#![allow(clippy::all)]

use std::{
    path::PathBuf,
    sync::{atomic::AtomicU32, Once},
};

use clap::Parser;
use replikey::{
    cert::UsageType,
    ops::{
        cert::{CertCommand, CertSubCommand},
        network::{NetworkCommand, NetworkSubCommand},
    },
};
use rustls::crypto::{aws_lc_rs, CryptoProvider};
use time::OffsetDateTime;
use tokio::{
    io::{AsyncRead, AsyncReadExt as _, AsyncWrite, AsyncWriteExt as _},
    task::JoinSet,
};

static NEXT_PORT: AtomicU32 = AtomicU32::new(12311);

static TEST_SETUP: Once = Once::new();

fn setup_once() {
    TEST_SETUP.call_once(|| {
        if std::env::var("RUST_LOG").is_err() {
            std::env::set_var("RUST_LOG", "info");
        }
        env_logger::init();
        CryptoProvider::install_default(aws_lc_rs::default_provider())
            .expect("Failed to install crypto provider");
    });
}

fn next_port() -> u32 {
    NEXT_PORT.fetch_add(1, std::sync::atomic::Ordering::SeqCst)
}

async fn test_stream_sequence<
    const WRITE_SIZE: usize,
    L: AsyncRead + AsyncWrite + Unpin + Send + Sync + 'static,
    R: AsyncRead + AsyncWrite + Unpin + Send + Sync + 'static,
>(
    left: L,
    right: R,
) {
    let (mut l_rx, mut l_tx) = tokio::io::split(left);

    let (mut r_rx, mut r_tx) = tokio::io::split(right);

    let l_write = async move {
        let mut buf = [0u8; WRITE_SIZE];
        for i in 0..100 {
            buf.iter_mut()
                .enumerate()
                .for_each(|(j, x)| *x = ((i + j) ^ 123) as u8);
            l_tx.write_all(&buf).await?;
        }
        l_tx.shutdown().await?;

        Ok::<_, tokio::io::Error>(())
    };
    let r_write = async move {
        let mut buf = [0u8; WRITE_SIZE];
        for i in 0..100 {
            buf.iter_mut()
                .enumerate()
                .for_each(|(j, x)| *x = ((i + j) ^ 321) as u8);
            r_tx.write_all(&buf).await?;
        }
        r_tx.shutdown().await?;
        Ok(())
    };
    let l_read = async move {
        let mut buf = [0u8; WRITE_SIZE];
        for i in 0..100 {
            l_rx.read_exact(&mut buf).await?;
            for j in 0..WRITE_SIZE {
                assert_eq!(buf[j], ((i + j) ^ 321) as u8);
            }
        }
        assert_eq!(l_rx.read(&mut buf).await?, 0, "expected eof");
        Ok(())
    };
    let r_read = async move {
        let mut buf = [0u8; WRITE_SIZE];
        for i in 0..100 {
            r_rx.read_exact(&mut buf).await?;
            for j in 0..WRITE_SIZE {
                assert_eq!(buf[j], ((i + j) ^ 123) as u8);
            }
        }
        assert_eq!(r_rx.read(&mut buf).await?, 0, "expected eof");
        Ok(())
    };

    tokio::try_join!(l_write, r_write, l_read, r_read).expect("stream sequence failed");
}

#[tokio::test]
async fn in_memory_stream_works() {
    let (left, right) = tokio::io::duplex(1024);
    test_stream_sequence::<1024, _, _>(left, right).await;
    let (left, right) = tokio::io::duplex(1024);
    test_stream_sequence::<1, _, _>(left, right).await;
    let (left, right) = tokio::io::duplex(1024);
    test_stream_sequence::<3543, _, _>(left, right).await;
}

fn test_ca(dir: &PathBuf) -> (PathBuf, PathBuf) {
    let id = OffsetDateTime::now_utc().unix_timestamp_nanos();

    let path = dir.join(format!("ca-{}/", id));

    std::fs::create_dir_all(&path).expect("failed to create ca dir");

    let cmd = [
        "replikey".to_string(),
        "create-ca".to_string(),
        "--valid-days".to_string(),
        "365".to_string(),
        "--dn-common-name".to_string(),
        "replikey-test-ca".to_string(),
        "--output".to_string(),
        path.to_string_lossy().to_string(),
    ];

    let parsed = CertCommand::parse_from(&cmd);

    if let CertSubCommand::CreateCa(opts) = parsed.subcmd {
        replikey::ops::cert::create_ca(opts, false);
    } else {
        panic!("failed to parse create-ca");
    }

    let pem = path.join("ca.pem");
    let key = path.join("ca.key");

    assert!(pem.exists());
    assert!(key.exists());

