#!/usr/bin/python -u
#
# p7zr library
#
# Copyright (c) 2019,2020 Hiroshi Miura <miurahr@linux.com>
# Copyright (c) 2004-2015 by Joachim Bauch, mail@joachim-bauch.de
# 7-Zip Copyright (C) 1999-2010 Igor Pavlov
# LZMA SDK Copyright (C) 1999-2010 Igor Pavlov
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#
"""Read 7zip format archives."""
import collections.abc
import datetime
import errno
import functools
import io
import os
import queue
import stat
import sys
import threading
from typing import IO, Any, BinaryIO, Dict, List, Optional, Tuple, Union

from py7zr.archiveinfo import Folder, Header, SignatureHeader
from py7zr.callbacks import ExtractCallback
from py7zr.compressor import get_methods_names_string
from py7zr.exceptions import Bad7zFile, CrcError, DecompressionError, InternalError, UnsupportedCompressionMethodError
from py7zr.helpers import ArchiveTimestamp, MemIO, NullIO, calculate_crc32, filetime_to_dt, readlink
from py7zr.properties import ARCHIVE_DEFAULT, ENCRYPTED_ARCHIVE_DEFAULT, MAGIC_7Z, READ_BLOCKSIZE

if sys.version_info < (3, 6):
    import contextlib2 as contextlib
    import pathlib2 as pathlib
else:
    import contextlib
    import pathlib

if sys.platform.startswith('win'):
    import _winapi

FILE_ATTRIBUTE_UNIX_EXTENSION = 0x8000
FILE_ATTRIBUTE_WINDOWS_MASK = 0x07fff


class ArchiveFile:
    """Represent each files metadata inside archive file.
    It holds file properties; filename, permissions, and type whether
    it is directory, link or normal file.

    Instances of the :class:`ArchiveFile` class are returned by iterating :attr:`files_list` of
    :class:`SevenZipFile` objects.
    Each object stores information about a single member of the 7z archive. Most of users use :meth:`extractall()`.

    The class also hold an archive parameter where file is exist in
    archive file folder(container)."""
    def __init__(self, id: int, file_info: Dict[str, Any]) -> None:
        self.id = id
        self._file_info = file_info

    def file_properties(self) -> Dict[str, Any]:
        """Return file properties as a hash object. Following keys are included: ‘readonly’, ‘is_directory’,
        ‘posix_mode’, ‘archivable’, ‘emptystream’, ‘filename’, ‘creationtime’, ‘lastaccesstime’,
        ‘lastwritetime’, ‘attributes’
        """
        properties = self._file_info
        if properties is not None:
            properties['readonly'] = self.readonly
            properties['posix_mode'] = self.posix_mode
            properties['archivable'] = self.archivable
            properties['is_directory'] = self.is_directory
        return properties

    def _get_property(self, key: str) -> Any:
        try:
            return self._file_info[key]
        except KeyError:
            return None

    @property
    def origin(self) -> pathlib.Path:
        return self._get_property('origin')

    @property
    def folder(self) -> Folder:
        return self._get_property('folder')

    @property
    def filename(self) -> str:
        """return filename of archive file."""
        return self._get_property('filename')

    @property
    def emptystream(self) -> bool:
        """True if file is empty(0-byte file), otherwise False"""
        return self._get_property('emptystream')

    @property
    def uncompressed(self) -> List[int]:
        return self._get_property('uncompressed')

    @property
    def compressed(self) -> Optional[int]:
        """Compressed size"""
        return self._get_property('compressed')

    @property
    def crc32(self) -> Optional[int]:
        """CRC of archived file(optional)"""
        return self._get_property('digest')

    def _test_attribute(self, target_bit: int) -> bool:
        attributes = self._get_property('attributes')
        if attributes is None:
            return False
        return attributes & target_bit == target_bit

    @property
    def archivable(self) -> bool:
        """File has a Windows `archive` flag."""
        return self._test_attribute(stat.FILE_ATTRIBUTE_ARCHIVE)  # type: ignore  # noqa

    @property
    def is_directory(self) -> bool:
        """True if file is a directory, otherwise False."""
        return self._test_attribute(stat.FILE_ATTRIBUTE_DIRECTORY)  # type: ignore  # noqa

    @property
    def readonly(self) -> bool:
        """True if file is readonly, otherwise False."""
        return self._test_attribute(stat.FILE_ATTRIBUTE_READONLY)  # type: ignore  # noqa

    def _get_unix_extension(self) -> Optional[int]:
        attributes = self._get_property('attributes')
        if self._test_attribute(FILE_ATTRIBUTE_UNIX_EXTENSION):
            return attributes >> 16
        return None

    @property
    def is_symlink(self) -> bool:
        """True if file is a symbolic link, otherwise False."""
        e = self._get_unix_extension()
        if e is not None:
            return stat.S_ISLNK(e)
        return self._test_attribute(stat.FILE_ATTRIBUTE_REPARSE_POINT)  # type: ignore  # noqa

    @property
    def is_junction(self) -> bool:
        """True if file is a junction/reparse point on windows, otherwise False."""
        return self._test_attribute(stat.FILE_ATTRIBUTE_REPARSE_POINT |  # type: ignore  # noqa
                                    stat.FILE_ATTRIBUTE_DIRECTORY)  # type: ignore  # noqa

    @property
    def is_socket(self) -> bool:
        """True if file is a socket, otherwise False."""
        e = self._get_unix_extension()
        if e is not None:
            return stat.S_ISSOCK(e)
        return False

