from datetime import timedelta
from ..feedformatter import Feed
from .youtube import APIClient


def construct_rss(client: APIClient, channel_id: str) -> str:
    """
    Build a RSS stream for a YouTube channel.

    :param client: YouTube API client
    :param channel_id: channel ID
    :returns: RSS stream
    :raises HTTPException: if one of the requests fail
    :raises NoSuchChannel: if the channel does not exist
    """
    channel_info = client.channel(channel_id)

    # Retrieve channel playlist which excludes short videos
    # see <https://stackoverflow.com/a/76602819/3452708>
    videos_playlist = "UULF" + channel_id.removeprefix("UC")
    videos = client.playlist(videos_playlist)

    feed = Feed()
    channel_url = f"https://www.youtube.com/channel/{channel_id}"

    # Set the feed/channel level properties
    feed.feed["title"] = channel_info["title"]
    feed.feed["link"] = channel_url
    feed.feed["author"] = "Feedleware"
    feed.feed["description"] = channel_info["description"]
    feed.feed["ttl"] = "30"

    for video in videos:
        feed.items.append({
            "guid": video["id"],
            "title": video["title"],
            "link": video["url"],
            "description": (
                f'Durée: {video["duration"]}<br><br>'
                + f'<a href="{video["url"]}"><img src="{video["thumbnail"]}" /></a><br><br>'
                + video["description"]
            ),
            "pubDate": video["published"].timetuple(),
        })

    return feed.format_rss2_string()