startup

term.clear()
react = peripheral.wrap("back")
term.clear()
local menu_options = {
  [1] = {text="Reactor ON/OFF Toggle", color=colors.blue},
  [2] = {text="Reactor Fuel Level", color=colors.black},
  [3] = {text="Reactor Power Level", color=colors.orange}
}
local termX, termY = term.getSize()
local function menuDraw(selected)
  local yPos = termY/2 - #menu_options/2
  for index, data in pairs(menu_options) do
    menu_options[index].bounds = {
      x1 = termX/2 - (#data.text+4)/2,
      x2 = termX/2 + (#data.text+4)/2,
      y = yPos
    }
    term.setTextColor(data.color)
    term.setCursorPos(data.bounds.x1, data.bounds.y)

    local text =
      index==selected and "[ "..data.text.." ]" or
      "  "..data.text.."  "
      term.write(text)
      yPos = yPos+1
    end
  end

  local function checkClick(x,y)
    for index, data in pairs(menu_options) do
      if x>= data.bounds.x1 and x<= data.bounds.x2 and y==data.bounds.y then
        return index
      end
    end
    return false
  end

  term.setBackgroundColor(colors.white)
  term.clear()
  local selector = 1
  while true do
    menuDraw(selector)
    local e = {os.pullEvent()}
    if e[1] == "keys" then
      if e[2] == keys.down then
         selector = selector < #menu_options and selector+1 or 1
     elseif e[2] == keys.up then
        selector = selector > 1 and selector -1 or #menu_options
      elseif e[2] == keys.enter then
        break
      end
    elseif e[1] == "mouse_click" then
      local value = checkClick(e[3], e[4])
      if value then
        selector = value
        break
      end
    end
 end
 term.clear()
 term.setCursorPos(1,1)
 if selector == 1 then
   if react.getActive() == true then
     react.setActive(false)
     shell.run("startup")
   elseif react.getActive() == false then
     react.setActive(true)
     shell.run("startup")
   end
 elseif selector == 2 then
   write(react.getFuelAmount().."/"..react.getFuelAmountMax())
   sleep(2)
   shell.run("startup")
 elseif selector == 3 then
   write(react.getEnergyStored().."/10,000,000")
   sleep(2)
   shell.run("startup")
 end