use std::{process::Command, sync::Arc, time::Duration};

use bytes::Bytes;
use rustls::RootCertStore;
use tempfile::tempdir;
use tokio::time::timeout;
use wgcloak::{
    config::Config,
    protocol, transport,
    transport::{
        AdmissionController, TlsTcpConnector, TlsTcpServer, TransportConnector, TransportError,
    },
};

const SECRET: &str = "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";

fn free_port() -> u16 {
    std::net::TcpListener::bind("127.0.0.1:0")
        .unwrap()
        .local_addr()
        .unwrap()
        .port()
}

#[tokio::test]
async fn tls_tcp_authenticates_round_trips_and_classifies_failures() {
    if Command::new("openssl").arg("version").output().is_err() {
        return;
    }
    let dir = tempdir().unwrap();
    let cert = dir.path().join("cert.pem");
    let key = dir.path().join("key.pem");
    let generated = Command::new("openssl")
        .args([
            "req",
            "-x509",
            "-newkey",
            "rsa:2048",
            "-nodes",
            "-subj",
            "/CN=localhost",
            "-addext",
            "subjectAltName=DNS:localhost",
            "-addext",
            "basicConstraints=critical,CA:FALSE",
            "-days",
            "1",
            "-keyout",
        ])
        .arg(&key)
        .args(["-out"])
        .arg(&cert)
        .output()
        .unwrap();
    assert!(
        generated.status.success(),
        "openssl failed: {:?}",
        generated
    );
    let port = free_port();
    let server_config = Config::from_str(&format!(
        "[server]\nlisten = \"127.0.0.1\"\n[backend]\ntarget = \"127.0.0.1:51820\"\n[transports.direct_udp]\nenabled = false\n[transports.quic]\nenabled = false\n[transports.http3]\nenabled = false\n[transports.tls_tcp]\nenabled = true\nport = {port}\n[limits]\nhandshake_timeout_ms = 500\n[tls]\ncertificate = \"{}\"\nprivate_key = \"{}\"\n[[auth.clients]]\nid = \"test\"\nsecret = \"{SECRET}\"\n",
        cert.display(),
        key.display()
    ))
    .unwrap()
    .into_server()
    .unwrap();
    let client_config = Config::from_str(&format!(
        "[client]\nserver = \"localhost\"\nid = \"test\"\nsecret = \"{SECRET}\"\n[transport]\nmode = \"tls_tcp\"\n[transport.tls_tcp]\nport = {port}\nkeepalive_secs = 1\n[network]\nmax_datagram_size = 1200\n"
    ))
    .unwrap()
    .into_client()
    .unwrap();
    let mismatch_config = client_config.clone();
    let certs = transport::tls_tcp::load_certificates(&cert).unwrap();
    let mut roots = RootCertStore::empty();
    roots.add(certs[0].clone()).unwrap();
    let client_tls = (*transport::tls_tcp::client_tls_config(roots)).clone();
    let admission = AdmissionController::new(&server_config.limits);
    let server = Arc::new(
        TlsTcpServer::bind_with_admission(&server_config, admission.clone())
            .await
            .unwrap(),
    );
    let slow_server = server.clone();
    let slow_handshake = tokio::spawn(async move { slow_server.accept_session().await });
    let slow_peer = tokio::net::TcpStream::connect(server.local_addr().unwrap())
        .await
        .unwrap();
    tokio::time::sleep(Duration::from_millis(50)).await;
    let accept = {
        let server = server.clone();
        tokio::spawn(async move { server.accept_session().await })
    };
    let client = TlsTcpConnector::with_client_config(client_config, client_tls.clone());
    let client_session = client.connect().await.unwrap();
    let server_session = accept.await.unwrap().unwrap();
    assert_eq!(
        client_session.authenticated_keepalive_interval(),
        Some(Duration::from_secs(1))
    );
    assert_eq!(client_session.rtt(), None);
    assert_eq!(
        client_session.remote_addr().unwrap().ip(),
        "127.0.0.1".parse::<std::net::IpAddr>().unwrap()
    );
    assert_eq!(admission.active_sessions(), 1);
    assert_eq!(admission.pending_handshakes(), 1);
    client_session.send_keepalive().await.unwrap();
    client_session
        .send_datagram(Bytes::from_static(b"tls-opaque"))
        .await
        .unwrap();
    assert_eq!(
        timeout(Duration::from_secs(2), server_session.recv_datagram())
            .await
            .unwrap()
            .unwrap(),
        Bytes::from_static(b"tls-opaque")
    );
    client_session.close().await.unwrap();
    server_session.close().await.unwrap();
    assert!(matches!(
        timeout(Duration::from_secs(1), slow_handshake)
            .await
            .unwrap()
            .unwrap(),
        Err(TransportError::HandshakeTimeout)
    ));
    drop(slow_peer);
    assert_eq!(admission.active_sessions(), 0);
    assert_eq!(admission.pending_handshakes(), 0);

    let mut wrong_credentials = mismatch_config.clone();
    wrong_credentials.client.secret.secret =
        Some("BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB".to_owned());
    let server_accept = {
        let server = server.clone();
        tokio::spawn(async move { server.accept_session().await })
    };
    let wrong_client = TlsTcpConnector::with_client_config(wrong_credentials, client_tls.clone());
    assert!(matches!(
        timeout(Duration::from_secs(2), wrong_client.connect())
            .await
            .unwrap(),
        Err(TransportError::AuthenticationRejected(
            protocol::RejectReason::AuthenticationFailed
        ))
    ));
    assert!(matches!(
        timeout(Duration::from_secs(2), server_accept)
            .await
            .unwrap()
            .unwrap(),
        Err(TransportError::AuthenticationRejected(
            protocol::RejectReason::AuthenticationFailed
        ))
    ));

    let server_accept = {
        let server = server.clone();
        tokio::spawn(async move { server.accept_session().await })
    };
    let mut mismatch_config = mismatch_config;
    mismatch_config.client.server = "127.0.0.1".to_owned();
    let mismatch_client = TlsTcpConnector::with_client_config(mismatch_config, client_tls);
    assert!(matches!(
        timeout(Duration::from_secs(2), mismatch_client.connect())
            .await
            .unwrap(),
        Err(TransportError::Io(_))
    ));
    assert!(timeout(Duration::from_secs(2), server_accept)
        .await
        .unwrap()
        .unwrap()
        .is_err());
}