use super::clientside::LateInitObjectKey;
use super::*;
use hecs::CommandBuffer;
use log::{debug, trace, warn};
use macros::simple_event_shunt;
use std::os::fd::AsFd;
use wayland_client::{protocol as client, Proxy};
use wayland_protocols::{
    wp::{
        fractional_scale::v1::client::wp_fractional_scale_v1,
        pointer_constraints::zv1::server::{
            zwp_confined_pointer_v1::ZwpConfinedPointerV1 as ConfinedPointerServer,
            zwp_locked_pointer_v1::ZwpLockedPointerV1 as LockedPointerServer,
        },
        relative_pointer::zv1::{
            client::zwp_relative_pointer_v1,
            server::zwp_relative_pointer_v1::ZwpRelativePointerV1 as RelativePointerServer,
        },
        tablet::zv2::{
            client::{
                zwp_tablet_pad_group_v2, zwp_tablet_pad_ring_v2, zwp_tablet_pad_strip_v2,
                zwp_tablet_pad_v2, zwp_tablet_seat_v2, zwp_tablet_tool_v2,
                zwp_tablet_v2::{self, ZwpTabletV2 as TabletClient},
            },
            server::{
                zwp_tablet_pad_group_v2::ZwpTabletPadGroupV2 as TabletPadGroupServer,
                zwp_tablet_pad_ring_v2::ZwpTabletPadRingV2 as TabletPadRingServer,
                zwp_tablet_pad_strip_v2::ZwpTabletPadStripV2 as TabletPadStripServer,
                zwp_tablet_pad_v2::ZwpTabletPadV2 as TabletPadServer,
                zwp_tablet_seat_v2::ZwpTabletSeatV2 as TabletSeatServer,
                zwp_tablet_tool_v2::ZwpTabletToolV2 as TabletToolServer,
                zwp_tablet_v2::ZwpTabletV2 as TabletServer,
            },
        },
    },
    xdg::{
        shell::client::{xdg_popup, xdg_surface, xdg_toplevel},
        xdg_output::zv1::{
            client::zxdg_output_v1, server::zxdg_output_v1::ZxdgOutputV1 as XdgOutputServer,
        },
    },
};
use wayland_server::protocol::{
    wl_buffer::WlBuffer, wl_keyboard::WlKeyboard, wl_output::WlOutput, wl_pointer::WlPointer,
    wl_seat::WlSeat, wl_touch::WlTouch,
};

#[derive(Copy, Clone)]
pub(super) struct SurfaceScaleFactor(pub f64);

#[derive(hecs::Bundle)]
pub(super) struct SurfaceBundle {
    pub client: client::wl_surface::WlSurface,
    pub server: WlSurface,
    pub viewport: WpViewport,
    pub scale: SurfaceScaleFactor,
}

#[derive(Debug)]
pub(crate) enum SurfaceEvents {
    WlSurface(client::wl_surface::Event),
    XdgSurface(xdg_surface::Event),
    Toplevel(xdg_toplevel::Event),
    Popup(xdg_popup::Event),
    FractionalScale(wp_fractional_scale_v1::Event),
}
macro_rules! impl_from {
    ($type:ty, $variant:ident) => {
        impl From<$type> for ObjectEvent {
            fn from(value: $type) -> Self {
                Self::Surface(SurfaceEvents::$variant(value))
            }
        }
    };
}
impl_from!(client::wl_surface::Event, WlSurface);
impl_from!(xdg_surface::Event, XdgSurface);
impl_from!(xdg_toplevel::Event, Toplevel);
impl_from!(xdg_popup::Event, Popup);
impl_from!(wp_fractional_scale_v1::Event, FractionalScale);

impl Event for SurfaceEvents {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        match self {
            SurfaceEvents::WlSurface(event) => Self::surface_event(event, target, state),
            SurfaceEvents::XdgSurface(event) => Self::xdg_event(event, target, state),
            SurfaceEvents::Toplevel(event) => Self::toplevel_event(event, target, state),
            SurfaceEvents::Popup(event) => Self::popup_event(event, target, state),
            SurfaceEvents::FractionalScale(event) => match event {
                wp_fractional_scale_v1::Event::PreferredScale { scale } => {
                    let entity = state.world.entity(target).unwrap();
                    let factor = scale as f64 / 120.0;
                    debug!(
                        "{} scale factor: {}",
                        entity.get::<&WlSurface>().unwrap().id(),
                        factor
                    );

                    entity.get::<&mut SurfaceScaleFactor>().unwrap().0 = factor;

                    if let Some(OnOutput(output)) = entity.get::<&OnOutput>().as_deref().copied() {
                        if update_output_scale(
                            state.world.query_one(output).unwrap(),
                            OutputScaleFactor::Fractional(factor),
                        ) {
                            state.updated_outputs.push(output);
                        }
                    }
                    if entity.has::<WindowData>() {
                        update_surface_viewport(state.world.query_one(target).unwrap());
                    }
                }
                _ => unreachable!(),
            },
        }
    }
}

impl SurfaceEvents {
    fn surface_event(
        event: client::wl_surface::Event,
        target: Entity,
        state: &mut ServerState<impl XConnection>,
    ) {
        use client::wl_surface::Event;

        let data = state.world.entity(target).unwrap();
        let surface = data.get::<&WlSurface>().unwrap();
        let mut cmd = CommandBuffer::new();
        match event {
            Event::Enter { output } => {
                let output_entity = output.data().copied().unwrap();
                let Ok(output_data) = state.world.entity(output_entity) else {
                    return;
                };
                let Some(output) = output_data.get::<&WlOutput>() else {
                    return;
                };

