from typing import IO, List, Optional

from unstructured.chunking import add_chunking_strategy
from unstructured.documents.elements import Element, process_metadata
from unstructured.file_utils.filetype import FileType, add_metadata_with_filetype
from unstructured.partition.html import convert_and_partition_html
from unstructured.partition.lang import apply_lang_metadata

DETECTION_ORIGIN: str = "epub"


@process_metadata()
@add_metadata_with_filetype(FileType.EPUB)
@add_chunking_strategy()
def partition_epub(
    filename: Optional[str] = None,
    file: Optional[IO[bytes]] = None,
    include_page_breaks: bool = False,
    include_metadata: bool = True,
    metadata_filename: Optional[str] = None,
    metadata_last_modified: Optional[str] = None,
    chunking_strategy: Optional[str] = None,
    languages: Optional[List[str]] = ["auto"],
    detect_language_per_element: bool = False,
    **kwargs,
) -> List[Element]:
    """Partitions an EPUB document. The document is first converted to HTML and then
    partitioned using partition_html.

    Parameters
    ----------
    filename
        A string defining the target filename path.
    file
        A file-like object using "rb" mode --> open(filename, "rb").
    include_page_breaks
        If True, the output will include page breaks if the filetype supports it
    metadata_last_modified
        The last modified date for the document.
    languages
        User defined value for `metadata.languages` if provided. Otherwise language is detected
        using naive Bayesian filter via `langdetect`. Multiple languages indicates text could be
        in either language.
        Additional Parameters:
            detect_language_per_element
                Detect language per element instead of at the document level.
    """

    elements = convert_and_partition_html(
        filename=filename,
        file=file,
        include_page_breaks=include_page_breaks,
        metadata_filename=metadata_filename,
        metadata_last_modified=metadata_last_modified,
        source_format="epub",
        detection_origin=DETECTION_ORIGIN,
    )

    elements = list(
        apply_lang_metadata(
            elements,
            languages=languages,
            detect_language_per_element=detect_language_per_element,
        ),
    )

    return elements