#!/usr/bin/env ruby
#
# sms.rb
#
# Copyright (c) 2007 Naoki Hiroshima
# You can redistribute it and/or modify it under the same terms as GPL2.
#
# Author:: Naoki Hiroshima <n at h7a dot org>
#
# Also see UniMotion
#  http://members.optusnet.com.au/lbramsay/programs/unimotion.html
#
require 'ioservice.rb'

class SuddenMotionSensor < IOService
  Sensors = {
    :mbp => {:cmd=>5, :size=>40, :parser=>:mbp, :service=>"SMCMotionSensor"},
    :pb => {:cmd=>21, :size=>60, :parser=>:pb,  :service=>"IOI2CMotionSensor"},
    :hires => {:cmd=>21, :size=>60, :parser=>:pb,  :service=>"PMUMotionSensor"},
  }

  def initialize
    super
    @key = detect
  end

  def open(service=nil, &block)
    super service || Sensors[@key][:service]
  end

  def get
    v = Sensors[@key]
    i = alloc_structure v[:size]
    o = alloc_structure v[:size]
    sizeO = OSX::ObjcPtr.allocate_as_int32
    sizeO.assign v[:size]

    if 0 == structure_io(v[:cmd], v[:size], sizeO, i, o)
      bytes = o.bytestr
      return send(v[:parser], bytes)
    end
    [nil, nil, nil]
  end

  private

  def detect
    Sensors.each do |k,v|
      open(v[:service]) do
        i = alloc_structure v[:size]
        o = alloc_structure v[:size]
        sizeO = OSX::ObjcPtr.allocate_as_int32
        sizeO.assign v[:size]
        if 0 == structure_io(v[:cmd], v[:size], sizeO, i, o)
          return k
        end
      end
    end
    raise Exception.new("It's time to get MacBook Pro!")
  end

  def mbp(bytes)
    x = bytes[1] * 256 + bytes[0]
    y = bytes[3] * 256 + bytes[2]
    z = bytes[5] * 256 + bytes[4]
    x -= 65536 if x > 32767
    y -= 65536 if y > 32767
    z -= 65536 if z > 32767
    return [x, y, z]
  end

  def pb(bytes)
    x = bytes[0]
    y = bytes[1]
    z = bytes[2]
    return [x, y, z]
  end
end

if $0 == __FILE__
  trap(:INT) {raise Exception('SIGINT')}
  
  SuddenMotionSensor.new.open do |sms|
    begin
      while true
        v = sms.get
        print "X:%4d    Y:%4d    Z:%4d" % [v[0], v[1], v[2]]
        STDOUT.flush
        print "\033[80D"
        sleep 1
      end
    rescue Exception
    end
  end
end