// This file is part of Substrate.

// Copyright (C) 2020 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.

//! Treasury pallet tests.

#![cfg(test)]

use super::*;
use std::cell::RefCell;
use frame_support::{
	assert_noop, assert_ok, impl_outer_origin, impl_outer_event, parameter_types,
	traits::{OnInitialize}
};
use frame_system::{self as system};

use sp_core::H256;
use sp_runtime::{
	ModuleId,
	testing::Header,
	traits::{BlakeTwo256, IdentityLookup},
};

impl_outer_origin! {
	pub enum Origin for Test where system = frame_system {}
}

mod treasury {
	// Re-export needed for `impl_outer_event!`.
	pub use super::super::*;
}

impl_outer_event! {
	pub enum Event for Test {
		system<T>,
		pallet_balances<T>,
		treasury<T>,
	}
}

#[derive(Clone, Eq, PartialEq)]
pub struct Test;
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 Test {
	type BaseCallFilter = ();
	type BlockWeights = ();
	type BlockLength = ();
	type DbWeight = ();
	type Origin = Origin;
	type Index = u64;
	type BlockNumber = u64;
	type Call = ();
	type Hash = H256;
	type Hashing = BlakeTwo256;
	type AccountId = u128; // u64 is not enough to hold bytes used to generate bounty account
	type Lookup = IdentityLookup<Self::AccountId>;
	type Header = Header;
	type Event = Event;
	type BlockHashCount = BlockHashCount;
	type Version = ();
	type PalletInfo = ();
	type AccountData = pallet_balances::AccountData<u64>;
	type OnNewAccount = ();
	type OnKilledAccount = ();
	type SystemWeightInfo = ();
	type SS58Prefix = ();
}
parameter_types! {
	pub const ExistentialDeposit: u64 = 1;
}
impl pallet_balances::Config for Test {
	type MaxLocks = ();
	type Balance = u64;
	type Event = Event;
	type DustRemoval = ();
	type ExistentialDeposit = ExistentialDeposit;
	type AccountStore = System;
	type WeightInfo = ();
}
thread_local! {
	static TEN_TO_FOURTEEN: RefCell<Vec<u128>> = RefCell::new(vec![10,11,12,13,14]);
}
parameter_types! {
	pub const ProposalBond: Permill = Permill::from_percent(5);
	pub const ProposalBondMinimum: u64 = 1;
	pub const SpendPeriod: u64 = 2;
	pub const Burn: Permill = Permill::from_percent(50);
	pub const TreasuryModuleId: ModuleId = ModuleId(*b"py/trsry");
	pub const BountyUpdatePeriod: u32 = 20;
	pub const BountyCuratorDeposit: Permill = Permill::from_percent(50);
	pub const BountyValueMinimum: u64 = 1;
}
impl Config for Test {
	type ModuleId = TreasuryModuleId;
	type Currency = pallet_balances::Module<Test>;
	type ApproveOrigin = frame_system::EnsureRoot<u128>;
	type RejectOrigin = frame_system::EnsureRoot<u128>;
	type Event = Event;
	type OnSlash = ();
	type ProposalBond = ProposalBond;
	type ProposalBondMinimum = ProposalBondMinimum;
	type SpendPeriod = SpendPeriod;
	type Burn = Burn;
	type BurnDestination = ();  // Just gets burned.
	type WeightInfo = ();
	type SpendFunds = ();
}
type System = frame_system::Module<Test>;
type Balances = pallet_balances::Module<Test>;
type Treasury = Module<Test>;

pub fn new_test_ext() -> sp_io::TestExternalities {
	let mut t = frame_system::GenesisConfig::default().build_storage::<Test>().unwrap();
	pallet_balances::GenesisConfig::<Test>{
		// Total issuance will be 200 with treasury account initialized at ED.
		balances: vec![(0, 100), (1, 98), (2, 1)],
	}.assimilate_storage(&mut t).unwrap();
	GenesisConfig::default().assimilate_storage::<Test, _>(&mut t).unwrap();
	t.into()
}

#[test]
fn genesis_config_works() {
	new_test_ext().execute_with(|| {
		assert_eq!(Treasury::pot(), 0);
		assert_eq!(Treasury::proposal_count(), 0);
	});
}

#[test]
fn minting_works() {
	new_test_ext().execute_with(|| {
		// Check that accumulate works when we have Some value in Dummy already.
		Balances::make_free_balance_be(&Treasury::account_id(), 101);
		assert_eq!(Treasury::pot(), 100);
	});
}

