pub use jay_keyboard::{KbvmContext, KbvmError, KbvmMap, KbvmMapId, KbvmState};

use {
    crate::{
        backend::KeyState,
        ifs::wl_seat::WlSeatGlobal,
        utils::{syncqueue::SyncQueue, vecset::VecSet},
    },
    kbvm::{
        Keycode,
        state_machine::{Direction, Event},
    },
    std::{
        cell::{Cell, RefCell},
        rc::Rc,
    },
};

pub struct PhysicalKeyboardState {
    state: Rc<RefCell<KbvmState>>,
    inner: RefCell<PkInner>,
    events: SyncQueue<Event>,
    flushing: Cell<bool>,
}

#[derive(Default)]
struct PkInner {
    pressed_keys: VecSet<u32>,
    event_stash: Vec<Event>,
}

impl PhysicalKeyboardState {
    pub fn new(state: &Rc<RefCell<KbvmState>>) -> Self {
        Self {
            state: state.clone(),
            inner: Default::default(),
            events: Default::default(),
            flushing: Cell::new(false),
        }
    }

    fn flush(&self, time_usec: u64, seat: &Rc<WlSeatGlobal>) {
        if self.flushing.replace(true) {
            return;
        }
        seat.key_events(time_usec, &self.events, &self.state);
        self.flushing.set(false);
    }

    pub fn update(&self, time_usec: u64, seat: &Rc<WlSeatGlobal>, key: u32, key_state: KeyState) {
        {
            let inner = &mut *self.inner.borrow_mut();
            match key_state {
                KeyState::Released => {
                    if !inner.pressed_keys.remove(&key) {
                        return;
                    }
                }
                KeyState::Pressed => {
                    if !inner.pressed_keys.insert(key) {
                        return;
                    }
                }
                KeyState::Repeated => {
                    return;
                }
            }
            let state = &mut *self.state.borrow_mut();
            state.map.state_machine.handle_key(
                &mut state.state,
                &mut inner.event_stash,
                Keycode::from_evdev(key),
                match key_state {
                    KeyState::Released => Direction::Up,
                    KeyState::Pressed => Direction::Down,
                    KeyState::Repeated => unreachable!(),
                },
            );
            self.events.append(&mut inner.event_stash);
        }
        self.flush(time_usec, seat);
    }

    pub fn destroy(&self, time_usec: u64, seat: &Rc<WlSeatGlobal>) {
        {
            let inner = &mut *self.inner.borrow_mut();
            let state = &mut *self.state.borrow_mut();
            let sm = &state.map.state_machine;
            while let Some(key) = inner.pressed_keys.pop() {
                sm.handle_key(
                    &mut state.state,
                    &mut inner.event_stash,
                    Keycode::from_evdev(key),
                    Direction::Up,
                );
            }
            self.events.append(&mut inner.event_stash);
        }
        self.flush(time_usec, seat);
    }
}