/*
    Hurry Curry! - a game about cooking
    Copyright 2024 metamuffin

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, version 3 of the License only.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

*/
use anyhow::anyhow;
use async_compression::tokio::{bufread::ZstdDecoder, write::ZstdEncoder};
use clap::Parser;
use futures_util::{SinkExt, StreamExt};
use hurrycurry_protocol::{PacketC, PacketS};
use log::{debug, info, warn, LevelFilter};
use serde::{Deserialize, Serialize};
use std::{path::PathBuf, time::Instant};
use tokio::{
    fs::File,
    io::{AsyncBufReadExt, AsyncWriteExt, BufReader, BufWriter},
    net::TcpListener,
};
use tokio_tungstenite::tungstenite::Message;

#[derive(Parser)]
enum Args {
    Record { url: String, output: PathBuf },
    Replay { input: PathBuf },
}

#[derive(Serialize, Deserialize)]
struct Event {
    ts: f64,
    packet: PacketC,
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    env_logger::builder()
        .filter_level(LevelFilter::Info)
        .parse_env("LOG")
        .init();

    let args = Args::parse();

    match args {
        Args::Record { url, output } => {
            let mut file = BufWriter::new(ZstdEncoder::new(File::create(&output).await?));
            info!("connecting to {url:?}...");
            let (mut sock, _) = tokio_tungstenite::connect_async(url).await?;
            info!("starting recording.");
            let start = Instant::now();

            while let Some(Ok(message)) = sock.next().await {
                match message {
                    Message::Text(line) => {
                        let packet: PacketC = match serde_json::from_str(&line) {
                            Ok(p) => p,
                            Err(e) => {
                                warn!("invalid packet: {e}");
                                break;
                            }
                        };
                        debug!("<- {packet:?}");

                        let is_end = matches!(packet, PacketC::SetIngame { state: false, .. });

                        file.write_all(
                            format!(
                                "{}\n",
                                serde_json::to_string(&Event {
                                    ts: start.elapsed().as_secs_f64(),
                                    packet: packet
                                })
                                .unwrap()
                            )
                            .as_bytes(),
                        )
                        .await?;

                        if is_end {
                            info!("stopping replay...");
                            break;
                        }
                    }
                    Message::Close(_) => break,
                    _ => (),
                }
            }
            drop(file);
            info!("done")
        }
        Args::Replay { input } => {
            let ws_listener = TcpListener::bind("0.0.0.0:27032").await?;
            info!("listening for websockets on {}", ws_listener.local_addr()?);

            loop {
                let mut file =
                    BufReader::new(ZstdDecoder::new(BufReader::new(File::open(&input).await?)))
                        .lines();

                let mut next_event =
                    serde_json::from_str::<Event>(&file.next_line().await?.ok_or(anyhow!("eof"))?)?;
                let mut time = 0.;

                info!("ready");
                let (sock, addr) = ws_listener.accept().await?;
                let Ok(mut sock) = tokio_tungstenite::accept_async(sock).await else {
                    warn!("invalid ws handshake");
                    continue;
                };
                info!("{addr} connected via ws");

                sock.send(tokio_tungstenite::tungstenite::Message::Text(
                    serde_json::to_string(&PacketC::ReplayStart).unwrap(),
                ))
                .await?;
                'outer: while let Some(Ok(message)) = sock.next().await {
                    match message {
                        Message::Text(line) => {
                            let packet: PacketS = match serde_json::from_str(&line) {
                                Ok(p) => p,
                                Err(e) => {
                                    warn!("invalid packet: {e}");
                                    break;
                                }
                            };
                            debug!("<- {packet:?}");

                            match packet {
                                PacketS::Join { .. } => {
                                    sock.send(tokio_tungstenite::tungstenite::Message::Text(
                                        serde_json::to_string(&PacketC::ServerMessage {
                                            text: "Replays cannot be joined".to_string(),
                                        })
                                        .unwrap(),
                                    ))
                                    .await?;
                                }
                                PacketS::ReplayTick { dt } => {
                                    time += dt;
                                    while next_event.ts < time {
                                        debug!("<- {:?}", next_event.packet);
                                        sock.send(tokio_tungstenite::tungstenite::Message::Text(
                                            serde_json::to_string(&next_event.packet).unwrap(),
                                        ))
                                        .await?;

                                        let Some(next) = &file.next_line().await? else {
                                            info!("reached end");
                                            break 'outer;
                                        };
                                        next_event = serde_json::from_str::<Event>(next)?;
                                    }
                                }
                                x => warn!("unhandled client packet: {x:?}"),
                            }
                        }
                        Message::Close(_) => break,
                        _ => (),
                    }
                }
                info!("{addr} left");
            }
        }
    }
    Ok(())
}