#![feature(result_option_inspect)]

use clap::Parser;
use futures::stream::StreamExt;
use signal_hook_tokio::Signals;
use tokio::select;
use tokio::time;

use std::convert::Infallible;
use std::net::SocketAddr;
use std::path;
use std::str::FromStr;
use std::sync;

use domiply::domain::acme::manager::Manager as AcmeManager;
use domiply::domain::manager::Manager;

#[derive(Parser, Debug)]
#[command(version)]
#[command(about = "A domiply to another dimension")]
struct Cli {
    #[arg(long, required = true, env = "DOMIPLY_HTTP_DOMAIN")]
    http_domain: String,

    #[arg(long, default_value_t = SocketAddr::from_str("[::]:3030").unwrap(), env = "DOMIPLY_HTTP_LISTEN_ADDR")]
    http_listen_addr: SocketAddr,

    #[arg(
        long,
        help = "E.g. '[::]:443', if given then SSL certs will automatically be retrieved for all domains using LetsEncrypt",
        env = "DOMIPLY_HTTPS_LISTEN_ADDR"
    )]
    https_listen_addr: Option<SocketAddr>,

    #[arg(long, required = true, env = "DOMIPLY_PASSPHRASE")]
    passphrase: String,

    #[arg(long, required = true, env = "DOMIPLY_ORIGIN_STORE_GIT_DIR_PATH")]
    origin_store_git_dir_path: path::PathBuf,

    #[arg(long, required = true, env = "DOMIPLY_DOMAIN_CHECKER_TARGET_A")]
    domain_checker_target_a: std::net::Ipv4Addr,

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

    #[arg(long, required = true, env = "DOMIPLY_DOMAIN_CONFIG_STORE_DIR_PATH")]
    domain_config_store_dir_path: path::PathBuf,

    #[arg(long, required = true, env = "DOMIPLY_DOMAIN_ACME_STORE_DIR_PATH")]
    domain_acme_store_dir_path: path::PathBuf,

    #[arg(long, required = true, env = "DOMIPLY_DOMAIN_ACME_CONTACT_EMAIL")]
    domain_acme_contact_email: String,
}

fn main() {
    let config = Cli::parse();

    let tokio_runtime = std::sync::Arc::new(
        tokio::runtime::Builder::new_multi_thread()
            .enable_all()
            .build()
            .unwrap(),
    );

    let canceller = tokio_runtime.block_on(async { tokio_util::sync::CancellationToken::new() });

    {
        let canceller = canceller.clone();
        tokio_runtime.spawn(async move {
            let mut signals =
                Signals::new(signal_hook::consts::TERM_SIGNALS).expect("initialized signals");

            if (signals.next().await).is_some() {
                println!("Gracefully shutting down...");
                canceller.cancel();
            }

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

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

    let domain_checker = domiply::domain::checker::new(
        tokio_runtime.clone(),
        config.domain_checker_target_a,
        &config.domain_checker_resolver_addr,
    )
    .expect("domain checker initialized");

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

    let domain_acme_manager = config.https_listen_addr.and_then(|_addr| {
        let domain_acme_store =
            domiply::domain::acme::store::new(&config.domain_acme_store_dir_path)
                .expect("domain acme store initialized");

        let domain_acme_manager = tokio_runtime.block_on(async {
            domiply::domain::acme::manager::new(
                domain_acme_store,
                &config.domain_acme_contact_email,
            )
            .await
            .expect("domain acme manager initialized")
        });

        Some(domain_acme_manager)
    });

    let manager = domiply::domain::manager::new(
        origin_store,
        domain_config_store,
        domain_checker,
        domain_acme_manager.clone(),
    );

    let origin_syncer_handler = {
        let manager = manager.clone();
        let canceller = canceller.clone();

        tokio_runtime.spawn(async move {
            let mut interval = time::interval(time::Duration::from_secs(20 * 60));

            loop {
                select! {
                _ = interval.tick() => (),
                _ = canceller.cancelled() => return,
                }

                let errors_iter = manager.sync_all_origins();

                if let Err(err) = errors_iter {
                    println!("Got error calling sync_all_origins: {err}");
                    continue;
                }

                errors_iter
                    .unwrap()
                    .into_iter()
                    .for_each(|(descr, err)| match descr {
                        None => println!("error while syncing unknown descr: {err}"),
                        Some(descr) => println!("failed to sync {descr:?}: {err}"),
                    });
            }
        })
    };

    let service = domiply::service::new(
        manager,
        config.domain_checker_target_a,
        config.passphrase,
        config.http_domain.clone(),
    );

    let service = sync::Arc::new(service);

    let make_service =
        hyper::service::make_service_fn(move |_conn: &hyper::server::conn::AddrStream| {
            let service = service.clone();

            // Create a `Service` for responding to the request.
            let service = hyper::service::service_fn(move |req| {
                domiply::service::handle_request(service.clone(), req)
            });

            // Return the service to hyper.
            async move { Ok::<_, Infallible>(service) }
        });

    let server_handler = {
        let http_domain = config.http_domain.clone();

        tokio_runtime.spawn(async move {
            let addr = config.http_listen_addr;

            println!("Listening on http://{}:{}", http_domain, addr.port());
            let server = hyper::Server::bind(&addr).serve(make_service);

            let graceful = server.with_graceful_shutdown(async {
                canceller.cancelled().await;
            });

            if let Err(e) = graceful.await {
                panic!("server error: {}", e);
            };
        })
    };

    // if there's an acme manager then it means that https is enabled, and we should ensure that
    // the http domain for domiply itself has a valid certificate.
    if let Some(domain_acme_manager) = domain_acme_manager {
        let domain = domiply::domain::Name::from_str(&config.http_domain)
            .expect("--http-domain parses as a domain");

        tokio_runtime.spawn(async move {
            _ = domain_acme_manager
                .sync_domain(domain.clone())
                .await
                .inspect_err(|err| {
                    println!("Error while getting cert for {}: {err}", domain.as_str())
                });
        });
    }

    tokio_runtime
        .block_on(async { futures::try_join!(origin_syncer_handler, server_handler) })
        .unwrap();

    println!("Graceful shutdown complete");
}