//! Tests for mutual TLS configuration.

use std::collections::HashMap;
use std::net::SocketAddr;
use std::thread;
use std::time::Duration;

use tidaldb::replication::WalSegmentId;
use tidaldb::replication::shard::{RegionId, ShardId};
use tidaldb::replication::transport::{Transport, WalSegmentPayload};

use tidal_net::GrpcTransport;
use tidal_net::config::{GrpcTransportConfig, TlsConfig};

fn free_addr() -> SocketAddr {
    let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
    listener.local_addr().unwrap()
}

/// Generate a self-signed CA and server/client certificates using rcgen.
fn generate_certs(dir: &std::path::Path) -> TlsConfig {
    use rcgen::{CertificateParams, KeyPair};

    // Generate CA.
    let ca_key = KeyPair::generate().unwrap();
    let mut ca_params = CertificateParams::new(vec!["tidaldb-ca".to_string()]).unwrap();
    ca_params.is_ca = rcgen::IsCa::Ca(rcgen::BasicConstraints::Unconstrained);
    let ca_cert = ca_params.self_signed(&ca_key).unwrap();

    // Generate server cert signed by CA.
    let server_key = KeyPair::generate().unwrap();
    let server_params =
        CertificateParams::new(vec!["localhost".to_string(), "127.0.0.1".to_string()]).unwrap();
    let server_cert = server_params
        .signed_by(&server_key, &ca_cert, &ca_key)
        .unwrap();

    // Generate client cert signed by CA.
    let client_key = KeyPair::generate().unwrap();
    let client_params = CertificateParams::new(vec!["tidaldb-client".to_string()]).unwrap();
    let client_cert = client_params
        .signed_by(&client_key, &ca_cert, &ca_key)
        .unwrap();

    // Write to files.
    let ca_cert_path = dir.join("ca.pem");
    let server_cert_path = dir.join("server.pem");
    let server_key_path = dir.join("server-key.pem");
    let client_cert_path = dir.join("client.pem");
    let client_key_path = dir.join("client-key.pem");

    std::fs::write(&ca_cert_path, ca_cert.pem()).unwrap();
    std::fs::write(&server_cert_path, server_cert.pem()).unwrap();
    std::fs::write(&server_key_path, server_key.serialize_pem()).unwrap();
    std::fs::write(&client_cert_path, client_cert.pem()).unwrap();
    std::fs::write(&client_key_path, client_key.serialize_pem()).unwrap();

    TlsConfig {
        ca_cert: ca_cert_path,
        server_cert: server_cert_path,
        server_key: server_key_path,
        client_cert: Some(client_cert_path),
        client_key: Some(client_key_path),
    }
}

#[test]
fn mtls_send_and_receive() {
    let tmp = tempfile::tempdir().unwrap();
    let tls = generate_certs(tmp.path());

    let addr0 = free_addr();
    let addr1 = free_addr();

    let config0 = GrpcTransportConfig {
        local_shard: ShardId(0),
        listen_addr: addr0,
        peers: HashMap::from([(ShardId(1), addr1)]),
        tls: Some(tls.clone()),
        insecure: false,
        ..Default::default()
    };

    let config1 = GrpcTransportConfig {
        local_shard: ShardId(1),
        listen_addr: addr1,
        peers: HashMap::from([(ShardId(0), addr0)]),
        tls: Some(tls),
        insecure: false,
        ..Default::default()
    };

    let t0 = GrpcTransport::new(config0).expect("transport 0 with TLS");
    let t1 = GrpcTransport::new(config1).expect("transport 1 with TLS");
    thread::sleep(Duration::from_millis(200));

    let payload = WalSegmentPayload {
        id: WalSegmentId::new(RegionId::SINGLE, ShardId(0), 99),
        bytes: vec![0xEF; 64],
        event_count: 2,
    };
    t0.send_segment(ShardId(1), payload).unwrap();

    let received = t1.recv_segment().unwrap();
    assert_eq!(received.id.seqno, 99);
    assert_eq!(received.event_count, 2);
}

#[test]
fn plaintext_rejected_when_not_insecure() {
    let addr = free_addr();
    let config = GrpcTransportConfig {
        local_shard: ShardId(0),
        listen_addr: addr,
        peers: HashMap::new(),
        tls: None,
        insecure: false, // Should reject — no TLS and not insecure.
        ..Default::default()
    };

    let result = GrpcTransport::new(config);
    assert!(result.is_err(), "should reject plaintext when not insecure");
}