require 'fs/ntfs/utils'
require 'manageiq/gems/pending'
require 'util/win32/nt_util'
require 'binary_struct'
require 'miq_unicode'
require 'fs/ntfs/attrib_standard_information'

module NTFS
  using ManageIQ::UnicodeString

  #
  # FILE_NAME_ATTR - Attribute: Filename (0x30)
  #
  # NOTE: Always resident.
  # NOTE: All fields, except the parent_directory, are only updated when the
  #   filename is changed. Until then, they just become out of sync with
  #   reality and the more up to date values are present in the standard
  #   information attribute.
  # NOTE: There is conflicting information about the meaning of each of the time
  #   fields but the meaning as defined below has been verified to be
  #   correct by practical experimentation on Windows NT4 SP6a and is hence
  #   assumed to be the one and only correct interpretation.
  #
  # The $FILE_NAME attribute.
  ATTRIB_FILE_NAME = BinaryStruct.new([
    'Q',  'ref_to_parent_dir',  # Directory this filename is referenced from
    'Q',  'time_created',       # Time file was created
    'Q',  'time_altered',       # Time the data attribute was last modified
    'Q',  'time_mft_changed',   # Time this mft record    was last modified
    'Q',  'time_read',          # Last time this mft record was accessed
    'Q',  'allocated_size',     # Byte size of on-disk allocated space for the data attribute.
    # So for normal $DATA, this is the allocated_size from the unnamed
    # $DATA attribute and for compressed and/or sparse $DATA, this is
    # the compressed_size from the unnamed $DATA attribute.
    # NOTE: This is a multiple of the cluster size.
    'Q',  'data_size',          # Byte size of actual data in data attribute
    'L',  'flags',              # Flags describing the file
    'L',  'reparse_point_tag',  # Type of reparse point, present only in reparse points and only if there are no EAs
    'C1', 'name_length',        # Length of file name in (Unicode) characters
    'C1', 'namespace',          # Namespace of the file name
  ])
  # File name (in UNICODE) is appended to the previous structure.
  SIZEOF_ATTRIB_FILE_NAME = ATTRIB_FILE_NAME.size

  class FileName
    attr_reader :name, :namespace, :length, :permissions, :refParent

    NS_POSIX  = 0
    NS_WIN32  = 1
    NS_DOS    = 2
    NS_DOSWIN = 3

    UNNAMED = '[unnamed]'.AsciiToUtf8.freeze

    def initialize(buf)
      raise "MIQ(NTFS::FileName.initialize) Nil buffer" if buf.nil?
      buf          = buf.read(buf.length) if buf.kind_of?(DataRun)
      @afn         = ATTRIB_FILE_NAME.decode(buf)
      buf          = buf[SIZEOF_ATTRIB_FILE_NAME, buf.size]

      # Set accessor data.
      @permissions = @afn['flags']
      @length      = @afn['data_size']
      @namespace   = @afn['namespace']
      @refParent   = NTFS::Utils.MkRef(@afn['ref_to_parent_dir'])

      # If there's a name get it.
      len          = @afn['name_length'] * 2
      @name        = buf[0, len].UnicodeToUtf8 if len > 0

      # If name is nil use NT standard unnamed.
      @name ||= UNNAMED.dup
    end

    def to_s
      @name
    end

    def mTime
      @mTime ||= NtUtil.nt_filetime_to_ruby_time(@afn['time_altered'])
    end

    def aTime
      @aTime ||= NtUtil.nt_filetime_to_ruby_time(@afn['time_read'])
    end

    def cTime
      @cTime ||= NtUtil.nt_filetime_to_ruby_time(@afn['time_created'])
    end

    # Returns nil if not directory.
    def isDir?
      NTFS::Utils.gotBit?(@permissions, StandardInformation.FP_DIRECTORY)
    end

    def dump
      out = "\#<#{self.class}:0x#{'%08x' % object_id}>\n"
      out << "  Parent dir : seq #{@refParent[0]}, entry #{@refParent[1]}\n"
      out << "  Created    : #{@cTime}\n"
      out << "  Modified   : #{@mTime}\n"
      out << "  MFT changed: #{NtUtil.nt_filetime_to_ruby_time(@afn['time_mft_changed'])}\n"
      out << "  Accessed   : #{@aTime}\n"
      out << "  Allocated  : #{@afn['allocated_size']}\n"
      out << "  Real size  : #{@length}\n"
      out << "  Flags      : 0x#{'%08x' % @flags}\n"
      out << "  Reparse    : #{@afn['reparse_point_tag']}\n"
      out << "  Name length: #{@afn['name_length']}\n"
      out << "  Namespace  : #{@namespace}\n"
      out << "  Name       : #{@name}\n"
      out << "---\n"
    end
  end
end # module NTFS