    @property
    def lastwritetime(self) -> Optional[ArchiveTimestamp]:
        """Return last written timestamp of a file."""
        return self._get_property('lastwritetime')

    @property
    def posix_mode(self) -> Optional[int]:
        """
        posix mode when a member has a unix extension property, or None
        :return: Return file stat mode can be set by os.chmod()
        """
        e = self._get_unix_extension()
        if e is not None:
            return stat.S_IMODE(e)
        return None

    @property
    def st_fmt(self) -> Optional[int]:
        """
        :return: Return the portion of the file mode that describes the file type
        """
        e = self._get_unix_extension()
        if e is not None:
            return stat.S_IFMT(e)
        return None


class ArchiveFileList(collections.abc.Iterable):
    """Iteratable container of ArchiveFile."""

    def __init__(self, offset: int = 0):
        self.files_list = []  # type: List[dict]
        self.index = 0
        self.offset = offset

    def append(self, file_info: Dict[str, Any]) -> None:
        self.files_list.append(file_info)

    def __len__(self) -> int:
        return len(self.files_list)

    def __iter__(self) -> 'ArchiveFileListIterator':
        return ArchiveFileListIterator(self)

    def __getitem__(self, index):
        if index > len(self.files_list):
            raise IndexError
        if index < 0:
            raise IndexError
        res = ArchiveFile(index + self.offset, self.files_list[index])
        return res


class ArchiveFileListIterator(collections.abc.Iterator):

    def __init__(self, archive_file_list):
        self._archive_file_list = archive_file_list
        self._index = 0

    def __next__(self) -> ArchiveFile:
        if self._index == len(self._archive_file_list):
            raise StopIteration
        res = self._archive_file_list[self._index]
        self._index += 1
        return res


# ------------------
# Exported Classes
# ------------------
class ArchiveInfo:
    """Hold archive information"""

    def __init__(self, filename, size, header_size, method_names, solid, blocks, uncompressed):
        self.filename = filename
        self.size = size
        self.header_size = header_size
        self.method_names = method_names
        self.solid = solid
        self.blocks = blocks
        self.uncompressed = uncompressed


class FileInfo:
    """Hold archived file information."""

    def __init__(self, filename, compressed, uncompressed, archivable, is_directory, creationtime, crc32):
        self.filename = filename
        self.compressed = compressed
        self.uncompressed = uncompressed
        self.archivable = archivable
        self.is_directory = is_directory
        self.creationtime = creationtime
        self.crc32 = crc32


class SevenZipFile(contextlib.AbstractContextManager):
    """The SevenZipFile Class provides an interface to 7z archives."""

    def __init__(self, file: Union[BinaryIO, str, pathlib.Path], mode: str = 'r',
                 *, filters: Optional[List[Dict[str, int]]] = None, dereference=False, password: Optional[str] = None,
                 header_encryption=False) -> None:
        if mode not in ('r', 'w', 'x', 'a'):
            raise ValueError("ZipFile requires mode 'r', 'w', 'x', or 'a'")
        self.password_protected = (password is not None)
        # Check if we were passed a file-like object or not
        if isinstance(file, str):
            self._filePassed = False  # type: bool
            self.filename = file  # type: str
            if mode == 'r':
                self.fp = open(file, 'rb')  # type: BinaryIO
            elif mode == 'w':
                self.fp = open(file, 'w+b')
            elif mode == 'x':
                self.fp = open(file, 'x+b')
            elif mode == 'a':
                self.fp = open(file, 'r+b')
            else:
                raise ValueError("File open error.")
            self.mode = mode
        elif isinstance(file, pathlib.Path):
            self._filePassed = False
            self.filename = str(file)
            if mode == 'r':
                self.fp = file.open(mode='rb')  # type: ignore  # noqa   # typeshed issue: 2911
            elif mode == 'w':
                self.fp = file.open(mode='w+b')  # type: ignore  # noqa
            elif mode == 'x':
                self.fp = file.open(mode='x+b')  # type: ignore  # noqa
            elif mode == 'a':
                self.fp = file.open(mode='r+b')  # type: ignore  # noqa
            else:
                raise ValueError("File open error.")
            self.mode = mode
        elif isinstance(file, io.IOBase):
            self._filePassed = True
            self.fp = file
            self.filename = getattr(file, 'name', None)
            self.mode = mode  # type: ignore  #noqa
        else:
            raise TypeError("invalid file: {}".format(type(file)))
        self._fileRefCnt = 1
        try:
            if mode == "r":
                self._real_get_contents(password)
            elif mode in 'w':
                if password is not None and filters is None:
                    filters = ENCRYPTED_ARCHIVE_DEFAULT
                elif filters is None:
                    filters = ARCHIVE_DEFAULT
                else:
                    pass
                folder = Folder()
                folder.password = password
                folder.prepare_coderinfo(filters)
                self.files = ArchiveFileList()
                self.sig_header = SignatureHeader()
                self.sig_header._write_skelton(self.fp)
                self.afterheader = self.fp.tell()
                self.header = Header.build_header([folder])
                self.header.main_streams.packinfo.enable_digests = not self.password_protected  # FIXME
                self.fp.seek(self.afterheader)
                self.worker = Worker(self.files, self.afterheader, self.header)
            elif mode in 'x':
                raise NotImplementedError
            elif mode == 'a':
                raise NotImplementedError
            else:
                raise ValueError("Mode must be 'r', 'w', 'x', or 'a'")
        except Exception as e:
            self._fpclose()
            raise e
        self.encoded_header_mode = True
        self._dict = {}  # type: Dict[str, IO[Any]]
        self.dereference = dereference
        self.reporterd = None  # type: Optional[threading.Thread]
        self.q = queue.Queue()  # type: queue.Queue[Any]

