if not channel_name:
                    continue
                if channel_path.endswith(".json"):
                    messages = self._read_json(zip_file, channel_path)
                    for message in messages:
                        document = self._convert_message_to_document(
                            message, channel_name
                        )
                        docs.append(document)
        return docs
    def _read_json(self, zip_file: zipfile.ZipFile, file_path: str) -> List[dict]:
        """Read JSON data from a zip subfile."""
        with zip_file.open(file_path, "r") as f:
            data = json.load(f)
        return data
    def _convert_message_to_document(
        self, message: dict, channel_name: str
    ) -> Document:
        """
        Convert a message to a Document object.
        Args:
            message (dict): A message in the form of a dictionary.
            channel_name (str): The name of the channel the message belongs to.
        Returns:
            Document: A Document object representing the message.
        """
        text = message.get("text", "")
        metadata = self._get_message_metadata(message, channel_name)
        return Document(
            page_content=text,
            metadata=metadata,
        )
    def _get_message_metadata(self, message: dict, channel_name: str) -> dict:
        """Create and return metadata for a given message and channel."""
        timestamp = message.get("ts", "")
        user = message.get("user", "")
        source = self._get_message_source(channel_name, user, timestamp)
        return {
            "source": source,
            "channel": channel_name,
            "timestamp": timestamp,
            "user": user,
        }