# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
# Mobius Forensic Toolkit
# Copyright (C) 2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019 Eduardo Aguiar
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
# Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
import mobius
import binascii

# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
# @brief Entry
# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
class Entry (object):
  pass

# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
# @brief Piece
# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
class Piece (object):
  pass

# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
# @brief Decode data from TempDL/PHash_XXX.dat
# @see ICH_loadPieces - helper_ICH.pas (line 528)
# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
def decode (f):

  # try to open file
  reader = f.new_reader ()
  if not reader:
    return

  # decode header
  decoder = mobius.decoder.data_decoder (reader)

  signature = decoder.get_string_by_size (14)
  num64 = decoder.get_uint64_le ()
  len_item = decoder.get_uint32_le ()
  hash_sha1 = binascii.hexlify (decoder.get_bytearray_by_size (20))
  num32 = decoder.get_uint32_le ()

  if num64 != 1 or num32 != 1:
    return

  if signature == '__ARESDBP102__':
    version = 2

  elif signature == '__ARESDBP103__':
    version = 3

  else:
    return

  # create data object
  entry = Entry ()
  entry.signature = signature
  entry.version = version
  entry.hash_sha1 = hash_sha1
  entry.phash_path = f.path.replace ('/', '\\')
  entry.phash_creation_time = f.creation_time
  entry.phash_last_modification_time = f.last_modification_time
  entry.pieces = []

  # decode pieces
  pos = decoder.tell ()
  size = decoder.get_size ()
  
  while pos < size:
    piece = Piece ()

    if version == 2:
      piece.progress = 0
      piece.hash_sha1 = binascii.hexlify (decoder.get_bytearray_by_size (20))
      piece.done = False	# unknown
      pos += 20

    else:	# version 3
      piece.done = decoder.get_uint8 () == 1
      piece.progress = decoder.get_uint64_le ()
      piece.hash_sha1 = binascii.hexlify (decoder.get_bytearray_by_size (20))
      pos += 29
      
    entry.pieces.append (piece)

  return entry
