reactor = peripheral.wrap("BigReactors-Reactor_6")
monitor = peripheral.wrap("monitor_47")

-- Control Vars
setpoint = 21000
tolerance = 500
rod_level = 82
step = 0.5     -- loop time
i = 0          -- control iterator
rate = 4       -- how many steps between control rod updates

-- Reactor init
reactor.setActive(true)

while true do

  -- Reactor vars
  active = reactor.getActive()
  raw_power = reactor.getEnergyProducedLastTick()
  power = math.floor(raw_power/10)/100
  fuel = math.floor(reactor.getFuelAmount()/reactor.getFuelAmountMax()*10000)/100

  -- Reactor control loop
  if i >= rate - 1 then
    reactor.setAllControlRodLevels(rod_level)
    if raw_power < setpoint - tolerance then
      rod_level = rod_level - 1
    elseif raw_power > setpoint + tolerance then
      rod_level = rod_level + 1
    end
  else
    i = i + 1
  end

  if rod_level < 0 then rod_level = 0 end
  if rod_level > 100 then rod_level = 100 end

  -- Monitor init
  monitor.clear()
  monitor.setTextScale(1)
  monitor.setTextColor(colors.white)

  -- Reactor status
  if active then
    monitor.setCursorPos(24,1)
    monitor.write("Reactor: ")
    monitor.setTextColor(colors.green)
    monitor.write("Active")
  else
    monitor.setCursorPos(23,1)
    monitor.write("Reactor: ")
    monitor.setTextColor(colors.red)
    monitor.write("Inactive")
  end
  monitor.setTextColor(colors.white)

  -- Reactor power output
  monitor.setCursorPos(2,2)
  monitor.write("Power Output: " .. tostring(power) .. "K RF/t")

  -- Reactor fuel Level
  monitor.setCursorPos(2,3)
  monitor.write("Fuel: ")
  if fuel < 20 then
    monitor.setTextColor(colors.red)
  elseif fuel < 40 then
    monitor.setTextColor(colors.orange)
  elseif fuel < 70 then
    monitor.setTextColor(colors.yellow)
  else
    monitor.setTextColor(colors.green)
  end
  monitor.write(tostring(fuel) .. "%")
  monitor.setTextColor(colors.white)

  -- Control Rod Level Display
  if rod_level < 10 then
    monitor.setCursorPos(59,2)
  else
    monitor.setCursorPos(58,2)
  end
  monitor.write(tostring(rod_level) .. "%")

  for j = 1,16 do
    monitor.setCursorPos(58,2+j)
    monitor.setBackgroundColor(colors.yellow)
    monitor.write(" ")
    if j < 16/100*rod_level then
      monitor.setBackgroundColor(colors.gray)
      monitor.write(" ")
      monitor.setBackgroundColor(colors.yellow)
      monitor.write(" ")
    else
      monitor.write("  ")
    end
  end

  os.sleep(step)
end