// Copyright (C) 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.

use super::*;
use crate as xcmp_queue;
use alloc::collections::BTreeMap;
use core::marker::PhantomData;
use cumulus_pallet_parachain_system::AnyRelayNumber;
use cumulus_primitives_core::{ChannelInfo, IsSystem, ParaId};
use frame_support::{
	derive_impl, parameter_types,
	traits::{BatchesFootprints, ConstU32, Everything, OriginTrait},
	BoundedSlice,
};
use frame_system::EnsureRoot;
use sp_core::H256;
use sp_runtime::{
	traits::{BlakeTwo256, IdentityLookup},
	BuildStorage,
};
use xcm::prelude::*;
use xcm_executor::traits::ConvertOrigin;

type Block = frame_system::mocking::MockBlock<Test>;

// Configure a mock runtime to test the pallet.
frame_support::construct_runtime!(
	pub enum Test
	{
		System: frame_system::{Pallet, Call, Config<T>, Storage, Event<T>},
		Balances: pallet_balances::{Pallet, Call, Storage, Config<T>, Event<T>},
		ParachainSystem: cumulus_pallet_parachain_system::{
			Pallet, Call, Config<T>, Storage, Inherent, Event<T>,
		},
		XcmpQueue: xcmp_queue::{Pallet, Call, Storage, Event<T>},
	}
);

parameter_types! {
	pub const SS58Prefix: u8 = 42;
}

type AccountId = u64;

#[derive_impl(frame_system::config_preludes::TestDefaultConfig)]
impl frame_system::Config for Test {
	type BaseCallFilter = Everything;
	type BlockWeights = ();
	type BlockLength = ();
	type DbWeight = ();
	type RuntimeOrigin = RuntimeOrigin;
	type RuntimeCall = RuntimeCall;
	type Nonce = u64;
	type Hash = H256;
	type Hashing = BlakeTwo256;
	type AccountId = AccountId;
	type Lookup = IdentityLookup<Self::AccountId>;
	type Block = Block;
	type RuntimeEvent = RuntimeEvent;
	type Version = ();
	type PalletInfo = PalletInfo;
	type AccountData = pallet_balances::AccountData<u64>;
	type OnNewAccount = ();
	type OnKilledAccount = ();
	type SystemWeightInfo = ();
	type SS58Prefix = SS58Prefix;
	type OnSetCode = cumulus_pallet_parachain_system::ParachainSetCode<Test>;
	type MaxConsumers = frame_support::traits::ConstU32<16>;
}

parameter_types! {
	pub const ExistentialDeposit: u64 = 5;
}

pub type Balance = u64;

#[derive_impl(pallet_balances::config_preludes::TestDefaultConfig)]
impl pallet_balances::Config for Test {
	type ExistentialDeposit = ExistentialDeposit;
	type AccountStore = System;
}

impl cumulus_pallet_parachain_system::Config for Test {
	type WeightInfo = ();
	type RuntimeEvent = RuntimeEvent;
	type OnSystemEvent = ();
	type SelfParaId = ();
	type OutboundXcmpMessageSource = XcmpQueue;
	// Ignore all DMP messages by enqueueing them into `()`:
	type DmpQueue = frame_support::traits::EnqueueWithOrigin<(), sp_core::ConstU8<0>>;
	type ReservedDmpWeight = ();
	type XcmpMessageHandler = XcmpQueue;
	type ReservedXcmpWeight = ();
	type CheckAssociatedRelayNumber = AnyRelayNumber;
	type ConsensusHook = cumulus_pallet_parachain_system::consensus_hook::ExpectParentIncluded;
	type RelayParentOffset = ConstU32<0>;
}

parameter_types! {
	pub const RelayChain: Location = Location::parent();
	pub UniversalLocation: InteriorLocation = [Parachain(1u32)].into();
	pub UnitWeightCost: Weight = Weight::from_parts(1_000_000, 1024);
	pub const MaxInstructions: u32 = 100;
	pub const MaxAssetsIntoHolding: u32 = 64;
}

