use crate::entity::Handle as EntityHandle;
use crate::system::{Metadata as SystemMetadata, Param as SystemParam};
use crate::uid::Uid;
use crate::World;

#[derive(Debug)]
pub struct Obtainer<'world>
{
    world: &'world World,
}

impl<'world> SystemParam<'world> for Obtainer<'world>
{
    type Input = ();

    fn new(world: &'world World, _system_metadata: &SystemMetadata) -> Self
    {
        Self { world }
    }
}

impl Obtainer<'_>
{
    #[must_use]
    pub fn get_entity(&self, entity_id: Uid) -> Option<EntityHandle<'_>>
    {
        self.world.get_entity(entity_id)
    }
}