use std::io::Write;
use std::sync::Arc;

use clap::{App, AppSettings, Arg};
use util::conn::*;
use webrtc_dtls::cipher_suite::CipherSuiteId;
use webrtc_dtls::config::{Config, ExtendedMasterSecretType};
use webrtc_dtls::listener::listen;
use webrtc_dtls::Error;

// cargo run --example listen_psk -- --host 127.0.0.1:4444

#[tokio::main]
async fn main() -> Result<(), Error> {
    env_logger::Builder::new()
        .format(|buf, record| {
            writeln!(
                buf,
                "{}:{} [{}] {} - {}",
                record.file().unwrap_or("unknown"),
                record.line().unwrap_or(0),
                record.level(),
                chrono::Local::now().format("%H:%M:%S.%6f"),
                record.args()
            )
        })
        .filter(None, log::LevelFilter::Trace)
        .init();

    let mut app = App::new("DTLS Server")
        .version("0.1.0")
        .author("Rain Liu <yliu@webrtc.rs>")
        .about("An example of DTLS Server")
        .setting(AppSettings::DeriveDisplayOrder)
        .setting(AppSettings::SubcommandsNegateReqs)
        .arg(
            Arg::with_name("FULLHELP")
                .help("Prints more detailed help information")
                .long("fullhelp"),
        )
        .arg(
            Arg::with_name("host")
                .required_unless("FULLHELP")
                .takes_value(true)
                .default_value("127.0.0.1:4444")
                .long("host")
                .help("DTLS host name."),
        );

    let matches = app.clone().get_matches();

    if matches.is_present("FULLHELP") {
        app.print_long_help().unwrap();
        std::process::exit(0);
    }

    let host = matches.value_of("host").unwrap().to_owned();

    let cfg = Config {
        psk: Some(Arc::new(|hint: &[u8]| -> Result<Vec<u8>, Error> {
            println!("Client's hint: {}", String::from_utf8(hint.to_vec())?);
            Ok(vec![0xAB, 0xC1, 0x23])
        })),
        psk_identity_hint: Some("webrtc-rs DTLS Client".as_bytes().to_vec()),
        cipher_suites: vec![CipherSuiteId::Tls_Psk_With_Aes_128_Ccm_8],
        extended_master_secret: ExtendedMasterSecretType::Require,
        ..Default::default()
    };

    println!("listening {host}...\ntype 'exit' to shutdown gracefully");

    let listener = Arc::new(listen(host, cfg).await?);

    // Simulate a chat session
    let h = Arc::new(hub::Hub::new());

    let listener2 = Arc::clone(&listener);
    let h2 = Arc::clone(&h);
    tokio::spawn(async move {
        while let Ok((dtls_conn, _remote_addr)) = listener2.accept().await {
            // Register the connection with the chat hub
            h2.register(dtls_conn).await;
        }
    });

    h.chat().await;

    Ok(listener.close().await?)
}