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.close()

    def _fpclose(self) -> None:
        assert self._fileRefCnt > 0
        self._fileRefCnt -= 1
        if not self._fileRefCnt and not self._filePassed:
            self.fp.close()

    def _real_get_contents(self, password) -> None:
        if not self._check_7zfile(self.fp):
            raise Bad7zFile('not a 7z file')
        self.sig_header = SignatureHeader.retrieve(self.fp)
        self.afterheader = self.fp.tell()
        self.fp.seek(self.sig_header.nextheaderofs, os.SEEK_CUR)
        buffer = io.BytesIO(self.fp.read(self.sig_header.nextheadersize))
        if self.sig_header.nextheadercrc != calculate_crc32(buffer.getvalue()):
            raise Bad7zFile('invalid header data')
        header = Header.retrieve(self.fp, buffer, self.afterheader, password)
        header.size += 32 + self.sig_header.nextheadersize
        if header is None:
            return
        self.header = header
        buffer.close()
        self.files = ArchiveFileList()
        if getattr(self.header, 'files_info', None) is None:
            return
        # Initialize references for convenience
        if hasattr(self.header, 'main_streams') and self.header.main_streams is not None:
            folders = self.header.main_streams.unpackinfo.folders
            for folder in folders:
                folder.password = password
            packinfo = self.header.main_streams.packinfo
            packsizes = packinfo.packsizes
            subinfo = self.header.main_streams.substreamsinfo
            unpacksizes = subinfo.unpacksizes if subinfo.unpacksizes is not None else [x.unpacksizes[-1] for x in folders]
        else:
            subinfo = None
            folders = None
            packinfo = None
            packsizes = []
            unpacksizes = [0]

        pstat = self.ParseStatus()
        pstat.src_pos = self.afterheader
        file_in_solid = 0

        for file_id, file_info in enumerate(self.header.files_info.files):
            if not file_info['emptystream'] and folders is not None:
                folder = folders[pstat.folder]
                numinstreams = max([coder.get('numinstreams', 1) for coder in folder.coders])
                (maxsize, compressed, uncompressed,
                 packsize, solid) = self._get_fileinfo_sizes(pstat, subinfo, packinfo, folder, packsizes,
                                                             unpacksizes, file_in_solid, numinstreams)
                pstat.input += 1
                folder.solid = solid
                file_info['folder'] = folder
                file_info['maxsize'] = maxsize
                file_info['compressed'] = compressed
                file_info['uncompressed'] = uncompressed
                file_info['packsizes'] = packsize
                if subinfo.digestsdefined[pstat.outstreams]:
                    file_info['digest'] = subinfo.digests[pstat.outstreams]
                if folder is None:
                    pstat.src_pos += file_info['compressed']
                else:
                    if folder.solid:
                        file_in_solid += 1
                    pstat.outstreams += 1
                    if folder.files is None:
                        folder.files = ArchiveFileList(offset=file_id)
                    folder.files.append(file_info)
                    if pstat.input >= subinfo.num_unpackstreams_folders[pstat.folder]:
                        file_in_solid = 0
                        pstat.src_pos += sum(packinfo.packsizes[pstat.stream:pstat.stream + numinstreams])
                        pstat.folder += 1
                        pstat.stream += numinstreams
                        pstat.input = 0
            else:
                file_info['folder'] = None
                file_info['maxsize'] = 0
                file_info['compressed'] = 0
                file_info['uncompressed'] = 0
                file_info['packsizes'] = [0]

            if 'filename' not in file_info:
                # compressed file is stored without a name, generate one
                try:
                    basefilename = self.filename
                except AttributeError:
                    # 7z archive file doesn't have a name
                    file_info['filename'] = 'contents'
                else:
                    if basefilename is not None:
                        fn, ext = os.path.splitext(os.path.basename(basefilename))
                        file_info['filename'] = fn
                    else:
                        file_info['filename'] = 'contents'
            self.files.append(file_info)
        self.fp.seek(self.afterheader)
        self.worker = Worker(self.files, self.afterheader, self.header)

    class ParseStatus:
        def __init__(self, src_pos=0):
            self.src_pos = src_pos
            self.folder = 0  # 7zip folder where target stored
            self.outstreams = 0  # output stream count
            self.input = 0  # unpack stream count in each folder
            self.stream = 0  # target input stream position

    def _get_fileinfo_sizes(self, pstat, subinfo, packinfo, folder, packsizes, unpacksizes, file_in_solid, numinstreams):
        if pstat.input == 0:
            folder.solid = subinfo.num_unpackstreams_folders[pstat.folder] > 1
        maxsize = (folder.solid and packinfo.packsizes[pstat.stream]) or None
        uncompressed = unpacksizes[pstat.outstreams]
        if file_in_solid > 0:
            compressed = None
        elif pstat.stream < len(packsizes):  # file is compressed
            compressed = packsizes[pstat.stream]
        else:  # file is not compressed
            compressed = uncompressed
        packsize = packsizes[pstat.stream:pstat.stream + numinstreams]
        return maxsize, compressed, uncompressed, packsize, folder.solid

    def set_encoded_header_mode(self, mode: bool) -> None:
        self.encoded_header_mode = mode

