use std::{net::SocketAddr, path::PathBuf, sync::Arc, time::Duration};

use lanspread_db::db::GameDB;
use lanspread_proto::{Message as _, Request};
use lanspread_utils::maybe_addr;
use s2n_quic::{Connection, Server, provider::limits::Limits, stream::BidirectionalStream};

use crate::req::{RequestHandler, send_game_file_data};

static KEY_PEM: &str = include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/../../key.pem"));
static CERT_PEM: &str = include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/../../cert.pem"));

#[derive(Clone, Debug)]
struct ServerCtx {
    handler: RequestHandler,
    games_folder: PathBuf,
}

async fn handle_bidi_stream(stream: BidirectionalStream, ctx: Arc<ServerCtx>) -> eyre::Result<()> {
    let (mut rx, mut tx) = stream.split();

    let remote_addr = maybe_addr!(rx.connection().remote_addr());
    tracing::trace!("{remote_addr} stream opened");

    // handle streams
    loop {
        match rx.receive().await {
            Ok(Some(data)) => {
                tracing::trace!(
                    "{remote_addr} msg: (raw): {}",
                    String::from_utf8_lossy(&data)
                );

                let request = Request::decode(data);
                tracing::debug!("{remote_addr} msg: {request:?}");

                // special case for now (send game file data to client)
                if let Request::GetGameFileData(game_file_desc) = &request {
                    send_game_file_data(game_file_desc, &mut tx, &ctx.games_folder).await;
                    continue;
                }

                // normal case (handle request)
                if let Err(e) = ctx
                    .handler
                    .handle_request(request, &ctx.games_folder, &mut tx)
                    .await
                {
                    tracing::error!(?e, "{remote_addr} error handling request");
                }
            }
            Ok(None) => {
                tracing::trace!("{remote_addr} stream closed");
                break;
            }
            Err(e) => {
                tracing::error!("{remote_addr} stream error: {e}");
                break;
            }
        }
    }

    Ok(())
}

async fn handle_connection(mut connection: Connection, ctx: Arc<ServerCtx>) -> eyre::Result<()> {
    let remote_addr = maybe_addr!(connection.remote_addr());
    tracing::info!("{remote_addr} connected");

    // handle streams
    while let Ok(Some(stream)) = connection.accept_bidirectional_stream().await {
        let ctx = ctx.clone();
        let remote_addr = remote_addr.clone();

        // spawn a new task for the stream
        tokio::spawn(async move {
            if let Err(e) = handle_bidi_stream(stream, ctx).await {
                tracing::error!("{remote_addr} stream error: {e}");
            }
        });
    }

    Ok(())
}

pub(crate) async fn run_server(
    addr: SocketAddr,
    db: GameDB,
    games_folder: PathBuf,
) -> eyre::Result<()> {
    let limits = Limits::default()
        .with_max_handshake_duration(Duration::from_secs(3))?
        .with_max_idle_timeout(Duration::from_secs(3))?;

    let mut server = Server::builder()
        .with_tls((CERT_PEM, KEY_PEM))?
        .with_io(addr)?
        .with_limits(limits)?
        .start()?;

    let ctx = Arc::new(ServerCtx {
        handler: RequestHandler::new(db),
        games_folder,
    });

    while let Some(connection) = server.accept().await {
        let ctx = ctx.clone();
        // spawn a new task for the connection
        tokio::spawn(async move {
            if let Err(e) = handle_connection(connection, ctx).await {
                tracing::error!("Connection error: {}", e);
            }
        });
    }

    tracing::info!("Server shutting down");

    Ok(())
}