chat.lua

-- idea: split off two functions one to listen and one to type

args = {...}

STD_PING_CHAN = 5
STD_REPLY_CHAN = 1
MODEM_SIDE = "left"
local listeningChan
local replyChan



function setup()
    if #args >= 3 then
        replyChan = args[2]
        listeningChan = args[1]
    else
        if #args == 2 then
            listeningChan = args[1]
        else
            listeningChan = STD_PING_CHAN
        end
        replyChan = STD_REPLY_CHAN
    end

    print("Set up to listen on: " ..tostring(listeningChan).. " and reply on: " ..tostring(replyChan).. ".\n")
    write("Name: ")
    name = read()

end

function send(modem)
    term.setTextColor(colors.white)
    write("You: ")
    local input = read()
    if input == "quit" or input == "exit" then
        exitChat(modem)
    end
    modem.transmit(listeningChan, replyChan, name..": "..input)
    receiveReply(modem)
end

function receiveReply(modem)
    modem.open(replyChan)
    local event, side, senderChan, replyChan, message, dist = os.pullEvent("modem_message")
    term.setTextColor(colors.lightBlue)
    print("\t\t"..message)
end

function cursorToStart(textColor)
    term.setTextColor(textColor)
    term.clearLine()
    x,y = term.getCursorPos()
    term.setCursorPos(1, y)
end

function receive(modem)
    modem.open(listeningChan)
    local event, side, senderChan, replyChan, message, dist = os.pullEvent("modem_message")
    cursorToStart(colors.green)
    print(message)
    reply(modem)
end

function reply(modem)
    modem.transmit(replyChan, listeningChan, "<.>\n")
end

function exitChat(modem)
    print("Exiting chat.\n")
    modem.transmit(listeningChan, replyChan, name.." left the chat.\n")
    error()
end

function run()
    local modem = peripheral.wrap(MODEM_SIDE)
    term.clear()
    term.setTextColor(colors.white)
    print("Entered chat. type quit or exit to terminate.\n")
    while true do
        parallel.waitForAny(function()
            send(modem)
        end, function()
            receive(modem)
        end)
    end
end

setup()
run()