use anyhow::{anyhow, Context, Result};
use jellybase::CONF;
use jellycommon::{stream::StreamSpec, LocalTrack, Node};
use jellyremuxer::extract::extract_track;
use jellytranscoder::subtitles::webvtt_from_ass_blocks;
use tokio::io::{AsyncWriteExt, DuplexStream};

pub async fn webvtt_stream(
    node: Node,
    track_sources: Vec<LocalTrack>,
    spec: StreamSpec,
    mut b: DuplexStream,
) -> Result<()> {
    // TODO cache

    let local_track = track_sources
        .get(*spec.tracks.get(0).ok_or(anyhow!("no track selected"))?)
        .ok_or(anyhow!("track does not exist"))?
        .clone();

    let codec_private = local_track
        .codec_private
        .clone()
        .ok_or(anyhow!("ASS is missing required codec private data"))?;

    let ass_blocks =
        tokio::task::spawn_blocking(move || extract_track(CONF.library_path.clone(), local_track))
            .await??;

    let webvtt = webvtt_from_ass_blocks(node.public.title, codec_private, ass_blocks)
        .context("transcoding subtitles")?;

    tokio::task::spawn(async move {
        let _ = b.write_all(webvtt.as_bytes()).await;
    });
    Ok(())
}