Messenger (Client)

--MESSENGER CLIENT
bexit = false
id = os.getComputerID()
x,y = term.getSize()
i = 3

local function openRednet()
  for _,side in pairs(rs.getSides()) do
    if peripheral.isPresent(side) and peripheral.getType(side) == 'modem' then
      rednet.open(side)
      return(side)
    end
  end
  print("No modem present!")
end

function getid()
  if fs.exists("/.serverid") == true then
    file = fs.open("/.serverid")
    serverid = file.readAll()
    file.close()
    return true
  end
  return false
end

function slow(text,h)
  w = math.floor((x-string.len(text))/2)
  term.setCursorPos(w,h)
  textutils.slowPrint(text)
end

function drawTab()
  term.setTextColor(colors.yellow)
  --clear()
  term.setCursorPos(1,1)
  term.clearLine()
  print("Computer ID "..id)
  term.setCursorPos(1,2)
  term.clearLine()
  print("__________________________________________________")
  term.setCursorPos(1,y-3)
  term.clearLine()
  print("__________________________________________________")
  term.setTextColor(colors.white)
end

function clear()
  term.clear()
  term.setCursorPos(1,1)
end

function input()
  term.setTextColor(colors.white)
  term.setCursorPos(1,y-1)
  local message2 = read()
  if message2 == "exit" then
    --bexit = true
    clear()
    term.setTextColour(colours.orange)
    print("Thanks for using messenger by Xylem")
  else
    term.setCursorPos(1,y-1)
    term.clearLine()
    win("Me: "..message2)
    rednet.send(serverid,message2)
  end
end

function listen()
  id2,message = rednet.receive()
  if id2 == sid and message == "Server is shutdown" then
    --bexit = true
    clear()
    print("Server "..sid.." has shutdown been by host")
  else
    win(message)
  end
end

function win(text)
  if i > y-5 or i==y-5 then
    term.setCursorPos(1,y-3)
    term.clearLine()
    term.setCursorPos(1,4)
    term.clearLine()
    term.scroll(1)
    drawTab()
    term.setCursorPos(1,y-5)
    print(text)
  else
    term.setCursorPos(1,1+i)
    print(text)
    i = i+1
  end
end

modemSide = openRednet()

if modemSide == nil then
  print("No modem connected")
else
  print("Opened modem on "..modemSide.."!")
end


--Authenticator

if serverid == nil then
    bexit = false
    term.clear()
  --Intro
    term.setCursorPos(1,1)
    term.setTextColor(colours.yellow)
    term.write("Enter server ID: ")
    term.setTextColor(colours.white)
    --Input from intro to show the server id
    sinput = tonumber(read())
    rednet.send(tonumber(sinput),"request")
    --Recieve authentication
    sid, request = rednet.receive()
    --SID is temporary to see if authentication is fullfilled
  if request == "accepted" then -- No password set
      term.clear()
      term.setTextColor(colours.green)
      term.setCursorPos(1,1)
      print("Connected")
      sleep(1)
      rednet.send(tonumber(sinput),"connected")
      serverid = sid -- serverid is now established
    elseif request == "password" then -- Password set
      term.setTextColour(colours.yellow)
      term.write("Enter Password: ")
      term.setTextColour(colours.white)
      passatmp = read("*")
      rednet.send(sid,passatmp)
      id3,request2 = rednet.receive()
      if request2 == "denied" then -- Rejected request
        term.clear()
        .sapi.printColour(red)
        print("Incorrect Password")
        sleep(1)
        bexit = true -- Cancel program
      elseif request2 == "accepted" then -- Accepted request
        term.clear()
        .sapi.printColour(green,"Correct Password",1,1)
        sleep(1)
        serverid = sid
      end
    elseif request == nil then
      term.clear()
      .sapi.printColour(orange,"Error",1,1)
      bexit = true -- Cancel program
    end
end
--Main method
if modemSide ~= nil then
  sid, request = rednet.send(serverid,"rejoin",10)
  --[[if sid == nil and request == nil then
    bexit = true
    clear()
    print("Server is currently down")
  end]]
  clear()
  drawTab()
  while bexit == false do
    parallel.waitForAny(input,listen)
  end
else
  print("No modem was found. Please place a modem ")
end