// Copyright 2018-2020 Parity Technologies (UK) Ltd.
// This file is part of Substrate.

// Substrate 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.

// Substrate 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 Substrate. If not, see <http://www.gnu.org/licenses/>.

// TODO: #1417 Add more integration tests
// also remove the #![allow(unused)] below.

#![allow(unused)]

use crate::{
	BalanceOf, ComputeDispatchFee, ContractAddressFor, ContractInfo, ContractInfoOf, GenesisConfig,
	Module, RawAliveContractInfo, RawEvent, Trait, TrieId, TrieIdFromParentCounter, Schedule,
	TrieIdGenerator, account_db::{AccountDb, DirectAccountDb, OverlayAccountDb},
	gas::Gas,
};
use assert_matches::assert_matches;
use hex_literal::*;
use codec::{Decode, Encode, KeyedVec};
use sp_runtime::{
	Perbill, BuildStorage, transaction_validity::{InvalidTransaction, ValidTransaction},
	traits::{BlakeTwo256, Hash, IdentityLookup, SignedExtension, Convert},
	testing::{Digest, DigestItem, Header, UintAuthorityId, H256},
};
use frame_support::{
	assert_ok, assert_err, assert_err_ignore_postinfo, impl_outer_dispatch, impl_outer_event,
	impl_outer_origin, parameter_types,
	storage::child, StorageMap, StorageValue, traits::{Currency, Get},
	weights::{DispatchInfo, DispatchClass, Weight, PostDispatchInfo, Pays},
};
use std::{cell::RefCell, sync::atomic::{AtomicUsize, Ordering}};
use sp_core::storage::well_known_keys;
use frame_system::{self as system, EventRecord, Phase};

mod contracts {
	// Re-export contents of the root. This basically
	// needs to give a name for the current crate.
	// This hack is required for `impl_outer_event!`.
	pub use super::super::*;
	use frame_support::impl_outer_event;
}

use pallet_balances as balances;

impl_outer_event! {
	pub enum MetaEvent for Test {
		system<T>,
		balances<T>,
		contracts<T>,
	}
}
impl_outer_origin! {
	pub enum Origin for Test  where system = frame_system { }
}
impl_outer_dispatch! {
	pub enum Call for Test where origin: Origin {
		balances::Balances,
		contracts::Contracts,
	}
}

thread_local! {
	static EXISTENTIAL_DEPOSIT: RefCell<u64> = RefCell::new(0);
}

pub struct ExistentialDeposit;
impl Get<u64> for ExistentialDeposit {
	fn get() -> u64 { EXISTENTIAL_DEPOSIT.with(|v| *v.borrow()) }
}

#[derive(Clone, Eq, PartialEq, Debug)]
pub struct Test;
parameter_types! {
	pub const BlockHashCount: u64 = 250;
	pub const MaximumBlockWeight: Weight = 1024;
	pub const MaximumBlockLength: u32 = 2 * 1024;
	pub const AvailableBlockRatio: Perbill = Perbill::one();
}
impl frame_system::Trait for Test {
	type Origin = Origin;
	type Index = u64;
	type BlockNumber = u64;
	type Hash = H256;
	type Call = ();
	type Hashing = BlakeTwo256;
	type AccountId = u64;
	type Lookup = IdentityLookup<Self::AccountId>;
	type Header = Header;
	type Event = MetaEvent;
	type BlockHashCount = BlockHashCount;
	type MaximumBlockWeight = MaximumBlockWeight;
	type DbWeight = ();
	type BlockExecutionWeight = ();
	type ExtrinsicBaseWeight = ();
	type AvailableBlockRatio = AvailableBlockRatio;
	type MaximumBlockLength = MaximumBlockLength;
	type Version = ();
	type ModuleToIndex = ();
	type AccountData = pallet_balances::AccountData<u64>;
	type OnNewAccount = ();
	type OnKilledAccount = ();
}
impl pallet_balances::Trait for Test {
	type Balance = u64;
	type Event = MetaEvent;
	type DustRemoval = ();
	type ExistentialDeposit = ExistentialDeposit;
	type AccountStore = System;
}
parameter_types! {
	pub const MinimumPeriod: u64 = 1;
}
impl pallet_timestamp::Trait for Test {
	type Moment = u64;
	type OnTimestampSet = ();
	type MinimumPeriod = MinimumPeriod;
}
parameter_types! {
	pub const SignedClaimHandicap: u64 = 2;
	pub const TombstoneDeposit: u64 = 16;
	pub const StorageSizeOffset: u32 = 8;
	pub const RentByteFee: u64 = 4;
	pub const RentDepositOffset: u64 = 10_000;
	pub const SurchargeReward: u64 = 150;
	pub const MaxDepth: u32 = 100;
	pub const MaxValueSize: u32 = 16_384;
}

parameter_types! {
	pub const TransactionByteFee: u64 = 0;
}

impl Convert<Weight, BalanceOf<Self>> for Test {
	fn convert(w: Weight) -> BalanceOf<Self> {
		w
	}
}

impl pallet_transaction_payment::Trait for Test {
	type Currency = Balances;
	type OnTransactionPayment = ();
	type TransactionByteFee = TransactionByteFee;
	type WeightToFee = Test;
	type FeeMultiplierUpdate = ();
}