#[test]
fn spend_proposal_takes_min_deposit() {
	new_test_ext().execute_with(|| {
		assert_ok!(Treasury::propose_spend(Origin::signed(0), 1, 3));
		assert_eq!(Balances::free_balance(0), 99);
		assert_eq!(Balances::reserved_balance(0), 1);
	});
}

#[test]
fn spend_proposal_takes_proportional_deposit() {
	new_test_ext().execute_with(|| {
		assert_ok!(Treasury::propose_spend(Origin::signed(0), 100, 3));
		assert_eq!(Balances::free_balance(0), 95);
		assert_eq!(Balances::reserved_balance(0), 5);
	});
}

#[test]
fn spend_proposal_fails_when_proposer_poor() {
	new_test_ext().execute_with(|| {
		assert_noop!(
			Treasury::propose_spend(Origin::signed(2), 100, 3),
			Error::<Test, _>::InsufficientProposersBalance,
		);
	});
}

#[test]
fn accepted_spend_proposal_ignored_outside_spend_period() {
	new_test_ext().execute_with(|| {
		Balances::make_free_balance_be(&Treasury::account_id(), 101);

		assert_ok!(Treasury::propose_spend(Origin::signed(0), 100, 3));
		assert_ok!(Treasury::approve_proposal(Origin::root(), 0));

		<Treasury as OnInitialize<u64>>::on_initialize(1);
		assert_eq!(Balances::free_balance(3), 0);
		assert_eq!(Treasury::pot(), 100);
	});
}

#[test]
fn unused_pot_should_diminish() {
	new_test_ext().execute_with(|| {
		let init_total_issuance = Balances::total_issuance();
		Balances::make_free_balance_be(&Treasury::account_id(), 101);
		assert_eq!(Balances::total_issuance(), init_total_issuance + 100);

		<Treasury as OnInitialize<u64>>::on_initialize(2);
		assert_eq!(Treasury::pot(), 50);
		assert_eq!(Balances::total_issuance(), init_total_issuance + 50);
	});
}

#[test]
fn rejected_spend_proposal_ignored_on_spend_period() {
	new_test_ext().execute_with(|| {
		Balances::make_free_balance_be(&Treasury::account_id(), 101);

		assert_ok!(Treasury::propose_spend(Origin::signed(0), 100, 3));
		assert_ok!(Treasury::reject_proposal(Origin::root(), 0));

		<Treasury as OnInitialize<u64>>::on_initialize(2);
		assert_eq!(Balances::free_balance(3), 0);
		assert_eq!(Treasury::pot(), 50);
	});
}

#[test]
fn reject_already_rejected_spend_proposal_fails() {
	new_test_ext().execute_with(|| {
		Balances::make_free_balance_be(&Treasury::account_id(), 101);

		assert_ok!(Treasury::propose_spend(Origin::signed(0), 100, 3));
		assert_ok!(Treasury::reject_proposal(Origin::root(), 0));
		assert_noop!(Treasury::reject_proposal(Origin::root(), 0), Error::<Test, _>::InvalidIndex);
	});
}

#[test]
fn reject_non_existent_spend_proposal_fails() {
	new_test_ext().execute_with(|| {
		assert_noop!(Treasury::reject_proposal(Origin::root(), 0), Error::<Test, _>::InvalidIndex);
	});
}

#[test]
fn accept_non_existent_spend_proposal_fails() {
	new_test_ext().execute_with(|| {
		assert_noop!(Treasury::approve_proposal(Origin::root(), 0), Error::<Test, _>::InvalidIndex);
	});
}

#[test]
fn accept_already_rejected_spend_proposal_fails() {
	new_test_ext().execute_with(|| {
		Balances::make_free_balance_be(&Treasury::account_id(), 101);

		assert_ok!(Treasury::propose_spend(Origin::signed(0), 100, 3));
		assert_ok!(Treasury::reject_proposal(Origin::root(), 0));
		assert_noop!(Treasury::approve_proposal(Origin::root(), 0), Error::<Test, _>::InvalidIndex);
	});
}

#[test]
fn accepted_spend_proposal_enacted_on_spend_period() {
	new_test_ext().execute_with(|| {
		Balances::make_free_balance_be(&Treasury::account_id(), 101);
		assert_eq!(Treasury::pot(), 100);

		assert_ok!(Treasury::propose_spend(Origin::signed(0), 100, 3));
		assert_ok!(Treasury::approve_proposal(Origin::root(), 0));

		<Treasury as OnInitialize<u64>>::on_initialize(2);
		assert_eq!(Balances::free_balance(3), 100);
		assert_eq!(Treasury::pot(), 0);
	});
}