                surface.enter(&output);
                let on_output = OnOutput(output_entity);

                debug!("{} entered {}", surface.id(), output.id());

                let mut query = data.query::<(&x::Window, &mut WindowData)>();
                if let Some((window, win_data)) = query.get() {
                    let dimensions = output_data.get::<&OutputDimensions>().unwrap();
                    win_data.update_output_offset(
                        *window,
                        WindowOutputOffset {
                            x: dimensions.x - state.global_output_offset.x.value,
                            y: dimensions.y - state.global_output_offset.y.value,
                        },
                        &mut state.connection,
                    );
                    if state.last_focused_toplevel == Some(*window) {
                        let output = get_output_name(Some(&on_output), &state.world);
                        let conn = state.connection.as_mut().unwrap();
                        debug!("focused window changed outputs - resetting primary output");
                        conn.focus_window(*window, output);
                    }

                    if state.fractional_scale.is_none() {
                        let output_scale = output_data.get::<&OutputScaleFactor>().unwrap().get();
                        data.get::<&mut SurfaceScaleFactor>().unwrap().0 = output_scale;
                        drop(query);
                        update_surface_viewport(state.world.query_one(target).unwrap());
                    } else {
                        let scale = data.get::<&SurfaceScaleFactor>().unwrap();
                        if update_output_scale(
                            state.world.query_one(on_output.0).unwrap(),
                            OutputScaleFactor::Fractional(scale.0),
                        ) {
                            state.updated_outputs.push(on_output.0);
                        }
                    }
                }
                cmd.insert_one(target, on_output);
            }
            Event::Leave { output } => {
                let output_entity = output.data().copied().unwrap();
                let Ok(output) = state.world.get::<&WlOutput>(output_entity) else {
                    return;
                };
                surface.leave(&output);
                if data
                    .get::<&OnOutput>()
                    .is_some_and(|o| o.0 == output_entity)
                {
                    cmd.remove_one::<OnOutput>(target);
                }
            }
            Event::PreferredBufferScale { .. } => {}
            other => warn!("unhandled surface request: {other:?}"),
        }

        drop(surface);
        cmd.run_on(&mut state.world);
    }

    fn xdg_event<C: XConnection>(
        event: xdg_surface::Event,
        target: Entity,
        state: &mut ServerState<C>,
    ) {
        let connection = state.connection.as_mut().unwrap();
        let xdg_surface::Event::Configure { serial } = event else {
            unreachable!();
        };

        let data = state.world.entity(target).unwrap();
        let mut xdg = hecs::RefMut::map(data.get::<&mut SurfaceRole>().unwrap(), |r| {
            r.xdg_mut().unwrap()
        });
        xdg.surface.ack_configure(serial);
        xdg.configured = true;

        let pending = xdg.pending.take();
        drop(xdg);

        if let Some(pending) = pending {
            let mut query = data.query::<(&SurfaceScaleFactor, &x::Window, &mut WindowData)>();
            let (scale_factor, window, window_data) = query.get().unwrap();

            let window = *window;
            let x = (pending.x as f64 * scale_factor.0) as i32 + window_data.output_offset.x;
            let y = (pending.y as f64 * scale_factor.0) as i32 + window_data.output_offset.y;
            let width = if pending.width > 0 {
                (pending.width as f64 * scale_factor.0) as u16
            } else {
                window_data.attrs.dims.width
            };
            let height = if pending.height > 0 {
                (pending.height as f64 * scale_factor.0) as u16
            } else {
                window_data.attrs.dims.height
            };
            debug!(
                "configuring {} ({window:?}): {x}x{y}, {width}x{height}",
                data.get::<&WlSurface>().unwrap().id(),
            );
            connection.set_window_dims(
                window,
                PendingSurfaceState {
                    x,
                    y,
                    width: width as _,
                    height: height as _,
                },
            );
            window_data.attrs.dims = WindowDims {
                x: x as i16,
                y: y as i16,
                width,
                height,
            };

            drop(query);
            update_surface_viewport(state.world.query_one(target).unwrap());
        }

        let (surface, attach, callback) = state
            .world
            .query_one_mut::<(
                &client::wl_surface::WlSurface,
                Option<&SurfaceAttach>,
                Option<&WlCallback>,
            )>(target)
            .unwrap();

        let mut cmd = CommandBuffer::new();

        if let Some(SurfaceAttach { buffer, x, y }) = attach {
            surface.attach(buffer.as_ref(), *x, *y);
            cmd.remove_one::<SurfaceAttach>(target);
        }
        if let Some(cb) = callback {
            surface.frame(&state.qh, cb.clone());
            cmd.remove_one::<client::wl_callback::WlCallback>(target);
        }
        surface.commit();
        cmd.run_on(&mut state.world);
    }

    fn toplevel_event<C: XConnection>(
        event: xdg_toplevel::Event,
        target: Entity,
        state: &mut ServerState<C>,
    ) {
        let data = state.world.entity(target).unwrap();
        match event {
            xdg_toplevel::Event::Configure {
                width,
                height,
                states,
            } => {
                debug!(
                    "configuring toplevel {} {width}x{height}, {states:?}",
                    data.get::<&WlSurface>().unwrap().id()
                );

