/*
    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) 2025 metamuffin <metamuffin.org>
*/

use crate::{stream_info, SMediaInfo};
use anyhow::{anyhow, Result};
use jellystream_types::{FormatNum, SegmentNum, StreamContainer, StreamSpec, TrackKind, TrackNum};
use std::{fmt::Write, ops::Range, sync::Arc};
use tokio::{
    io::{AsyncWriteExt, DuplexStream},
    task::spawn_blocking,
};

pub async fn hls_supermultivariant_stream(
    mut b: DuplexStream,
    info: Arc<SMediaInfo>,
    container: StreamContainer,
) -> Result<()> {
    let (_iinfo, info) = stream_info(info).await?;
    let mut out = String::new();
    writeln!(out, "#EXTM3U")?;
    writeln!(out, "#EXT-X-VERSION:4")?;
    for (i, _seg) in info.segments.iter().enumerate() {
        let uri = format!(
            "stream{}",
            StreamSpec::HlsMultiVariant {
                segment: i,
                container,
            }
            .to_query()
        );
        writeln!(out, "{uri}")?;
    }
    tokio::spawn(async move { b.write_all(out.as_bytes()).await });
    Ok(())
}

pub async fn hls_multivariant_stream(
    mut b: DuplexStream,
    info: Arc<SMediaInfo>,
    segment: SegmentNum,
    container: StreamContainer,
) -> Result<()> {
    let (_iinfo, info) = stream_info(info).await?;
    let seg = info
        .segments
        .get(segment)
        .ok_or(anyhow!("segment not found"))?;

    let mut out = String::new();
    writeln!(out, "#EXTM3U")?;
    writeln!(out, "#EXT-X-VERSION:4")?;
    // writeln!(out, "#EXT-X-INDEPENDENT-SEGMENTS")?;
    for (i, t) in seg.tracks.iter().enumerate() {
        let uri = format!(
            "stream{}",
            StreamSpec::HlsVariant {
                segment,
                track: i,
                container,
                format: 0
            }
            .to_query()
        );
        let r#type = match t.kind {
            TrackKind::Video => "VIDEO",
            TrackKind::Audio => "AUDIO",
            TrackKind::Subtitle => "SUBTITLES",
        };
        // TODO bw
        writeln!(out, "#EXT-X-STREAM-INF:BANDWIDTH=5000000,TYPE={type}")?;
        writeln!(out, "{uri}")?;
    }
    tokio::spawn(async move { b.write_all(out.as_bytes()).await });
    Ok(())
}

pub async fn hls_variant_stream(
    mut b: DuplexStream,
    info: Arc<SMediaInfo>,
    segment: SegmentNum,
    track: TrackNum,
    format: FormatNum,
    container: StreamContainer,
) -> Result<()> {
    let (iinfo, info) = stream_info(info).await?;
    let (file_index, track_num) = *iinfo
        .track_to_file
        .get(track)
        .ok_or(anyhow!("track not found"))?;
    let seg = info
        .segments
        .get(segment)
        .ok_or(anyhow!("segment not found"))?;

    let frags = spawn_blocking(move || {
        jellyremuxer::fragment::fragment_index(&iinfo.paths[file_index], track_num)
    })
    .await??;

    let mut out = String::new();
    writeln!(out, "#EXTM3U")?;
    writeln!(out, "#EXT-X-PLAYLIST-TYPE:VOD")?;
    writeln!(out, "#EXT-X-TARGETDURATION:{}", seg.duration)?;
    writeln!(out, "#EXT-X-VERSION:4")?;
    writeln!(out, "#EXT-X-MEDIA-SEQUENCE:0")?;

    for (index, Range { start, end }) in frags.iter().enumerate() {
        writeln!(out, "#EXTINF:{:},", end - start)?;
        writeln!(
            out,
            "stream{}",
            StreamSpec::Fragment {
                segment,
                track,
                index,
                container,
                format,
            }
            .to_query()
        )?;
    }

    writeln!(out, "#EXT-X-ENDLIST")?;

    tokio::spawn(async move { b.write_all(out.as_bytes()).await });
    Ok(())
}