import re
import requests
from urllib.parse import urlparse

from ..common.common import video_metadata
from ..common.innertube import prepare_infocards, prepare_endcards, G

def prepare_metadata(metadata):
    meta = metadata['videoDetails']

    # the actual video streams have exact information:
    try:
        sd = metadata['streamingData']
        some_stream = (sd.get('adaptiveFormats',[]) + sd.get('formats',[]))[0]
        aspect_ratio = some_stream['width'] / some_stream['height']
    # if that's unavailable (e.g. on livestreams), fall back to 16:9
    except:
        aspect_ratio = 16/9

    # Note: we could get subtitles in multiple formats directly by querying
    # https://video.google.com/timedtext?hl=en&type=list&v=<VIDEO_ID> followed by
    # https://www.youtube.com/api/timedtext?lang=<LANG_CODE>&v=<VIDEO_ID>&fmt={srv1|srv2|srv3|ttml|vtt},
    # but that won't give us autogenerated subtitles (and is an extra request).
    # we can still add &fmt= to the extracted URLs below (first one takes precedence).
    try: # find the native language captions (assuming there is only 1 audioTrack) (any level might not exist):
        default_track = metadata.get('captions',{}).get('playerCaptionsTracklistRenderer',{}).get('defaultAudioTrackIndex', 0)
        main_subtitle = metadata['captions']['playerCaptionsTracklistRenderer']['audioTracks'][default_track]['captionTrackIndices']
    except:
        main_subtitle = -1
    subtitles = sorted([
        {'url':cc['baseUrl'],
         'code':cc['languageCode'],
         'autogenerated':cc.get('kind')=="asr",
         'name':cc['name']|G.text,
         'default':i==main_subtitle,
         'query':"fmt=vtt&"+urlparse(cc['baseUrl']).query} # for our internal proxy
        for i,cc in enumerate(metadata|G('captions')
            |G('playerCaptionsTracklistRenderer')
            |G('captionTracks') or [])
    # sort order: default lang gets weight 0 (first), other manually translated weight 1, autogenerated weight 2:
    ], key=lambda cc: (not cc['default']) + cc['autogenerated'])

    endcards = prepare_endcards(metadata)

    # the rating goes from 1 to 5, and is the ratio of up- to down votes, plus 1
    if meta.get('averageRating', 0) != 0:
        thumbs_up = 100 * (meta['averageRating']-1) / 4  # reconstructed ratio
        thumbs_dn = 100 - thumbs_up
    else:  # no thumbs given
        thumbs_up = 0
        thumbs_dn = 0

    thumbs = meta['thumbnail']['thumbnails']
    poster = sorted(thumbs, key=lambda t: t['width'], reverse=True)[0]['url']

    return {
        **video_metadata(metadata),
        'description': meta['shortDescription'],
        'rating': meta.get('averageRating', 0),
        'thumbs_up': thumbs_up,
        'thumbs_dn': thumbs_dn,
        'aspectr': aspect_ratio,
        'unlisted': not meta['isCrawlable'],
        'poster': poster,
        'endcards': endcards,
        'all_cards': endcards,
        'subtitles': subtitles,
    }

def channel_exists(feed_id):
    feed_type = "channel_id" if re.match(r"^UC[A-Za-z0-9_-]{22}$", feed_id) else "user"
    r = requests.head("https://www.youtube.com/feeds/videos.xml", params={
        feed_type: feed_id,
    })
    return r.ok