impl Trait for Test {
	type Time = Timestamp;
	type Randomness = Randomness;
	type Call = Call;
	type DetermineContractAddress = DummyContractAddressFor;
	type Event = MetaEvent;
	type TrieIdGenerator = DummyTrieIdGenerator;
	type RentPayment = ();
	type SignedClaimHandicap = SignedClaimHandicap;
	type TombstoneDeposit = TombstoneDeposit;
	type StorageSizeOffset = StorageSizeOffset;
	type RentByteFee = RentByteFee;
	type RentDepositOffset = RentDepositOffset;
	type SurchargeReward = SurchargeReward;
	type MaxDepth = MaxDepth;
	type MaxValueSize = MaxValueSize;
}

type Balances = pallet_balances::Module<Test>;
type Timestamp = pallet_timestamp::Module<Test>;
type Contracts = Module<Test>;
type System = frame_system::Module<Test>;
type Randomness = pallet_randomness_collective_flip::Module<Test>;

pub struct DummyContractAddressFor;
impl ContractAddressFor<H256, u64> for DummyContractAddressFor {
	fn contract_address_for(_code_hash: &H256, _data: &[u8], origin: &u64) -> u64 {
		*origin + 1
	}
}

pub struct DummyTrieIdGenerator;
impl TrieIdGenerator<u64> for DummyTrieIdGenerator {
	fn trie_id(account_id: &u64) -> TrieId {
		use sp_core::storage::well_known_keys;

		let new_seed = super::AccountCounter::mutate(|v| {
			*v = v.wrapping_add(1);
			*v
		});

		let mut res = vec![];
		res.extend_from_slice(&new_seed.to_le_bytes());
		res.extend_from_slice(&account_id.to_le_bytes());
		res
	}
}

pub struct DummyComputeDispatchFee;
impl ComputeDispatchFee<Call, u64> for DummyComputeDispatchFee {
	fn compute_dispatch_fee(call: &Call) -> u64 {
		69
	}
}

const ALICE: u64 = 1;
const BOB: u64 = 2;
const CHARLIE: u64 = 3;
const DJANGO: u64 = 4;

const GAS_LIMIT: Gas = 10_000_000_000;

pub struct ExtBuilder {
	existential_deposit: u64,
}
impl Default for ExtBuilder {
	fn default() -> Self {
		Self {
			existential_deposit: 1,
		}
	}
}
impl ExtBuilder {
	pub fn existential_deposit(mut self, existential_deposit: u64) -> Self {
		self.existential_deposit = existential_deposit;
		self
	}
	pub fn set_associated_consts(&self) {
		EXISTENTIAL_DEPOSIT.with(|v| *v.borrow_mut() = self.existential_deposit);
	}
	pub fn build(self) -> sp_io::TestExternalities {
		self.set_associated_consts();
		let mut t = frame_system::GenesisConfig::default().build_storage::<Test>().unwrap();
		pallet_balances::GenesisConfig::<Test> {
			balances: vec![],
		}.assimilate_storage(&mut t).unwrap();
		GenesisConfig {
			current_schedule: Schedule {
				enable_println: true,
				..Default::default()
			},
		}.assimilate_storage(&mut t).unwrap();
		let mut ext = sp_io::TestExternalities::new(t);
		ext.execute_with(|| System::set_block_number(1));
		ext
	}
}

/// Generate Wasm binary and code hash from wabt source.
fn compile_module<T>(wabt_module: &str)
	-> Result<(Vec<u8>, <T::Hashing as Hash>::Output), wabt::Error>
	where T: frame_system::Trait
{
	let wasm = wabt::wat2wasm(wabt_module)?;
	let code_hash = T::Hashing::hash(&wasm);
	Ok((wasm, code_hash))
}

// Perform a simple transfer to a non-existent account.
// Then we check that only the base costs are returned as actual costs.
#[test]
fn returns_base_call_cost() {
	ExtBuilder::default().build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 100_000_000);

		assert_eq!(
			Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, Vec::new()),
			Ok(
				PostDispatchInfo {
					actual_weight: Some(67500000),
				}
			)
		);
	});
}

#[test]
fn account_removal_does_not_remove_storage() {
	ExtBuilder::default().existential_deposit(100).build().execute_with(|| {
		let trie_id1 = <Test as Trait>::TrieIdGenerator::trie_id(&1);
		let trie_id2 = <Test as Trait>::TrieIdGenerator::trie_id(&2);
		let key1 = &[1; 32];
		let key2 = &[2; 32];

		// Set up two accounts with free balance above the existential threshold.
		{
			Balances::deposit_creating(&1, 110);
			ContractInfoOf::<Test>::insert(1, &ContractInfo::Alive(RawAliveContractInfo {
				trie_id: trie_id1.clone(),
				storage_size: <Test as Trait>::StorageSizeOffset::get(),
				deduct_block: System::block_number(),
				code_hash: H256::repeat_byte(1),
				rent_allowance: 40,
				last_write: None,
			}));

			let mut overlay = OverlayAccountDb::<Test>::new(&DirectAccountDb);
			overlay.set_storage(&1, key1.clone(), Some(b"1".to_vec()));
			overlay.set_storage(&1, key2.clone(), Some(b"2".to_vec()));
			DirectAccountDb.commit(overlay.into_change_set());

			Balances::deposit_creating(&2, 110);
			ContractInfoOf::<Test>::insert(2, &ContractInfo::Alive(RawAliveContractInfo {
				trie_id: trie_id2.clone(),
				storage_size: <Test as Trait>::StorageSizeOffset::get(),
				deduct_block: System::block_number(),
				code_hash: H256::repeat_byte(2),
				rent_allowance: 40,
				last_write: None,
			}));

			let mut overlay = OverlayAccountDb::<Test>::new(&DirectAccountDb);
			overlay.set_storage(&2, key1.clone(), Some(b"3".to_vec()));
			overlay.set_storage(&2, key2.clone(), Some(b"4".to_vec()));
			DirectAccountDb.commit(overlay.into_change_set());
		}

