"""The NTFS file entry implementation."""

import copy

import pyfsntfs
import pyfwnt

from dfdatetime import filetime as dfdatetime_filetime

from dfvfs.lib import definitions
from dfvfs.lib import errors
from dfvfs.path import ntfs_path_spec
from dfvfs.resolver import resolver
from dfvfs.vfs import attribute
from dfvfs.vfs import extent
from dfvfs.vfs import file_entry
from dfvfs.vfs import ntfs_attribute
from dfvfs.vfs import ntfs_data_stream
from dfvfs.vfs import ntfs_directory


class NTFSFileEntry(file_entry.FileEntry):
    """File system file entry that uses pyfsntfs."""

    TYPE_INDICATOR = definitions.TYPE_INDICATOR_NTFS

    _ATTRIBUTE_TYPE_CLASS_MAPPINGS = {
        0x00000010: ntfs_attribute.StandardInformationNTFSAttribute,
        0x00000030: ntfs_attribute.FileNameNTFSAttribute,
        0x00000040: ntfs_attribute.ObjectIdentifierNTFSAttribute,
        0x00000050: ntfs_attribute.SecurityDescriptorNTFSAttribute,
    }

    _FILE_REFERENCE_MFT_ENTRY_BITMASK = 0xFFFFFFFFFFFF

    def __init__(
        self,
        resolver_context,
        file_system,
        path_spec,
        fsntfs_file_entry=None,
        is_root=False,
        is_virtual=False,
    ):
        """Initializes the file entry object.

        Args:
          resolver_context (Context): resolver context.
          file_system (FileSystem): file system.
          path_spec (PathSpec): path specification.
          fsntfs_file_entry (Optional[pyfsntfs.file_entry]): NTFS file entry.
          is_root (Optional[bool]): True if the file entry is the root file entry
              of the corresponding file system.
          is_virtual (Optional[bool]): True if the file entry is a virtual file
              entry emulated by the corresponding file system.

        Raises:
          BackEndError: if the pyfsntfs file entry is missing.
        """
        if not fsntfs_file_entry:
            fsntfs_file_entry = file_system.GetNTFSFileEntryByPathSpec(path_spec)
        if not fsntfs_file_entry:
            raise errors.BackEndError("Missing pyfsntfs file entry.")

        super().__init__(
            resolver_context,
            file_system,
            path_spec,
            is_root=is_root,
            is_virtual=is_virtual,
        )
        self._fsntfs_file_entry = fsntfs_file_entry

        self._link = self._fsntfs_file_entry.symbolic_link_target
        if self._link and self._link.startswith("\\??\\"):
            # Strip off the '\\??\\' prefix.
            self._link = self._link[4:]

        file_attribute_flags = fsntfs_file_entry.file_attribute_flags
        if self._link:
            self.entry_type = definitions.FILE_ENTRY_TYPE_LINK
        elif fsntfs_file_entry.has_directory_entries_index():
            self.entry_type = definitions.FILE_ENTRY_TYPE_DIRECTORY
        elif self._IsDevice(file_attribute_flags):
            self.entry_type = definitions.FILE_ENTRY_TYPE_DEVICE
        else:
            self.entry_type = definitions.FILE_ENTRY_TYPE_FILE

    def _GetAttributes(self):
        """Retrieves the attributes.

        Returns:
          list[Attribute]: attributes.
        """
        if self._attributes is None:
            self._attributes = []

            for fsntfs_attribute in self._fsntfs_file_entry.attributes:
                attribute_class = self._ATTRIBUTE_TYPE_CLASS_MAPPINGS.get(
                    fsntfs_attribute.attribute_type, ntfs_attribute.NTFSAttribute
                )

                attribute_object = attribute_class(fsntfs_attribute)
                self._attributes.append(attribute_object)

        return self._attributes

    def _GetDataStreams(self):
        """Retrieves the data streams.

        Returns:
          list[NTFSDataStream]: data streams.
        """
        if self._data_streams is None:
            self._data_streams = []
            if self._fsntfs_file_entry.has_default_data_stream():
                data_stream = ntfs_data_stream.NTFSDataStream(self, None)
                self._data_streams.append(data_stream)

            for fsntfs_data_stream in self._fsntfs_file_entry.alternate_data_streams:
                data_stream = ntfs_data_stream.NTFSDataStream(self, fsntfs_data_stream)
                self._data_streams.append(data_stream)

        return self._data_streams

    def _GetDirectory(self):
        """Retrieves a directory.

