//! Integration coverage for the handshake and camera-selection contract.
//!
//! Scope: exercise the real client handshake against a local server and the
//! server camera selection logic that feeds the handshake response.
//! Targets: `client/src/handshake.rs`, `server/src/handshake.rs`, and
//! `server/src/camera.rs`.
//! Why: the handshake path is the narrow entrypoint that decides whether the
//! client and server agree on output mode, so it deserves a centralized
//! contract test.

use lesavka_client::handshake::{PeerCaps, negotiate};
use serial_test::serial;
use std::net::TcpListener;
use std::time::Duration;
use temp_env::with_var;
use tokio::runtime::Runtime;
use tokio::sync::oneshot;
use tonic::transport::Server;

async fn negotiate_against_local_server() -> PeerCaps {
    let listener = TcpListener::bind("127.0.0.1:0").expect("bind local handshake listener");
    let addr = listener.local_addr().expect("listener addr");
    drop(listener);

    let (shutdown_tx, shutdown_rx) = oneshot::channel::<()>();
    let server = tokio::spawn(async move {
        Server::builder()
            .add_service(lesavka_server::handshake::HandshakeSvc::server())
            .serve_with_shutdown(addr, async move {
                let _ = shutdown_rx.await;
            })
            .await
            .expect("serve handshake server");
    });

    tokio::time::sleep(Duration::from_millis(50)).await;
    let caps = negotiate(&format!("http://{addr}")).await;
    let _ = shutdown_tx.send(());
    let _ = server.await;
    caps
}

#[test]
#[serial]
fn handshake_returns_uvc_caps_with_explicit_dimensions_and_fps() {
    with_var("LESAVKA_CAM_OUTPUT", Some("uvc"), || {
        with_var("LESAVKA_UVC_WIDTH", Some("1024"), || {
            with_var("LESAVKA_UVC_HEIGHT", Some("576"), || {
                with_var("LESAVKA_UVC_FPS", Some("12"), || {
                    let rt = Runtime::new().expect("create runtime");
                    let caps = rt.block_on(negotiate_against_local_server());
                    assert!(caps.camera);
                    assert!(caps.microphone);
                    assert_eq!(caps.camera_output, Some(String::from("uvc")));
                    assert_eq!(caps.camera_codec, Some(String::from("mjpeg")));
                    assert_eq!(caps.camera_width, Some(1024));
                    assert_eq!(caps.camera_height, Some(576));
                    assert_eq!(caps.camera_fps, Some(12));
                });
            });
        });
    });
}

#[test]
#[serial]
fn handshake_uses_uvc_interval_when_fps_is_unset() {
    with_var("LESAVKA_CAM_OUTPUT", Some("uvc"), || {
        with_var("LESAVKA_UVC_WIDTH", Some("640"), || {
            with_var("LESAVKA_UVC_HEIGHT", Some("360"), || {
                with_var("LESAVKA_UVC_INTERVAL", Some("250000"), || {
                    let rt = Runtime::new().expect("create runtime");
                    let caps = rt.block_on(negotiate_against_local_server());
                    assert_eq!(caps.camera_output, Some(String::from("uvc")));
                    assert_eq!(caps.camera_codec, Some(String::from("mjpeg")));
                    assert_eq!(caps.camera_width, Some(640));
                    assert_eq!(caps.camera_height, Some(360));
                    assert_eq!(caps.camera_fps, Some(40));
                    assert!(caps.camera);
                    assert!(caps.microphone);
                });
            });
        });
    });
}

#[test]
#[serial]
fn handshake_returns_hdmi_caps_with_h264_codec() {
    with_var("LESAVKA_CAM_OUTPUT", Some("hdmi"), || {
        with_var("LESAVKA_DISABLE_UAC", Some("1"), || {
            let rt = Runtime::new().expect("create runtime");
            let caps = rt.block_on(negotiate_against_local_server());
            assert_eq!(caps.camera_output, Some(String::from("hdmi")));
            assert_eq!(caps.camera_codec, Some(String::from("h264")));
            assert_eq!(caps.camera_fps, Some(30));
            assert!(!caps.microphone);
            assert!(caps.camera);
            assert!(matches!(caps.camera_width, Some(1280) | Some(1920)));
            assert!(matches!(caps.camera_height, Some(720) | Some(1080)));
        });
    });
}

#[test]
#[serial]
fn handshake_auto_mode_falls_back_to_a_valid_camera_configuration() {
    with_var("LESAVKA_CAM_OUTPUT", Some("auto"), || {
        let rt = Runtime::new().expect("create runtime");
        let caps = rt.block_on(negotiate_against_local_server());
        match caps.camera_output.as_deref() {
            Some("uvc") => {
                assert_eq!(caps.camera_codec.as_deref(), Some("mjpeg"));
                assert!(matches!(caps.camera_width, Some(1280) | Some(640)));
                assert!(matches!(caps.camera_height, Some(720) | Some(360)));
            }
            Some("hdmi") => {
                assert_eq!(caps.camera_codec.as_deref(), Some("h264"));
                assert!(matches!(caps.camera_width, Some(1280) | Some(1920)));
                assert!(matches!(caps.camera_height, Some(720) | Some(1080)));
            }
            other => panic!("unexpected camera output: {other:?}"),
        }
        assert!(caps.camera);
    });
}