use rustix::event::{poll, PollFd, PollFlags};
use std::mem::ManuallyDrop;
use std::os::fd::{AsRawFd, BorrowedFd};
use std::os::unix::net::UnixStream;
use std::sync::mpsc;
use std::sync::Once;
use std::thread::JoinHandle;
use std::time::Duration;
use wayland_protocols::xdg::shell::server::xdg_toplevel;
use wayland_server::Resource;
use xcb::{x, Xid};
use xwayland_satellite as xwls;

struct Fixture {
    testwl: testwl::Server,
    thread: ManuallyDrop<JoinHandle<Option<()>>>,
    pollfd: PollFd<'static>,
}

impl Drop for Fixture {
    fn drop(&mut self) {
        let thread = unsafe { ManuallyDrop::take(&mut self.thread) };
        if thread.is_finished() {
            thread.join().expect("Main thread panicked");
        }
    }
}

xcb::atoms_struct! {
    struct Atoms {
        wm_protocols => b"WM_PROTOCOLS",
        wm_delete_window => b"WM_DELETE_WINDOW",
        wm_class => b"WM_CLASS",
        wm_name => b"WM_NAME",
    }
}

static INIT: Once = Once::new();
impl Fixture {
    #[track_caller]
    fn new() -> Self {
        INIT.call_once(|| {
            env_logger::builder()
                .is_test(true)
                .filter_level(log::LevelFilter::Debug)
                .init();
        });

        let (a, b) = UnixStream::pair().unwrap();
        let mut testwl = testwl::Server::new(false);
        testwl.connect(a);

        let (send, recv) = mpsc::channel();
        let thread = std::thread::spawn(move || xwls::main(Some(b), Some(send)));

        // wait for connection
        let fd = unsafe { BorrowedFd::borrow_raw(testwl.poll_fd().as_raw_fd()) };
        let pollfd = PollFd::from_borrowed_fd(fd, PollFlags::IN);
        assert!(poll(&mut [pollfd.clone()], 100).unwrap() > 0);
        testwl.dispatch();

        let wait = Duration::from_secs(1);
        assert_eq!(
            recv.recv_timeout(wait),
            Ok(xwls::StateEvent::CreatedServer),
            "creating server"
        );
        assert_eq!(
            recv.recv_timeout(wait),
            Ok(xwls::StateEvent::ConnectedServer),
            "connecting to server"
        );

        let mut f = [pollfd.clone()];
        let start = std::time::Instant::now();
        // Give Xwayland time to do its thing
        while start.elapsed() < Duration::from_millis(500) {
            let n = poll(&mut f, 100).unwrap();
            if n > 0 {
                testwl.dispatch();
            }
        }

        assert_eq!(
            recv.try_recv(),
            Ok(xwls::StateEvent::XwaylandReady),
            "connecting to xwayland"
        );

        Self {
            testwl,
            thread: ManuallyDrop::new(thread),
            pollfd,
        }
    }

    #[track_caller]
    fn wait_and_dispatch(&mut self) {
        let mut pollfd = [self.pollfd.clone()];
        assert!(
            poll(&mut pollfd, 50).unwrap() > 0,
            "Did not receive any events"
        );
        self.pollfd.clear_revents();
        self.testwl.dispatch();

        while poll(&mut pollfd, 50).unwrap() > 0 {
            self.testwl.dispatch();
            self.pollfd.clear_revents();
        }
    }

    fn create_and_map_window(
        &mut self,
        connection: &xcb::Connection,
        override_redirect: bool,
        x: i16,
        y: i16,
        width: u16,
        height: u16,
    ) -> (x::Window, testwl::SurfaceId) {
        let screen = connection.get_setup().roots().next().unwrap();
        let wid = connection.generate_id();
        let req = x::CreateWindow {
            depth: x::COPY_FROM_PARENT as _,
            wid,
            parent: screen.root(),
            x,
            y,
            width,
            height,
            border_width: 0,
            class: x::WindowClass::InputOutput,
            visual: screen.root_visual(),
            value_list: &[
                x::Cw::BackPixel(screen.white_pixel()),
                x::Cw::OverrideRedirect(override_redirect),
            ],
        };
        connection.send_and_check_request(&req).unwrap();

        let req = x::MapWindow { window: wid };
        connection.send_and_check_request(&req).unwrap();
        self.wait_and_dispatch();

        let id = self
            .testwl
            .last_created_surface_id()
            .expect("No surface created for window");