    (pem, key)
}

struct PeerCert {
    key: PathBuf,
    csr: PathBuf,
    self_signed: PathBuf,
    signed_cert: Option<PathBuf>,
}

impl PeerCert {
    fn signed_by(&self, usage: UsageType, ca_key: &PathBuf) -> PeerCert {
        let id = OffsetDateTime::now_utc().unix_timestamp_nanos();

        let path = ca_key.parent().unwrap().join(format!("signed-{}/", id));

        std::fs::create_dir_all(&path).expect("failed to create signed dir");

        let cmd = [
            "replikey".to_string(),
            "sign-server-csr".to_string(),
            "--valid-days".to_string(),
            "365".to_string(),
            "--ca-dir".to_string(),
            ca_key.parent().unwrap().to_string_lossy().to_string(),
            "--input-csr".to_string(),
            self.csr.to_string_lossy().to_string(),
            "-d".to_string(),
            "target1.local".to_string(),
            "-d".to_string(),
            "target2.local".to_string(),
            "-d".to_string(),
            "*.targets.local".to_string(),
            "--output".to_string(),
            format!("{}/server-signed.pem", path.to_string_lossy()),
        ];

        let parsed = CertCommand::parse_from(&cmd);

        if let CertSubCommand::SignServerCSR(opts) = parsed.subcmd {
            replikey::ops::cert::sign_csr(opts, usage, false);
        } else {
            panic!("failed to parse sign-server-csr");
        }

        PeerCert {
            key: self.key.clone(),
            csr: self.csr.clone(),
            self_signed: self.self_signed.clone(),
            signed_cert: Some(path.join("server-signed.pem")),
        }
    }
}

fn test_server_cert(dir: &PathBuf) -> PeerCert {
    let id = OffsetDateTime::now_utc().unix_timestamp_nanos();

    let path = dir.join(format!("server-{}/", id));

    std::fs::create_dir_all(&path).expect("failed to create server dir");

    let cmd = [
        "replikey".to_string(),
        "create-server".to_string(),
        "--valid-days".to_string(),
        "365".to_string(),
        "--dn-common-name".to_string(),
        "replikey-test-server".to_string(),
        "-d".to_string(),
        "target1.local".to_string(),
        "-d".to_string(),
        "target2.local".to_string(),
        "-d".to_string(),
        "*.targets.local".to_string(),
        "--output".to_string(),
        path.to_string_lossy().to_string(),
    ];

    let parsed = CertCommand::parse_from(&cmd);

    if let CertSubCommand::CreateServer(opts) = parsed.subcmd {
        replikey::ops::cert::create_server(opts);
    } else {
        panic!("failed to parse create-server");
    }

    let pem = path.join("server.pem");
    let key = path.join("server.key");
    let csr = path.join("server.csr");

    assert!(pem.exists());
    assert!(key.exists());

    PeerCert {
        key,
        csr,
        self_signed: pem,
        signed_cert: None,
    }
}

fn test_client_cert(dir: &PathBuf) -> PeerCert {
    let id = OffsetDateTime::now_utc().unix_timestamp_nanos();

    let path = dir.join(format!("client-{}/", id));

    std::fs::create_dir_all(&path).expect("failed to create client dir");

    let cmd = [
        "replikey".to_string(),
        "create-client".to_string(),
        "--valid-days".to_string(),
        "365".to_string(),
        "--dn-common-name".to_string(),
        "replikey-test-client".to_string(),
        "--output".to_string(),
        path.to_string_lossy().to_string(),
    ];

    let parsed = CertCommand::parse_from(&cmd);

    if let CertSubCommand::CreateClient(opts) = parsed.subcmd {
        replikey::ops::cert::create_client(opts);
    } else {
        panic!("failed to parse create-client");
    }

    let pem = path.join("client.pem");
    let key = path.join("client.key");
    let csr = path.join("client.csr");

    assert!(pem.exists());
    assert!(key.exists());

