# paperdoorknob: Print glowfic
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation, version 3.


from argparse import ArgumentParser
import itertools
import os.path

from typing import Iterable

from bs4 import BeautifulSoup
from bs4.element import Tag
import requests
import requests_cache
from xdg_base_dirs import xdg_cache_home


def command_line_parser() -> ArgumentParser:
    parser = ArgumentParser(prog='paperdoorknob', description='Print glowfic')
    parser.add_argument(
        '--cache_path',
        metavar='PATH',
        help='Where to keep the http cache (instead of %(default)s)',
        default=os.path.join(xdg_cache_home(), "paperdoorknob"))
    parser.add_argument(
        '--timeout',
        help='How long to wait for HTTP requests, in seconds',
        default=30)
    parser.add_argument('url', help='URL to retrieve')
    return parser


def fetch(url: str, session: requests.Session, timeout: int) -> BeautifulSoup:
    with session.get(url, timeout=timeout) as r:
        r.raise_for_status()
        return BeautifulSoup(r.text, 'html.parser')


def clean(html: BeautifulSoup) -> BeautifulSoup:
    for eb in html.find_all("div", class_="post-edit-box"):
        eb.decompose()
    for footer in html.find_all("div", class_="post-footer"):
        footer.decompose()
    return html


def replies(html: BeautifulSoup) -> Iterable[Tag]:
    def text() -> Tag:
        body = html.body
        assert body
        text = body.find_next("div", class_="post-post")
        assert isinstance(text, Tag)
        return text

    def the_replies() -> Iterable[Tag]:
        rs = html.find_all("div", class_="post-reply")
        assert all(isinstance(r, Tag) for r in rs)
        return rs

    return itertools.chain([text()], the_replies())


def process(
        url: str,
        session: requests.Session,
        timeout: int) -> Iterable[Tag]:
    html = clean(fetch(url, session, timeout))
    return replies(html)


def main() -> None:
    args = command_line_parser().parse_args()
    with requests_cache.CachedSession(args.cache_path, cache_control=True) as session:
        process(args.url, session, args.timeout)


if __name__ == '__main__':
    main()