        Returns:
          NTFSDirectory: a directory.
        """
        if self.entry_type != definitions.FILE_ENTRY_TYPE_DIRECTORY:
            return None

        return ntfs_directory.NTFSDirectory(
            self._file_system, self.path_spec, self._fsntfs_file_entry
        )

    def _GetLink(self):
        """Retrieves the link.

        Returns:
          str: path of the linked file.
        """
        return self._link

    def _GetStatAttribute(self):
        """Retrieves a stat attribute.

        Returns:
          StatAttribute: a stat attribute or None if not available.
        """
        stat_attribute = attribute.StatAttribute()
        stat_attribute.inode_number = getattr(
            self._fsntfs_file_entry, "file_reference", None
        )
        stat_attribute.number_of_links = getattr(
            self._fsntfs_file_entry, "number_of_links", None
        )
        stat_attribute.size = getattr(self._fsntfs_file_entry, "size", None)
        stat_attribute.type = self.entry_type

        return stat_attribute

    def _GetSubFileEntries(self):
        """Retrieves sub file entries.

        Yields:
          NTFSFileEntry: a sub file entry.
        """
        if self._directory is None:
            self._directory = self._GetDirectory()

        if self._directory:
            for path_spec in self._directory.entries:
                yield NTFSFileEntry(
                    self._resolver_context, self._file_system, path_spec
                )

    def _IsDevice(self, file_attribute_flags):
        """Determines if a file entry is a device.

        Args:
          file_attribute_flags (int): file attribute flags.

        Returns:
          bool: True if a file entry is device link, false otherwise.
        """
        if file_attribute_flags is None:
            return False
        return bool(file_attribute_flags & pyfsntfs.file_attribute_flags.DEVICE)

    @property
    def access_time(self):
        """dfdatetime.DateTimeValues: access time or None if not available."""
        timestamp = self._fsntfs_file_entry.get_access_time_as_integer()
        if timestamp is None:
            return None

        return dfdatetime_filetime.Filetime(timestamp=timestamp)

    @property
    def change_time(self):
        """dfdatetime.DateTimeValues: change time or None if not available."""
        timestamp = self._fsntfs_file_entry.get_entry_modification_time_as_integer()
        if timestamp is None:
            return None

        return dfdatetime_filetime.Filetime(timestamp=timestamp)

    @property
    def creation_time(self):
        """dfdatetime.DateTimeValues: creation time or None if not available."""
        timestamp = self._fsntfs_file_entry.get_creation_time_as_integer()
        if timestamp is None:
            return None

        return dfdatetime_filetime.Filetime(timestamp=timestamp)

    @property
    def modification_time(self):
        """dfdatetime.DateTimeValues: modification time or None if not available."""
        timestamp = self._fsntfs_file_entry.get_modification_time_as_integer()
        if timestamp is None:
            return None

        return dfdatetime_filetime.Filetime(timestamp=timestamp)

    @property
    def name(self):
        """str: name of the file entry, which does not include the full path."""
        # The root directory file name is typically '.', dfVFS however uses ''.
        if self._is_root:
            return ""

        mft_attribute = getattr(self.path_spec, "mft_attribute", None)
        if mft_attribute is not None:
            return self._fsntfs_file_entry.get_name_by_attribute_index(mft_attribute)

        return self._fsntfs_file_entry.get_name()

    @property
    def size(self):
        """int: size of the file entry in bytes or None if not available."""
        return getattr(self._fsntfs_file_entry, "size", None)

    def GetExtents(self):
        """Retrieves the extents.