                let mut role = data.get::<&mut SurfaceRole>().unwrap();
                if let SurfaceRole::Toplevel(Some(toplevel)) = &mut *role {
                    let prev_fs = toplevel.fullscreen;
                    toplevel.fullscreen =
                        states.contains(&(u32::from(xdg_toplevel::State::Fullscreen) as u8));
                    if toplevel.fullscreen != prev_fs {
                        state.connection.as_mut().unwrap().set_fullscreen(
                            *data.get::<&x::Window>().unwrap(),
                            toplevel.fullscreen,
                        );
                    }
                };

                role.xdg_mut().unwrap().pending = Some(PendingSurfaceState {
                    width,
                    height,
                    ..Default::default()
                });
            }
            xdg_toplevel::Event::Close => {
                let window = *data.get::<&x::Window>().unwrap();
                state.close_x_window(window);
            }
            // TODO: support capabilities (minimize, maximize, etc)
            xdg_toplevel::Event::WmCapabilities { .. } => {}
            xdg_toplevel::Event::ConfigureBounds { .. } => {}
            ref other => warn!("unhandled xdgtoplevel event: {other:?}"),
        }
    }

    fn popup_event<C: XConnection>(
        event: xdg_popup::Event,
        target: Entity,
        state: &mut ServerState<C>,
    ) {
        let data = state.world.entity(target).unwrap();
        match event {
            xdg_popup::Event::Configure {
                x,
                y,
                width,
                height,
            } => {
                trace!(
                    "popup configure {}: {x}x{y}, {width}x{height}",
                    data.get::<&WlSurface>().unwrap().id()
                );
                data.get::<&mut SurfaceRole>()
                    .unwrap()
                    .xdg_mut()
                    .unwrap()
                    .pending = Some(PendingSurfaceState {
                    x,
                    y,
                    width,
                    height,
                });
            }
            xdg_popup::Event::Repositioned { .. } => {}
            xdg_popup::Event::PopupDone => {
                state
                    .connection
                    .as_mut()
                    .unwrap()
                    .unmap_window(*data.get::<&x::Window>().unwrap());
            }
            other => todo!("{other:?}"),
        }
    }
}

pub(super) fn update_surface_viewport(
    mut surface_query: hecs::QueryOne<(
        &WindowData,
        &WpViewport,
        &SurfaceScaleFactor,
        Option<&SurfaceRole>,
        &WlSurface,
    )>,
) {
    let (window_data, viewport, scale_factor, role, surface) = surface_query.get().unwrap();
    let dims = &window_data.attrs.dims;
    let size_hints = &window_data.attrs.size_hints;

    let width = (dims.width as f64 / scale_factor.0) as i32;
    let height = (dims.height as f64 / scale_factor.0) as i32;
    if width > 0 && height > 0 {
        viewport.set_destination(width, height);
    }
    debug!("{} viewport: {width}x{height}", surface.id());
    if let Some(hints) = size_hints {
        let Some(SurfaceRole::Toplevel(Some(data))) = &role else {
            warn!(
                "Trying to update size hints on {}, but toplevel role data is missing",
                surface.id()
            );
            return;
        };

        if let Some(min) = hints.min_size {
            data.toplevel.set_min_size(
                (min.width as f64 / scale_factor.0) as i32,
                (min.height as f64 / scale_factor.0) as i32,
            );
        }
        if let Some(max) = hints.max_size {
            data.toplevel.set_max_size(
                (max.width as f64 / scale_factor.0) as i32,
                (max.height as f64 / scale_factor.0) as i32,
            );
        }
    }
}

impl Event for client::wl_buffer::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        // The only event from a buffer would be the release.
        state.world.get::<&WlBuffer>(target).unwrap().release();
    }
}

impl Event for client::wl_seat::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let server = state.world.get::<&WlSeat>(target).unwrap();
        simple_event_shunt! {
            server, self => [
                Capabilities { |capabilities| convert_wenum(capabilities) },
                Name { name }
            ]
        }
    }
}

struct PendingEnter(client::wl_pointer::Event);

impl Event for client::wl_pointer::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        // Workaround GTK (stupidly) autoclosing popups if it receives an wl_pointer.enter
        // event shortly after creation.
        // When Niri creates a popup, it immediately sends wl_pointer.enter on the new surface,
        // generating an EnterNotify event, and Xwayland will send a release button event.
        // In its menu implementation, GTK treats EnterNotify "this menu is now active" and will
        // destroy the menu if this occurs within a 500 ms interval (which it always does with
        // Niri). Other compositors do not run into this problem because they appear to not send
        // wl_pointer.enter until the user actually moves the mouse in the popup.

        match self {
            Self::Enter {
                serial,
                ref surface,
                surface_x,
                surface_y,
            } => {
                let mut cmd = CommandBuffer::new();
                let pending_enter = state.world.remove_one::<PendingEnter>(target).ok();
                let server = state.world.get::<&WlPointer>(target).unwrap();
                let mut query = surface.data().copied().and_then(|e| {
                    state
                        .world
                        .query_one::<(&WlSurface, &SurfaceRole, &SurfaceScaleFactor, &x::Window)>(e)
                        .ok()
                });
                let Some((surface, role, scale, window)) = query.as_mut().and_then(|q| q.get())
                else {
                    warn!("could not enter surface: stale surface");
                    return;
                };

                cmd.insert(target, (*scale,));

