Added chat

programs/chat.lua

@@ -1,8 +1,19 @@
+local modem = peripheral.find("modem")
+local PORT = 1
+
 local function start()
+    if modem then
+        modem.open(PORT)
+        modem.transmit(PORT, PORT, "User connected")
+    end
     print("Chat program started.")
 end
 
 local function stop()
+    if modem then
+        modem.transmit(PORT, PORT, "User disconnected")
+        modem.close(PORT)
+    end
     print("Chat program stopped.")
 end
 
@@ -11,15 +22,36 @@ local function restart()
     start()
 end
 
-local function main()
-    print("Chat main loop running...")
+local function receiveLoop()
     while true do
-        local event = os.pullEvent()
-        -- Chat logic here
-        if event == "char" then
-            print("Char typed")
+        local event, side, channel, replyChannel, message, distance = os.pullEvent("modem_message")
+        if channel == PORT then
+            local x, y = term.getCursorPos()
+            term.setCursorPos(1, y)
+            term.clearLine()
+            print("Received: " .. tostring(message))
+            write("> ")
         end
     end
 end
 
+local function sendLoop()
+    while true do
+        write("> ")
+        local input = read()
+        if modem then
+            modem.transmit(PORT, PORT, input)
+        end
+    end
+end
+
+local function main()
+    if not modem then
+        print("No modem attached")
+        while true do os.pullEvent() end
+    end
+    
+    parallel.waitForAny(receiveLoop, sendLoop)
+end
+
 return { start = start, stop = stop, restart = restart, main = main }