/*
    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>
*/
#![feature(iterator_try_collect)]
pub mod fragment;
pub mod hls;
pub mod jhls;
pub mod webvtt;

use anyhow::Result;
use ebml_struct::matroska::{Info, Tracks};
use jellybase::common::{
    stream::{StreamContainer, StreamSpec},
    LocalTrack, MediaInfo, Node,
};
use jellymatroska::block::LacingType;
use std::{ops::Range, sync::Arc};
use tokio::{
    fs::File,
    io::{duplex, AsyncReadExt, AsyncWriteExt, DuplexStream},
};
use tokio_util::io::SyncIoBridge;

pub struct StreamHead {
    pub content_type: &'static str,
    pub range_supported: bool,
}

pub fn stream_head(spec: &StreamSpec) -> StreamHead {
    let cons = |ct: &'static str, rs: bool| StreamHead {
        content_type: ct,
        range_supported: rs,
    };
    let container_ct = |x: StreamContainer| match x {
        StreamContainer::WebM => "video/webm",
        StreamContainer::Matroska => "video/x-matroska",
        StreamContainer::WebVTT => "text/vtt",
        StreamContainer::JVTT => "application/jellything-vtt+json",
    };
    match spec {
        StreamSpec::Whep { .. } => cons("application/x-todo", false),
        StreamSpec::WhepControl { .. } => cons("application/x-todo", false),
        StreamSpec::Remux { container, .. } => cons(container_ct(*container), true),
        StreamSpec::Original { .. } => cons("video/x-matroska", true),
        StreamSpec::HlsSuperMultiVariant { .. } => cons("application/vnd.apple.mpegurl", false),
        StreamSpec::HlsMultiVariant { .. } => cons("application/vnd.apple.mpegurl", false),
        StreamSpec::HlsVariant { .. } => cons("application/vnd.apple.mpegurl", false),
        StreamSpec::Info { .. } => cons("application/jellything-stream-info+json", false),
        StreamSpec::FragmentIndex { .. } => cons("application/jellything-frag-index+json", false),
        StreamSpec::Fragment { container, .. } => cons(container_ct(*container), false),
    }
}

pub async fn stream(
    info: Arc<MediaInfo>,
    spec: StreamSpec,
    range: Range<usize>,
) -> Result<DuplexStream> {
    let (a, b) = duplex(4096);

    match spec {
        StreamSpec::Whep { track, seek } => todo!(),
        StreamSpec::WhepControl { token } => todo!(),
        StreamSpec::Remux { tracks, container } => todo!(),
        StreamSpec::Original { track } => todo!(),
        StreamSpec::HlsSuperMultiVariant { container } => todo!(),
        StreamSpec::HlsMultiVariant { segment, container } => todo!(),
        StreamSpec::HlsVariant {
            segment,
            track,
            container,
            format,
        } => todo!(),
        StreamSpec::Info { segment } => todo!(),
        StreamSpec::FragmentIndex { segment, track } => todo!(),
        StreamSpec::Fragment {
            segment,
            track,
            index,
            container,
            format,
        } => todo!(),
    }

    Ok(a)
}

async fn remux_stream(
    node: Arc<Node>,
    local_tracks: Vec<LocalTrack>,
    spec: StreamSpec,
    range: Range<usize>,
    b: DuplexStream,
) -> Result<()> {
    let b = SyncIoBridge::new(b);

    // tokio::task::spawn_blocking(move || {
    //     jellyremuxer::remux_stream_into(
    //         b,
    //         range,
    //         CONF.media_path.to_owned(),
    //         &node,
    //         local_tracks,
    //         spec.track,
    //         spec.webm.unwrap_or(false),
    //     )
    // });

    Ok(())
}

async fn original_stream(
    local_tracks: Vec<LocalTrack>,
    spec: StreamSpec,
    range: Range<usize>,
    b: DuplexStream,
) -> Result<()> {
    // if spec.track.len() != 1 {
    //     bail!("invalid amout of source \"tracks\". original only allows for exactly one.")
    // }

    // let source = local_tracks[spec.track[0]].clone();
    // let mut file = File::open(CONF.media_path.join(source.path))
    //     .await
    //     .context("opening source")?;
    // file.seek(SeekFrom::Start(range.start as u64))
    //     .await
    //     .context("seek source")?;

    // tokio::task::spawn(copy_stream(file, b, range.end - range.start));

    Ok(())
}

async fn copy_stream(mut inp: File, mut out: DuplexStream, mut amount: usize) -> Result<()> {
    let mut buf = [0u8; 4096];
    loop {
        let size = inp.read(&mut buf[..amount.min(4096)]).await?;
        if size == 0 {
            break Ok(());
        }
        out.write_all(&buf[..size]).await?;
        amount -= size;
    }
}

// TODO functions to test seekability, get live status and enumate segments
trait MediaSource {
    /// Seeks to some position close to, but before, `time` ticks.
    fn seek(&mut self, time: u64) -> Result<()>;
    /// Retrieve headers (info and tracks) for some segment.
    fn segment_headers(&mut self, seg: u64) -> Result<(Info, Tracks)>;
    /// Returns the next block and the current segment index
    fn next(&mut self) -> Result<Option<(u64, AbsBlock)>>;
}
pub struct AbsBlock {
    track: u64,
    pts: u64,
    keyframe: bool,
    lacing: Option<LacingType>,
    data: Vec<u8>,
}