Sensor Alert (ComputerCraft)

K_VERSION = 0.093 -- Version of program. Need for auto-update


--===========================================================
-- Inline help functions
--===========================================================
local function clearScreen()     term.clear(); term.setCursorPos(1,1) end
local function tblLen(tbl)       local n=0;       for _,_  in pairs(tbl) do n = n + 1 end return n end
local function makeSet(list)     local set = {};  for _, v in pairs(list) do set[v] = true end return set end
local function pressAnyKey()     local event, param1 = os.pullEvent ("key") end
local function getChar(str, pos) return string.sub(str, pos, pos) end

-- Redefine global function for faster acces
local floor = math.floor
local ceil  = math.ceil
local insert= table.insert
local min   = math.min
local max   = math.max

local scrW, scrH = term.getSize() -- Get screen params
local source = "http://pastebin.com/raw.php?i=dsQ8c2UR"


-- ==============================
-- Auto-update
-- Download and replace running file
-- ==============================
local function autoUpdate()
  -- Get version of last
  if not http then return end
  local httpResponce = http.get(source)
  local allText = httpResponce.readAll()
  httpResponce.close()

  local newVersion = 0
  local _,verPos = string.find(allText, 'K_VERSION *= *')
  if verPos then
    newVersion = tonumber(string.match(allText, '%d+[%.?%d*]*', verPos+1))
  end

  -- Compare and replace
  if K_VERSION < newVersion then
    local sFile = shell.getRunningProgram()
    local f = fs.open(sFile, "w")
    f.write(allText)
    f.close()
    clearScreen()
    print("New version downloaded!")
    print("Rebooting to apply changes...")
    sleep(0.1)
    os.reboot()
    sleep(10)
  end
end


-- ################################################################################## --
-- ##                                   Main                                       ## --
-- ################################################################################## --
local function setAllOutput(state)
  for k,v in pairs(redstone.getSides()) do
    redstone.setOutput(v, state)
  end
end


function main()

  -- Update on background
  autoUpdate()

  local sensor = peripheral.find('openperipheral_sensor')
  local maxPlayers = 1
  local whitelist = {}
  local pl

  while true do
    -- Start the timer
    local timer
    timer = os.startTimer( 3 )

    while true do
      local sEvent, p1, p2, p3, p4, p5 = os.pullEvent()

      if sEvent == "key" then
        if p1 == keys.minus then
          maxPlayers = math.max(0, maxPlayers - 1)
        elseif p1 == keys.equals then
          maxPlayers = maxPlayers + 1
        elseif p1 == keys.insert then
          if pl then
            for k,v in pairs(pl) do
              whitelist[v.name] = true
            end
          end
        elseif p1 == keys.delete then
          whitelist = {}
        end
      elseif sEvent == "timer" and p1 == timer then
        pl = sensor.getPlayers()
        local catchedPlayers = {}

        clearScreen()
        print("Players found:")
        for k,v in pairs(pl) do
          print(v.name)
          if not whitelist[v.name] then
            table.insert(catchedPlayers, v.name)
          end
        end


        term.setCursorPos(scrW-20, 1)
        write("Whitelisted players:")
        local i=1
        for k,v in pairs(whitelist) do
          term.setCursorPos(scrW-20, 1+i)
          write(k)
          i=i+1
        end

        if #catchedPlayers>maxPlayers then
          setAllOutput(true)
        else
          setAllOutput(false)
        end

        term.setCursorPos(1, scrH-3)
        write("MaxPlayers: "..maxPlayers)
        term.setCursorPos(1, scrH-2)
        print("Press -/+ to change max player")
        print("Press [insert] to add all players to whitelist")
        write("Press [delete] to clear whitelist")

        break
      end
    end
  end
end

main()