *UserRecord) GetCommandPrompt(fullRedraw bool, forcePromptType ...string) string {
+func (u *UserRecord) GetCommandPrompt(fullRedraw bool) string {
 
 	promptOut := ``
 
-	if len(forcePromptType) == 0 || forcePromptType[0] != `mprompt` {
-		if u.activePrompt != nil {
+	if u.activePrompt != nil {
 
-			if activeQuestion := u.activePrompt.GetNextQuestion(); activeQuestion != nil {
-				promptOut = activeQuestion.String()
-			}
+		if activeQuestion := u.activePrompt.GetNextQuestion(); activeQuestion != nil {
+			promptOut = activeQuestion.String()
 		}
 	}
 
+	goAhead := ``
+	if connections.GetClientSettings(u.ConnectionId()).SendTelnetGoAhead {
+		goAhead = term.TelnetGoAhead.String()
+	}
+
 	if len(promptOut) == 0 {
 
 		var customPrompt any = nil
 		var inCombat bool = u.Character.Aggro != nil
 
-		if len(forcePromptType) > 0 {
-			customPrompt = u.GetConfigOption(forcePromptType[0] + `-compiled`)
-		} else {
-
-			if inCombat {
-				customPrompt = u.GetConfigOption(`fprompt-compiled`)
-			}
+		if inCombat {
+			customPrompt = u.GetConfigOption(`fprompt-compiled`)
+		}
 
-			// No other custom prompts? try the default setting
-			if customPrompt == nil {
-				customPrompt = u.GetConfigOption(`prompt-compiled`)
-			}
+		// No other custom prompts? try the default setting
+		if customPrompt == nil {
+			customPrompt = u.GetConfigOption(`prompt-compiled`)
 		}
 
 		var ok bool
@@ -339,10 +337,10 @@ func (u *UserRecord) GetCommandPrompt(fullRedraw bool, forcePromptType ...string
 		if len(suggested) > 0 {
 			suggested = `<ansi fg="suggested-text">` + suggested + `</ansi>`
 		}
-		return term.AnsiMoveCursorColumn.String() + term.AnsiEraseLine.String() + promptOut + unsent + suggested
+		return term.AnsiMoveCursorColumn.String() + term.AnsiEraseLine.String() + promptOut + unsent + suggested + goAhead
 	}
 
-	return promptOut
+	return promptOut + goAhead
 }
 
 func (u *UserRecord) ProcessPromptString(promptStr string) string {

main.go

@@ -297,6 +297,11 @@ func handleTelnetConnection(connDetails *connections.ConnectionDetails, wg *sync
 		connDetails.ConnectionId(),
 	)
 
+	connections.SendTo(
+		term.TelnetSuppressGoAhead.BytesWithPayload(nil),
+		connDetails.ConnectionId(),
+	)
+
 	clientSetupCommands := "" + //term.AnsiAltModeStart.String() + // alternative mode (No scrollback)
 		//term.AnsiCursorHide.String() + // Hide Cursor (Because we will manually echo back)
 		//term.AnsiCharSetUTF8.String() + // UTF8 mode