    @staticmethod
    def _check_7zfile(fp: Union[BinaryIO, io.BufferedReader]) -> bool:
        result = MAGIC_7Z == fp.read(len(MAGIC_7Z))[:len(MAGIC_7Z)]
        fp.seek(-len(MAGIC_7Z), 1)
        return result

    def _get_method_names(self) -> str:
        try:
            return get_methods_names_string([folder.coders for folder in self.header.main_streams.unpackinfo.folders])
        except KeyError:
            raise UnsupportedCompressionMethodError("Unknown method")

    def _read_digest(self, pos: int, size: int) -> int:
        self.fp.seek(pos)
        remaining_size = size
        digest = 0
        while remaining_size > 0:
            block = min(READ_BLOCKSIZE, remaining_size)
            digest = calculate_crc32(self.fp.read(block), digest)
            remaining_size -= block
        return digest

    def _write_archive(self):
        folder = self.header.main_streams.unpackinfo.folders[0]
        self.worker.archive(self.fp, folder, deref=self.dereference)
        # Write header and update signature header
        (header_pos, header_len, header_crc) = self.header.write(self.fp, self.afterheader,
                                                                 encoded=self.encoded_header_mode)
        self.sig_header.nextheaderofs = header_pos - self.afterheader
        self.sig_header.calccrc(header_len, header_crc)
        self.sig_header.write(self.fp)
        return

    def _is_solid(self):
        for f in self.header.main_streams.substreamsinfo.num_unpackstreams_folders:
            if f > 1:
                return True
        return False

    def _var_release(self):
        self._dict = None
        self.files = None
        self.header = None
        self.worker = None
        self.sig_header = None

    @staticmethod
    def _make_file_info(target: pathlib.Path, arcname: Optional[str] = None, dereference=False) -> Dict[str, Any]:
        f = {}  # type: Dict[str, Any]
        f['origin'] = target
        if arcname is not None:
            f['filename'] = pathlib.Path(arcname).as_posix()
        else:
            f['filename'] = target.as_posix()
        if os.name == 'nt':
            fstat = target.lstat()
            if target.is_symlink():
                if dereference:
                    fstat = target.stat()
                    if stat.S_ISDIR(fstat.st_mode):
                        f['emptystream'] = True
                        f['attributes'] = fstat.st_file_attributes & FILE_ATTRIBUTE_WINDOWS_MASK  # type: ignore  # noqa
                    else:
                        f['emptystream'] = False
                        f['attributes'] = stat.FILE_ATTRIBUTE_ARCHIVE  # type: ignore  # noqa
                        f['uncompressed'] = fstat.st_size
                else:
                    f['emptystream'] = False
                    f['attributes'] = fstat.st_file_attributes & FILE_ATTRIBUTE_WINDOWS_MASK  # type: ignore  # noqa
                    # f['attributes'] |= stat.FILE_ATTRIBUTE_REPARSE_POINT  # type: ignore  # noqa
            elif target.is_dir():
                f['emptystream'] = True
                f['attributes'] = fstat.st_file_attributes & FILE_ATTRIBUTE_WINDOWS_MASK  # type: ignore  # noqa
            elif target.is_file():
                f['emptystream'] = False
                f['attributes'] = stat.FILE_ATTRIBUTE_ARCHIVE  # type: ignore  # noqa
                f['uncompressed'] = fstat.st_size
        else:
            fstat = target.lstat()
            if target.is_symlink():
                if dereference:
                    fstat = target.stat()
                    if stat.S_ISDIR(fstat.st_mode):
                        f['emptystream'] = True
                        f['attributes'] = stat.FILE_ATTRIBUTE_DIRECTORY  # type: ignore  # noqa
                        f['attributes'] |= FILE_ATTRIBUTE_UNIX_EXTENSION | (stat.S_IFDIR << 16)
                        f['attributes'] |= (stat.S_IMODE(fstat.st_mode) << 16)
                    else:
                        f['emptystream'] = False
                        f['attributes'] = stat.FILE_ATTRIBUTE_ARCHIVE  # type: ignore  # noqa
                        f['attributes'] |= FILE_ATTRIBUTE_UNIX_EXTENSION | (stat.S_IMODE(fstat.st_mode) << 16)
                else:
                    f['emptystream'] = False
                    f['attributes'] = stat.FILE_ATTRIBUTE_ARCHIVE | stat.FILE_ATTRIBUTE_REPARSE_POINT # type: ignore  # noqa
                    f['attributes'] |= FILE_ATTRIBUTE_UNIX_EXTENSION | (stat.S_IFLNK << 16)
                    f['attributes'] |= (stat.S_IMODE(fstat.st_mode) << 16)
            elif target.is_dir():
                f['emptystream'] = True
                f['attributes'] = stat.FILE_ATTRIBUTE_DIRECTORY  # type: ignore  # noqa
                f['attributes'] |= FILE_ATTRIBUTE_UNIX_EXTENSION | (stat.S_IFDIR << 16)
                f['attributes'] |= (stat.S_IMODE(fstat.st_mode) << 16)
            elif target.is_file():
                f['emptystream'] = False
                f['uncompressed'] = fstat.st_size
                f['attributes'] = stat.FILE_ATTRIBUTE_ARCHIVE  # type: ignore  # noqa
                f['attributes'] |= FILE_ATTRIBUTE_UNIX_EXTENSION | (stat.S_IMODE(fstat.st_mode) << 16)

        f['creationtime'] = fstat.st_ctime
        f['lastwritetime'] = fstat.st_mtime
        f['lastaccesstime'] = fstat.st_atime
        return f

