use std::cell::RefCell;
use smithay::{
    wayland::{
        output::Output,
        seat::Seat,
    },
    utils::{Rectangle, Transform, Logical},
};
use crate::{
    input::ActiveOutput,
    state::Common,
};

pub use crate::{
    state::State,
};

pub trait OutputExt {
    fn geometry(&self) -> Rectangle<i32, Logical>;
}

impl OutputExt for Output {
    fn geometry(&self) -> Rectangle<i32, Logical> {
        Rectangle::from_loc_and_size(
            self.current_location(),
            {
                Transform::from(self.current_transform()).transform_size(
                    self.current_mode().map(|m| m.size).unwrap_or_else(|| (0,0).into())
                ).to_f64().to_logical(self.current_scale().fractional_scale()).to_i32_round()
            },
        )
    }
}

pub fn active_output(seat: &Seat<State>, state: &Common) -> Output {
    seat.user_data()
        .get::<ActiveOutput>()
        .map(|x| x.0.borrow().clone())
        .unwrap_or_else(|| {
            state
                .shell
                .outputs()
                .next()
                .cloned()
                .expect("Backend has no outputs?")
        })
}

pub fn set_active_output(seat: &Seat<State>, output: &Output) {
    if !seat
        .user_data()
        .insert_if_missing(|| ActiveOutput(RefCell::new(output.clone())))
    {
        *seat
            .user_data()
            .get::<ActiveOutput>()
            .unwrap()
            .0
            .borrow_mut() = output.clone();
    }
}