startup

monitor=peripheral.wrap("top")
rednet.open("right")
monitor.setTextScale(2)


portals={
         {"Tower",colors.blue,1},
         {"Thaumcraft",colors.purple,2}
        }

button={
        {"<",1,6,"siteL"},
        {">",12,6,"siteR"},
        {"Set",6,6,"set"}
       }


function clear()
  monitor.clear()
  monitor.setCursorPos(1,1)
  monitor.setBackgroundColor(colors.black)
  monitor.setTextColor(colors.white)
end

function length(txt)
  counter=0
  for i=1, #txt do
    counter=counter+1
  end
  return counter
end

function site(tb)
  clear()
  monitor.setTextColor(colors.lightGray)
  monitor.setCursorPos(5,1)
  monitor.write("Portal")
  aLaenge=length(portals[tb][1])
  bLaenge=aLaenge / 2
  cursor=8-bLaenge
  monitor.setCursorPos(cursor,3)
  monitor.setTextColor(portals[tb][2])
  abc = tonumber(aCount)
  if tb == abc then
    monitor.setBackgroundColor(colors.gray)
  end
  monitor.write(portals[tb][1])
  monitor.setBackgroundColor(colors.black)

  for i=1, #button do
    monitor.setTextColor(colors.gray)
    monitor.setCursorPos(button[i][2],button[i][3])
    monitor.write("["..button[i][1].."]")
  end
end

function fileIn(ins)
  a=fs.open("Portal","w")
  a.write(ins)
  a.close()
end

function fileOut()
  a=fs.open("Portal","r")
  b=a.readAll()
  a.close()
  return b
end

bCount=1
while true do
  cCount=0

  for i=1, #portals do
    cCount=cCount+1
  end

  aCount=fileOut()
  site(bCount)

  event={os.pullEvent()}

  if event[1]=="monitor_touch"then

    for i=1, #button do

      anfang=button[i][2]
      ende=anfang+length(button[i][1])+1

      if event[4] == button[i][3] and event[3] >= anfang and event[3] <= ende then
        if button[i][4] == "set" then
          rednet.send(87,aCount)
          sleep(0.5)
          rednet.send(87,"out")
          fileIn(bCount)
          sleep(0.5)
          rednet.send(87,bCount)
          sleep(0.5)
          rednet.send(87,"in")
        elseif button[i][4] == "siteL" then
          if bCount > 1 then
            bCount = bCount - 1
          end
        elseif button[i][4] == "siteR" then
          if bCount < cCount then
            bCount = bCount + 1
          end
        end
        else
      end
    end
  end
end