use clap::Parser;
use futures::stream::StreamExt;
use signal_hook::consts::signal;
use signal_hook_tokio::Signals;
use tokio::sync::oneshot;

use std::net::SocketAddr;
use std::path;
use std::str::FromStr;

#[derive(Parser, Debug)]
#[command(version)]
#[command(about = "A gateway to another dimension")]
struct Cli {
    #[arg(long, default_value_t = SocketAddr::from_str("127.0.0.1:3030").unwrap(), env = "GATEWAY_HTTP_LISTEN_ADDR")]
    http_listen_addr: SocketAddr,

    #[arg(long, required = true, env = "GATEWAY_ORIGIN_STORE_GIT_DIR_PATH")]
    origin_store_git_dir_path: Option<path::PathBuf>,

    #[arg(long, required = true, env = "GATEWAY_DOMAIN_CHECKER_TARGET_CNAME")]
    domain_checker_target_cname: Option<String>,

    #[arg(long, default_value_t = String::from("1.1.1.1:53"), env = "GATEWAY_DOMAIN_CHECKER_RESOLVER_ADDR")]
    domain_checker_resolver_addr: String,

    #[arg(long, required = true, env = "GATEWAY_DOMAIN_CONFIG_STORE_DIR_PATH")]
    domain_config_store_dir_path: Option<path::PathBuf>,
}

#[tokio::main]
async fn main() {
    let config = Cli::parse();

    // set up signal handling, stop_ch_rx will be used to signal that the stop signal has been
    // received
    let stop_ch_rx = {
        let mut signals = Signals::new(&[signal::SIGTERM, signal::SIGINT, signal::SIGQUIT])
            .expect("initialized signals");

        let (stop_ch_tx, stop_ch_rx) = oneshot::channel();

        tokio::spawn(async move {
            if let Some(_) = signals.next().await {
                println!("Gracefully shutting down...");
                let _ = stop_ch_tx.send(());
            }

            if let Some(_) = signals.next().await {
                println!("Forcefully shutting down");
                std::process::exit(1);
            }
        });

        stop_ch_rx
    };

    let origin_store = gateway::origin::store::git::new(config.origin_store_git_dir_path.unwrap())
        .expect("git origin store initialized");

    let domain_checker = gateway::domain::checker::new(
        &config.domain_checker_target_cname.unwrap(),
        &config.domain_checker_resolver_addr,
    )
    .expect("domain checker initialized");

    let domain_config_store =
        gateway::domain::config::new(&config.domain_config_store_dir_path.unwrap())
            .expect("domain config store initialized");

    let manager = gateway::domain::manager::new(origin_store, domain_config_store, domain_checker);

    let service = gateway::service::new(manager).expect("service initialized");

    let (addr, server) =
        warp::serve(service).bind_with_graceful_shutdown(config.http_listen_addr, async {
            stop_ch_rx.await.ok();
        });

    println!("Listening on {addr}");
    tokio::task::spawn(server)
        .await
        .expect("server shutdown gracefully");

    println!("Graceful shutdown complete");
}