		// Transfer funds from account 1 of such amount that after this transfer
		// the balance of account 1 will be below the existential threshold.
		//
		// This does not remove the contract storage as we are not notified about a
		// account removal. This cannot happen in reality because a contract can only
		// remove itself by `ext_terminate`. There is no external event that can remove
		// the account appart from that.
		assert_ok!(Balances::transfer(Origin::signed(1), 2, 20));

		// Verify that no entries are removed.
		{
			assert_eq!(
				<dyn AccountDb<Test>>::get_storage(&DirectAccountDb, &1, Some(&trie_id1), key1),
				Some(b"1".to_vec())
			);
			assert_eq!(
				<dyn AccountDb<Test>>::get_storage(&DirectAccountDb, &1, Some(&trie_id1), key2),
				Some(b"2".to_vec())
			);

			assert_eq!(
				<dyn AccountDb<Test>>::get_storage(&DirectAccountDb, &2, Some(&trie_id2), key1),
				Some(b"3".to_vec())
			);
			assert_eq!(
				<dyn AccountDb<Test>>::get_storage(&DirectAccountDb, &2, Some(&trie_id2), key2),
				Some(b"4".to_vec())
			);
		}
	});
}

#[test]
fn instantiate_and_call_and_deposit_event() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("return_from_start_fn.wat"))
		.unwrap();

	ExtBuilder::default().existential_deposit(100).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);

		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

		// Check at the end to get hash on error easily
		let creation = Contracts::instantiate(
			Origin::signed(ALICE),
			100,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		);

		assert_eq!(System::events(), vec![
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(pallet_balances::RawEvent::Endowed(1, 1_000_000)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::CodeStored(code_hash.into())),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(BOB)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(
					pallet_balances::RawEvent::Endowed(BOB, 100)
				),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::Transfer(ALICE, BOB, 100)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::ContractExecution(BOB, vec![1, 2, 3, 4])),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::Instantiated(ALICE, BOB)),
				topics: vec![],
			}
		]);

		assert_ok!(creation);
		assert!(ContractInfoOf::<Test>::contains_key(BOB));
	});
}

#[test]
fn dispatch_call() {
	// This test can fail due to the encoding changes. In case it becomes too annoying
	// let's rewrite so as we use this module controlled call or we serialize it in runtime.
	let encoded = Encode::encode(&Call::Balances(pallet_balances::Call::transfer(CHARLIE, 50)));
	assert_eq!(&encoded[..], &hex!("00000300000000000000C8")[..]);

	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("dispatch_call.wat"))
		.unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);

		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

		// Let's keep this assert even though it's redundant. If you ever need to update the
		// wasm source this test will fail and will show you the actual hash.
		assert_eq!(System::events(), vec![
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(pallet_balances::RawEvent::Endowed(1, 1_000_000)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::CodeStored(code_hash.into())),
				topics: vec![],
			},
		]);

		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		));

		assert_ok!(Contracts::call(
			Origin::signed(ALICE),
			BOB, // newly created account
			0,
			GAS_LIMIT,
			vec![],
		));

		assert_eq!(System::events(), vec![
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(pallet_balances::RawEvent::Endowed(1, 1_000_000)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::CodeStored(code_hash.into())),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(BOB)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(
					pallet_balances::RawEvent::Endowed(BOB, 100)
				),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::Transfer(ALICE, BOB, 100)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::Instantiated(ALICE, BOB)),
				topics: vec![],
			},

			// Dispatching the call.
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(CHARLIE)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(
					pallet_balances::RawEvent::Endowed(CHARLIE, 50)
				),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(
					pallet_balances::RawEvent::Transfer(BOB, CHARLIE, 50)
				),
				topics: vec![],
			},

			// Event emitted as a result of dispatch.
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::Dispatched(BOB, true)),
				topics: vec![],
			}
		]);
	});
}

#[test]
fn dispatch_call_not_dispatched_after_top_level_transaction_failure() {
	// This test can fail due to the encoding changes. In case it becomes too annoying
	// let's rewrite so as we use this module controlled call or we serialize it in runtime.
	let encoded = Encode::encode(&Call::Balances(pallet_balances::Call::transfer(CHARLIE, 50)));
	assert_eq!(&encoded[..], &hex!("00000300000000000000C8")[..]);

	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("dispatch_call_then_trap.wat"))
		.unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);

		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

		// Let's keep this assert even though it's redundant. If you ever need to update the
		// wasm source this test will fail and will show you the actual hash.
		assert_eq!(System::events(), vec![
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(pallet_balances::RawEvent::Endowed(1, 1_000_000)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::CodeStored(code_hash.into())),
				topics: vec![],
			},
		]);

		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		));

		// Call the newly instantiated contract. The contract is expected to dispatch a call
		// and then trap.
		assert_err_ignore_postinfo!(
			Contracts::call(
				Origin::signed(ALICE),
				BOB, // newly created account
				0,
				GAS_LIMIT,
				vec![],
			),
			"contract trapped during execution"
		);
		assert_eq!(System::events(), vec![
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(pallet_balances::RawEvent::Endowed(1, 1_000_000)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::CodeStored(code_hash.into())),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(BOB)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(
					pallet_balances::RawEvent::Endowed(BOB, 100)
				),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::Transfer(ALICE, BOB, 100)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::Instantiated(ALICE, BOB)),
				topics: vec![],
			},
			// ABSENCE of events which would be caused by dispatched Balances::transfer call
		]);
	});
}

