Get YouTube Thumbnail URL

youtube_thumbnail.py

#!/usr/bin/env python3
import sys
from enum import Enum
from IPython import get_ipython
URL_TYPE = Enum('URL_TYPE', ['unsupported', 'long_url', 'short_url', 'shorts', 'music'])
def determine_url_type(url: str):
    if url[:29] == 'https://www.youtube.com/watch':
        url_type = URL_TYPE.long_url
    elif url[:17] == 'https://youtu.be/':
        url_type = URL_TYPE.short_url
    elif url[:31] == 'https://www.youtube.com/shorts/':
        url_type = URL_TYPE.shorts
    elif url[:31] == 'https://music.youtube.com/watch':
        url_type = URL_TYPE.music
    else:
        url_type = URL_TYPE.unsupported
    return url_type
def get_url_with_args(url: str):
    url_without_args, url_args = url.split('?')
    url_args = url_args.split('&')
    url_args_dict = {}
    for url_arg in url_args:
        key, value = url_arg.split('=')
        url_args_dict[key] = value
    return url_without_args, url_args_dict
def get_video_id(url: str):
    url_without_args, url_args_dict = get_url_with_args(url)
    url_type = determine_url_type(url)
    if url_type == URL_TYPE.long_url or url_type == URL_TYPE.music:
        video_id = url_args_dict['v']
    elif url_type == URL_TYPE.short_url or url_type == URL_TYPE.shorts:
        video_id = url_without_args.split('/')[-1]
    else:
        raise Exception('Unsupported URL, URL should start with:\nhttps://www.youube.com/watch')
    return video_id
def get_thumbnail_url(url: str):
    video_id = get_video_id(url)
    return f'https://i.ytimg.com/vi_webp/{video_id}/maxresdefault.webp'
def test_get_thumbnail_url():
    '''
    Outputs:
    URL_TYPE.long_url https://i.ytimg.com/vi_webp/dfl9KIX1WpU/maxresdefault.webp
    URL_TYPE.short_url https://i.ytimg.com/vi_webp/dfl9KIX1WpU/maxresdefault.webp
    URL_TYPE.shorts https://i.ytimg.com/vi_webp/ANXvsktKf78/maxresdefault.webp
    URL_TYPE.music https://i.ytimg.com/vi_webp/JQGRg8XBnB4/maxresdefault.webp
    '''
    test_urls = [
    'https://www.youtube.com/watch?v=dfl9KIX1WpU&t=30',
    'https://youtu.be/dfl9KIX1WpU?t=30',
    'https://www.youtube.com/shorts/ANXvsktKf78?app=desktop',
    'https://music.youtube.com/watch?v=JQGRg8XBnB4',
    ]
    for test_url in test_urls:
        print(determine_url_type(test_url), get_thumbnail_url(test_url))
def main_get_thumbnail_url(url):
    '''
    url: YouTube URL , e.g.
    https://www.youtube.com/watch?v=dfl9KIX1WpU&t=30
    https://youtu.be/dfl9KIX1WpU?t=30
    https://www.youtube.com/shorts/ANXvsktKf78?app=desktop
    '''
    try:
        thunmbnail_url = get_thumbnail_url(url)
    except Exception as e:
        print(*e.args, file=sys.stderr)
    else:
        print(get_thumbnail_url(url))

def get_non_whitespace_char_index(str_: str) -> int:
    import itertools
    whitespace_chars = {' ', '\t'}
    for char, index in zip(str_, itertools.count()):
        if char not in whitespace_chars:
            return index
            break
    return len(str_)
def remove_whitespace_prefix(str_: str) -> str:
    index = get_non_whitespace_char_index(str_)
    return str_[index:]
def remove_indent(str_multiline: str) -> str:
    strs = str_multiline.splitlines()
    ret_strs = []
    for str_ in strs:
        ret_strs.append(remove_whitespace_prefix(str_))
    return '\n'.join(ret_strs)

# Remove indent of usage
def remove_indent_and_strip_newline(str_multiline: str) -> str:
    str_multiline = remove_indent(str_multiline)
    str_multiline = str_multiline.strip('\n')
    return str_multiline

def usage():
    print(remove_indent_and_strip_newline('''
    Usage:
    ./youtube_thumbnail.py <YouTube video URL>
    e.g.
    ./youtube_thumbnail.py https://youtu.be/dfl9KIX1WpU?t=30
    
    Prints YouTube thumbnail URL
    '''))

def main(args):
    if len(args) != 2:
        usage()
    elif(args[1] == '-h' or args[1] == '--help'):
        usage()
    elif(args[1] == '-t' or args[1] == '--test'):
        test_get_thumbnail_url()
    else:
        url = args[1]
        main_get_thumbnail_url(url)

# BETTER return None?

if __name__ == '__main__':
    def is_ipython():
        return get_ipython() is not None
    # TODO test
    if is_ipython():
        args = [
            './youtube_thumbnail.py',
            'https://youtu.be/dfl9KIX1WpU?t=30'
        ]
    else:
        args = sys.argv
    main(args)