    # --------------------------------------------------------------------------
    # The public methods which SevenZipFile provides:
    def getnames(self) -> List[str]:
        """Return the members of the archive as a list of their names. It has
           the same order as the list returned by getmembers().
        """
        return list(map(lambda x: x.filename, self.files))

    def archiveinfo(self) -> ArchiveInfo:
        fstat = os.stat(self.filename)
        total_uncompressed = functools.reduce(lambda x, y: x + y, [f.uncompressed for f in self.files])
        return ArchiveInfo(self.filename, fstat.st_size, self.header.size, self._get_method_names(),
                           self._is_solid(), len(self.header.main_streams.unpackinfo.folders),
                           total_uncompressed)

    def list(self) -> List[FileInfo]:
        """Returns contents information """
        alist = []  # type: List[FileInfo]
        creationtime = None  # type: Optional[datetime.datetime]
        for f in self.files:
            if f.lastwritetime is not None:
                creationtime = filetime_to_dt(f.lastwritetime)
            alist.append(FileInfo(f.filename, f.compressed, f.uncompressed, f.archivable, f.is_directory,
                                  creationtime, f.crc32))
        return alist

    def readall(self) -> Optional[Dict[str, IO[Any]]]:
        return self._extract(path=None, return_dict=True)

    def extractall(self, path: Optional[Any] = None, callback: Optional[ExtractCallback] = None) -> None:
        """Extract all members from the archive to the current working
           directory and set owner, modification time and permissions on
           directories afterwards. `path' specifies a different directory
           to extract to.
        """
        self._extract(path=path, return_dict=False, callback=callback)

    def read(self, targets: Optional[List[str]] = None) -> Optional[Dict[str, IO[Any]]]:
        return self._extract(path=None, targets=targets, return_dict=True)

    def extract(self, path: Optional[Any] = None, targets: Optional[List[str]] = None) -> None:
        self._extract(path, targets, return_dict=False)

    def _extract(self, path: Optional[Any] = None, targets: Optional[List[str]] = None,
                 return_dict: bool = False, callback: Optional[ExtractCallback] = None) -> Optional[Dict[str, IO[Any]]]:
        if callback is not None and not isinstance(callback, ExtractCallback):
            raise ValueError('Callback specified is not a subclass of py7zr.callbacks.ExtractCallback class')
        elif callback is not None:
            self.reporterd = threading.Thread(target=self.reporter, args=(callback,), daemon=True)
            self.reporterd.start()
        target_junction = []  # type: List[pathlib.Path]
        target_sym = []  # type: List[pathlib.Path]
        target_files = []  # type: List[Tuple[pathlib.Path, Dict[str, Any]]]
        target_dirs = []  # type: List[pathlib.Path]
        if path is not None:
            if isinstance(path, str):
                path = pathlib.Path(path)
            try:
                if not path.exists():
                    path.mkdir(parents=True)
                else:
                    pass
            except OSError as e:
                if e.errno == errno.EEXIST and path.is_dir():
                    pass
                else:
                    raise e
        fnames = []  # type: List[str]  # check duplicated filename in one archive?
        self.q.put(('pre', None, None))
        for f in self.files:
            # TODO: sanity check
            # check whether f.filename with invalid characters: '../'
            if f.filename.startswith('../'):
                raise Bad7zFile
            # When archive has a multiple files which have same name
            # To guarantee order of archive, multi-thread decompression becomes off.
            # Currently always overwrite by latter archives.
            # TODO: provide option to select overwrite or skip.
            if f.filename not in fnames:
                outname = f.filename
            else:
                i = 0
                while True:
                    outname = f.filename + '_%d' % i
                    if outname not in fnames:
                        break
            fnames.append(outname)
            if path is not None:
                outfilename = path.joinpath(outname)
            else:
                outfilename = pathlib.Path(outname)
            if os.name == 'nt':
                if outfilename.is_absolute():
                    # hack for microsoft windows path length limit < 255
                    outfilename = pathlib.WindowsPath('\\\\?\\' + str(outfilename))
            if targets is not None and f.filename not in targets:
                self.worker.register_filelike(f.id, None)
                continue
            if f.is_directory:
                if not outfilename.exists():
                    target_dirs.append(outfilename)
                    target_files.append((outfilename, f.file_properties()))
                else:
                    pass
            elif f.is_socket:
                pass
            elif return_dict:
                fname = outfilename.as_posix()
                _buf = io.BytesIO()
                self._dict[fname] = _buf
                self.worker.register_filelike(f.id, MemIO(_buf))
            elif f.is_symlink:
                target_sym.append(outfilename)
                try:
                    if outfilename.exists():
                        outfilename.unlink()
                except OSError as ose:
                    if ose.errno not in [errno.ENOENT]:
                        raise
                self.worker.register_filelike(f.id, outfilename)
            elif f.is_junction:
                target_junction.append(outfilename)
                self.worker.register_filelike(f.id, outfilename)
            else:
                self.worker.register_filelike(f.id, outfilename)
                target_files.append((outfilename, f.file_properties()))
        for target_dir in sorted(target_dirs):
            try:
                target_dir.mkdir(parents=True)
            except FileExistsError:
                if target_dir.is_dir():
                    pass
                elif target_dir.is_file():
                    raise DecompressionError("Directory {} is existed as a normal file.".format(str(target_dir)))
                else:
                    raise DecompressionError("Directory {} making fails on unknown condition.".format(str(target_dir)))