#[test]
fn run_out_of_gas() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("run_out_of_gas.wat"))
		.unwrap();

	ExtBuilder::default()
		.existential_deposit(50)
		.build()
		.execute_with(|| {
			Balances::deposit_creating(&ALICE, 1_000_000);

			assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

			assert_ok!(Contracts::instantiate(
				Origin::signed(ALICE),
				100,
				GAS_LIMIT,
				code_hash.into(),
				vec![],
			));

			// Call the contract with a fixed gas limit. It must run out of gas because it just
			// loops forever.
			assert_err_ignore_postinfo!(
				Contracts::call(
					Origin::signed(ALICE),
					BOB, // newly created account
					0,
					67_500_000,
					vec![],
				),
				"ran out of gas during contract execution"
			);
		});
}

/// Input data for each call in set_rent code
mod call {
	pub fn set_storage_4_byte() -> Vec<u8> { vec![] }
	pub fn remove_storage_4_byte() -> Vec<u8> { vec![0] }
	pub fn transfer() -> Vec<u8> { vec![0, 0] }
	pub fn null() -> Vec<u8> { vec![0, 0, 0] }
}

/// Test correspondence of set_rent code and its hash.
/// Also test that encoded extrinsic in code correspond to the correct transfer
#[test]
fn test_set_rent_code_and_hash() {
	// This test can fail due to the encoding changes. In case it becomes too annoying
	// let's rewrite so as we use this module controlled call or we serialize it in runtime.
	let encoded = Encode::encode(&Call::Balances(pallet_balances::Call::transfer(CHARLIE, 50)));
	assert_eq!(&encoded[..], &hex!("00000300000000000000C8")[..]);

	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("set_rent.wat")).unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

		// If you ever need to update the wasm source this test will fail
		// and will show you the actual hash.
		assert_eq!(System::events(), vec![
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(pallet_balances::RawEvent::Endowed(1, 1_000_000)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::CodeStored(code_hash.into())),
				topics: vec![],
			},
		]);
	});
}

#[test]
fn storage_size() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("set_rent.wat")).unwrap();

	// Storage size
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			30_000,
			GAS_LIMIT, code_hash.into(),
			<Test as pallet_balances::Trait>::Balance::from(1_000u32).encode() // rent allowance
		));
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.storage_size, <Test as Trait>::StorageSizeOffset::get() + 4);

		assert_ok!(Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::set_storage_4_byte()));
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.storage_size, <Test as Trait>::StorageSizeOffset::get() + 4 + 4);

		assert_ok!(Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::remove_storage_4_byte()));
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.storage_size, <Test as Trait>::StorageSizeOffset::get() + 4);
	});
}

fn initialize_block(number: u64) {
	System::initialize(
		&number,
		&[0u8; 32].into(),
		&[0u8; 32].into(),
		&Default::default(),
		Default::default(),
	);
}

#[test]
fn deduct_blocks() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("set_rent.wat")).unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			30_000,
			GAS_LIMIT, code_hash.into(),
			<Test as pallet_balances::Trait>::Balance::from(1_000u32).encode() // rent allowance
		));

		// Check creation
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.rent_allowance, 1_000);

		// Advance 4 blocks
		initialize_block(5);

		// Trigger rent through call
		assert_ok!(Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::null()));

		// Check result
		let rent = (8 + 4 - 3) // storage size = size_offset + deploy_set_storage - deposit_offset
			* 4 // rent byte price
			* 4; // blocks to rent
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.rent_allowance, 1_000 - rent);
		assert_eq!(bob_contract.deduct_block, 5);
		assert_eq!(Balances::free_balance(BOB), 30_000 - rent);

		// Advance 7 blocks more
		initialize_block(12);

		// Trigger rent through call
		assert_ok!(Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::null()));

		// Check result
		let rent_2 = (8 + 4 - 2) // storage size = size_offset + deploy_set_storage - deposit_offset
			* 4 // rent byte price
			* 7; // blocks to rent
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.rent_allowance, 1_000 - rent - rent_2);
		assert_eq!(bob_contract.deduct_block, 12);
		assert_eq!(Balances::free_balance(BOB), 30_000 - rent - rent_2);

		// Second call on same block should have no effect on rent
		assert_ok!(Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::null()));

		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.rent_allowance, 1_000 - rent - rent_2);
		assert_eq!(bob_contract.deduct_block, 12);
		assert_eq!(Balances::free_balance(BOB), 30_000 - rent - rent_2);
	});
}

#[test]
fn call_contract_removals() {
	removals(|| {
		// Call on already-removed account might fail, and this is fine.
		Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::null());
		true
	});
}

#[test]
fn inherent_claim_surcharge_contract_removals() {
	removals(|| Contracts::claim_surcharge(Origin::NONE, BOB, Some(ALICE)).is_ok());
}

#[test]
fn signed_claim_surcharge_contract_removals() {
	removals(|| Contracts::claim_surcharge(Origin::signed(ALICE), BOB, None).is_ok());
}

#[test]
fn claim_surcharge_malus() {
	// Test surcharge malus for inherent
	claim_surcharge(4, || Contracts::claim_surcharge(Origin::NONE, BOB, Some(ALICE)).is_ok(), true);
	claim_surcharge(3, || Contracts::claim_surcharge(Origin::NONE, BOB, Some(ALICE)).is_ok(), true);
	claim_surcharge(2, || Contracts::claim_surcharge(Origin::NONE, BOB, Some(ALICE)).is_ok(), true);
	claim_surcharge(1, || Contracts::claim_surcharge(Origin::NONE, BOB, Some(ALICE)).is_ok(), false);

