/*
    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
    Copyright (C) 2023 metamuffin <metamuffin.org>
*/
use anyhow::{anyhow, bail, Result};
use jellybase::{permission::PermissionSetExt, AssetLocationExt, CONF};
use jellycommon::{
    stream::StreamSpec,
    user::{PermissionSet, UserPermission},
    LocalTrack, Node,
};
use jellytranscoder::snippet::transcode;
use log::warn;
use tokio::{fs::File, io::DuplexStream};
use tokio_util::io::SyncIoBridge;

pub async fn segment_stream(
    node: Node,
    local_tracks: Vec<LocalTrack>,
    spec: StreamSpec,
    mut b: DuplexStream,
    perms: &PermissionSet,
) -> Result<()> {
    if spec.tracks.len() != 1 {
        bail!("unsupported number of tracks for segment, must be exactly one");
    }
    let track = spec.tracks[0];
    let n = spec.index.ok_or(anyhow!("segment index missing"))?;

    let local_track = local_tracks
        .get(0)
        .ok_or(anyhow!("track missing"))?
        .to_owned();

    if let Some(profile) = spec.profile {
        perms.assert(&UserPermission::Transcode)?;
        let location = transcode(
            &format!("{track} {n} {:?}", node.private.source), // TODO maybe not use the entire source
            CONF.transcoding_profiles
                .get(profile)
                .ok_or(anyhow!("profile out of range"))?,
            move |b| {
                tokio::task::spawn_blocking(move || {
                    if let Err(err) = jellyremuxer::write_snippet_into(
                        SyncIoBridge::new(b),
                        &CONF.library_path,
                        &node.public,
                        &local_track,
                        track,
                        false,
                        n,
                    ) {
                        warn!("segment stream error: {err}");
                    }
                });
            },
        )
        .await?;
        let mut output = File::open(location.path()).await?;
        tokio::task::spawn(async move {
            if let Err(err) = tokio::io::copy(&mut output, &mut b).await {
                warn!("cannot write stream: {err}")
            }
        });
    } else {
        let b = SyncIoBridge::new(b);
        tokio::task::spawn_blocking(move || {
            if let Err(err) = jellyremuxer::write_snippet_into(
                b,
                &CONF.library_path,
                &node.public,
                &local_track,
                track,
                spec.webm.unwrap_or(false),
                n,
            ) {
                warn!("segment stream error: {err}");
            }
        });
    }

    Ok(())
}