#!/usr/bin/env ruby
#
# smc.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 Fan Control
#  http://www.lobotomo.com/products/FanControl/
#
require 'ioservice.rb'

class ServiceManagementControl < IOService

  def open(&block)
    super("AppleSMC")
  end

  def read_keyinfo(key)
    i = alloc_structure key
    i[42] = 0x09
    if o = structure_io(i)
      size  = o[31] << 12
      size += o[30] << 8
      size += o[29] << 4
      size += o[28]
      type  = o[35].chr
      type += o[34].chr
      type += o[33].chr
      type += o[32].chr
      return {:size => size, :type => type}
    end
  end

  def read_raw(key)
    info = read_keyinfo(key)

    i = alloc_structure key
    i[28] = info[:size]
    i[42] = 0x05
    if o = structure_io(i)
      a = []
      info[:size].times do |i|
        a << o[48+i]
      end
      info[:raw] = a
      info[:value] = parse(info[:type], a)
      return info
    end
    {}
  end

  def read_value(key)
    read_raw(key)[:value]
  end

  def keys
    read_value('#KEY') || 0
  end

  def key(index)
    i = alloc_structure
    i[42] = 0x08
    i[44] = index
    if o = structure_io(i)
      return o.bytestr[0..3].reverse
    end
    nil
  end

  def each
    keys.times do |i|
      k = key(i)
      v = read_raw(k)
      yield k, v
    end
  end

  private

  def structure_io(i)
    o = alloc_structure
    sizeO = OSX::ObjcPtr.allocate_as_int32
    sizeO.assign 80
    super(2, 80, sizeO, i, o) == 0 ? o : nil
  end

  def alloc_structure(key=nil)
    i = super 80
    if key
      i[0] = key[3]
      i[1] = key[2]
      i[2] = key[1]
      i[3] = key[0]
    end
    return i
  end

  def parse(type, value)
    case type
    when 'ch8*'
      value.pack('c*')
    when 'ui8 ', 'flag'
      value[0]
    when 'ui16'
      value.pack('C*').unpack('n*')[0]
    when 'ui32'
      value.pack('C*').unpack('N*')[0]
    when 'fpe2'
      value.pack('C*').unpack('n*')[0] / 4.0
    when 'sp78'
      v = value.pack('C*').unpack('n*')[0]
      v -= 65536 if v > 32767
      v / 256.0
    else
      nil
    end
  end

end

if $0 == __FILE__
  ServiceManagementControl.new.open do |smc|
    case ARGV[0]
    when 'all'
      smc.each do |k, v|
        puts "%s   %s[%2d]   %s ... %s" %
          [k, v[:type][0]>0 ? v[:type] : '----', v[:size], v[:value], v[:raw].inspect ]
      end
    else
      puts " CPU-1: %.2f C" % smc.read_value('TC0D')
      puts " CPU-2: %.2f C" % smc.read_value('TC0P')
      puts "Motion: X(%.3f) Y(%.3f) X(%.3f)" %
        ['MO_X','MO_Y','MO_Z'].map { |m| smc.read_value(m) }

      fans = smc.read_value('FNum')
      puts "  Fans: #{fans}"
      fans.times do |i|
        cur = smc.read_value("F#{i}Ac")
        puts "     %d: %.2f RPM" % [i, cur]
      end
    end
  end
end