P2P Chat V2

print("Loading P2PChat API by WhiteTec Software...")
--[[ P2P Chat Help File Link! ]]
function version()
print("You are using the P2PChat API by WhiteTec Software\nVersion: 1")
end
function ping(x,y,z)
local reddata = {}
local success = 0
rednet.open(y)
for i=1,x do
  reddata[1] = "PING"
  rednet.send(z, textutils.serialize(reddata))
  local id, mesg, dist = rednet.receive(1)
  if mesg == nil then
   print("No response.")
  else
   local decoded = textutils.unserialize(mesg)
   if decoded[1] == "PONG" then
    print("Got response from "..(id).." at "..(dist).." blocks away")
    success = success+1
   else
    print("Malformed packet from "..(id).." at "..(dist).." blocks away")
   end
  end
  sleep(0.5)
end
--rednet.close(y)
return success
end
function editor(x)
if x == nil then
  temp = fs.open("serverid", "r")
  data = temp.readAll()
  temp.close()
else
  temp = fs.open("serverid", "w")
  temp.write(x)
  temp.close()
  data = "Wrote"
end
end
function check()
if fs.exists("serverid") then
  editor()
else
  temp = fs.open("serverid", "w")
  temp.close()
  editor()
end
if data == "" then
  firstrun()
else
  server = tonumber(data)
  main()
end
end
function firstrun()
print("")
textutils.slowPrint("Welcome to P2P Chat by WhiteTec Software.", 50)
print("Input your local server ID.")
serverid = read()
serverid = tonumber(serverid)
print("Input where the connection is on your computer. (Back, Front, etc.)")
port = read()
checkport(port)
print("Checking if server is online...\n")
isgood = ping(5,port,serverid)
function starttest()
  if isgood == 5 then
   print("Connection successful!\nPress a key to start the menu.")
   editor(serverid)
   server = serverid
   os.pullEvent("key")
   term.clear()
   term.setCursorPos(1,1)
   main()
  elseif isgood < 5 then
   print("Connection had failures, try again or start set-up?\n[y/n/s]")
   local question = read()
   if question == "y" then
    starttest()
   elseif question == "s" then
    firstrun()
   else
    print("\nPress a key to start the menu.")
    editor(serverid)
    server = serverid
    os.pullEvent("key")
    term.clear()
    term.setCursorPos(1,1)
    main()
   end
  end
end
starttest()
end
function receive(x,y)
if 0<x<=60 or y == "Force" then
  local id, mesg, dist = rednet.receive(x)
  local decoded = textutils.unserialize(mesg)
  return id, decoded, dist
else
  return false
end
end
function checkport(x)
if peripheral.getType(x) == nil then
  print("No Device")
  firstrun()
elseif peripheral.isPresent(x) == false or peripheral.getType(x) ~= "modem" then
  print("Invalid Device: "..(firstToUpper(peripheral.getType(x))).."")
  firstrun()
end
local temp = peripheral.wrap(x)
if temp.isWireless() then
  print("Wirelessly Connected\n")
else
  print("Wired Connection\n")
end
end
function firstToUpper(str)
    return (str:gsub("^%l", string.upper))
end
function main()
term.clear()
term.setCursorPos(1,1)
textutils.slowPrint("Welcome to P2P Chat by WhiteTec Software.", 50)
print("Please put in what you want to do.")
os.pullEvent("key")
term.clear()
term.setCursorPos(1,1)
firstrun()
end
print("P2PChat API Ready.")
check(

function rt()
local ntime = os.time()
ntime = textutils.formatTime( ntime, false)
return ntime
end
term.clear()
term.setCursorPos(1,1)
print(""..(rt())..": Loading P2P Chat Server Version 1 by WhiteTec software...")
function rt()
local ntime = os.time()
ntime = textutils.formatTime( ntime, false)
return ntime
end
function editor(x,y)
if x == nil then
  temp = fs.open(y, "r")
  fdata = temp.readAll()
  temp.close()
else
  temp = fs.open(y, "w")
  temp.write(x)
  temp.close()
  return true
end
end
function listen()
rednet.open(port)
print(""..(rt())..": Listening...")
local id, mesg, dist = rednet.receive()
checkreply(id, mesg, dist)
end
function checkreply(x,y,z)
print(""..(rt())..": Message received from "..(x).." at "..(z).." blocks away.")
local decoded = textutils.unserialize(y)
if decoded[1] == "PING" then
  pingreply(x)
elseif decoded[1] == "MESSAGE" then
  archive(decoded,x)
elseif decoded[1] == "CHECK" then
  sendinbox(x)
else
  invaild(x,"INVALIDCOMMAND")
end
end
function invaild(x,y)
if y == "INVALIDCOMMAND" then
  print(""..(rt())..": Invalid command was received.")
elseif y == "NORECIPIENT" then
  print(""..(rt())..": No recipient was received.")
end
local reddata = {}
reddata[1] = "ERROR"
reddata[4] = y
rednet.send(x,textutils.serialize(reddata))
end
function pingreply(x)
print(""..(rt())..": Pinged. Responding back...")
local reddata = {}
reddata[1] = "PONG"
rednet.send(x,textutils.serialize(reddata))
listen()
end
function archive(x,y)
local r = x[2]
local s = x[3]
print(""..(s).." sent message to "..(r)..", saving...")
if r == nil or r == "" then
  invaild(y,"NORECIPIENT")
  listen()
else
  editor(editortextutils.serialize(x),tostring(r))
  listen()
end
end
function sendinbox(x)
print(""..(rt())..": "..(x).." requested Inbox")
if fs.exists(tostring(x)) then
  print(""..(rt())..": "..(x).." has mail, sending...")
  editor(nil,tostring(x))
  rednet.send(x,fdata)
  listen()
else
  print(""..(rt())..": "..(x).." has no mail, sending error...")
  local t = {}
  t[1] = "ERROR"
  t[4] = "NOMESSAGE"
  rednet.send(x,textutils.serialize(t))
  listen()
end
end
print(""..(rt())..": Server loaded, starting service...")
print("Choose a port to connect to.")
port = read()
listen()