updated

programs/chat.lua

@@ -1,19 +1,22 @@
 local modem = peripheral.find("modem")
-local PORT = 1
 local speaker = require("speaker-driver")
+local SERVER_PORT = 100
+local CLIENT_PORT = 101
+
+local username = os.getComputerLabel() or ("User" .. os.getComputerID())
 
 local function start()
     if modem then
-        modem.open(PORT)
-        modem.transmit(PORT, PORT, "User connected")
+        modem.open(CLIENT_PORT)
+        modem.transmit(SERVER_PORT, CLIENT_PORT, { type = "join", username = username })
     end
-    print("Chat program started.")
+    print("Chat program started as " .. username)
 end
 
 local function stop()
     if modem then
-        modem.transmit(PORT, PORT, "User disconnected")
-        modem.close(PORT)
+        modem.transmit(SERVER_PORT, CLIENT_PORT, { type = "leave", username = username })
+        modem.close(CLIENT_PORT)
     end
     print("Chat program stopped.")
 end
@@ -26,12 +29,19 @@ end
 local function receiveLoop()
     while true do
         local event, side, channel, replyChannel, message, distance = os.pullEvent("modem_message")
-        if channel == PORT then
+        if channel == CLIENT_PORT and type(message) == "table" then
             local x, y = term.getCursorPos()
             term.setCursorPos(1, y)
             term.clearLine()
-            print("Received: " .. tostring(message))
-            speaker.play("notification")
+            
+            if message.type == "system" then
+                print("[System] " .. message.content)
+                speaker.play("notification")
+            elseif message.type == "chat" then
+                print(message.username .. ": " .. message.content)
+                speaker.play("notification")
+            end
+            
             write("> ")
         end
     end
@@ -42,7 +52,7 @@ local function sendLoop()
         write("> ")
         local input = read()
         if modem then
-            modem.transmit(PORT, PORT, input)
+            modem.transmit(SERVER_PORT, CLIENT_PORT, { type = "chat", username = username, content = input })
         end
     end
 end