                let surface_is_popup = matches!(role, SurfaceRole::Popup(_));
                let mut do_enter = || {
                    debug!("pointer entering {} ({serial} {})", surface.id(), scale.0);
                    server.enter(serial, surface, surface_x * scale.0, surface_y * scale.0);
                    state.connection.as_mut().unwrap().raise_to_top(*window);
                    if !surface_is_popup {
                        state.last_hovered = Some(*window);
                    }
                };

                if !surface_is_popup {
                    do_enter();
                } else {
                    match pending_enter {
                        Some(e) => {
                            let PendingEnter(client::wl_pointer::Event::Enter {
                                serial: pending_serial,
                                ..
                            }) = e
                            else {
                                unreachable!();
                            };
                            if serial == pending_serial {
                                do_enter();
                            } else {
                                cmd.insert(target, (PendingEnter(self),));
                            }
                        }
                        None => {
                            cmd.insert(target, (PendingEnter(self),));
                        }
                    }
                }
                drop(query);
                drop(server);
                cmd.run_on(&mut state.world);
            }
            client::wl_pointer::Event::Leave { serial, surface } => {
                let _ = state.world.remove_one::<PendingEnter>(target);
                if !surface.is_alive() {
                    return;
                }
                debug!("leaving surface ({serial})");
                let _ = state.world.remove_one::<PendingEnter>(target);
                if let Some(surface) = surface
                    .data()
                    .copied()
                    .and_then(|key| state.world.get::<&WlSurface>(key).ok())
                {
                    state
                        .world
                        .get::<&WlPointer>(target)
                        .unwrap()
                        .leave(serial, &surface);
                } else {
                    warn!("could not leave surface: stale surface");
                }
            }
            client::wl_pointer::Event::Motion {
                time,
                surface_x,
                surface_y,
            } => {
                let pending_enter = state.world.get::<&PendingEnter>(target).ok();
                match pending_enter.as_deref() {
                    Some(p) => {
                        let PendingEnter(client::wl_pointer::Event::Enter {
                            serial,
                            surface,
                            surface_x,
                            surface_y,
                        }) = p
                        else {
                            unreachable!();
                        };
                        if surface
                            .data()
                            .copied()
                            .is_some_and(|key| state.world.contains(key))
                        {
                            trace!("resending enter ({serial}) before motion");
                            let enter_event = client::wl_pointer::Event::Enter {
                                serial: *serial,
                                surface: surface.clone(),
                                surface_x: *surface_x,
                                surface_y: *surface_y,
                            };

                            drop(pending_enter);
                            Self::handle(enter_event, target, state);
                            Self::handle(self, target, state);
                        } else {
                            warn!("could not move pointer to surface ({serial}): stale surface");
                        }
                    }
                    None => {
                        drop(pending_enter);
                        let (server, scale) = state
                            .world
                            .query_one_mut::<(&WlPointer, &SurfaceScaleFactor)>(target)
                            .unwrap();
                        trace!(
                            target: "pointer_position",
                            "pointer motion {} {}",
                            surface_x * scale.0,
                            surface_y * scale.0
                        );
                        server.motion(time, surface_x * scale.0, surface_y * scale.0);
                    }
                }
            }
            _ => {
                let server = state.world.get::<&WlPointer>(target).unwrap();
                simple_event_shunt! {
                    server, self => [
                        Frame,
                        Button {
                            serial,
                            time,
                            button,
                            |state| convert_wenum(state)
                        },
                        Axis {
                            time,
                            |axis| convert_wenum(axis),
                            value
                        },
                        AxisSource {
                            |axis_source| convert_wenum(axis_source)
                        },
                        AxisStop {
                            time,
                            |axis| convert_wenum(axis)
                        },
                        AxisDiscrete {
                            |axis| convert_wenum(axis),
                            discrete
                        },
                        AxisValue120 {
                            |axis| convert_wenum(axis),
                            value120
                        },
                        AxisRelativeDirection {
                            |axis| convert_wenum(axis),
                            |direction| convert_wenum(direction)
                        }
                    ]
                }
            }
        }
    }
}

impl Event for client::wl_keyboard::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let data = state.world.entity(target).unwrap();
        let keyboard = data.get::<&WlKeyboard>().unwrap();
        match self {
            client::wl_keyboard::Event::Enter {
                serial,
                surface,
                keys,
            } => {
                let mut query = surface.data().copied().and_then(|key| {
                    state
                        .world
                        .query_one::<(&x::Window, &WlSurface, Option<&OnOutput>)>(key)
                        .ok()
                });
                let Some((window, surface, output)) = query.as_mut().and_then(|q| q.get()) else {
                    return;
                };
                state.last_kb_serial = Some((
                    data.get::<&client::wl_seat::WlSeat>()
                        .as_deref()
                        .unwrap()
                        .clone(),
                    serial,
                ));
                let output_name = get_output_name(output, &state.world);
                state.to_focus = Some(FocusData {
                    window: *window,
                    output_name,
                });
                keyboard.enter(serial, surface, keys);
            }
            client::wl_keyboard::Event::Leave { serial, surface } => {
                if !surface.is_alive() {
                    return;
                }
                let mut query = surface
                    .data()
                    .copied()
                    .and_then(|key| state.world.query_one::<(&x::Window, &WlSurface)>(key).ok());
                let Some((window, surface)) = query.as_mut().and_then(|q| q.get()) else {
                    return;
                };
                if state.to_focus.as_ref().map(|d| d.window) == Some(*window) {
                    state.to_focus.take();
                } else {
                    state.unfocus = true;
                }
                keyboard.leave(serial, surface);
            }
            client::wl_keyboard::Event::Key {
                serial,
                time,
                key,
                state: key_state,
            } => {
                state.last_kb_serial = Some((
                    data.get::<&client::wl_seat::WlSeat>()
                        .as_deref()
                        .unwrap()
                        .clone(),
                    serial,
                ));
                keyboard.key(serial, time, key, convert_wenum(key_state));
            }
            _ => simple_event_shunt! {
                keyboard, self => [
                    Keymap {
                        |format| convert_wenum(format),
                        |fd| fd.as_fd(),
                        size
                    },
                    Modifiers {
                        serial,
                        mods_depressed,
                        mods_latched,
                        mods_locked,
                        group
                    },
                    RepeatInfo {
                        rate,
                        delay
                    }
                ]
            },
        }
    }
}

