use crate::constants::*;
use bevy::prelude::*;

#[derive(Component)]
#[require(Transform)]
pub struct Cursor {}

pub fn setup_cursor(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands.spawn((
        Transform::from_xyz(0., 0., 10.).with_scale(Vec3::splat(PIXEL_RATIO)),
        Sprite {
            image: asset_server.load("cursor.png"),
            ..Default::default()
        },
        Cursor {},
    ));
}

pub fn move_cursor(
    camera_query: Single<(&Camera, &GlobalTransform)>,
    windows: Query<&Window>,
    mut query: Query<(&Cursor, &mut Transform), With<Transform>>,
) {
    for mut transform in query.iter_mut() {
        let (camera, camera_transform) = *camera_query;

        let Ok(window) = windows.single() else {
            return;
        };

        let Some(cursor_position) = window.cursor_position() else {
            return;
        };

        // Calculate a world position based on the cursor's position.
        let Ok(point) = camera.viewport_to_world_2d(camera_transform, cursor_position) else {
            return;
        };
        transform.1.translation = Vec3::new(
            ((point.x / (TILE_SIZE) + 0.5).floor()) * TILE_SIZE,
            ((point.y / (TILE_SIZE) + 0.5).floor()) * TILE_SIZE,
            100.0,
        );
    }
}