    PeerCert {
        key,
        csr,
        self_signed: pem,
        signed_cert: None,
    }
}

async fn start_test_target_1() -> u32 {
    let port = next_port();
    let listener = tokio::net::TcpListener::bind(format!("127.0.0.1:{}", port))
        .await
        .expect("failed to bind listener");

    tokio::spawn(async move {
        loop {
            let (mut stream, _) = listener.accept().await.expect("failed to accept");
            log::info!("accepted connection on target1");
            tokio::spawn(async move {
                let (mut rx, mut tx) = stream.split();
                let n = tokio::io::copy(&mut rx, &mut tx)
                    .await
                    .expect("failed to copy");
                log::info!("copied {} bytes", n);
                tx.shutdown().await.expect("failed to close");
            });
        }
    });

    port
}

async fn start_test_target_2() -> u32 {
    let port = next_port();
    let listener = tokio::net::TcpListener::bind(format!("127.0.0.1:{}", port))
        .await
        .expect("failed to bind listener");

    tokio::spawn(async move {
        loop {
            let (mut stream, _) = listener.accept().await.expect("failed to accept");
            log::info!("accepted connection on target2");
            tokio::spawn(async move {
                let (mut rx, mut tx) = stream.split();
                let mut buf = [0u8; 1024];
                let mut total = 0;
                loop {
                    let n = rx.read(&mut buf).await.expect("failed to read");
                    total += n;
                    if n == 0 {
                        break;
                    }
                    buf[..n].iter_mut().for_each(|x| *x = !*x);
                    tx.write_all(&buf[..n]).await.expect("failed to write");
                }
                log::info!("copied {} bytes", total);
                tx.shutdown().await.expect("failed to close");
            });
        }
    });

    port
}

async fn start_reverse_proxy(
    target1: u32,
    target2: u32,
    cert: &PathBuf,
    key: &PathBuf,
    ca_cert: &PathBuf,
    compression: &str,
) -> u32 {
    let port = next_port();

    let cmd = [
        "replikey".to_string(),
        "reverse-proxy".to_string(),
        "--listen".to_string(),
        format!("127.0.0.1:{}", port),
        "--target".to_string(),
        format!("target1.local/127.0.0.1:{}", target1),
        "--target".to_string(),
        format!("target2.local/127.0.0.1:{}", target2),
        "--target".to_string(),
        format!("target1.targets.local/127.0.0.1:{}", target1),
        "--target".to_string(),
        format!("target2.targets.local/127.0.0.1:{}", target2),
        "--cert".to_string(),
        cert.to_string_lossy().to_string(),
        "--key".to_string(),
        key.to_string_lossy().to_string(),
        "--ca".to_string(),
        ca_cert.to_string_lossy().to_string(),
        "--compression".to_string(),
        compression.to_string(),
    ];

    let parsed = NetworkCommand::parse_from(&cmd);

    if let NetworkSubCommand::ReverseProxy(opts) = parsed.subcmd {
        tokio::spawn(async move {
            replikey::ops::network::reverse_proxy(opts)
                .await
                .expect("failed to run reverse proxy");
        });

        port
    } else {
        panic!("failed to parse reverse-proxy");
    }
}

async fn start_forward_proxy(
    addr: &str,
    sni: &str,
    cert: &PathBuf,
    key: &PathBuf,
    ca_cert: &PathBuf,
    compression: &str,
) -> u32 {
    let port = next_port();

