lyra-engine/lyra-reflect/src/component.rs

use std::{any::{Any, TypeId}, cell::{Ref, RefMut}};

use lyra_ecs::{Component, ComponentInfo, World, Entity, DynamicBundle};

use crate::{Reflect, FromType};

#[derive(Clone)]
pub struct ReflectedComponent {
    pub type_id: TypeId,
    pub info: ComponentInfo,
    //value: Value,
    //from_world: 

    //from_world: for<'a> fn (world: &'a mut World) -> Box<dyn Reflect>,
    /// Inserts component into entity in the world
    fn_insert: for<'a> fn (world: &'a mut World, entity: Entity, component: Box<dyn Reflect>),
    /// Inserts component into a bundle
    fn_bundle_insert: for<'a> fn (dynamic_bundle: &'a mut DynamicBundle, component: Box<dyn Reflect>),
    fn_reflect: for<'a> fn (world: &'a World, entity: Entity) -> Option<Ref<'a, dyn Reflect>>,
    fn_reflect_mut: for<'a> fn (world: &'a mut World, entity: Entity) -> Option<RefMut<'a, dyn Reflect>>,
}

impl ReflectedComponent {
    /// Insert the reflected component into an entity.
    pub fn insert(&self, world: &mut World, entity: Entity, component: Box<dyn Reflect>) {
        (self.fn_insert)(world, entity, component);
    }

    /// Insert this component into a DynamicBundle
    pub fn bundle_insert(&self, dynamic_bundle: &mut DynamicBundle, component: Box<dyn Reflect>) {
        (self.fn_bundle_insert)(dynamic_bundle, component)
    }

    /// Retrieves a reflected component from an entity.
    pub fn reflect<'a>(&'a self, world: &'a World, entity: Entity) -> Option<Ref<'a, dyn Reflect>> {
        (self.fn_reflect)(world, entity)
    }

    /// Retrieves a reflected component from an entity.
    pub fn reflect_mut<'a>(&'a mut self, world: &'a mut World, entity: Entity) -> Option<RefMut<'a, dyn Reflect>> {
        (self.fn_reflect_mut)(world, entity)
    }
}

impl<C: Component + Reflect> FromType<C> for ReflectedComponent {
    fn from_type() -> Self {
        ReflectedComponent {
            type_id: TypeId::of::<C>(),
            info: ComponentInfo::new::<C>(),
            fn_insert: |world: &mut World, entity: Entity, component: Box<dyn Reflect>| {
                let c = component as Box<dyn Any>;
                let c = c.downcast::<C>()
                    .expect("Provided a non-matching type to ReflectedComponent insert method!");
                let c = *c;
                world.insert(entity, (c,));
            },
            fn_bundle_insert: |bundle: &mut DynamicBundle, component: Box<dyn Reflect>| {
                let c = component as Box<dyn Any>;
                let c = c.downcast::<C>()
                    .expect("Provided a non-matching type to ReflectedComponent insert method!");
                let c = *c;
                bundle.push(c);
            },
            fn_reflect: |world: &World, entity: Entity| {
                world.view_one::<&C>(entity)
                    .get().map(|c| c as Ref<dyn Reflect>)
            },
            fn_reflect_mut: |world: &mut World, entity: Entity| {
                world.view_one::<&mut C>(entity)
                    .get().map(|c| c as RefMut<dyn Reflect>)
            },
        }
    }
}