// This file is part of Substrate.

// Copyright (C) 2019-2021 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.

//! Test utilities

#![cfg(test)]

use std::cell::RefCell;

use frame_support::{parameter_types, weights::Weight};
use pallet_session::historical as pallet_session_historical;
use sp_core::H256;
use sp_runtime::{
	testing::{Header, TestXt, UintAuthorityId},
	traits::{BlakeTwo256, ConvertInto, IdentityLookup},
	Permill,
};
use sp_staking::{
	offence::{OffenceError, ReportOffence},
	SessionIndex,
};

use crate as imonline;
use crate::Config;

type UncheckedExtrinsic = frame_system::mocking::MockUncheckedExtrinsic<Runtime>;
type Block = frame_system::mocking::MockBlock<Runtime>;

frame_support::construct_runtime!(
	pub enum Runtime where
		Block = Block,
		NodeBlock = Block,
		UncheckedExtrinsic = UncheckedExtrinsic,
	{
		System: frame_system::{Pallet, Call, Config, Storage, Event<T>},
		Session: pallet_session::{Pallet, Call, Storage, Event, Config<T>},
		ImOnline: imonline::{Pallet, Call, Storage, Config<T>, Event<T>},
		Historical: pallet_session_historical::{Pallet},
	}
);

thread_local! {
	pub static VALIDATORS: RefCell<Option<Vec<u64>>> = RefCell::new(Some(vec![
		1,
		2,
		3,
	]));
}

pub struct TestSessionManager;
impl pallet_session::SessionManager<u64> for TestSessionManager {
	fn new_session(_new_index: SessionIndex) -> Option<Vec<u64>> {
		VALIDATORS.with(|l| l.borrow_mut().take())
	}
	fn end_session(_: SessionIndex) {}
	fn start_session(_: SessionIndex) {}
}

impl pallet_session::historical::SessionManager<u64, u64> for TestSessionManager {
	fn new_session(_new_index: SessionIndex) -> Option<Vec<(u64, u64)>> {
		VALIDATORS.with(|l| {
			l.borrow_mut()
				.take()
				.map(|validators| validators.iter().map(|v| (*v, *v)).collect())
		})
	}
	fn end_session(_: SessionIndex) {}
	fn start_session(_: SessionIndex) {}
}

/// An extrinsic type used for tests.
pub type Extrinsic = TestXt<Call, ()>;
type IdentificationTuple = (u64, u64);
type Offence = crate::UnresponsivenessOffence<IdentificationTuple>;

thread_local! {
	pub static OFFENCES: RefCell<Vec<(Vec<u64>, Offence)>> = RefCell::new(vec![]);
}

/// A mock offence report handler.
pub struct OffenceHandler;
impl ReportOffence<u64, IdentificationTuple, Offence> for OffenceHandler {
	fn report_offence(reporters: Vec<u64>, offence: Offence) -> Result<(), OffenceError> {
		OFFENCES.with(|l| l.borrow_mut().push((reporters, offence)));
		Ok(())
	}

	fn is_known_offence(_offenders: &[IdentificationTuple], _time_slot: &SessionIndex) -> bool {
		false
	}
}

pub fn new_test_ext() -> sp_io::TestExternalities {
	let t = frame_system::GenesisConfig::default().build_storage::<Runtime>().unwrap();
	t.into()
}

parameter_types! {
	pub const BlockHashCount: u64 = 250;
	pub BlockWeights: frame_system::limits::BlockWeights =
		frame_system::limits::BlockWeights::simple_max(1024);
}

impl frame_system::Config for Runtime {
	type BaseCallFilter = frame_support::traits::Everything;
	type BlockWeights = ();
	type BlockLength = ();
	type DbWeight = ();
	type Origin = Origin;
	type Index = u64;
	type BlockNumber = u64;
	type Call = Call;
	type Hash = H256;
	type Hashing = BlakeTwo256;
	type AccountId = u64;
	type Lookup = IdentityLookup<Self::AccountId>;
	type Header = Header;
	type Event = Event;
	type BlockHashCount = BlockHashCount;
	type Version = ();
	type PalletInfo = PalletInfo;
	type AccountData = ();
	type OnNewAccount = ();
	type OnKilledAccount = ();
	type SystemWeightInfo = ();
	type SS58Prefix = ();
	type OnSetCode = ();
}

