use proc_macro::TokenStream;
use quote::quote;
use syn::{parse_macro_input, ItemFn};

extern crate proc_macro;

#[proc_macro]
pub fn plugin(metadata: TokenStream) -> TokenStream {
    emit_plugin_api().into()
}

#[proc_macro_attribute]
pub fn plugin_init(attribute: TokenStream, item: TokenStream) -> TokenStream {
    let input = parse_macro_input!(item as ItemFn);

    let func = input.sig.ident.clone();

    quote! {
        #[doc(hidden)]
        #[no_mangle]
        unsafe extern "C" fn __plugin_init() {
            #func(&mut ::giterated_plugin::local::PluginStackBuilder::new()).unwrap()
        }

        #input
    }
    .into()
}

fn emit_plugin_api() -> impl Into<TokenStream> {
    quote! {
        #[doc(hidden)]
        #[no_mangle]
        unsafe extern "C" fn __load_runtime_vtable(vtable: &'static ::giterated_plugin::abi::vtable::VTable<::giterated_plugin::abi::vtable::runtime::RuntimeHandle>) {
            todo!()
        }

        #[doc(hidden)]
        #[no_mangle]
        unsafe extern "C" fn __get_plugin_vtable() -> &'static ::giterated_plugin::abi::vtable::VTable<::giterated_plugin::abi::vtable::plugin::Plugin> {
            todo!()
        }
    }
}