local Array   = require('array')
local kinetic = require('neural.kinetic')
local Point   = require('point')

local device = _G.device
local os     = _G.os

local pos = { x = 0, y = 0, z = 0 }
local sensor = device['plethora:sensor'] or error('Missing sensor')
local intro  = device['plethora:introspection'] or error('Missing introspection module')

local ownerId = intro.getMetaOwner().id
local targets = { }

local function findTargets()
  local now = os.clock()
  local moved = { }

  local l = Array.filter(sensor.sense(), function(a)
    if math.abs(a.motionY) > 0 and ownerId ~= a.id then
      local loc = table.concat({ a.x, a.y, a.z }, ':')
      if not targets[a.id] then
        targets[a.id] = { c = now }
      elseif targets[a.id].loc ~= loc then
        targets[a.id].c = now
        table.insert(moved, a)
      end
      targets[a.id].loc = loc
      a.c = targets[a.id].c
      return now - a.c < 5
    end
  end)

  if #moved > 0 then
    table.sort(moved, function(e1, e2)
      return Point.distance(e1, pos) < Point.distance(e2, pos)
    end)
    return moved[1]
  end

  if #l > 1 then
    table.sort(l, function(e1, e2)
      return now - e1.c < now - e2.c
    end)
    return targets[1]
  end
  return l[1]
end

local count = 50

while true do
  local target = findTargets()
  if target then
    count = 0
    kinetic.lookAt(target)
    os.sleep(0)
  elseif count > 25 then
    kinetic.lookAt({
      x = math.random(-10, 10),
      y = math.random(-10, 10),
      z = math.random(-10, 10)
    })
    os.sleep(3)
  else
    count = count + 1
    os.sleep(.1)
  end
end