use bevy::prelude::*;
use common::prelude::*;

pub fn plugin(app: &mut App) {
    app.add_observer(insert_block_visuals);
    app.load_resource::<BlockAssets>();
}

#[derive(Resource, Asset, Reflect, Clone)]
#[reflect(Resource)]
pub struct BlockAssets {
    #[dependency]
    mesh: Handle<Mesh>,
    #[dependency]
    material: Handle<StandardMaterial>,
}

impl FromWorld for BlockAssets {
    fn from_world(world: &mut World) -> Self {
        let assets = world.resource::<AssetServer>();
        Self {
            mesh: assets.add(Cuboid::new(1.0, 1.0, 1.0).into()),
            material: assets.add(Color::srgb_u8(124, 144, 255).into()),
        }
    }
}

/// Observer which automatically inserts block visuals (mesh and
/// material) when an entity has the `Block` component added to it.
fn insert_block_visuals(
    add: On<Add, Block>,
    mut commands: Commands,
    block_assets: Res<BlockAssets>,
) {
    commands.entity(add.entity).insert((
        Mesh3d(block_assets.mesh.clone()),
        MeshMaterial3d(block_assets.material.clone()),
    ));
}