    let cmd = [
        "replikey".to_string(),
        "forward-proxy".to_string(),
        "--listen".to_string(),
        format!("127.0.0.1:{}", port),
        "--target".to_string(),
        addr.to_string(),
        "--sni".to_string(),
        sni.to_string(),
        "--cert".to_string(),
        cert.to_string_lossy().to_string(),
        "--key".to_string(),
        key.to_string_lossy().to_string(),
        "--ca".to_string(),
        ca_cert.to_string_lossy().to_string(),
        "--compression".to_string(),
        compression.to_string(),
    ];

    let parsed = NetworkCommand::parse_from(&cmd);

    if let NetworkSubCommand::ForwardProxy(opts) = parsed.subcmd {
        tokio::spawn(async move {
            replikey::ops::network::forward_proxy(opts)
                .await
                .expect("failed to run forward proxy");
        });

        port
    } else {
        panic!("failed to parse forward-proxy");
    }
}

async fn wait_for_port(port: u32) {
    loop {
        tokio::select! {
            _ = tokio::time::sleep(std::time::Duration::from_secs(5)) => {
                panic!("timeout waiting for port");
            }
            res = tokio::net::TcpStream::connect(format!("127.0.0.1:{}", port)) => {
                if res.is_ok() {
                    break;
                }
            }
        }
    }
}

async fn should_not_get_anything(port: u32) {
    let mut stream = tokio::net::TcpStream::connect(format!("127.0.0.1:{}", port))
        .await
        .expect("failed to connect");

    let res = stream.read(&mut [0u8; 1024]).await;

    match res {
        Ok(n) => {
            assert_eq!(n, 0);
        }
        Err(e) => {
            assert_eq!(e.kind(), std::io::ErrorKind::ConnectionReset);
        }
    }
}

async fn expect_target1_signature(port: u32) {
    let stream = tokio::net::TcpStream::connect(format!("127.0.0.1:{}", port))
        .await
        .expect("failed to connect");
    let (mut rx, mut tx) = tokio::io::split(stream);

    for batch in 0..8 {
        log::debug!("expect_target1_signature batch {}", batch);
        let mut data = "GET / HTTP/1.0\r\n\r\n".repeat(1024).into_bytes();
        let expect = data.clone();

        let mut write_size = (1..4096).cycle();

        let (_, rx_data) = tokio::join!(
            async {
                while !data.is_empty() {
                    let n = write_size.next().unwrap().min(data.len());
                    tx.write_all(&data[..n]).await.expect("failed to write");
                    log::trace!("wrote {} bytes for target1", n);
                    data = data.split_off(n);
                }
                tx.flush().await.expect("failed to flush");
                log::info!("wrote {} bytes for target1", expect.len());
            },
            async {
                let mut rxed = Vec::new();
                let mut buf = [0u8; 1024];
                loop {
                    let n = rx.read(&mut buf).await.expect("failed to read");
                    log::trace!("read {} bytes for target1", n);
                    if n == 0 {
                        break;
                    }
                    rxed.extend_from_slice(&buf[..n]);
                    if rxed.len() >= expect.len() {
                        break;
                    }
                }
                rxed
            }
        );

        assert_eq!(rx_data, expect);
    }

    tx.shutdown().await.expect("failed to close");
}

async fn expect_target2_signature(port: u32) {
    let stream = tokio::net::TcpStream::connect(format!("127.0.0.1:{}", port))
        .await
        .expect("failed to connect");

    let (mut rx, mut tx) = tokio::io::split(stream);

    for _batch in 0..8 {
        let mut data = "GET / HTTP/1.0\r\n\r\n".repeat(1024).into_bytes();
        let expect = data.iter().map(|x| !x).collect::<Vec<_>>();

        let mut write_size = (1..4096).cycle();

        let (_, rx_data) = tokio::join!(
            async {
                while !data.is_empty() {
                    let n = write_size.next().unwrap().min(data.len());
                    tx.write_all(&data[..n]).await.expect("failed to write");
                    data = data.split_off(n);
                }
                tx.flush().await.expect("failed to flush");
            },
            async {
                let mut rxed = Vec::new();
                let mut buf = [0u8; 1024];
                loop {
                    let n = rx.read(&mut buf).await.expect("failed to read");
                    if n == 0 {
                        break;
                    }
                    rxed.extend_from_slice(&buf[..n]);
                    if rxed.len() >= expect.len() {
                        break;
                    }
                }
                rxed
            }
        );

