update_website

#!/usr/bin/env python3
"""
This script is used to quickly make updates to the course webpage, such as
adding a link to lecture slides / video.

Usage:
  ./update_website [-d | --dry] demo <lec_num>
  ./update_website [-d | --dry] <command> <lec_num> <url>

  Where <command> is one of:
    video
    slides
    demo

Options:
  -h --help     Show this screen.
  -d --dry      Prints resulting HTML instead of modifying file
"""

from docopt import docopt
from bs4 import BeautifulSoup

# Name of HTML file
INDEX = 'index.html'

# HTML class of the calendar div
CALENDAR_CLASS = 'calendar'

# Column that contains the lecture information
LECTURE_COL = 2

# Text of the links to add
DEMO_TEXT = '(demo)'
VIDEO_TEXT = '(video)'
SLIDES_TEXT = '(slides)'

DEMO_FORMAT = 'http://data8.haas.berkeley.edu/user-redirect/interact?repo=data8assets&path=lec/su17/lec{:02d}_live.ipynb'


def parse_index() -> BeautifulSoup:
    with open(INDEX, 'r') as fp:
        return BeautifulSoup(fp, 'html5lib')


def write_index(soup: BeautifulSoup):
    with open(INDEX, 'w') as fp:
        fp.write(soup.prettify())


def get_calendar(soup: BeautifulSoup) -> [BeautifulSoup]:
    return soup.find('div', 'calendar').table.find_all('tr')


def make_link(soup: BeautifulSoup, text: str, url: str) -> BeautifulSoup:
    link = soup.new_tag('a', href=url)
    link.string = text
    return link

def lec_num_to_index(lec_num):
    """
    Since every Friday has 2 lectures, we need to decrement the lec_num by 1
    each week.

    And then I add three since July 4 was a holiday and the midterm technically
    stands in place of 2 lectures.
    """
    lec_num += 3
    return lec_num - lec_num // 6


def _add_link(soup: BeautifulSoup,
              lec_num: int,
              url: str,
              text: str) -> BeautifulSoup:
    calendar = get_calendar(soup)
    cell = calendar[lec_num_to_index(lec_num)].select('td')[LECTURE_COL]
    link = make_link(soup, text, url)

    cell.append('\n')
    cell.append(link)
    return soup

def add_video_link(soup: BeautifulSoup,
                   lec_num: int,
                   url: str) -> BeautifulSoup:
    return _add_link(soup, lec_num, url, VIDEO_TEXT)

def add_slides_link(soup: BeautifulSoup,
                    lec_num: int,
                    url: str) -> BeautifulSoup:
    return _add_link(soup, lec_num, url, SLIDES_TEXT)

def add_demo_link(soup: BeautifulSoup,
                  lec_num: int,
                  url: 'unused') -> BeautifulSoup:
    url = DEMO_FORMAT.format(lec_num)
    return _add_link(soup, lec_num, url, DEMO_TEXT)


ARG_TO_COMMAND = {
    'video': add_video_link,
    'slides': add_slides_link,
    'demo': add_demo_link,
}

if __name__ == '__main__':
    arguments = docopt(__doc__)

    soup = parse_index()

    if arguments['demo']:
        command = ARG_TO_COMMAND['demo']
    else:
        command = ARG_TO_COMMAND[arguments['<command>']]

    lec_num = int(arguments['<lec_num>'])
    url = arguments['<url>']

    result = command(soup, lec_num, url)

    if arguments['--dry']:
        print(soup.prettify())
    else:
        write_index(soup)