/*
    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::{AssetLocationExt, CONF};
use jellycommon::{stream::StreamSpec, LocalTrack, Node};
use jellytranscoder::snippet::{transcode, Encoding};
use log::warn;
use tokio::{fs::File, io::DuplexStream};
use tokio_util::io::SyncIoBridge;

pub async fn segment_stream(
    node: Node,
    track_sources: Vec<LocalTrack>,
    spec: StreamSpec,
    mut b: DuplexStream,
) -> 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"))?;

    if let Some(width) = spec.width {
        let width = width_steps(width);
        let location = transcode(
            "",
            Encoding::Video {
                codec: "libsvtav1",
                preset: 8,
                bitrate: spec.bitrate.unwrap_or(2_000_000),
                width,
            },
            move |b| {
                tokio::task::spawn_blocking(move || {
                    if let Err(err) = jellyremuxer::write_snippet_into(
                        SyncIoBridge::new(b),
                        &CONF.library_path,
                        &node.public,
                        track_sources,
                        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,
                track_sources,
                track,
                spec.webm.unwrap_or(false),
                n,
            ) {
                warn!("segment stream error: {err}");
            }
        });
    }

    Ok(())
}

fn width_steps(width: usize) -> usize {
    match width {
        x if x >= 3840 => 3840,
        x if x >= 1920 => 1920,
        _ => 720,
    }
}