	// Test surcharge malus for signed
	claim_surcharge(4, || Contracts::claim_surcharge(Origin::signed(ALICE), BOB, None).is_ok(), true);
	claim_surcharge(3, || Contracts::claim_surcharge(Origin::signed(ALICE), BOB, None).is_ok(), false);
	claim_surcharge(2, || Contracts::claim_surcharge(Origin::signed(ALICE), BOB, None).is_ok(), false);
	claim_surcharge(1, || Contracts::claim_surcharge(Origin::signed(ALICE), BOB, None).is_ok(), false);
}

/// Claim surcharge with the given trigger_call at the given blocks.
/// If `removes` is true then assert that the contract is a tombstone.
fn claim_surcharge(blocks: u64, trigger_call: impl Fn() -> bool, removes: bool) {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("set_rent.wat")).unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100,
			GAS_LIMIT, code_hash.into(),
			<Test as pallet_balances::Trait>::Balance::from(1_000u32).encode() // rent allowance
		));

		// Advance blocks
		initialize_block(blocks);

		// Trigger rent through call
		assert!(trigger_call());

		if removes {
			assert!(ContractInfoOf::<Test>::get(BOB).unwrap().get_tombstone().is_some());
		} else {
			assert!(ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().is_some());
		}
	});
}

/// Test for all kind of removals for the given trigger:
/// * if balance is reached and balance > subsistence threshold
/// * if allowance is exceeded
/// * if balance is reached and balance < subsistence threshold
fn removals(trigger_call: impl Fn() -> bool) {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("set_rent.wat")).unwrap();

	// Balance reached and superior to subsistence threshold
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm.clone()));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100,
			GAS_LIMIT, code_hash.into(),
			<Test as pallet_balances::Trait>::Balance::from(1_000u32).encode() // rent allowance
		));

		let subsistence_threshold = 50 /*existential_deposit*/ + 16 /*tombstone_deposit*/;

		// Trigger rent must have no effect
		assert!(trigger_call());
		assert_eq!(ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap().rent_allowance, 1_000);
		assert_eq!(Balances::free_balance(BOB), 100);

		// Advance blocks
		initialize_block(10);

		// Trigger rent through call
		assert!(trigger_call());
		assert!(ContractInfoOf::<Test>::get(BOB).unwrap().get_tombstone().is_some());
		assert_eq!(Balances::free_balance(BOB), subsistence_threshold);

		// Advance blocks
		initialize_block(20);

		// Trigger rent must have no effect
		assert!(trigger_call());
		assert!(ContractInfoOf::<Test>::get(BOB).unwrap().get_tombstone().is_some());
		assert_eq!(Balances::free_balance(BOB), subsistence_threshold);
	});

	// Allowance exceeded
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm.clone()));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			1_000,
			GAS_LIMIT, code_hash.into(),
			<Test as pallet_balances::Trait>::Balance::from(100u32).encode() // rent allowance
		));

		// Trigger rent must have no effect
		assert!(trigger_call());
		assert_eq!(ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap().rent_allowance, 100);
		assert_eq!(Balances::free_balance(BOB), 1_000);

		// Advance blocks
		initialize_block(10);

		// Trigger rent through call
		assert!(trigger_call());
		assert!(ContractInfoOf::<Test>::get(BOB).unwrap().get_tombstone().is_some());
		// Balance should be initial balance - initial rent_allowance
		assert_eq!(Balances::free_balance(BOB), 900);

		// Advance blocks
		initialize_block(20);

		// Trigger rent must have no effect
		assert!(trigger_call());
		assert!(ContractInfoOf::<Test>::get(BOB).unwrap().get_tombstone().is_some());
		assert_eq!(Balances::free_balance(BOB), 900);
	});

	// Balance reached and inferior to subsistence threshold
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm.clone()));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			50+Balances::minimum_balance(),
			GAS_LIMIT, code_hash.into(),
			<Test as pallet_balances::Trait>::Balance::from(1_000u32).encode() // rent allowance
		));

		// Trigger rent must have no effect
		assert!(trigger_call());
		assert_eq!(ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap().rent_allowance, 1_000);
		assert_eq!(Balances::free_balance(BOB), 50 + Balances::minimum_balance());

		// Transfer funds
		assert_ok!(Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::transfer()));
		assert_eq!(ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap().rent_allowance, 1_000);
		assert_eq!(Balances::free_balance(BOB), Balances::minimum_balance());

		// Advance blocks
		initialize_block(10);

		// Trigger rent through call
		assert!(trigger_call());
		assert!(ContractInfoOf::<Test>::get(BOB).is_none());
		assert_eq!(Balances::free_balance(BOB), Balances::minimum_balance());

		// Advance blocks
		initialize_block(20);

		// Trigger rent must have no effect
		assert!(trigger_call());
		assert!(ContractInfoOf::<Test>::get(BOB).is_none());
		assert_eq!(Balances::free_balance(BOB), Balances::minimum_balance());
	});
}

#[test]
fn call_removed_contract() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("set_rent.wat")).unwrap();

	// Balance reached and superior to subsistence threshold
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm.clone()));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100,
			GAS_LIMIT, code_hash.into(),
			<Test as pallet_balances::Trait>::Balance::from(1_000u32).encode() // rent allowance
		));

		// Calling contract should succeed.
		assert_ok!(Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::null()));

		// Advance blocks
		initialize_block(10);

		// Calling contract should remove contract and fail.
		assert_err_ignore_postinfo!(
			Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::null()),
			"contract has been evicted"
		);
		// Calling a contract that is about to evict shall emit an event.
		assert_eq!(System::events(), vec![
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::Evicted(BOB, true)),
				topics: vec![],
			},
		]);

