#![feature(
    generators,
    generator_trait,
    type_alias_impl_trait,
    impl_trait_in_assoc_type
)]

mod core;
mod prelude;
mod projections;
mod protos;
mod util;

use std::future::Future;

use figment::providers::Format;
use figment::{providers::Toml, Figment};
use prometheus::Registry as MetricsRegistry;
use serde::Deserialize;

use crate::core::player::PlayerRegistry;
use crate::core::repo::Storage;
use crate::core::room::RoomRegistry;
use crate::prelude::*;

#[derive(Deserialize, Debug)]
struct ServerConfig {
    telemetry: util::telemetry::ServerConfig,
    irc: projections::irc::ServerConfig,
    xmpp: projections::xmpp::ServerConfig,
    storage: core::repo::StorageConfig,
}

fn load_config() -> Result<ServerConfig> {
    let raw_config = Figment::new().merge(Toml::file("config.toml"));
    let config: ServerConfig = raw_config.extract()?;
    Ok(config)
}

#[tokio::main]
async fn main() -> Result<()> {
    set_up_logging()?;
    let sleep = ctrl_c()?;
    let config = load_config()?;

    tracing::info!("Booting up");
    tracing::info!("Loaded config: {config:?}");
    let ServerConfig {
        telemetry: telemetry_config,
        irc: irc_config,
        xmpp: xmpp_config,
        storage: storage_config,
    } = config;
    let mut metrics = MetricsRegistry::new();
    let storage = Storage::open(storage_config).await?;
    let rooms = RoomRegistry::new(&mut metrics, storage.clone())?;
    let mut players = PlayerRegistry::empty(&rooms, &metrics)?;

    // unsafe: outer future is never dropped, scope is joined on `scope.collect`
    let mut scope = unsafe { Scope::create() };
    let telemetry_terminator = util::telemetry::launch(telemetry_config, &metrics, &rooms, &mut scope).await?;
    let irc = projections::irc::launch(&irc_config, &players, &rooms, &metrics, &storage, &mut scope).await?;
    let xmpp = projections::xmpp::launch(xmpp_config, &players, &rooms, &metrics, &mut scope).await?;
    tracing::info!("Started");

    sleep.await;

    tracing::info!("Begin shutdown");
    let _ = xmpp.send(());
    let _ = irc.send(());
    let _ = telemetry_terminator.send(());
    let _ = scope.collect().await;
    drop(scope);

    players.shutdown_all().await?;
    drop(players);
    drop(rooms);
    storage.close().await?;
    tracing::info!("Shutdown complete");
    Ok(())
}

#[cfg(windows)]
fn ctrl_c() -> Result<impl Future<Output = ()>> {
    use tokio::signal::windows::*;
    let chan = ctrl_c()?;
    async fn recv(mut chan: CtrlC) {
        let _ = chan.recv().await;
    }
    Ok(recv(chan))
}

#[cfg(unix)]
fn ctrl_c() -> Result<impl Future<Output = ()>> {
    use tokio::signal::unix::*;
    let chan = signal(SignalKind::interrupt())?;
    async fn recv(mut chan: Signal) {
        let _ = chan.recv().await;
    }
    Ok(recv(chan))
}

fn set_up_logging() -> Result<()> {
    tracing_subscriber::fmt::init();
    Ok(())
}