// Copyright 2015-2020 Parity Technologies (UK) Ltd.
// This file is part of Open Ethereum.

// Open Ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Open Ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Open Ethereum.  If not, see <http://www.gnu.org/licenses/>.

use std::path::Path;

use ethereum_types::U256;
use ethjson::test_helpers::difficulty::DifficultyTest;
use types::header::Header;
use spec::Spec;

use super::HookType;

pub fn json_difficulty_test<H: FnMut(&str, HookType)>(
	path: &Path,
	json_data: &[u8],
	spec: Spec,
	start_stop_hook: &mut H
) -> Vec<String> {
	let _ = env_logger::try_init();
	let tests = DifficultyTest::load(json_data)
		.expect(&format!("Could not parse JSON difficulty test data from {}", path.display()));
	let engine = &spec.engine;

	for (name, test) in tests.into_iter() {
		start_stop_hook(&name, HookType::OnStart);

		flushed_writeln!("   - {}...", name);

		let mut parent_header = Header::new();
		let block_number: u64 = test.current_block_number.into();
		parent_header.set_number(block_number - 1);
		parent_header.set_gas_limit(0x20000.into());
		parent_header.set_timestamp(test.parent_timestamp.into());
		parent_header.set_difficulty(test.parent_difficulty.into());
		parent_header.set_uncles_hash(test.parent_uncles.into());
		let mut header = Header::new();
		header.set_number(block_number);
		header.set_timestamp(test.current_timestamp.into());
		engine.populate_from_parent(&mut header, &parent_header);
		let expected_difficulty: U256 = test.current_difficulty.into();
		assert_eq!(header.difficulty(), &expected_difficulty);
		flushed_writeln!("OK");

		start_stop_hook(&name, HookType::OnStop);
	}
	vec![]
}

macro_rules! difficulty_json_test {
	( $spec:ident ) => {

	use std::path::Path;
	use super::json_difficulty_test;
	use tempfile::TempDir;
	use json_tests::HookType;

	fn do_json_test<H: FnMut(&str, HookType)>(path: &Path, json_data: &[u8], h: &mut H) -> Vec<String> {
		let tempdir = TempDir::new().unwrap();
		json_difficulty_test(path, json_data, crate::spec::$spec(&tempdir.path()), h)
	}

	}
}

macro_rules! difficulty_json_test_nopath {
	( $spec:ident ) => {
	use std::path::Path;

	use super::json_difficulty_test;
	use json_tests::HookType;

	fn do_json_test<H: FnMut(&str, HookType)>(path: &Path, json_data: &[u8], h: &mut H) -> Vec<String> {
		json_difficulty_test(path, json_data, crate::spec::$spec(), h)
	}

	}
}

mod difficulty_test {
	difficulty_json_test!(new_foundation);
	declare_test!{DifficultyTests_difficulty, "BasicTests/difficulty.json"}
}

mod difficulty_test_byzantium {
	difficulty_json_test_nopath!(new_byzantium_test);
	declare_test!{DifficultyTests_difficultyByzantium, "BasicTests/difficultyByzantium.json"}
}

mod difficulty_test_foundation {
	difficulty_json_test!(new_foundation);
	declare_test!{DifficultyTests_difficultyMainNetwork, "BasicTests/difficultyMainNetwork.json"}
}

// Disabling Ropsten diff tests; waiting for upstream ethereum/tests Constantinople update
//mod difficulty_test_ropsten {
//	difficulty_json_test_nopath!(new_ropsten_test);
//	declare_test!{DifficultyTests_difficultyRopsten, "BasicTests/difficultyRopsten.json"}
//}

mod difficulty_test_frontier {
	difficulty_json_test_nopath!(new_frontier_test);
	declare_test!{DifficultyTests_difficultyFrontier, "BasicTests/difficultyFrontier.json"}
}

mod difficulty_test_homestead {
	difficulty_json_test_nopath!(new_homestead_test);
	declare_test!{DifficultyTests_difficultyHomestead, "BasicTests/difficultyHomestead.json"}
}