#[test]
fn pot_underflow_should_not_diminish() {
	new_test_ext().execute_with(|| {
		Balances::make_free_balance_be(&Treasury::account_id(), 101);
		assert_eq!(Treasury::pot(), 100);

		assert_ok!(Treasury::propose_spend(Origin::signed(0), 150, 3));
		assert_ok!(Treasury::approve_proposal(Origin::root(), 0));

		<Treasury as OnInitialize<u64>>::on_initialize(2);
		assert_eq!(Treasury::pot(), 100); // Pot hasn't changed

		let _ = Balances::deposit_into_existing(&Treasury::account_id(), 100).unwrap();
		<Treasury as OnInitialize<u64>>::on_initialize(4);
		assert_eq!(Balances::free_balance(3), 150); // Fund has been spent
		assert_eq!(Treasury::pot(), 25); // Pot has finally changed
	});
}

// Treasury account doesn't get deleted if amount approved to spend is all its free balance.
// i.e. pot should not include existential deposit needed for account survival.
#[test]
fn treasury_account_doesnt_get_deleted() {
	new_test_ext().execute_with(|| {
		Balances::make_free_balance_be(&Treasury::account_id(), 101);
		assert_eq!(Treasury::pot(), 100);
		let treasury_balance = Balances::free_balance(&Treasury::account_id());

		assert_ok!(Treasury::propose_spend(Origin::signed(0), treasury_balance, 3));
		assert_ok!(Treasury::approve_proposal(Origin::root(), 0));

		<Treasury as OnInitialize<u64>>::on_initialize(2);
		assert_eq!(Treasury::pot(), 100); // Pot hasn't changed

		assert_ok!(Treasury::propose_spend(Origin::signed(0), Treasury::pot(), 3));
		assert_ok!(Treasury::approve_proposal(Origin::root(), 1));

		<Treasury as OnInitialize<u64>>::on_initialize(4);
		assert_eq!(Treasury::pot(), 0); // Pot is emptied
		assert_eq!(Balances::free_balance(Treasury::account_id()), 1); // but the account is still there
	});
}

// In case treasury account is not existing then it works fine.
// This is useful for chain that will just update runtime.
#[test]
fn inexistent_account_works() {
	let mut t = frame_system::GenesisConfig::default().build_storage::<Test>().unwrap();
	pallet_balances::GenesisConfig::<Test>{
		balances: vec![(0, 100), (1, 99), (2, 1)],
	}.assimilate_storage(&mut t).unwrap();
	// Treasury genesis config is not build thus treasury account does not exist
	let mut t: sp_io::TestExternalities = t.into();

	t.execute_with(|| {
		assert_eq!(Balances::free_balance(Treasury::account_id()), 0); // Account does not exist
		assert_eq!(Treasury::pot(), 0); // Pot is empty

		assert_ok!(Treasury::propose_spend(Origin::signed(0), 99, 3));
		assert_ok!(Treasury::approve_proposal(Origin::root(), 0));
		assert_ok!(Treasury::propose_spend(Origin::signed(0), 1, 3));
		assert_ok!(Treasury::approve_proposal(Origin::root(), 1));
		<Treasury as OnInitialize<u64>>::on_initialize(2);
		assert_eq!(Treasury::pot(), 0); // Pot hasn't changed
		assert_eq!(Balances::free_balance(3), 0); // Balance of `3` hasn't changed

		Balances::make_free_balance_be(&Treasury::account_id(), 100);
		assert_eq!(Treasury::pot(), 99); // Pot now contains funds
		assert_eq!(Balances::free_balance(Treasury::account_id()), 100); // Account does exist

		<Treasury as OnInitialize<u64>>::on_initialize(4);

		assert_eq!(Treasury::pot(), 0); // Pot has changed
		assert_eq!(Balances::free_balance(3), 99); // Balance of `3` has changed
	});
}

#[test]
fn genesis_funding_works() {
	let mut t = frame_system::GenesisConfig::default().build_storage::<Test>().unwrap();
	let initial_funding = 100;
	pallet_balances::GenesisConfig::<Test>{
		// Total issuance will be 200 with treasury account initialized with 100.
		balances: vec![(0, 100), (Treasury::account_id(), initial_funding)],
	}.assimilate_storage(&mut t).unwrap();
	GenesisConfig::default().assimilate_storage::<Test, _>(&mut t).unwrap();
	let mut t: sp_io::TestExternalities = t.into();

	t.execute_with(|| {
		assert_eq!(Balances::free_balance(Treasury::account_id()), initial_funding);
		assert_eq!(Treasury::pot(), initial_funding - Balances::minimum_balance());
	});
}