        assert_eq!(rx_data, expect);
    }

    tx.shutdown().await.expect("failed to close");
}

#[tokio::test(flavor = "multi_thread", worker_threads = 16)]
async fn test_mtls_integrated() {
    setup_once();
    let (ca_cert, ca_key) = test_ca(&PathBuf::from("target/test-ca"));
    let server_cert = test_server_cert(&PathBuf::from("target/test-server"));
    let client_cert = test_client_cert(&PathBuf::from("target/test-client"));

    let server_cert = server_cert.signed_by(UsageType::Server, &ca_key);
    let client_cert = client_cert.signed_by(UsageType::Client, &ca_key);

    let target1 = start_test_target_1().await;
    let target2 = start_test_target_2().await;
    log::info!("target1: {}, target2: {}", target1, target2);
    wait_for_port(target1).await;
    wait_for_port(target2).await;
    expect_target1_signature(target1).await;
    expect_target2_signature(target2).await;

    for compression in ["none", "zstd", "brotli"] {
        let proxy_port_self_signed = start_reverse_proxy(
            target1,
            target2,
            &server_cert.self_signed,
            &server_cert.key,
            &ca_cert,
            compression,
        )
        .await;
        wait_for_port(proxy_port_self_signed).await;
        log::info!("reverse_proxy_port_self_signed: {}", proxy_port_self_signed);

        let proxy_port = start_reverse_proxy(
            target1,
            target2,
            server_cert.signed_cert.as_ref().unwrap(),
            &server_cert.key,
            &ca_cert,
            compression,
        )
        .await;
        wait_for_port(proxy_port).await;
        log::info!("reverse_proxy_port: {}", proxy_port);

        for server_signed in [false, true] {
            let forward_proxy_target1_self_signed = start_forward_proxy(
                &format!(
                    "127.0.0.1:{}",
                    if server_signed {
                        proxy_port
                    } else {
                        proxy_port_self_signed
                    }
                ),
                "target1.local",
                &client_cert.self_signed,
                &client_cert.key,
                &ca_cert,
                compression,
            )
            .await;
            log::info!(
                "forward_proxy_target1_self_signed: {}",
                forward_proxy_target1_self_signed
            );

            let forward_proxy_target1 = start_forward_proxy(
                &format!(
                    "127.0.0.1:{}",
                    if server_signed {
                        proxy_port
                    } else {
                        proxy_port_self_signed
                    }
                ),
                "target1.local",
                client_cert.signed_cert.as_ref().unwrap(),
                &client_cert.key,
                &ca_cert,
                compression,
            )
            .await;
            log::info!("forward_proxy_target1: {}", forward_proxy_target1);

            let forward_proxy_target2 = start_forward_proxy(
                &format!(
                    "127.0.0.1:{}",
                    if server_signed {
                        proxy_port
                    } else {
                        proxy_port_self_signed
                    }
                ),
                "target2.local",
                client_cert.signed_cert.as_ref().unwrap(),
                &client_cert.key,
                &ca_cert,
                compression,
            )
            .await;
            log::info!("forward_proxy_target2: {}", forward_proxy_target2);

            let forward_proxy_target1_wildcard = start_forward_proxy(
                &format!(
                    "127.0.0.1:{}",
                    if server_signed {
                        proxy_port
                    } else {
                        proxy_port_self_signed
                    }
                ),
                "target1.targets.local",
                client_cert.signed_cert.as_ref().unwrap(),
                &client_cert.key,
                &ca_cert,
                compression,
            )
            .await;

            let forward_proxy_target2_wildcard: u32 = start_forward_proxy(
                &format!(
                    "127.0.0.1:{}",
                    if server_signed {
                        proxy_port
                    } else {
                        proxy_port_self_signed
                    }
                ),
                "target2.targets.local",
                client_cert.signed_cert.as_ref().unwrap(),
                &client_cert.key,
                &ca_cert,
                compression,
            )
            .await;
            log::info!(
                "forward_proxy_target2_wildcard: {}",
                forward_proxy_target2_wildcard
            );

