#!/usr/bin/env python

"""
A simple script to download a course by name from ILIAS.
"""

import argparse
import os
import re
from pathlib import Path, PurePath
from typing import Optional
from urllib.parse import urlparse

from PFERD import Pferd
from PFERD.cookie_jar import CookieJar
from PFERD.ilias import (IliasCrawler, IliasElementType,
                         KitShibbolethAuthenticator)
from PFERD.utils import to_path


def sanitize_path(path: PurePath) -> Optional[PurePath]:
    # Escape windows illegal path characters
    if os.name == 'nt':
        sanitized_parts = [re.sub(r'[<>:"/|?]', "_", x) for x in list(path.parts)]
        return PurePath(*sanitized_parts)
    return path


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument("--test-run", action="store_true")
    parser.add_argument('-c', '--cookies', nargs='?', default=None, help="File to store cookies in")
    parser.add_argument('--no-videos', nargs='?', default=None, help="Don't download videos")
    parser.add_argument('url', help="URL to the course page")
    parser.add_argument('folder', nargs='?', default=None, help="Folder to put stuff into")
    args = parser.parse_args()

    url = urlparse(args.url)

    cookie_jar = CookieJar(to_path(args.cookies) if args.cookies else None)
    session = cookie_jar.create_session()
    authenticator = KitShibbolethAuthenticator()
    crawler = IliasCrawler(url.scheme + '://' + url.netloc, session,
                           authenticator, lambda x, y: True)

    cookie_jar.load_cookies()

    if args.folder is not None:
        folder = args.folder
        # Initialize pferd at the *parent of the passed folder*
        # This is needed so Pferd's internal protections against escaping the working directory
        # do not trigger (e.g. if somebody names a file in ILIAS '../../bad thing.txt')
        pferd = Pferd(Path(Path(__file__).parent, folder).parent, test_run=args.test_run)
    else:
        # fetch course name from ilias
        folder = crawler.find_element_name(args.url)
        cookie_jar.save_cookies()

        # Initialize pferd at the location of the script
        pferd = Pferd(Path(__file__).parent, test_run=args.test_run)

    def dir_filter(_: Path, element: IliasElementType) -> bool:
        if args.no_videos:
            return element not in [IliasElementType.VIDEO_FILE, IliasElementType.VIDEO_FOLDER]
        return True

    pferd.enable_logging()
    # fetch
    pferd.ilias_kit_folder(
        target=folder,
        full_url=args.url,
        cookies=args.cookies,
        dir_filter=dir_filter,
        transform=sanitize_path
    )


if __name__ == "__main__":
    main()