require 'binary_struct'

module NTFS
  #
  # VOLUME_INFORMATION - Attribute: Volume information (0x70).
  #
  # NOTE: Always resident.
  # NOTE: Present only in FILE_Volume.
  # NOTE: Windows 2000 uses NTFS 3.0 while Windows NT4 service pack 6a uses NTFS 1.2.
  #

  ATTRIB_VOLUME_INFORMATION = BinaryStruct.new([
    'Q',  nil,          # No information.
    'C1', 'ver_major',  # File system major version number.
    'C1', 'ver_minor',  # File system minor version number.
    'S',  'flags',      # Volume flags (see VF_ below).
  ])

  class VolumeInformation
    attr_reader :version, :flags

    VF_IS_DIRTY            = 0x0001
    VF_RESIZE_LOG_FILE     = 0x0002
    VF_UPGRADE_ON_MOUNT    = 0x0004
    VF_MOUNTED_ON_NT4      = 0x0008
    VF_DELETE_USN_UNDERWAY = 0x0010
    VF_REPAIR_OBJECT_ID    = 0x0020
    VF_CHKDSK_UNDERWAY     = 0x4000
    VF_MODIFIED_BY_CHKDSK  = 0x8000

    def initialize(buf)
      raise "MIQ(NTFS::VolumeInformation.initialize) Nil buffer" if buf.nil?
      buf      = buf.read(buf.length) if buf.kind_of?(DataRun)
      @avi     = ATTRIB_VOLUME_INFORMATION.decode(buf)

      # Get accessor data.
      @version = @avi['ver_major'].to_s + "." + @avi['ver_minor'].to_s
      @flags   = @avi['flags']
    end

    def to_s
      @version
    end

    def dump
      out = "\#<#{self.class}:0x#{'%08x' % object_id}>\n"
      out << "  Major ver: #{@avi['ver_major'].to_i}\n"
      out << "  Minor ver: #{@avi['ver_minor'].to_i}\n"
      out << "  Flags    : 0x#{'%04x' % @flags}\n"
      out << "---\n"
    end
  end
end # module NTFS