use syn;
use quote;

pub fn impl_rr_data(ast: &syn::DeriveInput) -> quote::Tokens {
	if !ast.generics.ty_params.is_empty() {
		panic!("Type parameters not supported for deriving RRData");
	}

	if !ast.generics.where_clause.predicates.is_empty() {
		panic!("Where clauses not supported for deriving RRData");
	}

	if !ast.generics.lifetimes.is_empty() {
		panic!("Lifetimes not supported for deriving RRData");
	}

	let name = &ast.ident;
	let name_str: &str = name.as_ref();

	let test_mod_name = syn::Ident::from(format!("test_rr_{}", name));

	quote!{
		impl ::dnsbox_base::ser::RRData for #name {
			fn rr_type() -> ::dnsbox_base::common_types::Type {
				::dnsbox_base::records::types::#name
			}

			fn rr_type_name() -> ::std::borrow::Cow<'static, str> {
				::std::borrow::Cow::Borrowed(#name_str)
			}
		}

		// #[cfg(test)]
		#[allow(non_snake_case, unused_imports)]
		mod #test_mod_name {
			use ::dnsbox_base::records::registry;
			use ::dnsbox_base::records::types;

			#[test]
			fn test_registry() {
				assert_eq!(
					registry::known_name_to_type(#name_str),
					Some(types::#name)
				);
			}
		}
	}
}