        Returns:
          list[Extent]: the extents.
        """
        extents = []
        for extent_index in range(self._fsntfs_file_entry.number_of_extents):
            extent_offset, extent_size, extent_flags = (
                self._fsntfs_file_entry.get_extent(extent_index)
            )

            if extent_flags & 0x1:
                extent_type = definitions.EXTENT_TYPE_SPARSE
            else:
                extent_type = definitions.EXTENT_TYPE_DATA

            data_stream_extent = extent.Extent(
                extent_type=extent_type, offset=extent_offset, size=extent_size
            )
            extents.append(data_stream_extent)

        return extents

    def GetFileObject(self, data_stream_name=""):
        """Retrieves a file-like object of a specific data stream.

        Args:
          data_stream_name (Optional[str]): data stream name, where an empty
              string represents the default data stream.

        Returns:
          NTFSFileIO: file-like object or None.
        """
        if (
            not data_stream_name
            and not self._fsntfs_file_entry.has_default_data_stream()
        ):
            return None

        # Make sure to make the changes on a copy of the path specification, so we
        # do not alter self.path_spec.
        path_spec = copy.deepcopy(self.path_spec)
        if data_stream_name:
            setattr(path_spec, "data_stream", data_stream_name)

        return resolver.Resolver.OpenFileObject(
            path_spec, resolver_context=self._resolver_context
        )

    def GetLinkedFileEntry(self):
        """Retrieves the linked file entry, e.g. for a symbolic link.

        Returns:
          NTFSFileEntry: linked file entry or None.
        """
        if self._link:
            return None

        # TODO: is there a way to determine the MFT entry here?
        link_mft_entry = None

        parent_path_spec = getattr(self.path_spec, "parent", None)
        path_spec = ntfs_path_spec.NTFSPathSpec(
            location=self._link, parent=parent_path_spec
        )

        is_root = bool(
            self._link == self._file_system.LOCATION_ROOT
            or link_mft_entry == self._file_system.MFT_ENTRY_ROOT_DIRECTORY
        )

        return NTFSFileEntry(
            self._resolver_context, self._file_system, path_spec, is_root=is_root
        )

    def GetNTFSFileEntry(self):
        """Retrieves the NTFS file entry.

        Returns:
          pyfsntfs.file_entry: NTFS file entry.
        """
        return self._fsntfs_file_entry

    def GetParentFileEntry(self):
        """Retrieves the parent file entry.

        Returns:
          NTFSFileEntry: parent file entry or None if not available.
        """
        location = getattr(self.path_spec, "location", None)
        if location is not None:
            parent_location = self._file_system.DirnamePath(location)
            if parent_location == "":
                parent_location = self._file_system.PATH_SEPARATOR

        parent_file_reference = None
        mft_attribute = getattr(self.path_spec, "mft_attribute", None)
        if mft_attribute is not None:
            parent_file_reference = (
                self._fsntfs_file_entry.get_parent_file_reference_by_attribute_index(
                    mft_attribute
                )
            )
        else:
            parent_file_reference = self._fsntfs_file_entry.get_parent_file_reference()

        if parent_file_reference is None:
            return None

        parent_mft_entry = (
            parent_file_reference & self._FILE_REFERENCE_MFT_ENTRY_BITMASK
        )

        parent_path_spec = getattr(self.path_spec, "parent", None)
        # TODO: determine and pass the mft_attribute of the parent
        # for a faster resolve of the file entry.
        path_spec = ntfs_path_spec.NTFSPathSpec(
            location=parent_location,
            mft_entry=parent_mft_entry,
            parent=parent_path_spec,
        )

        # TODO: handle parent correctly use attribute index?
        is_root = bool(
            parent_location == self._file_system.LOCATION_ROOT
            or parent_mft_entry == self._file_system.MFT_ENTRY_ROOT_DIRECTORY
        )

        return NTFSFileEntry(
            self._resolver_context, self._file_system, path_spec, is_root=is_root
        )

    def GetSecurityDescriptor(self):
        """Retrieves the security descriptor.

        Returns:
          pyfwnt.security_descriptor: security descriptor.
        """
        fwnt_security_descriptor = pyfwnt.security_descriptor()
        fwnt_security_descriptor.copy_from_byte_stream(
            self._fsntfs_file_entry.security_descriptor_data
        )

        return fwnt_security_descriptor

    def IsAllocated(self):
        """Determines if the file entry is allocated.

        Returns:
          bool: True if the file entry is allocated.
        """
        return self._fsntfs_file_entry.is_allocated()
