local suppression_distance = 20
local sensor_side = "top"
local alarm_side = "right"
local timeout = 60 * 10

local cnt_trolled = 0
local cnt_suppressed = 0

local function is_player_in_range()
  local prox = peripheral.wrap(sensor_side)
  if prox == nil then
    fatal("Sensor not found")
  end

  for k,target in pairs(prox.getTargets()) do
    if target.IsPlayer then
      local sqrt = math.sqrt
      local pow = math.pow
      local player = target.Position
      local distance = sqrt(
        pow(player.X, 2) +
        pow(player.Z, 2)
      )
      if distance < 20 then
        return true
      end
    end
  end
  return false
end

local function on()
  redstone.setOutput(alarm_side, true)
end

local function off()
  redstone.setOutput(alarm_side, false)
end

local function alarm()
  on()
  os.sleep(1)
  off()
end

local function inc_troll_cnt()
  cnt_trolled = cnt_trolled + 1
end

local function inc_suppr_cnt()
  cnt_suppressed = cnt_suppressed + 1
end

local function print_stats()
  term.clear()
  term.setCursorPos(1,1)
  print('We trolled ' .. tostring(cnt_trolled) ..
        ' times and needed to suppress ' .. tostring(cnt_suppressed) ..
        ' times.')
end

local function troll()
  if not is_player_in_range() then
    inc_troll_cnt()
    alarm()
  else
    inc_suppr_cnt()
  end
  print_stats()
end

while true do
  troll()
  os.sleep(timeout)
end