impl Event for client::wl_touch::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        match self {
            Self::Down {
                serial,
                time,
                surface,
                id,
                x,
                y,
            } => {
                let mut cmd = CommandBuffer::new();
                {
                    let mut s_query = surface.data().copied().and_then(|key| {
                        state
                            .world
                            .query_one::<(&WlSurface, &SurfaceScaleFactor)>(key)
                            .ok()
                    });
                    let Some((s_surface, s_factor)) = s_query.as_mut().and_then(|q| q.get()) else {
                        return;
                    };

                    cmd.insert(target, (*s_factor,));
                    let touch = state.world.get::<&WlTouch>(target).unwrap();
                    touch.down(serial, time, s_surface, id, x * s_factor.0, y * s_factor.0);
                }
                cmd.run_on(&mut state.world);
            }
            Self::Motion { time, id, x, y } => {
                let (touch, scale) = state
                    .world
                    .query_one_mut::<(&WlTouch, &SurfaceScaleFactor)>(target)
                    .unwrap();
                touch.motion(time, id, x * scale.0, y * scale.0);
            }
            _ => {
                let touch = state.world.get::<&WlTouch>(target).unwrap();
                simple_event_shunt! {
                    touch, self => [
                        Up { serial, time, id },
                        Frame,
                        Cancel,
                        Shape { id, major, minor },
                        Orientation { id, orientation }
                    ]
                }
            }
        }
    }
}

#[derive(Copy, Clone)]
pub(super) struct OnOutput(pub Entity);
struct OutputName(String);
fn get_output_name(output: Option<&OnOutput>, world: &World) -> Option<String> {
    output.map(|o| world.get::<&OutputName>(o.0).unwrap().0.clone())
}

#[derive(Copy, Clone, PartialEq, Debug)]
pub(super) enum OutputScaleFactor {
    Output(i32),
    Fractional(f64),
}

impl OutputScaleFactor {
    pub(super) fn get(&self) -> f64 {
        match *self {
            Self::Output(o) => o as _,
            Self::Fractional(f) => f,
        }
    }
}

#[must_use]
fn update_output_scale(
    mut output_scale: hecs::QueryOne<&mut OutputScaleFactor>,
    factor: OutputScaleFactor,
) -> bool {
    let output_scale = output_scale.get().unwrap();
    if matches!(output_scale, OutputScaleFactor::Fractional(..))
        && matches!(factor, OutputScaleFactor::Output(..))
    {
        return false;
    }

    if *output_scale != factor {
        *output_scale = factor;
        return true;
    }

    false
}

enum OutputDimensionsSource {
    // The data in this variant is the values needed for the wl_output.geometry event.
    Wl {
        physical_width: i32,
        physical_height: i32,
        subpixel: WEnum<client::wl_output::Subpixel>,
        make: String,
        model: String,
        transform: WEnum<client::wl_output::Transform>,
    },
    Xdg,
}

pub(super) struct OutputDimensions {
    source: OutputDimensionsSource,
    pub x: i32,
    pub y: i32,
    pub width: i32,
    pub height: i32,
    rotated_90: bool,
}

impl Default for OutputDimensions {
    fn default() -> Self {
        Self {
            source: OutputDimensionsSource::Wl {
                physical_height: 0,
                physical_width: 0,
                subpixel: WEnum::Value(client::wl_output::Subpixel::Unknown),
                make: "<unknown>".to_string(),
                model: "<unknown>".to_string(),
                transform: WEnum::Value(client::wl_output::Transform::Normal),
            },
            x: 0,
            y: 0,
            width: 0,
            height: 0,
            rotated_90: false,
        }
    }
}

fn update_output_offset(
    output: Entity,
    source: OutputDimensionsSource,
    x: i32,
    y: i32,
    state: &mut ServerState<impl XConnection>,
) {
    {
        let mut dimensions = state.world.get::<&mut OutputDimensions>(output).unwrap();
        if matches!(source, OutputDimensionsSource::Wl { .. })
            && matches!(dimensions.source, OutputDimensionsSource::Xdg)
        {
            return;
        }

        let global_offset = &mut state.global_output_offset;
        let mut maybe_update_dimension = |value, dim: &mut GlobalOutputOffsetDimension| {
            if value < dim.value {
                *dim = GlobalOutputOffsetDimension {
                    owner: Some(output),
                    value,
                };
                state.global_offset_updated = true;
            } else if dim.owner == Some(output) && value > dim.value {
                *dim = Default::default();
                state.global_offset_updated = true;
            }
        };

        maybe_update_dimension(x, &mut global_offset.x);
        maybe_update_dimension(y, &mut global_offset.y);

