import re
import requests
from datetime import datetime, timezone

from ..common.innertube import G

def fetch_ajax(endpoint, **kwargs):
    """
    fetch data using a continuation protobuf
    """
    # TODO: handle auto_generated!
    today = datetime.now(timezone.utc).strftime("%Y%m%d")

    # TODO: this is not cached any more! -> https://github.com/reclosedev/requests-cache/issues/154
    # Note: this 'innertube' API key exists since at least 2015: https://stackoverflow.com/q/33511165
    r = requests.post(f"https://www.youtube.com/youtubei/v1/{endpoint}?key=AIzaSyAO_FJ2SlqU8Q4STEHLGCilw_Y9_11qcW8", json={
        **kwargs,
        'context': {'client': {
            'gl': 'US',
            'hl': 'en',
            'clientName': 'WEB',
            'clientVersion': f'2.{today}.01.01',
        }},
    })

    if not r.ok:
        return None

    return r.json()

def canonicalize_channel(name, typ="c"):
    if re.fullmatch(r"(UC[A-Za-z0-9_-]{22})", name):
        return name

    # get UCID of /c/ (vanity URLs):
    today = datetime.now(timezone.utc).strftime("%Y%m%d")
    typ += "/" if typ != "@" else ""
    r = requests.get(f'https://www.youtube.com/{typ}{name}/about?pbj=1&hl=en_US', headers={
        'x-youtube-client-name': '1',
        'x-youtube-client-version': f'2.{today}.01.01', # see fetch_searchresults()
    })
    try:
        return r.json()[1]['response']['metadata']['channelMetadataRenderer']['rssUrl'].split("=")[1]
    except:
        pass

    # unable to extract:
    return None

def find_and_parse_error(result):
    error_obj = (
        result|G('responseContext')|G('errors')|G('error')|G(0)
        or result|G('alerts')|G(0)|G('alertRenderer')
        or result|G('error')
    )
    if error_obj is None:
        return None

    error_type = error_obj|G('code', 'type', 'status') or 'Error'
    error = (
        error_obj|G('debugInfo', 'externalErrorMessage')
        or error_obj|G('text')|G.text
        or error_obj|G('message')
        or "unknown error"
    )
    return f"{error_type}: {error.rstrip('.')}"