// Copyright (C) 2022 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use proc_macro2::TokenStream;
use syn::{parse2, Result};

use super::{parse::*, *};

pub(crate) fn impl_orchestra_gen(
	attr: TokenStream,
	orig: TokenStream,
) -> Result<proc_macro2::TokenStream> {
	let args: OrchestraAttrArgs = parse2(attr)?;
	let message_wrapper = args.message_wrapper;

	let of: OrchestraGuts = parse2(orig)?;

	let support_crate = support_crate().expect("The crate this macro is run for, includes the proc-macro support as dependency, otherwise it could not be run in the first place. qed");
	let info = OrchestraInfo {
		support_crate,
		subsystems: of.subsystems,
		baggage: of.baggage,
		orchestra_name: of.name,
		message_wrapper,
		message_channel_capacity: args.message_channel_capacity,
		signal_channel_capacity: args.signal_channel_capacity,
		extern_event_ty: args.extern_event_ty,
		extern_signal_ty: args.extern_signal_ty,
		extern_error_ty: args.extern_error_ty,
		outgoing_ty: args.outgoing_ty,
	};

	let mut additive = impl_orchestra_struct(&info);
	additive.extend(impl_builder(&info));

	additive.extend(impl_orchestrated_subsystem(&info));
	additive.extend(impl_channels_out_struct(&info));
	additive.extend(impl_subsystem_types_all(&info)?);

	additive.extend(impl_message_wrapper_enum(&info)?);

	let ts = expander::Expander::new("orchestra-expansion")
		.add_comment("Generated orchestra code by `#[orchestra(..)]`".to_owned())
		.dry(!cfg!(feature = "expand"))
		.verbose(true)
		// once all our needed format options are available on stable
		// we should enabled this again, until then too many warnings
		// are generated
		// .fmt(expander::Edition::_2021)
		.write_to_out_dir(additive)
		.expect("Expander does not fail due to IO in OUT_DIR. qed");

	Ok(ts)
}