odt_format.py

import zipfile


def is_valid(resource, file):
    """Check if the content is a ODT file."""

    if not zipfile.is_zipfile(file.name):
        resource["error"] = "Not a ZIP file."
        return False

    with zipfile.ZipFile(file.name, "r") as zip_ref:
        zip_contents = zip_ref.namelist()

        required_files = ["mimetype", "content.xml", "meta.xml", "styles.xml"]

        if not all(file in zip_contents for file in required_files):
            resource["error"] = "That does not look like an ODT file."
            return False

        with zip_ref.open("mimetype") as mimetype_file:
            mimetype_content = mimetype_file.read().decode("utf-8").strip()

        if mimetype_content != "application/vnd.oasis.opendocument.text":
            resource["error"] = f"Incorrect MIME type: {mimetype_content}"
            return False

        return True