		// Subsequent contract calls should also fail.
		assert_err_ignore_postinfo!(
			Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::null()),
			"contract has been evicted"
		);
	})
}

#[test]
fn default_rent_allowance_on_instantiate() {
	let (wasm, code_hash) = compile_module::<Test>(
		&load_wasm("check_default_rent_allowance.wat")).unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			30_000,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		));

		// Check creation
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.rent_allowance, <BalanceOf<Test>>::max_value());

		// Advance blocks
		initialize_block(5);

		// Trigger rent through call
		assert_ok!(Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::null()));

		// Check contract is still alive
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive();
		assert!(bob_contract.is_some())
	});
}

#[test]
fn restorations_dirty_storage_and_different_storage() {
	restoration(true, true);
}

#[test]
fn restorations_dirty_storage() {
	restoration(false, true);
}

#[test]
fn restoration_different_storage() {
	restoration(true, false);
}

#[test]
fn restoration_success() {
	restoration(false, false);
}

fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage: bool) {
	let (set_rent_wasm, set_rent_code_hash) =
		compile_module::<Test>(&load_wasm("set_rent.wat")).unwrap();
	let (restoration_wasm, restoration_code_hash) =
		compile_module::<Test>(&load_wasm("restoration.wat")).unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), restoration_wasm));
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), set_rent_wasm));

		// If you ever need to update the wasm source this test will fail
		// and will show you the actual hash.
		assert_eq!(System::events(), vec![
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::balances(pallet_balances::RawEvent::Endowed(1, 1_000_000)),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::CodeStored(restoration_code_hash.into())),
				topics: vec![],
			},
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(RawEvent::CodeStored(set_rent_code_hash.into())),
				topics: vec![],
			},
		]);

		// Create an account with address `BOB` with code `CODE_SET_RENT`.
		// The input parameter sets the rent allowance to 0.
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			30_000,
			GAS_LIMIT,
			set_rent_code_hash.into(),
			<Test as pallet_balances::Trait>::Balance::from(0u32).encode()
		));

		// Check if `BOB` was created successfully and that the rent allowance is
		// set to 0.
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.rent_allowance, 0);

		if test_different_storage {
			assert_ok!(Contracts::call(
				Origin::signed(ALICE),
				BOB, 0, GAS_LIMIT,
				call::set_storage_4_byte())
			);
		}

		// Advance 4 blocks, to the 5th.
		initialize_block(5);

		/// Preserve `BOB`'s code hash for later introspection.
		let bob_code_hash = ContractInfoOf::<Test>::get(BOB).unwrap()
			.get_alive().unwrap().code_hash;
		// Call `BOB`, which makes it pay rent. Since the rent allowance is set to 0
		// we expect that it will get removed leaving tombstone.
		assert_err_ignore_postinfo!(
			Contracts::call(Origin::signed(ALICE), BOB, 0, GAS_LIMIT, call::null()),
			"contract has been evicted"
		);
		assert!(ContractInfoOf::<Test>::get(BOB).unwrap().get_tombstone().is_some());
		assert_eq!(System::events(), vec![
			EventRecord {
				phase: Phase::Initialization,
				event: MetaEvent::contracts(
					RawEvent::Evicted(BOB.clone(), true)
				),
				topics: vec![],
			},
		]);

		/// Create another account with the address `DJANGO` with `CODE_RESTORATION`.
		///
		/// Note that we can't use `ALICE` for creating `DJANGO` so we create yet another
		/// account `CHARLIE` and create `DJANGO` with it.
		Balances::deposit_creating(&CHARLIE, 1_000_000);
		assert_ok!(Contracts::instantiate(
			Origin::signed(CHARLIE),
			30_000,
			GAS_LIMIT,
			restoration_code_hash.into(),
			<Test as pallet_balances::Trait>::Balance::from(0u32).encode()
		));

		// Before performing a call to `DJANGO` save its original trie id.
		let django_trie_id = ContractInfoOf::<Test>::get(DJANGO).unwrap()
			.get_alive().unwrap().trie_id;

		if !test_restore_to_with_dirty_storage {
			// Advance 1 block, to the 6th.
			initialize_block(6);
		}

		// Perform a call to `DJANGO`. This should either perform restoration successfully or
		// fail depending on the test parameters.
		assert_ok!(Contracts::call(
			Origin::signed(ALICE),
			DJANGO,
			0,
			GAS_LIMIT,
			vec![],
		));