        dimensions.source = source;
        dimensions.x = x;
        dimensions.y = y;
        debug!(
            "moving {} to {x}x{y}",
            state.world.get::<&WlOutput>(output).unwrap().id()
        );
    }

    update_window_output_offsets(
        output,
        &state.global_output_offset,
        &state.world,
        &mut state.connection,
    );
}

fn update_window_output_offsets(
    output: Entity,
    global_output_offset: &GlobalOutputOffset,
    world: &World,
    connection: &mut Option<impl XConnection>,
) {
    let dimensions = world.get::<&OutputDimensions>(output).unwrap();
    let mut query = world.query::<(&x::Window, &mut WindowData, &OnOutput)>();

    for (_, (window, data, _)) in query
        .into_iter()
        .filter(|(_, (_, _, on_output))| on_output.0 == output)
    {
        data.update_output_offset(
            *window,
            WindowOutputOffset {
                x: dimensions.x - global_output_offset.x.value,
                y: dimensions.y - global_output_offset.y.value,
            },
            connection,
        );
    }
}

pub(super) fn update_global_output_offset(
    output: Entity,
    global_output_offset: &GlobalOutputOffset,
    world: &World,
    connection: &mut Option<impl XConnection>,
) {
    let entity = world.entity(output).unwrap();
    let mut query = entity.query::<(&OutputDimensions, &WlOutput)>();
    let (dimensions, server) = query.get().unwrap();

    let x = dimensions.x - global_output_offset.x.value;
    let y = dimensions.y - global_output_offset.y.value;

    match &dimensions.source {
        OutputDimensionsSource::Wl {
            physical_width,
            physical_height,
            subpixel,
            make,
            model,
            transform,
        } => {
            server.geometry(
                x,
                y,
                *physical_width,
                *physical_height,
                convert_wenum(*subpixel),
                make.clone(),
                model.clone(),
                convert_wenum(*transform),
            );
        }
        OutputDimensionsSource::Xdg => {
            entity
                .get::<&XdgOutputServer>()
                .unwrap()
                .logical_position(x, y);
        }
    }

    server.done();
    drop(query);

    update_window_output_offsets(output, global_output_offset, world, connection);
}

#[derive(Debug)]
pub enum OutputEvent {
    Wl(client::wl_output::Event),
    Xdg(zxdg_output_v1::Event),
}

impl From<client::wl_output::Event> for ObjectEvent {
    fn from(value: client::wl_output::Event) -> Self {
        Self::Output(OutputEvent::Wl(value))
    }
}

impl From<zxdg_output_v1::Event> for ObjectEvent {
    fn from(value: zxdg_output_v1::Event) -> Self {
        Self::Output(OutputEvent::Xdg(value))
    }
}

impl Event for OutputEvent {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        match self {
            OutputEvent::Xdg(event) => Self::xdg_event(event, target, state),
            OutputEvent::Wl(event) => Self::wl_event(event, target, state),
        }
    }
}

impl OutputEvent {
    fn wl_event<C: XConnection>(
        event: client::wl_output::Event,
        target: Entity,
        state: &mut ServerState<C>,
    ) {
        use client::wl_output::Event;
        match event {
            Event::Geometry {
                x,
                y,
                physical_width,
                physical_height,
                subpixel,
                make,
                model,
                transform,
            } => {
                update_output_offset(
                    target,
                    OutputDimensionsSource::Wl {
                        physical_width,
                        physical_height,
                        subpixel,
                        make: make.clone(),
                        model: model.clone(),
                        transform,
                    },
                    x,
                    y,
                    state,
                );

                let (output, dimensions, xdg) = state
                    .world
                    .query_one_mut::<(&WlOutput, &mut OutputDimensions, Option<&XdgOutputServer>)>(
                        target,
                    )
                    .unwrap();

                output.geometry(
                    x - state.global_output_offset.x.value,
                    y - state.global_output_offset.y.value,
                    physical_width,
                    physical_height,
                    convert_wenum(subpixel),
                    make,
                    model,
                    convert_wenum(transform),
                );
                dimensions.rotated_90 = transform.into_result().is_ok_and(|t| {
                    matches!(
                        t,
                        client::wl_output::Transform::_90
                            | client::wl_output::Transform::_270
                            | client::wl_output::Transform::Flipped90
                            | client::wl_output::Transform::Flipped270
                    )
                });
                if let Some(xdg) = xdg {
                    if dimensions.rotated_90 {
                        xdg.logical_size(dimensions.height, dimensions.width);
                    } else {
                        xdg.logical_size(dimensions.width, dimensions.height);
                    }
                }
            }
            Event::Mode {
                flags,
                width,
                height,
                refresh,
            } => {
                let (output, dimensions) = state
                    .world
                    .query_one_mut::<(&WlOutput, &mut OutputDimensions)>(target)
                    .unwrap();

                if flags
                    .into_result()
                    .is_ok_and(|f| f.contains(client::wl_output::Mode::Current))
                {
                    dimensions.width = width;
                    dimensions.height = height;
                    debug!("{} dimensions: {width}x{height}", output.id());
                }
                output.mode(convert_wenum(flags), width, height, refresh);
            }
            Event::Scale { factor } => {
                debug!(
                    "{} scale: {factor}",
                    state.world.get::<&WlOutput>(target).unwrap().id()
                );
                if update_output_scale(
                    state.world.query_one(target).unwrap(),
                    OutputScaleFactor::Output(factor),
                ) {
                    state.updated_outputs.push(target);
                }
                if state.fractional_scale.is_none() {
                    state.world.get::<&WlOutput>(target).unwrap().scale(factor);
                }
            }
            Event::Name { name } => {
                state
                    .world
                    .get::<&WlOutput>(target)
                    .unwrap()
                    .name(name.clone());
                state.world.insert(target, (OutputName(name),)).unwrap();
            }
            _ => simple_event_shunt! {
                state.world.get::<&WlOutput>(target).unwrap(),
                event: client::wl_output::Event => [
                    Description { description },
                    Done
                ]
            },
        }
    }

