use bevy::app::{App, Update};
use bevy::window::PrimaryWindow;
use crate::ecs::MainCamera;
use crate::prelude::*;


pub fn input_plugin(app: &mut App) {
    app
        .insert_resource(CursorWorldCoordinates(None))
        .add_systems(Update, update_cursor_position);
}


#[derive(Resource, Default)]
pub struct CursorWorldCoordinates(pub Option<Vec2>);

fn update_cursor_position(
    q_windows: Query<&Window, With<PrimaryWindow>>,
    q_camera: Query<(&Camera, &GlobalTransform), With<MainCamera>>,
    mut coords: ResMut<CursorWorldCoordinates>,
) {
    let (camera, camera_transform) = q_camera.single().unwrap();
    let window = q_windows.single().unwrap();

    if let Some(world_position) = window
        .cursor_position()
        .and_then(|cursor| camera.viewport_to_world(camera_transform, cursor).ok())
        .map(|ray| ray.origin.truncate())
    {
        coords.0 = Some(world_position);
    } else {
        coords.0 = None;
    }
}