parameter_types! {
	pub const Period: u64 = 1;
	pub const Offset: u64 = 0;
}

impl pallet_session::Config for Runtime {
	type ShouldEndSession = pallet_session::PeriodicSessions<Period, Offset>;
	type SessionManager =
		pallet_session::historical::NoteHistoricalRoot<Runtime, TestSessionManager>;
	type SessionHandler = (ImOnline,);
	type ValidatorId = u64;
	type ValidatorIdOf = ConvertInto;
	type Keys = UintAuthorityId;
	type Event = Event;
	type NextSessionRotation = pallet_session::PeriodicSessions<Period, Offset>;
	type WeightInfo = ();
}

impl pallet_session::historical::Config for Runtime {
	type FullIdentification = u64;
	type FullIdentificationOf = ConvertInto;
}

parameter_types! {
	pub const UncleGenerations: u32 = 5;
}

impl pallet_authorship::Config for Runtime {
	type FindAuthor = ();
	type UncleGenerations = UncleGenerations;
	type FilterUncle = ();
	type EventHandler = ImOnline;
}

thread_local! {
	pub static MOCK_CURRENT_SESSION_PROGRESS: RefCell<Option<Option<Permill>>> = RefCell::new(None);
}

thread_local! {
	pub static MOCK_AVERAGE_SESSION_LENGTH: RefCell<Option<u64>> = RefCell::new(None);
}

pub struct TestNextSessionRotation;

impl frame_support::traits::EstimateNextSessionRotation<u64> for TestNextSessionRotation {
	fn average_session_length() -> u64 {
		// take the mock result if any and return it
		let mock = MOCK_AVERAGE_SESSION_LENGTH.with(|p| p.borrow_mut().take());

		mock.unwrap_or(pallet_session::PeriodicSessions::<Period, Offset>::average_session_length())
	}

	fn estimate_current_session_progress(now: u64) -> (Option<Permill>, Weight) {
		let (estimate, weight) =
			pallet_session::PeriodicSessions::<Period, Offset>::estimate_current_session_progress(
				now,
			);

		// take the mock result if any and return it
		let mock = MOCK_CURRENT_SESSION_PROGRESS.with(|p| p.borrow_mut().take());

		(mock.unwrap_or(estimate), weight)
	}

	fn estimate_next_session_rotation(now: u64) -> (Option<u64>, Weight) {
		pallet_session::PeriodicSessions::<Period, Offset>::estimate_next_session_rotation(now)
	}
}

parameter_types! {
	pub const UnsignedPriority: u64 = 1 << 20;
	pub const MaxKeys: u32 = 10_000;
	pub const MaxPeerInHeartbeats: u32 = 10_000;
	pub const MaxPeerDataEncodingSize: u32 = 1_000;
}

impl Config for Runtime {
	type AuthorityId = UintAuthorityId;
	type Event = Event;
	type ValidatorSet = Historical;
	type NextSessionRotation = TestNextSessionRotation;
	type ReportUnresponsiveness = OffenceHandler;
	type UnsignedPriority = UnsignedPriority;
	type WeightInfo = ();
	type MaxKeys = MaxKeys;
	type MaxPeerInHeartbeats = MaxPeerInHeartbeats;
	type MaxPeerDataEncodingSize = MaxPeerDataEncodingSize;
}

impl<LocalCall> frame_system::offchain::SendTransactionTypes<LocalCall> for Runtime
where
	Call: From<LocalCall>,
{
	type OverarchingCall = Call;
	type Extrinsic = Extrinsic;
}

pub fn advance_session() {
	let now = System::block_number().max(1);
	System::set_block_number(now + 1);
	Session::rotate_session();
	let keys = Session::validators().into_iter().map(UintAuthorityId).collect();
	ImOnline::set_keys(keys);
	assert_eq!(Session::current_index(), (now / Period::get()) as u32);
}