Server

options = {"Log","Exit"}--S1
--shelloptions = {"Kick","Ban","Message","List Clients","Back"}--S2
--Screen Options

tsize = table.getn(options)
hid = os.getComputerID()
--tsize2 = table.getn(shelloptions)
--Function variables

running = true
srunning = true
subexit = true
--Booleans

index = 1
index2 = 1
unindex = 1
--Integers

pass = "test" -- Password set here
--Strings

os.loadAPI("/screen")
rednet.open("top")
--Initalised Varibles

state = nil
logger = {}
--Misc Variables

local function addLog(element)
    logger[unindex] = element
    unindex = unindex + 1
end

function writeClient(idno)
    file = fs.open(".log",'w')
    if clientid == nil then
        clientid = {}
        clientid[1] = idno
        temp2 = textutils.serialise(clientid)
        file.write(temp2)
    else
        maxn = table.getn(clientid)
        clientid[maxn+1] = idno
        temp2 = textutils.serialise(clientid)
        file.write(temp2)
    end
    file.close()
end

function readClient()
    file = fs.open(".log",'r')
    clientid = textutils.unserialise(file.readAll())
    file.close()
    return clientid
end


function sendAll(senderid, text)
    for i in ipairs(clientid) do
        if senderid ~= clientid[i] then
            rednet.send(clientid[i],text)
        end
    end
end

function test(variable)
    if clientid ~= nil then
    for i in ipairs(clientid) do
        if variable == clientid[i] then
            return true
        elseif i == table.maxn(clientid) then
            return false
        end
    end
    else
        return false
    end
end

clientid = readClient()

if clientid ~= nil then
    addLog("Saved IDs :")
    for i in ipairs(clientid) do
        addLog(clientid[i]..",")
    end
else
    addLog("No saved IDs")
end

function handleMsg()
  id, message  = rednet.receive()
  if test(id) == false then
          addLog(test(id))
        if message == "request" then
            addLog("Requested: "..message..", From: "..id)
            sleep(2)
            if state == nil then
          HM = "accepted"
              rednet.send(id,HM)
              writeClient(id)
          atmp2 = nil
        elseif state == "password" then
            rednet.send(id,state)
            HM = "password"
            atmpid, atmp2 = rednet.receive()
          end
        addLog("Sent "..HM)
        if atmp2 == nil then
          if atmp2 == pass then
              rednet.send(atmpid,"accepted")
              addLog("Correct Password")
              writeClient(id)
            else
              addLog("Incorrect Pass, "..atmpid)
          end
          end
        end
    elseif test(id) == true and message == "request" then
        rednet.send(id,"accepted")
        addLog("Computer: "..id.." connected")
    else
    if message ~= "request" then
          addLog(id..": "..message..", was received")
          sendAll(id,id..": "..message)
    end
  end
end

function printLog()
    while true do
        term.clear()
        term.setCursorPos(1,1)
        print("> Exit <")
        if logger ~= nil then
            for i in ipairs(logger) do
                term.setCursorPos(1,i+2)
                print(logger[i])
            end
        end
        sleep(1)

    end
end

function uiEvent()
    event, key = os.pullEvent("key")
    if key == 28 then
        subexit = false
        return subexit
    end
end

--[[function sinit()
  term.clear()
  screen.drawTab()
  screen.drawTitle("Commands")
  screen.drawMenu(shelloptions)
end]]

--[[function shell()

  while srunning do
    sinit()
    screen.select(index2,shelloptions[index2])
    event, key = os.pullEvent("key")
    if key == 208 and index2 < tsize2 then--down
        index2 = index2 + 1
    elseif key == 200 and index2 > 1 then--up
        index2 = index2 - 1
    elseif key == 28 then
      if index2 == 1 then -- Kick

      elseif index2 == 2 then -- Ban

      elseif index2 == 3 then -- Message

      elseif index2 == 2 then -- List clients
        shell()
      elseif index2 == 5 then -- Back
        srunning = false
        term.clear()
        index = 1
        init()
      end
    end
  end
end]]

function init()
  term.clear()
  screen.drawTab()
  screen.drawTitle("Messenger Server") -- The title you want for your program
  screen.drawMenu(options)
  subexit = true
  clientid = readClient()
end

function ui ()
    init()
    screen.select(index,options[index])
    event, key = os.pullEvent("key")
    if key == 208 and index < tsize then--down
        index = index + 1
    elseif key == 200 and index > 1 then--up
        index = index - 1
    elseif key == 28 then
        if index == 1 then
            while subexit do
                parallel.waitForAny(uiEvent,printLog)
            end
        --elseif index == 2 then
            --shell()
        elseif index == 2 then
            running = false
            term.clear()
            term.setTextColour(colors.red)
            term.setCursorPos(1,1)
            term.write("Server Shutting Down")
            textutils.slowPrint(".................")
            term.setTextColour(colours.white)
        sendAll(hid,"Server is shutdown")
        end
    end
end

if fs.exists("/.log") == false then
   file = fs.open("/.log",'w')
  file.close(file)
end

if pass ~= "" then
  state = "password"
else
  state = nil
end

while running do
  parallel.waitForAny(handleMsg,ui) -- Run the UI and the Logger
end