        try:
            if callback is not None:
                self.worker.extract(self.fp, parallel=(not self.password_protected and not self._filePassed), q=self.q)
            else:
                self.worker.extract(self.fp, parallel=(not self.password_protected and not self._filePassed))
        except CrcError as ce:
            raise Bad7zFile("CRC32 error on archived file {}.".format(str(ce)))

        self.q.put(('post', None, None))
        if return_dict:
            return self._dict
        else:
            # create symbolic links on target path as a working directory.
            # if path is None, work on current working directory.
            for t in target_sym:
                sym_dst = t.resolve()
                with sym_dst.open('rb') as b:
                    sym_src = b.read().decode(encoding='utf-8')  # symlink target name stored in utf-8
                sym_dst.unlink()  # unlink after close().
                sym_dst.symlink_to(pathlib.Path(sym_src))
            # create junction point only on windows platform
            if sys.platform.startswith('win'):
                for t in target_junction:
                    junction_dst = t.resolve()
                    with junction_dst.open('rb') as b:
                        junction_target = pathlib.Path(b.read().decode(encoding='utf-8'))
                        junction_dst.unlink()
                        _winapi.CreateJunction(junction_target, str(junction_dst))  # type: ignore  # noqa
            # set file properties
            for outfilename, properties in target_files:
                # creation time
                creationtime = ArchiveTimestamp(properties['lastwritetime']).totimestamp()
                if creationtime is not None:
                    os.utime(str(outfilename), times=(creationtime, creationtime))
                if os.name == 'posix':
                    st_mode = properties['posix_mode']
                    if st_mode is not None:
                        outfilename.chmod(st_mode)
                        continue
                # fallback: only set readonly if specified
                if properties['readonly'] and not properties['is_directory']:
                    ro_mask = 0o777 ^ (stat.S_IWRITE | stat.S_IWGRP | stat.S_IWOTH)
                    outfilename.chmod(outfilename.stat().st_mode & ro_mask)
            return None

    def reporter(self, callback: ExtractCallback):
        while True:
            try:
                item = self.q.get(timeout=1)  # type: Optional[Tuple[str, str, str]]
            except queue.Empty:
                pass
            else:
                if item is None:
                    break
                elif item[0] == 's':
                    callback.report_start(item[1], item[2])
                elif item[0] == 'e':
                    callback.report_end(item[1], item[2])
                elif item[0] == 'pre':
                    callback.report_start_preparation()
                elif item[0] == 'post':
                    callback.report_postprocess()
                elif item[0] == 'w':
                    callback.report_warning(item[1])
                else:
                    pass
                self.q.task_done()

    def writeall(self, path: Union[pathlib.Path, str], arcname: Optional[str] = None):
        """Write files in target path into archive."""
        if isinstance(path, str):
            path = pathlib.Path(path)
        if not path.exists():
            raise ValueError("specified path does not exist.")
        if path.is_dir() or path.is_file():
            self._writeall(path, arcname)
        else:
            raise ValueError("specified path is not a directory or a file")

    def _writeall(self, path, arcname):
        try:
            if path.is_symlink() and not self.dereference:
                self.write(path, arcname)
            elif path.is_file():
                self.write(path, arcname)
            elif path.is_dir():
                if not path.samefile('.'):
                    self.write(path, arcname)
                for nm in sorted(os.listdir(str(path))):
                    arc = os.path.join(arcname, nm) if arcname is not None else None
                    self._writeall(path.joinpath(nm), arc)
            else:
                return  # pathlib ignores ELOOP and return False for is_*().
        except OSError as ose:
            if self.dereference and ose.errno in [errno.ELOOP]:
                return  # ignore ELOOP here, this resulted to stop looped symlink reference.
            elif self.dereference and sys.platform == 'win32' and ose.errno in [errno.ENOENT]:
                return  # ignore ENOENT which is happened when a case of ELOOP on windows.
            else:
                raise

    def write(self, file: Union[pathlib.Path, str], arcname: Optional[str] = None):
        """Write single target file into archive(Not implemented yet)."""
        if isinstance(file, str):
            path = pathlib.Path(file)
        elif isinstance(file, pathlib.Path):
            path = file
        else:
            raise ValueError("Unsupported file type.")
        file_info = self._make_file_info(path, arcname, self.dereference)
        self.files.append(file_info)

    def close(self):
        """Flush all the data into archive and close it.
        When close py7zr start reading target and writing actual archive file.
        """
        if 'w' in self.mode:
            self._write_archive()
        if 'r' in self.mode:
            if self.reporterd is not None:
                self.q.put_nowait(None)
                self.reporterd.join(1)
                if self.reporterd.is_alive():
                    raise InternalError("Progress report thread terminate error.")
                self.reporterd = None
        self._fpclose()
        self._var_release()

    def reset(self) -> None:
        """When read mode, it reset file pointer, decompress worker and decompressor"""
        if self.mode == 'r':
            self.fp.seek(self.afterheader)
            self.worker = Worker(self.files, self.afterheader, self.header)
            if self.header.main_streams is not None and self.header.main_streams.unpackinfo.numfolders > 0:
                for i, folder in enumerate(self.header.main_streams.unpackinfo.folders):
                    folder.decompressor = None

    def test(self) -> Optional[bool]:
        self.fp.seek(self.afterheader)
        self.worker = Worker(self.files, self.afterheader, self.header)
        crcs = self.header.main_streams.packinfo.crcs  # type: Optional[List[int]]
        if crcs is None or len(crcs) == 0:
            return None
        packpos = self.afterheader + self.header.main_streams.packinfo.packpos
        packsizes = self.header.main_streams.packinfo.packsizes
        digestdefined = self.header.main_streams.packinfo.digestdefined
        j = 0
        for i, d in enumerate(digestdefined):
            if d:
                if self._read_digest(packpos, packsizes[i]) != crcs[j]:
                    return False
                j += 1
            packpos += packsizes[i]
        return True

    def testzip(self) -> Optional[str]:
        self.fp.seek(self.afterheader)
        self.worker = Worker(self.files, self.afterheader, self.header)
        for f in self.files:
            self.worker.register_filelike(f.id, None)
        try:
            self.worker.extract(self.fp, parallel=(not self.password_protected))  # TODO: print progress
        except CrcError as crce:
            return str(crce)
        else:
            return None


