client

-- VARIABLES
local host_id = os.computerID()
local serv_id
local id_found = false
local want_exit = false

-- FUNCTIONS

function find_id()
  rednet.broadcast("server_id", "server_id")
  serv_id = rednet.receive("server_id_response", 5)
  if serv_id ~= nil then
    id_found = true
  end
end

function join(server_id)
  rednet.send(server_id, "join", "join")
end

function leave(server_id)
  rednet.send(server_id, "leave", "leave")
  textutils.slowPrint("Closing client . . .")
  sleep(2)
  want_exit = true
end

function list(server_id)
  rednet.send(server_id, "list", "list")
  local id, list = rednet.receive("list_response", 5)
  print(list)
end

function message_send(server_id, message)
  rednet.send(server_id, message, "message")
end

function message_receive(message)
  print(message)
end

function input()
  write(">")
  local input = read()
  if string.sub(input, 0, 1) == "/" then
    if input == "/help" then
      print("/help for help")
      print("/exit for exit")
      print("/list for list")
    elseif input == "/exit" then
      leave(serv_id)
    elseif input == "/list" then
      list(serv_id)
    else
      print("Unknown command, type /help")
    end
  else
    message_send(serv_id, input)
  end
end
-- MAIN CODE
rednet.open("back")
while not id_found do
  textutils.slowPrint("Looking for a server . . .")
  find_id()
end
join(serv_id)
while true do
  event, param1, param2, param3 = os.pullEvent()
  if event == "rednet_message" then
    if param3 == "message" then
      message_receive(param2)
    end
  elseif event == "key" then
    input()
  end
  if want_exit then
    break
  end
end