from __future__ import annotations from functools import cached_property from typing import TYPE_CHECKING, cast from pypdf._utils import format_iso8824_date, parse_iso8824_date from pypdf.constants import CatalogAttributes as CA from pypdf.constants import FileSpecificationDictionaryEntries from pypdf.constants import PageAttributes as PG from pypdf.errors import PdfReadError from pypdf.generic import ( ArrayObject, ByteStringObject, DecodedStreamObject, DictionaryObject, NameObject, NullObject, NumberObject, StreamObject, TextStringObject, is_null_or_none, ) if TYPE_CHECKING: import datetime from collections.abc import Generator from pypdf._writer import PdfWriter class EmbeddedFile: """ Container holding the information on an embedded file. Attributes are evaluated lazily if possible. Further information on embedded files can be found in section 7.11 of the PDF 2.0 specification. """ def __init__(self, name: str, pdf_object: DictionaryObject) -> None: """ Args: name: The (primary) name as provided in the name tree. pdf_object: The corresponding PDF object to allow retrieving further data. """ self._name = name self.pdf_object = pdf_object @property def name(self) -> str: """The (primary) name of the embedded file as provided in the name tree.""" return self._name @classmethod def _create_new(cls, writer: PdfWriter, name: str, content: str | bytes) -> EmbeddedFile: """ Create a new embedded file and add it to the PdfWriter. Args: writer: The PdfWriter instance to add the embedded file to. name: The filename to display. content: The data in the file. Returns: EmbeddedFile instance for the newly created embedded file. """ # Convert string content to bytes if needed if isinstance(content, str): content = content.encode("latin-1") # Create the file entry (the actual embedded file stream) file_entry = DecodedStreamObject() file_entry.set_data(content) file_entry.update({NameObject(PG.TYPE): NameObject("/EmbeddedFile")}) # Create the /EF entry ef_entry = DictionaryObject() ef_entry.update({NameObject("/F"): writer._add_object(file_entry)}) # Create the filespec dictionary from pypdf.generic import create_string_object # noqa: PLC0415 filespec = DictionaryObject() filespec.update( { NameObject(PG.TYPE): NameObject("/Filespec"), NameObject(FileSpecificationDictionaryEntries.F): create_string_object(name), NameObject(FileSpecificationDictionaryEntries.EF): ef_entry, } ) # Add to the catalog's names tree if CA.NAMES not in writer._root_object: writer._root_object[NameObject(CA.NAMES)] = writer._add_object(DictionaryObject()) names_dict = cast(DictionaryObject, writer._root_object[CA.NAMES]) if "/EmbeddedFiles" not in names_dict: embedded_files_names_dictionary = DictionaryObject( {NameObject(CA.NAMES): ArrayObject()} ) names_dict[NameObject("/EmbeddedFiles")] = writer._add_object(embedded_files_names_dictionary) else: embedded_files_names_dictionary = cast(DictionaryObject, names_dict["/EmbeddedFiles"]) # Add the name and filespec to the names array names_array = cast(ArrayObject, embedded_files_names_dictionary[CA.NAMES]) names_array.extend([create_string_object(name), filespec]) # Return an EmbeddedFile instance return cls(name=name, pdf_object=filespec) @property def alternative_name(self) -> str | None: """Retrieve the alternative name (file specification).""" for key in [FileSpecificationDictionaryEntries.UF, FileSpecificationDictionaryEntries.F]: # PDF 2.0 reference, table 43: # > A PDF reader shall use the value of the UF key, when present, instead of the F key. if key in self.pdf_object: value = self.pdf_object[key].get_object() if not is_null_or_none(value): return cast(str, value) return None @alternative_name.setter def alternative_name(self, value: TextStringObject | None) -> None: """Set the alternative name (file specification).""" if value is None: if FileSpecificationDictionaryEntries.UF in self.pdf_object: self.pdf_object[NameObject(FileSpecificationDictionaryEntries.UF)] = NullObject() if FileSpecificationDictionaryEntries.F in self.pdf_object: self.pdf_object[NameObject(FileSpecificationDictionaryEntries.F)] = NullObject() else: if FileSpecificationDictionaryEntries.UF in self.pdf_object: self.pdf_object[NameObject(FileSpecificationDictionaryEntries.UF)] = value if FileSpecificationDictionaryEntries.F in self.pdf_object: self.pdf_object[NameObject(FileSpecificationDictionaryEntries.F)] = value @property def description(self) -> str | None: """Retrieve the description.""" value = self.pdf_object.get(FileSpecificationDictionaryEntries.DESC) if is_null_or_none(value): return None return value @description.setter def description(self, value: TextStringObject | None) -> None: """Set the description.""" if value is None: self.pdf_object[NameObject(FileSpecificationDictionaryEntries.DESC)] = NullObject() else: self.pdf_object[NameObject(FileSpecificationDictionaryEntries.DESC)] = value @property def associated_file_relationship(self) -> str: """Retrieve the relationship of the referring document to this embedded file.""" return self.pdf_object.get("/AFRelationship", "/Unspecified") @associated_file_relationship.setter def associated_file_relationship(self, value: NameObject) -> None: """Set the relationship of the referring document to this embedded file.""" self.pdf_object[NameObject("/AFRelationship")] = value @property def _embedded_file(self) -> StreamObject: """Retrieve the actual embedded file stream.""" if "/EF" not in self.pdf_object: raise PdfReadError(f"/EF entry not found: {self.pdf_object}") ef = cast(DictionaryObject, self.pdf_object["/EF"]) for key in [FileSpecificationDictionaryEntries.UF, FileSpecificationDictionaryEntries.F]: if key in ef: return cast(StreamObject, ef[key].get_object()) raise PdfReadError(f"No /(U)F key found in file dictionary: {ef}") @property def _params(self) -> DictionaryObject: """Retrieve the file-specific parameters.""" return self._embedded_file.get("/Params", DictionaryObject()).get_object() @cached_property def _ensure_params(self) -> DictionaryObject: """Ensure the /Params dictionary exists and return it.""" embedded_file = self._embedded_file if "/Params" not in embedded_file: embedded_file[NameObject("/Params")] = DictionaryObject() return cast(DictionaryObject, embedded_file["/Params"]) @property def subtype(self) -> str | None: """Retrieve the subtype. This is a MIME media type, prefixed by a slash.""" value = self._embedded_file.get("/Subtype") if is_null_or_none(value): return None return value @subtype.setter def subtype(self, value: NameObject | None) -> None: """Set the subtype. This should be a MIME media type, prefixed by a slash.""" embedded_file = self._embedded_file if value is None: embedded_file[NameObject("/Subtype")] = NullObject() else: embedded_file[NameObject("/Subtype")] = value @property def content(self) -> bytes: """Retrieve the actual file content.""" return self._embedded_file.get_data() @content.setter def content(self, value: str | bytes) -> None: """Set the file content.""" if isinstance(value, str): value = value.encode("latin-1") self._embedded_file.set_data(value) @property def size(self) -> int | None: """Retrieve the size of the uncompressed file in bytes.""" value = self._params.get("/Size") if is_null_or_none(value): return None return value @size.setter def size(self, value: NumberObject | None) -> None: """Set the size of the uncompressed file in bytes.""" params = self._ensure_params if value is None: params[NameObject("/Size")] = NullObject() else: params[NameObject("/Size")] = value @property def creation_date(self) -> datetime.datetime | None: """Retrieve the file creation datetime.""" return parse_iso8824_date(self._params.get("/CreationDate")) @creation_date.setter def creation_date(self, value: datetime.datetime | None) -> None: """Set the file creation datetime.""" params = self._ensure_params if value is None: params[NameObject("/CreationDate")] = NullObject() else: date_str = format_iso8824_date(value) params[NameObject("/CreationDate")] = TextStringObject(date_str) @property def modification_date(self) -> datetime.datetime | None: """Retrieve the datetime of the last file modification.""" return parse_iso8824_date(self._params.get("/ModDate")) @modification_date.setter def modification_date(self, value: datetime.datetime | None) -> None: """Set the datetime of the last file modification.""" params = self._ensure_params if value is None: params[NameObject("/ModDate")] = NullObject() else: date_str = format_iso8824_date(value) params[NameObject("/ModDate")] = TextStringObject(date_str) @property def checksum(self) -> bytes | None: """Retrieve the MD5 checksum of the (uncompressed) file.""" value = self._params.get("/CheckSum") if is_null_or_none(value): return None return value @checksum.setter def checksum(self, value: ByteStringObject | None) -> None: """Set the MD5 checksum of the (uncompressed) file.""" params = self._ensure_params if value is None: params[NameObject("/CheckSum")] = NullObject() else: params[NameObject("/CheckSum")] = value def __repr__(self) -> str: return f"<{self.__class__.__name__} name={self.name!r}>" @classmethod def _load_from_names(cls, names: ArrayObject) -> Generator[EmbeddedFile]: """ Convert the given name tree into class instances. Args: names: The name tree to load the data from. Returns: Iterable of class instances for the files found. """ # This is a name tree of the format [name_1, reference_1, name_2, reference_2, ...] for i, name in enumerate(names): if not isinstance(name, str): # Skip plain strings and retrieve them as `direct_name` by index. file_dictionary = name.get_object() direct_name = names[i - 1].get_object() yield EmbeddedFile(name=direct_name, pdf_object=file_dictionary) @classmethod def _load(cls, catalog: DictionaryObject) -> Generator[EmbeddedFile]: """ Load the embedded files for the given document catalog. This method and its signature are considered internal API and thus not exposed publicly for now. Args: catalog: The document catalog to load from. Returns: Iterable of class instances for the files found. """ try: container = cast( DictionaryObject, cast(DictionaryObject, catalog["/Names"])["/EmbeddedFiles"], ) except KeyError: return if "/Kids" in container: for kid in cast(ArrayObject, container["/Kids"].get_object()): # There might be further (nested) kids here. # Wait for an example before evaluating an implementation. kid = kid.get_object() if "/Names" in kid: yield from cls._load_from_names(cast(ArrayObject, kid["/Names"])) if "/Names" in container: yield from cls._load_from_names(cast(ArrayObject, container["/Names"]))