# --------------------
# exported functions
# --------------------
def is_7zfile(file: Union[BinaryIO, str, pathlib.Path]) -> bool:
    """Quickly see if a file is a 7Z file by checking the magic number.
    The file argument may be a filename or file-like object too.
    """
    result = False
    try:
        if isinstance(file, io.IOBase) and hasattr(file, "read"):
            result = SevenZipFile._check_7zfile(file)  # type: ignore  # noqa
        elif isinstance(file, str):
            with open(file, 'rb') as fp:
                result = SevenZipFile._check_7zfile(fp)
        elif isinstance(file, pathlib.Path) or isinstance(file, pathlib.PosixPath) or \
                isinstance(file, pathlib.WindowsPath):
            with file.open(mode='rb') as fp:  # type: ignore  # noqa
                result = SevenZipFile._check_7zfile(fp)
        else:
            raise TypeError('invalid type: file should be str, pathlib.Path or BinaryIO, but {}'.format(type(file)))
    except OSError:
        pass
    return result


def unpack_7zarchive(archive, path, extra=None):
    """Function for registering with shutil.register_unpack_format()"""
    arc = SevenZipFile(archive)
    arc.extractall(path)
    arc.close()


def pack_7zarchive(base_name, base_dir, owner=None, group=None, dry_run=None, logger=None):
    """Function for registering with shutil.register_archive_format()"""
    target_name = '{}.7z'.format(base_name)
    archive = SevenZipFile(target_name, mode='w')
    archive.writeall(path=base_dir)
    archive.close()


class Worker:
    """Extract worker class to invoke handler"""

    def __init__(self, files, src_start: int, header) -> None:
        self.target_filepath = {}  # type: Dict[int, Union[MemIO, pathlib.Path, None]]
        self.files = files
        self.src_start = src_start
        self.header = header

    def extract(self, fp: BinaryIO, parallel: bool, q=None) -> None:
        """Extract worker method to handle 7zip folder and decompress each files."""
        if hasattr(self.header, 'main_streams') and self.header.main_streams is not None:
            src_end = self.src_start + self.header.main_streams.packinfo.packpositions[-1]
            numfolders = self.header.main_streams.unpackinfo.numfolders
            if numfolders == 1:
                self.extract_single(fp, self.files, self.src_start, src_end, q)
            else:
                folders = self.header.main_streams.unpackinfo.folders
                positions = self.header.main_streams.packinfo.packpositions
                empty_files = [f for f in self.files if f.emptystream]
                if not parallel:
                    self.extract_single(fp, empty_files, 0, 0, q)
                    for i in range(numfolders):
                        self.extract_single(fp, folders[i].files, self.src_start + positions[i],
                                            self.src_start + positions[i + 1], q)
                else:
                    filename = getattr(fp, 'name', None)
                    self.extract_single(open(filename, 'rb'), empty_files, 0, 0, q)
                    extract_threads = []
                    for i in range(numfolders):
                        p = threading.Thread(target=self.extract_single,
                                             args=(filename, folders[i].files,
                                                   self.src_start + positions[i], self.src_start + positions[i + 1], q))
                        p.start()
                        extract_threads.append((p))
                    for p in extract_threads:
                        p.join()
        else:
            empty_files = [f for f in self.files if f.emptystream]
            self.extract_single(fp, empty_files, 0, 0, q)

    def extract_single(self, fp: Union[BinaryIO, str], files, src_start: int, src_end: int,
                       q: Optional[queue.Queue]) -> None:
        """Single thread extractor that takes file lists in single 7zip folder."""
        if files is None:
            return
        if isinstance(fp, str):
            fp = open(fp, 'rb')
        fp.seek(src_start)
        for f in files:
            if q is not None:
                q.put(('s', str(f.filename), str(f.compressed) if f.compressed is not None else '0'))
            fileish = self.target_filepath.get(f.id, None)
            if fileish is not None:
                fileish.parent.mkdir(parents=True, exist_ok=True)
                with fileish.open(mode='wb') as ofp:
                    if not f.emptystream:
                        # extract to file
                        crc32 = self.decompress(fp, f.folder, ofp, f.uncompressed, f.compressed, src_end)
                        ofp.seek(0)
                        if f.crc32 is not None and crc32 != f.crc32:
                            raise CrcError("{}".format(f.filename))
                    else:
                        pass  # just create empty file
            elif not f.emptystream:
                # read and bin off a data but check crc
                with NullIO() as ofp:
                    crc32 = self.decompress(fp, f.folder, ofp, f.uncompressed, f.compressed, src_end)
                if f.crc32 is not None and crc32 != f.crc32:
                    raise CrcError("{}".format(f.filename))
            if q is not None:
                q.put(('e', str(f.filename), str(f.uncompressed)))

    def decompress(self, fp: BinaryIO, folder, fq: IO[Any],
                   size: int, compressed_size: Optional[int], src_end: int) -> int:
        """decompressor wrapper called from extract method.