        (wid, id)
    }

    fn create_toplevel(
        &mut self,
        connection: &xcb::Connection,
        width: u16,
        height: u16,
    ) -> (x::Window, testwl::SurfaceId) {
        let (window, surface) = self.create_and_map_window(connection, false, 0, 0, width, height);
        let data = self
            .testwl
            .get_surface_data(surface)
            .expect("No surface data");
        assert!(
            matches!(data.role, Some(testwl::SurfaceRole::Toplevel(_))),
            "surface role was wrong: {:?}",
            data.role
        );

        self.testwl
            .configure_toplevel(surface, 100, 100, vec![xdg_toplevel::State::Activated]);
        self.wait_and_dispatch();
        let geometry = connection
            .wait_for_reply(connection.send_request(&x::GetGeometry {
                drawable: x::Drawable::Window(window),
            }))
            .unwrap();

        assert_eq!(geometry.x(), 0);
        assert_eq!(geometry.y(), 0);
        assert_eq!(geometry.width(), 100);
        assert_eq!(geometry.height(), 100);

        (window, surface)
    }

    /// Triggers a Wayland side toplevel Close event and processes the corresponding
    /// X11 side WM_DELETE_WINDOW client message
    fn close_toplevel(
        &mut self,
        connection: &mut Connection,
        window: x::Window,
        surface: testwl::SurfaceId,
    ) {
        self.testwl.close_toplevel(surface);
        connection.await_event();
        let event = connection
            .inner
            .poll_for_event()
            .unwrap()
            .expect("No close event");

        let xcb::Event::X(x::Event::ClientMessage(event)) = event else {
            panic!("Expected ClientMessage event, got {event:?}");
        };

        assert_eq!(event.window(), window);
        assert_eq!(event.format(), 32);
        assert_eq!(event.r#type(), connection.atoms.wm_protocols);
        match event.data() {
            x::ClientMessageData::Data32(d) => {
                assert_eq!(d[0], connection.atoms.wm_delete_window.resource_id())
            }
            other => panic!("wrong data type: {other:?}"),
        }
    }
}

struct Connection {
    inner: xcb::Connection,
    pollfd: PollFd<'static>,
    atoms: Atoms,
}

impl std::ops::Deref for Connection {
    type Target = xcb::Connection;
    fn deref(&self) -> &Self::Target {
        &self.inner
    }
}

impl Connection {
    fn new() -> Self {
        // TODO: this will not work if there is an Xserver at 1024, or whenever we add multiple
        // tests.
        let (inner, _) = xcb::Connection::connect(Some(":0")).unwrap();
        let fd = unsafe { BorrowedFd::borrow_raw(inner.as_raw_fd()) };
        let pollfd = PollFd::from_borrowed_fd(fd, PollFlags::IN);
        let atoms = Atoms::intern_all(&inner).unwrap();

        Self {
            inner,
            pollfd,
            atoms,
        }
    }

    #[track_caller]
    fn await_event(&mut self) {
        assert!(
            poll(&mut [self.pollfd.clone()], 100).expect("poll failed") > 0,
            "Did not get any X11 events"
        );
    }
}

#[test]
fn toplevel_flow() {
    let mut f = Fixture::new();
    let mut connection = Connection::new();
    let (window, surface) = f.create_toplevel(&connection.inner, 200, 200);

    connection
        .inner
        .send_and_check_request(&x::ChangeProperty {
            mode: x::PropMode::Replace,
            window,
            r#type: x::ATOM_STRING,
            property: connection.atoms.wm_name,
            data: c"window".to_bytes(),
        })
        .unwrap();

    connection
        .inner
        .send_and_check_request(&x::ChangeProperty {
            mode: x::PropMode::Replace,
            window,
            r#type: x::ATOM_STRING,
            property: connection.atoms.wm_class,
            data: &[
                c"instance".to_bytes_with_nul(),
                c"class".to_bytes_with_nul(),
            ]
            .concat(),
        })
        .unwrap();

    f.wait_and_dispatch();

    let data = f.testwl.get_surface_data(surface).unwrap();
    assert_eq!(data.toplevel().title, Some("window".into()));
    assert_eq!(data.toplevel().app_id, Some("class".into()));

    f.close_toplevel(&mut connection, window, surface);

    // Simulate killing client
    drop(connection);
    f.wait_and_dispatch();

    let data = f.testwl.get_surface_data(surface).expect("No surface data");
    assert!(!data.toplevel().toplevel.is_alive());
}