    fn xdg_event<C: XConnection>(
        event: zxdg_output_v1::Event,
        target: Entity,
        state: &mut ServerState<C>,
    ) {
        use zxdg_output_v1::Event;

        match event {
            Event::LogicalPosition { x, y } => {
                update_output_offset(target, OutputDimensionsSource::Xdg, x, y, state);
                state
                    .world
                    .get::<&XdgOutputServer>(target)
                    .unwrap()
                    .logical_position(
                        x - state.global_output_offset.x.value,
                        y - state.global_output_offset.y.value,
                    );
            }
            Event::LogicalSize { .. } => {
                let (xdg, dimensions) = state
                    .world
                    .query_one_mut::<(&XdgOutputServer, &OutputDimensions)>(target)
                    .unwrap();
                if dimensions.rotated_90 {
                    xdg.logical_size(dimensions.height, dimensions.width);
                } else {
                    xdg.logical_size(dimensions.width, dimensions.height);
                }
            }
            _ => simple_event_shunt! {
                state.world.get::<&XdgOutputServer>(target).unwrap(),
                event: zxdg_output_v1::Event => [
                    Done,
                    Name { name },
                    Description { description }
                ]
            },
        }
    }
}

impl Event for wl_drm::client::wl_drm::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let server = state.world.get::<&WlDrmServer>(target).unwrap();
        simple_event_shunt! {
            server, self => [
                Device { name },
                Format { format },
                Authenticated,
                Capabilities { value }
            ]
        }
    }
}

impl Event for c_dmabuf::zwp_linux_dmabuf_feedback_v1::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let server = state
            .world
            .get::<&s_dmabuf::zwp_linux_dmabuf_feedback_v1::ZwpLinuxDmabufFeedbackV1>(target)
            .unwrap();
        simple_event_shunt! {
            server, self => [
                Done,
                FormatTable { |fd| fd.as_fd(), size },
                MainDevice { device },
                TrancheDone,
                TrancheTargetDevice { device },
                TrancheFormats { indices },
                TrancheFlags { |flags| convert_wenum(flags) }
            ]
        }
    }
}

impl Event for zwp_relative_pointer_v1::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let server = state.world.get::<&RelativePointerServer>(target).unwrap();
        simple_event_shunt! {
            server, self => [
                RelativeMotion {
                    utime_hi,
                    utime_lo,
                    dx,
                    dy,
                    dx_unaccel,
                    dy_unaccel
                }
            ]
        }
    }
}

impl Event for zwp_locked_pointer_v1::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let server = state.world.get::<&LockedPointerServer>(target).unwrap();
        simple_event_shunt! {
            server, self => [
                Locked,
                Unlocked
            ]
        }
    }
}

impl Event for zwp_confined_pointer_v1::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let server = state.world.get::<&ConfinedPointerServer>(target).unwrap();
        simple_event_shunt! {
            server, self => [
                Confined,
                Unconfined
            ]
        }
    }
}

impl Event for zwp_tablet_seat_v2::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let seat = state.world.get::<&TabletSeatServer>(target).unwrap();
        match self {
            Self::TabletAdded { id } => {
                let (e, tab) = from_client::<TabletServer, _, _>(&id, state);
                seat.tablet_added(&tab);
                drop(seat);
                state.world.spawn_at(e, (tab, id));
            }
            Self::ToolAdded { id } => {
                let (e, tool) = from_client::<TabletToolServer, _, _>(&id, state);
                seat.tool_added(&tool);
                drop(seat);
                state.world.spawn_at(e, (tool, id));
            }
            Self::PadAdded { id } => {
                let (e, pad) = from_client::<TabletPadServer, _, _>(&id, state);
                seat.pad_added(&pad);
                drop(seat);
                state.world.spawn_at(e, (pad, id));
            }
            _ => log::warn!("unhandled {}: {self:?}", std::any::type_name::<Self>()),
        }
    }
}

impl Event for zwp_tablet_v2::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let tab = state.world.get::<&TabletServer>(target).unwrap();
        simple_event_shunt! {
            tab, self => [
                Name { name },
                Id { vid, pid },
                Path { path },
                Done,
                Removed
            ]
        }
    }
}

impl Event for zwp_tablet_pad_v2::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let pad = state.world.get::<&TabletPadServer>(target).unwrap();
        let s_surf;
        match self {
            Self::Group { pad_group } => {
                let (e, s_group) = from_client::<TabletPadGroupServer, _, _>(&pad_group, state);
                pad.group(&s_group);
                drop(pad);
                state.world.spawn_at(e, (pad_group, s_group));
            }
            Self::Enter {
                serial,
                tablet,
                surface,
            } => {
                let (e_tab, s_tablet) = from_client::<TabletServer, _, _>(&tablet, state);
                let Some(surface) = surface
                    .data()
                    .copied()
                    .and_then(|key| state.world.get::<&WlSurface>(key).ok())
                else {
                    return;
                };
                pad.enter(serial, &s_tablet, &surface);
                drop(pad);
                drop(surface);
                state.world.spawn_at(e_tab, (tablet, s_tablet));
            }
            _ => simple_event_shunt! {
                pad, self => [
                    Path { path },
                    Buttons { buttons },
                    Done,
                    Button {
                        time,
                        button,
                        |state| convert_wenum(state)
                    },
                    Leave {
                        serial,
                        |surface| {
                            s_surf = surface.data().copied().and_then(|key| state.world.get::<&WlSurface>(key).ok());
                            if let Some(s) = &s_surf { s } else { return; }
                        }
                    },
                    Removed
                ]
            },
        }
    }
}