            let forward_proxy_unknown_sni = start_forward_proxy(
                &format!(
                    "127.0.0.1:{}",
                    if server_signed {
                        proxy_port
                    } else {
                        proxy_port_self_signed
                    }
                ),
                "some-other.place",
                client_cert.signed_cert.as_ref().unwrap(),
                &client_cert.key,
                &ca_cert,
                compression,
            )
            .await;
            log::info!("forward_proxy_unknown_sni: {}", forward_proxy_unknown_sni);

            wait_for_port(forward_proxy_target1).await;
            wait_for_port(forward_proxy_target2).await;
            wait_for_port(forward_proxy_target1_wildcard).await;
            wait_for_port(forward_proxy_target2_wildcard).await;
            wait_for_port(forward_proxy_unknown_sni).await;
            log::info!("Test: self-signed cert");
            should_not_get_anything(forward_proxy_target1_self_signed).await;

            if server_signed {
                let mut js = JoinSet::new();
                for _ in 0..100 {
                    js.spawn(expect_target1_signature(forward_proxy_target1));
                    js.spawn(expect_target2_signature(forward_proxy_target2));
                    js.spawn(expect_target1_signature(forward_proxy_target1_wildcard));
                    js.spawn(expect_target2_signature(forward_proxy_target2_wildcard));
                    js.spawn(should_not_get_anything(forward_proxy_unknown_sni));
                }
                js.join_all().await;
            } else {
                let mut js = JoinSet::new();
                for _ in 0..100 {
                    js.spawn(should_not_get_anything(forward_proxy_target1));
                    js.spawn(should_not_get_anything(forward_proxy_target2));
                    js.spawn(should_not_get_anything(forward_proxy_target1_wildcard));
                    js.spawn(should_not_get_anything(forward_proxy_target2_wildcard));
                    js.spawn(should_not_get_anything(forward_proxy_unknown_sni));
                }
                js.join_all().await;
            }
        }
    }
}

#[tokio::test]
async fn test_mtls_role_reverse() {
    let (ca_cert, ca_key) = test_ca(&PathBuf::from("target/test-ca"));

    let server_cert = test_server_cert(&PathBuf::from("target/test-server"));

    let server_cert = server_cert.signed_by(UsageType::Server, &ca_key);

    let client_cert = test_client_cert(&PathBuf::from("target/test-client"));

    let client_cert = client_cert.signed_by(UsageType::Client, &ca_key);

    let target1 = start_test_target_1().await;

    let target2 = start_test_target_2().await;

    wait_for_port(target1).await;
    wait_for_port(target2).await;

    let server_cert = server_cert.signed_by(UsageType::Server, &ca_key);
    let client_cert = client_cert.signed_by(UsageType::Client, &ca_key);

    let proxy_port = start_reverse_proxy(
        target1,
        target2,
        server_cert.signed_cert.as_ref().unwrap(),
        &server_cert.key,
        &ca_cert,
        "none",
    )
    .await;

    wait_for_port(proxy_port).await;

    let forward_proxy_target1 = start_forward_proxy(
        &format!("127.0.0.1:{}", proxy_port),
        "target1.local",
        client_cert.signed_cert.as_ref().unwrap(),
        &client_cert.key,
        &ca_cert,
        "none",
    )
    .await;
    wait_for_port(forward_proxy_target1).await;

    expect_target1_signature(forward_proxy_target1).await;

    let proxy_port_reversed = start_reverse_proxy(
        target1,
        target2,
        client_cert.signed_cert.as_ref().unwrap(),
        &client_cert.key,
        &ca_cert,
        "none",
    )
    .await;

    wait_for_port(proxy_port_reversed).await;

    let forward_proxy_target1_reversed = start_forward_proxy(
        &format!("127.0.0.1:{}", proxy_port_reversed),
        "target1.local",
        server_cert.signed_cert.as_ref().unwrap(),
        &server_cert.key,
        &ca_cert,
        "none",
    )
    .await;
    wait_for_port(forward_proxy_target1_reversed).await;

    should_not_get_anything(forward_proxy_target1_reversed).await;
}