use smithay::backend::input::{
    AbsolutePositionEvent, Axis, AxisSource, ButtonState, Event, InputBackend, InputEvent,
    KeyboardKeyEvent, PointerAxisEvent, PointerButtonEvent,
};
use smithay::input::keyboard::{keysyms, FilterResult};
use smithay::input::pointer::{AxisFrame, ButtonEvent, MotionEvent};
use smithay::reexports::wayland_server::protocol::wl_surface::WlSurface;
use smithay::utils::SERIAL_COUNTER;

use crate::niri::Niri;

enum InputAction {
    Quit,
    ChangeVt(i32),
}

impl Niri {
    pub fn process_input_event<I: InputBackend>(&mut self, event: InputEvent<I>) {
        trace!("process_input_event");

        match event {
            InputEvent::Keyboard { event, .. } => {
                let serial = SERIAL_COUNTER.next_serial();
                let time = Event::time_msec(&event);

                let action = self.seat.get_keyboard().unwrap().input(
                    self,
                    event.key_code(),
                    event.state(),
                    serial,
                    time,
                    |_, _, keysym| match keysym.modified_sym() {
                        keysyms::KEY_Escape => FilterResult::Intercept(InputAction::Quit),
                        keysym @ keysyms::KEY_XF86Switch_VT_1..=keysyms::KEY_XF86Switch_VT_12 => {
                            let vt = (keysym - keysyms::KEY_XF86Switch_VT_1 + 1) as i32;
                            FilterResult::Intercept(InputAction::ChangeVt(vt))
                        }
                        _ => FilterResult::Forward,
                    },
                );

                if let Some(action) = action {
                    match action {
                        InputAction::Quit => {
                            info!("quitting because Esc was pressed");
                            self.stop_signal.stop()
                        }
                        InputAction::ChangeVt(vt) => todo!(),
                    }
                }
            }
            InputEvent::PointerMotion { .. } => {}
            InputEvent::PointerMotionAbsolute { event, .. } => {
                let output = self.space.outputs().next().unwrap();

                let output_geo = self.space.output_geometry(output).unwrap();

                let pos = event.position_transformed(output_geo.size) + output_geo.loc.to_f64();

                let serial = SERIAL_COUNTER.next_serial();

                let pointer = self.seat.get_pointer().unwrap();

                let under = self.surface_under_pointer(&pointer);

                pointer.motion(
                    self,
                    under,
                    &MotionEvent {
                        location: pos,
                        serial,
                        time: event.time_msec(),
                    },
                );
            }
            InputEvent::PointerButton { event, .. } => {
                let pointer = self.seat.get_pointer().unwrap();
                let keyboard = self.seat.get_keyboard().unwrap();

                let serial = SERIAL_COUNTER.next_serial();

                let button = event.button_code();

                let button_state = event.state();

                if ButtonState::Pressed == button_state && !pointer.is_grabbed() {
                    if let Some((window, _loc)) = self
                        .space
                        .element_under(pointer.current_location())
                        .map(|(w, l)| (w.clone(), l))
                    {
                        self.space.raise_element(&window, true);
                        keyboard.set_focus(
                            self,
                            Some(window.toplevel().wl_surface().clone()),
                            serial,
                        );
                        self.space.elements().for_each(|window| {
                            window.toplevel().send_pending_configure();
                        });
                    } else {
                        self.space.elements().for_each(|window| {
                            window.set_activated(false);
                            window.toplevel().send_pending_configure();
                        });
                        keyboard.set_focus(self, Option::<WlSurface>::None, serial);
                    }
                };

                pointer.button(
                    self,
                    &ButtonEvent {
                        button,
                        state: button_state,
                        serial,
                        time: event.time_msec(),
                    },
                );
            }
            InputEvent::PointerAxis { event, .. } => {
                let source = event.source();

                // FIXME: this crashes on keyboard scroll.
                let horizontal_amount = event
                    .amount(Axis::Horizontal)
                    .unwrap_or_else(|| event.amount_discrete(Axis::Horizontal).unwrap() * 3.0);
                let vertical_amount = event
                    .amount(Axis::Vertical)
                    .unwrap_or_else(|| event.amount_discrete(Axis::Vertical).unwrap() * 3.0);
                let horizontal_amount_discrete = event.amount_discrete(Axis::Horizontal);
                let vertical_amount_discrete = event.amount_discrete(Axis::Vertical);

                let mut frame = AxisFrame::new(event.time_msec()).source(source);
                if horizontal_amount != 0.0 {
                    frame = frame.value(Axis::Horizontal, horizontal_amount);
                    if let Some(discrete) = horizontal_amount_discrete {
                        frame = frame.discrete(Axis::Horizontal, discrete as i32);
                    }
                } else if source == AxisSource::Finger {
                    frame = frame.stop(Axis::Horizontal);
                }
                if vertical_amount != 0.0 {
                    frame = frame.value(Axis::Vertical, vertical_amount);
                    if let Some(discrete) = vertical_amount_discrete {
                        frame = frame.discrete(Axis::Vertical, discrete as i32);
                    }
                } else if source == AxisSource::Finger {
                    frame = frame.stop(Axis::Vertical);
                }

                self.seat.get_pointer().unwrap().axis(self, frame);
            }
            _ => {}
        }
    }
}