		if test_different_storage || test_restore_to_with_dirty_storage {
			// Parametrization of the test imply restoration failure. Check that `DJANGO` aka
			// restoration contract is still in place and also that `BOB` doesn't exist.
			assert!(ContractInfoOf::<Test>::get(BOB).unwrap().get_tombstone().is_some());
			let django_contract = ContractInfoOf::<Test>::get(DJANGO).unwrap()
				.get_alive().unwrap();
			assert_eq!(django_contract.storage_size, 16);
			assert_eq!(django_contract.trie_id, django_trie_id);
			assert_eq!(django_contract.deduct_block, System::block_number());
			match (test_different_storage, test_restore_to_with_dirty_storage) {
				(true, false) => {
					assert_eq!(System::events(), vec![
						EventRecord {
							phase: Phase::Initialization,
							event: MetaEvent::contracts(
								RawEvent::Restored(DJANGO, BOB, bob_code_hash, 50, false)
							),
							topics: vec![],
						},
					]);
				}
				(_, true) => {
					assert_eq!(System::events(), vec![
						EventRecord {
							phase: Phase::Initialization,
							event: MetaEvent::contracts(RawEvent::Evicted(BOB, true)),
							topics: vec![],
						},
						EventRecord {
							phase: Phase::Initialization,
							event: MetaEvent::system(frame_system::RawEvent::NewAccount(CHARLIE)),
							topics: vec![],
						},
						EventRecord {
							phase: Phase::Initialization,
							event: MetaEvent::balances(pallet_balances::RawEvent::Endowed(CHARLIE, 1_000_000)),
							topics: vec![],
						},
						EventRecord {
							phase: Phase::Initialization,
							event: MetaEvent::system(frame_system::RawEvent::NewAccount(DJANGO)),
							topics: vec![],
						},
						EventRecord {
							phase: Phase::Initialization,
							event: MetaEvent::balances(pallet_balances::RawEvent::Endowed(DJANGO, 30_000)),
							topics: vec![],
						},
						EventRecord {
							phase: Phase::Initialization,
							event: MetaEvent::contracts(RawEvent::Transfer(CHARLIE, DJANGO, 30_000)),
							topics: vec![],
						},
						EventRecord {
							phase: Phase::Initialization,
							event: MetaEvent::contracts(RawEvent::Instantiated(CHARLIE, DJANGO)),
							topics: vec![],
						},
						EventRecord {
							phase: Phase::Initialization,
							event: MetaEvent::contracts(RawEvent::Restored(
								DJANGO,
								BOB,
								bob_code_hash,
								50,
								false,
							)),
							topics: vec![],
						},
					]);
				}
				_ => unreachable!(),
			}
		} else {
			// Here we expect that the restoration is succeeded. Check that the restoration
			// contract `DJANGO` ceased to exist and that `BOB` returned back.
			println!("{:?}", ContractInfoOf::<Test>::get(BOB));
			let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap()
				.get_alive().unwrap();
			assert_eq!(bob_contract.rent_allowance, 50);
			assert_eq!(bob_contract.storage_size, 12);
			assert_eq!(bob_contract.trie_id, django_trie_id);
			assert_eq!(bob_contract.deduct_block, System::block_number());
			assert!(ContractInfoOf::<Test>::get(DJANGO).is_none());
			assert_eq!(System::events(), vec![
				EventRecord {
					phase: Phase::Initialization,
					event: MetaEvent::system(system::RawEvent::KilledAccount(DJANGO)),
					topics: vec![],
				},
				EventRecord {
					phase: Phase::Initialization,
					event: MetaEvent::contracts(
						RawEvent::Restored(DJANGO, BOB, bob_contract.code_hash, 50, true)
					),
					topics: vec![],
				},
			]);
		}
	});
}

#[test]
fn storage_max_value_limit() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("storage_size.wat"))
		.unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			30_000,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		));

		// Check creation
		let bob_contract = ContractInfoOf::<Test>::get(BOB).unwrap().get_alive().unwrap();
		assert_eq!(bob_contract.rent_allowance, <BalanceOf<Test>>::max_value());

		// Call contract with allowed storage value.
		assert_ok!(Contracts::call(
			Origin::signed(ALICE),
			BOB,
			0,
			GAS_LIMIT,
			Encode::encode(&self::MaxValueSize::get()),
		));

		// Call contract with too large a storage value.
		assert_err_ignore_postinfo!(
			Contracts::call(
				Origin::signed(ALICE),
				BOB,
				0,
				GAS_LIMIT,
				Encode::encode(&(self::MaxValueSize::get() + 1)),
			),
			"contract trapped during execution"
		);
	});
}

#[test]
fn deploy_and_call_other_contract() {
	let (callee_wasm, callee_code_hash) =
		compile_module::<Test>(&load_wasm("return_with_data.wat")).unwrap();
	let (caller_wasm, caller_code_hash) =
		compile_module::<Test>(&load_wasm("caller_contract.wat")).unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), callee_wasm));
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), caller_wasm));

		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100_000,
			GAS_LIMIT,
			caller_code_hash.into(),
			vec![],
		));

		// Call BOB contract, which attempts to instantiate and call the callee contract and
		// makes various assertions on the results from those calls.
		assert_ok!(Contracts::call(
			Origin::signed(ALICE),
			BOB,
			0,
			GAS_LIMIT,
			callee_code_hash.as_ref().to_vec(),
		));
	});
}

#[test]
fn cannot_self_destruct_through_draning() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("drain.wat")).unwrap();
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

		// Instantiate the BOB contract.
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100_000,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		));

		// Check that the BOB contract has been instantiated.
		assert_matches!(
			ContractInfoOf::<Test>::get(BOB),
			Some(ContractInfo::Alive(_))
		);

		// Call BOB with no input data, forcing it to run until out-of-balance
		// and eventually trapping because below existential deposit.
		assert_err_ignore_postinfo!(
			Contracts::call(
				Origin::signed(ALICE),
				BOB,
				0,
				GAS_LIMIT,
				vec![],
			),
			"contract trapped during execution"
		);
	});
}

#[test]
fn cannot_self_destruct_while_live() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("self_destruct.wat"))
		.unwrap();
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

		// Instantiate the BOB contract.
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100_000,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		));

		// Check that the BOB contract has been instantiated.
		assert_matches!(
			ContractInfoOf::<Test>::get(BOB),
			Some(ContractInfo::Alive(_))
		);

		// Call BOB with input data, forcing it make a recursive call to itself to
		// self-destruct, resulting in a trap.
		assert_err_ignore_postinfo!(
			Contracts::call(
				Origin::signed(ALICE),
				BOB,
				0,
				GAS_LIMIT,
				vec![0],
			),
			"contract trapped during execution"
		);