impl Event for zwp_tablet_tool_v2::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        match self {
            Self::ProximityIn {
                serial,
                tablet,
                surface,
            } => {
                let mut cmd = CommandBuffer::new();
                {
                    let Some(mut query) = surface.data().copied().and_then(|key| {
                        state
                            .world
                            .query_one::<(&WlSurface, &SurfaceScaleFactor)>(key)
                            .ok()
                    }) else {
                        warn!("tablet tool proximity_in failed: stale surface");
                        return;
                    };
                    let (surface, scale) = query.get().unwrap();
                    cmd.insert(target, (*scale,));

                    let Some(s_tablet) =
                        tablet
                            .data()
                            .and_then(|key: &LateInitObjectKey<TabletClient>| {
                                state.world.get::<&TabletServer>(key.get()).ok()
                            })
                    else {
                        warn!("tablet tool proximity_in failed: stale tablet");
                        return;
                    };

                    state
                        .world
                        .get::<&TabletToolServer>(target)
                        .unwrap()
                        .proximity_in(serial, &s_tablet, surface);
                }
                cmd.run_on(&mut state.world);
            }
            Self::Motion { x, y } => {
                let (tool, scale) = state
                    .world
                    .query_one_mut::<(&TabletToolServer, Option<&SurfaceScaleFactor>)>(target)
                    .unwrap();
                let scale = scale.map(|s| s.0).unwrap_or(1.0);
                tool.motion(x * scale, y * scale);
            }
            _ => {
                let tool = state.world.get::<&TabletToolServer>(target).unwrap();
                simple_event_shunt! {
                    tool, self => [
                        Type { |tool_type| convert_wenum(tool_type) },
                        HardwareSerial { hardware_serial_hi, hardware_serial_lo },
                        HardwareIdWacom { hardware_id_hi, hardware_id_lo },
                        Capability { |capability| convert_wenum(capability) },
                        Done,
                        Removed,
                        ProximityOut,
                        Down { serial },
                        Up,
                        Distance { distance },
                        Pressure { pressure },
                        Tilt { tilt_x, tilt_y },
                        Rotation { degrees },
                        Slider { position },
                        Wheel { degrees, clicks },
                        Button { serial, button, |state| convert_wenum(state) },
                        Frame { time },
                    ]
                }
            }
        }
    }
}

#[must_use]
fn from_client<Server: Resource + 'static, Client: Proxy + Send + Sync + 'static, C: XConnection>(
    client: &Client,
    state: &ServerState<C>,
) -> (Entity, Server)
where
    Client::Event: Send + Into<ObjectEvent>,
    ServerState<C>: wayland_server::Dispatch<Server, Entity>,
{
    let entity = state.world.reserve_entity();
    let server = state
        .client
        .as_ref()
        .unwrap()
        .create_resource::<_, _, ServerState<C>>(&state.dh, 1, entity)
        .unwrap();
    let obj_key: &LateInitObjectKey<Client> = client.data().unwrap();
    obj_key.init(entity);
    (entity, server)
}

impl Event for zwp_tablet_pad_group_v2::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let group = state.world.get::<&TabletPadGroupServer>(target).unwrap();
        match self {
            Self::Buttons { buttons } => group.buttons(buttons),
            Self::Ring { ring } => {
                let (e, s_ring) = from_client::<TabletPadRingServer, _, _>(&ring, state);
                group.ring(&s_ring);
                drop(group);
                state.world.spawn_at(e, (s_ring, ring));
            }
            Self::Strip { strip } => {
                let (e, s_strip) = from_client::<TabletPadStripServer, _, _>(&strip, state);
                group.strip(&s_strip);
                drop(group);
                state.world.spawn_at(e, (s_strip, strip));
            }
            Self::Modes { modes } => group.modes(modes),
            Self::ModeSwitch { time, serial, mode } => group.mode_switch(time, serial, mode),
            Self::Done => group.done(),
            _ => log::warn!(
                "unhandled {} event: {self:?}",
                std::any::type_name::<Self>()
            ),
        }
    }
}

impl Event for zwp_tablet_pad_ring_v2::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let ring = state.world.get::<&TabletPadRingServer>(target).unwrap();
        simple_event_shunt! {
            ring, self => [
                Source { |source| convert_wenum(source) },
                Angle { degrees },
                Stop,
                Frame { time }
            ]
        }
    }
}

impl Event for zwp_tablet_pad_strip_v2::Event {
    fn handle<C: XConnection>(self, target: Entity, state: &mut ServerState<C>) {
        let strip = state.world.get::<&TabletPadStripServer>(target).unwrap();
        simple_event_shunt! {
            strip, self => [
                Source { |source| convert_wenum(source) },
                Position { position },
                Stop,
                Frame { time }
            ]
        }
    }
}