# Multiplayer Chat
# ================
#
# 1) Display chat messages from other aircraft to
#    the screen using screen.nas
#
# 2) Display a complete history of chat via dialog.
#
# 3) Allow chat messages to be written by the user.

var messages = {};

var check_messages = func
{

	var mp = props.globals.getNode("/ai/models").getChildren("multiplayer");
	var lseen = {};

	foreach (i; mp)
	{
		var lmsg           = getprop(i.getPath() ~ "/sim/multiplay/chat");
		var lcallsign      = getprop(i.getPath() ~ "/callsign");
		var lvalid         = getprop(i.getPath() ~ "/valid");

		if ((lvalid) and
			(lmsg != nil) and
			(lmsg != "") and 
			(lcallsign != nil) and 
			(lcallsign != ""))
		{
#print("Call Sign: " ~ lcallsign);
#print("lmsg: " ~ lmsg);
#print("Freq: " ~ ltransmitfreq);

			if (! contains(lseen, lcallsign))
			{
# Indicate that we've seen this callsign. This handles the case
# where we have two aircraft with the same callsign in the MP
# session.
				lseen[lcallsign] = 1;

				if ((! contains(messages, lcallsign)) or 
					(! streq(lmsg, messages[lcallsign])))
				{
# Save the message so we don't repeat it.
					messages[lcallsign] = lmsg;

# Display the message.
					echo_message(lmsg, lcallsign);
				}
			}
		}
	}

# Check for new messages every couple of seconds.
	settimer(check_messages, 3);
}

var echo_message = func(msg, callsign)
{
	if (callsign != nil)
	{
		msg = callsign ~ ": " ~ msg;
	}

	var ldisplay = getprop("/sim/multiplay/chat-display");

	if ((ldisplay != nil) and (ldisplay == "1"))
	{
# Only display the message to screen if configured.
		setprop("/sim/messages/ai-plane", msg);
	}

# Add the chat to the chat history.
	var lchat = getprop("/sim/multiplay/chat-history");

	if (lchat == nil)
	{
		setprop("/sim/multiplay/chat-history", msg);
	}
	else
	{
		if (substr(lchat, size(lchat) -1, 1) != "\n")
		{
			lchat = lchat ~ "\n";
		}

		setprop("/sim/multiplay/chat-history", lchat ~ msg);
	}
}

settimer(func {
# Call-back to ensure we see our own messages.
	setlistener("/sim/multiplay/chat", func(n) { echo_message(n.getValue(), getprop("/sim/multiplay/callsign")); });

# check for new messages
	check_messages();

}, 1);

# Message composition function, activated using the - key.
var prefix = "Chat Message:";
var input = "";
var kbdlistener = nil;

var compose_message = func(msg = "") 
{
	input = prefix ~ msg;
	gui.popupTip(input, 1000000);        

	kbdlistener = setlistener("/devices/status/keyboard/event", func (event) {
		var key = event.getNode("key");

# Only check the key when pressed.
		if (!event.getNode("pressed").getValue())
			return;

		if (handle_key(key.getValue()))
			key.setValue(0);           # drop key event
	});
}

var handle_key = func(key)
{
	if (key == `\n` or key == `\r`) 
	{  
# CR/LF -> send the message

# Trim off the prefix
		input = substr(input, size(prefix));
# Send the message and switch off the listener.
		setprop("/sim/multiplay/chat", input);
		removelistener(kbdlistener);
		gui.popdown();
		return 1;
	}
	elsif (key == 8) 
	{
# backspace -> remove a character

		if (size(input) > size(prefix))
		{
			input = substr(input, 0, size(input) - 1);
			gui.popupTip(input, 1000000);        
			return 1;
		}
	}
	elsif (key == 27) 
	{
# escape -> cancel
		removelistener(kbdlistener);
		gui.popdown();
		return 1;
	} 
	elsif ((key > 31) and (key < 128))
	{
# Normal character - add it to the input
		input ~= chr(key);
		gui.popupTip(input, 1000000);        
		return 1;
	}
	else
	{
# Unknown character - pass through
		return 0;    
	}
}