		// Check that BOB is still alive.
		assert_matches!(
			ContractInfoOf::<Test>::get(BOB),
			Some(ContractInfo::Alive(_))
		);
	});
}

#[test]
fn self_destruct_works() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("self_destruct.wat"))
		.unwrap();
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

		// Instantiate the BOB contract.
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100_000,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		));

		// Check that the BOB contract has been instantiated.
		assert_matches!(
			ContractInfoOf::<Test>::get(BOB),
			Some(ContractInfo::Alive(_))
		);

		// Call BOB without input data which triggers termination.
		assert_matches!(
			Contracts::call(
				Origin::signed(ALICE),
				BOB,
				0,
				GAS_LIMIT,
				vec![],
			),
			Ok(_)
		);

		// Check that account is gone
		assert!(ContractInfoOf::<Test>::get(BOB).is_none());

		// check that the beneficiary (django) got remaining balance
		assert_eq!(Balances::free_balance(DJANGO), 100_000);
	});
}

// This tests that one contract cannot prevent another from self-destructing by sending it
// additional funds after it has been drained.
#[test]
fn destroy_contract_and_transfer_funds() {
	let (callee_wasm, callee_code_hash) =
		compile_module::<Test>(&load_wasm("self_destruct.wat")).unwrap();
	let (caller_wasm, caller_code_hash) =
		compile_module::<Test>(&load_wasm("destroy_and_transfer.wat")).unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		// Create
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), callee_wasm));
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), caller_wasm));

		// This deploys the BOB contract, which in turn deploys the CHARLIE contract during
		// construction.
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			200_000,
			GAS_LIMIT,
			caller_code_hash.into(),
			callee_code_hash.as_ref().to_vec(),
		));

		// Check that the CHARLIE contract has been instantiated.
		assert_matches!(
			ContractInfoOf::<Test>::get(CHARLIE),
			Some(ContractInfo::Alive(_))
		);

		// Call BOB, which calls CHARLIE, forcing CHARLIE to self-destruct.
		assert_ok!(Contracts::call(
			Origin::signed(ALICE),
			BOB,
			0,
			GAS_LIMIT,
			CHARLIE.encode(),
		));

		// Check that CHARLIE has moved on to the great beyond (ie. died).
		assert!(ContractInfoOf::<Test>::get(CHARLIE).is_none());
	});
}

#[test]
fn cannot_self_destruct_in_constructor() {
	let (wasm, code_hash) =
		compile_module::<Test>(&load_wasm("self_destructing_constructor.wat")).unwrap();
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

		// Fail to instantiate the BOB because the call that is issued in the deploy
		// function exhausts all balances which puts it below the existential deposit.
		assert_err_ignore_postinfo!(
			Contracts::instantiate(
				Origin::signed(ALICE),
				100_000,
				GAS_LIMIT,
				code_hash.into(),
				vec![],
			),
			"contract trapped during execution"
		);
	});
}

fn get_runtime_storage() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("get_runtime_storage.wat"))
		.unwrap();
	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);

		frame_support::storage::unhashed::put_raw(
			&[1, 2, 3, 4],
			0x14144020u32.to_le_bytes().to_vec().as_ref()
		);

		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		));
		assert_ok!(Contracts::call(
			Origin::signed(ALICE),
			BOB,
			0,
			GAS_LIMIT,
			vec![],
		));
	});
}

#[test]
fn crypto_hashes() {
	let (wasm, code_hash) = compile_module::<Test>(&load_wasm("crypto_hashes.wat")).unwrap();

	ExtBuilder::default().existential_deposit(50).build().execute_with(|| {
		Balances::deposit_creating(&ALICE, 1_000_000);
		assert_ok!(Contracts::put_code(Origin::signed(ALICE), wasm));

		// Instantiate the CRYPTO_HASHES contract.
		assert_ok!(Contracts::instantiate(
			Origin::signed(ALICE),
			100_000,
			GAS_LIMIT,
			code_hash.into(),
			vec![],
		));
		// Perform the call.
		let input = b"_DEAD_BEEF";
		use sp_io::hashing::*;
		// Wraps a hash function into a more dynamic form usable for testing.
		macro_rules! dyn_hash_fn {
			($name:ident) => {
				Box::new(|input| $name(input).as_ref().to_vec().into_boxed_slice())
			};
		}
		// All hash functions and their associated output byte lengths.
		let test_cases: &[(Box<dyn Fn(&[u8]) -> Box<[u8]>>, usize)] = &[
			(dyn_hash_fn!(sha2_256), 32),
			(dyn_hash_fn!(keccak_256), 32),
			(dyn_hash_fn!(blake2_256), 32),
			(dyn_hash_fn!(blake2_128), 16),
		];
		// Test the given hash functions for the input: "_DEAD_BEEF"
		for (n, (hash_fn, expected_size)) in test_cases.iter().enumerate() {
			// We offset data in the contract tables by 1.
			let mut params = vec![(n + 1) as u8];
			params.extend_from_slice(input);
			let result = <Module<Test>>::bare_call(
				ALICE,
				BOB,
				0,
				GAS_LIMIT,
				params,
			).unwrap();
			assert_eq!(result.status, 0);
			let expected = hash_fn(input.as_ref());
			assert_eq!(&result.data[..*expected_size], &*expected);
		}
	})
}

fn load_wasm(file_name: &str) -> String {
	let path = ["tests/", file_name].concat();
	std::fs::read_to_string(&path).expect(&format!("Unable to read {} file", path))
}