           :parameter fp: archive source file pointer
           :parameter folder: Folder object that have decompressor object.
           :parameter fq: output file pathlib.Path
           :parameter size: uncompressed size of target file.
           :parameter compressed_size: compressed size of target file.
           :parameter src_end: end position of the folder
           :returns None
        """
        assert folder is not None
        out_remaining = size
        crc32 = 0
        decompressor = folder.get_decompressor(compressed_size)
        zero_request = False
        while out_remaining > 0:
            max_length = out_remaining
            rest_size = src_end - fp.tell()
            if rest_size == 0:
                # now we come to end of folder.
                tmp = decompressor.decompress(b'', max_length)
                if len(tmp) == 0 and zero_request:  # detect infinite loop
                    raise Exception("decompression get wrong: no output data.")
                zero_request = True
            else:
                if decompressor.unused_size >= READ_BLOCKSIZE:
                    tmp = decompressor.decompress(b'', max_length)
                else:
                    read_size = min(READ_BLOCKSIZE - decompressor.unused_size, rest_size)
                    inp = fp.read(read_size)
                    tmp = decompressor.decompress(inp, max_length)
            if len(tmp) > 0 and out_remaining >= len(tmp):
                out_remaining -= len(tmp)
                fq.write(tmp)
                crc32 = calculate_crc32(tmp, crc32)
            if out_remaining <= 0:
                break
        if fp.tell() >= src_end:
            if decompressor.crc is not None and not decompressor.check_crc():
                print('\nCRC error! expected: {}, real: {}'.format(decompressor.crc, decompressor.digest))
        return crc32

    def _find_link_target(self, target):
        """Find the target member of a symlink or hardlink member in the archive.
        """
        targetname = target.as_posix()  # type: str
        linkname = readlink(targetname)
        # Check windows full path symlinks
        if linkname.startswith("\\\\?\\"):
            linkname = linkname[4:]
        # normalize as posix style
        linkname = pathlib.Path(linkname).as_posix()  # type: str
        member = None
        for j in range(len(self.files)):
            if linkname == self.files[j].origin.as_posix():
                # FIXME: when API user specify arcname, it will break
                member = os.path.relpath(linkname, os.path.dirname(targetname))
                break
        if member is None:
            member = linkname
        return member

    def archive(self, fp: BinaryIO, folder, deref=False):
        """Run archive task for specified 7zip folder."""
        compressor = folder.get_compressor()
        unpacksize = 0
        self.header.main_streams.packinfo.numstreams = 1
        num_unpack_streams = 0
        self.header.main_streams.substreamsinfo.digests = []
        self.header.main_streams.substreamsinfo.digestsdefined = []
        last_file_index = 0
        foutsize = 0
        for i, f in enumerate(self.files):
            file_info = f.file_properties()
            self.header.files_info.files.append(file_info)
            self.header.files_info.emptyfiles.append(f.emptystream)
            foutsize = 0
            if f.is_symlink and not deref:
                last_file_index = i
                num_unpack_streams += 1
                link_target = self._find_link_target(f.origin)  # type: str
                tgt = link_target.encode('utf-8')  # type: bytes
                insize = len(tgt)
                crc = calculate_crc32(tgt, 0)  # type: int
                out = compressor.compress(tgt)
                foutsize += len(out)
                fp.write(out)
                self.header.main_streams.substreamsinfo.digestsdefined.append(True)
                self.header.main_streams.substreamsinfo.digests.append(crc)
                self.header.files_info.files[i]['digest'] = crc
                self.header.files_info.files[i]['maxsize'] = foutsize
                self.header.main_streams.substreamsinfo.unpacksizes.append(insize)
                unpacksize += insize
            elif not f.emptystream:
                last_file_index = i
                num_unpack_streams += 1
                insize = 0
                crc = 0
                with f.origin.open(mode='rb') as fd:
                    data = fd.read(READ_BLOCKSIZE)
                    insize += len(data)
                    while data:
                        crc = calculate_crc32(data, crc)
                        out = compressor.compress(data)
                        foutsize += len(out)
                        fp.write(out)
                        data = fd.read(READ_BLOCKSIZE)
                        insize += len(data)
                self.header.main_streams.substreamsinfo.digestsdefined.append(True)
                self.header.main_streams.substreamsinfo.digests.append(crc)
                self.header.files_info.files[i]['digest'] = crc
                self.header.files_info.files[i]['maxsize'] = foutsize
                self.header.main_streams.substreamsinfo.unpacksizes.append(insize)
                unpacksize += insize
        else:
            out = compressor.flush()
            foutsize += len(out)
            fp.write(out)
            if len(self.files) > 0:
                self.header.files_info.files[last_file_index]['maxsize'] = foutsize
        # Update size data in header
        self.header.main_streams.packinfo.crcs = [compressor.digest]
        self.header.main_streams.packinfo.digestdefined = [True]
        self.header.main_streams.packinfo.packsizes = [compressor.packsize]
        self.header.main_streams.substreamsinfo.num_unpackstreams_folders = [num_unpack_streams]
        folder.unpacksizes = compressor.unpacksizes

    def register_filelike(self, id: int, fileish: Union[MemIO, pathlib.Path, None]) -> None:
        """register file-ish to worker."""
        self.target_filepath[id] = fileish