"""
Utilities and helpers for retrieving the datasets
"""
# stdlib
import tarfile
import urllib.request
from pathlib import Path
from typing import Optional

from google_drive_downloader import GoogleDriveDownloader as gdd


def download_gdrive_if_needed(path: Path, file_id: str) -> None:
    """
    Helper for downloading a file from Google Drive, if it is now already on the disk.

    Parameters
    ----------
    path: Path
        Where to download the file
    file_id: str
        Google Drive File ID. Details: https://developers.google.com/drive/api/v3/about-files
    """
    path = Path(path)

    if path.exists():
        return

    gdd.download_file_from_google_drive(file_id=file_id, dest_path=path)


def download_http_if_needed(path: Path, url: str) -> None:
    """
    Helper for downloading a file, if it is now already on the disk.

    Parameters
    ----------
    path: Path
        Where to download the file.
    url: URL string
        HTTP URL for the dataset.
    """
    path = Path(path)

    if path.exists():
        return

    if url.lower().startswith("http"):
        urllib.request.urlretrieve(url, path)  # nosec
        return

    raise ValueError(f"Invalid url provided {url}")


def unarchive_if_needed(path: Path, output_folder: Path) -> None:
    """
    Helper for uncompressing archives. Supports .tar.gz and .tar.

    Parameters
    ----------
    path: Path
        Source archive.
    output_folder: Path
        Where to unarchive.
    """
    if str(path).endswith(".tar.gz"):
        tar = tarfile.open(path, "r:gz")
        tar.extractall(path=output_folder)
        tar.close()
    elif str(path).endswith(".tar"):
        tar = tarfile.open(path, "r:")
        tar.extractall(path=output_folder)
        tar.close()
    else:
        raise NotImplementedError(f"archive not supported {path}")


def download_if_needed(
    download_path: Path,
    file_id: Optional[str] = None,  # used for downloading from Google Drive
    http_url: Optional[str] = None,  # used for downloading from a HTTP URL
    unarchive: bool = False,  # unzip a downloaded archive
    unarchive_folder: Optional[Path] = None,  # unzip folder
) -> None:
    """
    Helper for retrieving online datasets.

    Parameters
    ----------
    download_path: str
        Where to download the archive
    file_id: str, optional
        Set this if you want to download from a public Google drive share
    http_url: str, optional
        Set this if you want to download from a HTTP URL
    unarchive: bool
        Set this if you want to try to unarchive the downloaded file
    unarchive_folder: str
        Mandatory if you set unarchive to True.
    """
    if file_id is not None:
        download_gdrive_if_needed(download_path, file_id)
    elif http_url is not None:
        download_http_if_needed(download_path, http_url)
    else:
        raise ValueError("Please provide a download URL")

    if unarchive and unarchive_folder is None:
        raise ValueError("Please provide a folder for the archive")
    if unarchive and unarchive_folder is not None:
        unarchive_if_needed(download_path, unarchive_folder)