// Copyright 2020 Parity Technologies (UK) Ltd.
// This file is part of Parity Bridges Common.

// Parity Bridges Common 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.

// Parity Bridges Common 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 Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.

//! Tests for Grandpa Justification code.

use bp_header_chain::justification::{verify_justification, Error, GrandpaJustification};
use bp_test_utils::*;
use codec::Encode;

type TestHeader = sp_runtime::testing::Header;

fn make_justification_for_header_1() -> GrandpaJustification<TestHeader> {
	make_justification_for_header(
		&test_header(1),
		TEST_GRANDPA_ROUND,
		TEST_GRANDPA_SET_ID,
		&authority_list(),
	)
}

#[test]
fn justification_with_invalid_encoding_rejected() {
	assert_eq!(
		verify_justification::<TestHeader>(header_id::<TestHeader>(1), TEST_GRANDPA_SET_ID, voter_set(), &[],),
		Err(Error::JustificationDecode),
	);
}

#[test]
fn justification_with_invalid_target_rejected() {
	assert_eq!(
		verify_justification::<TestHeader>(
			header_id::<TestHeader>(2),
			TEST_GRANDPA_SET_ID,
			voter_set(),
			&make_justification_for_header_1().encode(),
		),
		Err(Error::InvalidJustificationTarget),
	);
}

#[test]
fn justification_with_invalid_commit_rejected() {
	let mut justification = make_justification_for_header_1();
	justification.commit.precommits.clear();

	assert_eq!(
		verify_justification::<TestHeader>(
			header_id::<TestHeader>(1),
			TEST_GRANDPA_SET_ID,
			voter_set(),
			&justification.encode(),
		),
		Err(Error::InvalidJustificationCommit),
	);
}

#[test]
fn justification_with_invalid_authority_signature_rejected() {
	let mut justification = make_justification_for_header_1();
	justification.commit.precommits[0].signature = Default::default();

	assert_eq!(
		verify_justification::<TestHeader>(
			header_id::<TestHeader>(1),
			TEST_GRANDPA_SET_ID,
			voter_set(),
			&justification.encode(),
		),
		Err(Error::InvalidAuthoritySignature),
	);
}

#[test]
fn justification_with_invalid_precommit_ancestry() {
	let mut justification = make_justification_for_header_1();
	justification.votes_ancestries.push(test_header(10));

	assert_eq!(
		verify_justification::<TestHeader>(
			header_id::<TestHeader>(1),
			TEST_GRANDPA_SET_ID,
			voter_set(),
			&justification.encode(),
		),
		Err(Error::InvalidPrecommitAncestries),
	);
}

#[test]
fn valid_justification_accepted() {
	assert_eq!(
		verify_justification::<TestHeader>(
			header_id::<TestHeader>(1),
			TEST_GRANDPA_SET_ID,
			voter_set(),
			&make_justification_for_header_1().encode(),
		),
		Ok(()),
	);
}