#[cfg(not(feature = "mock_data"))]
use crate::ExternRef;

pub trait Cacheable {
    #[cfg(not(feature = "mock_data"))]
    fn get_cache<'a>() -> &'a mut hashbrown::HashMap<ExternRef<Self>, Self>
    where
        Self: Sized;

    #[cfg(not(feature = "mock_data"))]
    fn from_ref(ptr: ExternRef<Self>, ctor: &dyn Fn(ExternRef<Self>) -> Self) -> Self
    where
        Self: Sized,
        Self: Clone,
    {
        let opt = Self::get_cache().get(&ptr);
        if let Some(v) = opt {
            return v.clone();
        }
        let value = ctor(ptr);
        Self::get_cache().insert(ptr, value.clone());
        value
    }
}

macro_rules! cacheable {
    ($type: ty) => {
        paste::paste! {
            #[cfg(not(feature = "mock_data"))]
            static mut [<$type:upper _CACHE>]: Option<hashbrown::HashMap<ExternRef<$type>, $type>> =
                None;
            impl crate::handling::Cacheable for $type {
                #[cfg(not(feature = "mock_data"))]
                fn get_cache<'a>() -> &'a mut hashbrown::HashMap<ExternRef<$type>, $type> {
                    unsafe {
                        if let None = [<$type:upper _CACHE>] {
                            [<$type:upper _CACHE>] = Some(hashbrown::HashMap::new());
                        }

                        [<$type:upper _CACHE>].as_mut().unwrap()
                    }
                }
            }
        }
    };
}

pub(crate) use cacheable;