pub struct SystemParachainAsSuperuser<RuntimeOrigin>(PhantomData<RuntimeOrigin>);
impl<RuntimeOrigin: OriginTrait> ConvertOrigin<RuntimeOrigin>
	for SystemParachainAsSuperuser<RuntimeOrigin>
{
	fn convert_origin(
		origin: impl Into<Location>,
		kind: OriginKind,
	) -> Result<RuntimeOrigin, Location> {
		let origin = origin.into();
		if kind == OriginKind::Superuser &&
			matches!(
				origin.unpack(),
				(1,	[Parachain(id)]) if ParaId::from(*id).is_system(),
			) {
			Ok(RuntimeOrigin::root())
		} else {
			Err(origin)
		}
	}
}

parameter_types! {
	pub static EnqueuedMessages: Vec<(ParaId, Vec<u8>)> = Default::default();
	pub static FirstPagePos: BTreeMap<ParaId, usize> = Default::default();
}

/// An `EnqueueMessage` implementation that puts all messages in thread-local storage.
pub struct EnqueueToLocalStorage<T>(PhantomData<T>);

impl<T: OnQueueChanged<ParaId>> EnqueueMessage<ParaId> for EnqueueToLocalStorage<T> {
	type MaxMessageLen = sp_core::ConstU32<256>;

	fn enqueue_message(message: BoundedSlice<u8, Self::MaxMessageLen>, origin: ParaId) {
		let mut msgs = EnqueuedMessages::get();
		msgs.push((origin, message.to_vec()));
		EnqueuedMessages::set(msgs);
		T::on_queue_changed(origin, Self::footprint(origin));
	}

	fn enqueue_messages<'a>(
		iter: impl Iterator<Item = BoundedSlice<'a, u8, Self::MaxMessageLen>>,
		origin: ParaId,
	) {
		let mut msgs = EnqueuedMessages::get();
		msgs.extend(iter.map(|m| (origin, m.to_vec())));
		EnqueuedMessages::set(msgs);
		T::on_queue_changed(origin, Self::footprint(origin));
	}

	fn sweep_queue(origin: ParaId) {
		let mut msgs = EnqueuedMessages::get();
		msgs.retain(|(o, _)| o != &origin);
		EnqueuedMessages::set(msgs);
		T::on_queue_changed(origin, Self::footprint(origin));
	}
}

impl<T: OnQueueChanged<ParaId>> QueueFootprintQuery<ParaId> for EnqueueToLocalStorage<T> {
	type MaxMessageLen = sp_core::ConstU32<256>;

	fn footprint(origin: ParaId) -> QueueFootprint {
		let msgs = EnqueuedMessages::get();
		let mut footprint = QueueFootprint::default();
		for (o, m) in msgs {
			if o == origin {
				footprint.storage.count += 1;
				footprint.storage.size += m.len() as u64;
			}
		}
		// Let's consider that we add one message per page
		footprint.pages = footprint.storage.count as u32;
		footprint.ready_pages = footprint.pages;
		footprint
	}

	fn get_batches_footprints<'a>(
		origin: ParaId,
		msgs: impl Iterator<Item = BoundedSlice<'a, u8, Self::MaxMessageLen>>,
		total_pages_limit: u32,
	) -> BatchesFootprints {
		// Let's consider that we add one message per page
		let footprint = Self::footprint(origin);
		let mut batches_footprints = BatchesFootprints {
			first_page_pos: *FirstPagePos::get().entry(origin).or_default(),
			footprints: vec![],
		};
		for (idx, msg) in msgs.enumerate() {
			if footprint.pages + idx as u32 + 1 > total_pages_limit {
				break;
			}

			batches_footprints.push(msg.into(), true);
		}
		batches_footprints
	}
}

parameter_types! {
	/// The asset ID for the asset that we use to pay for message delivery fees.
	pub FeeAssetId: AssetId = AssetId(RelayChain::get());
	/// The base fee for the message delivery fees.
	pub const BaseDeliveryFee: Balance = 300_000_000;
	/// The fee per byte
	pub const ByteFee: Balance = 1_000_000;
}

pub type PriceForSiblingParachainDelivery = polkadot_runtime_common::xcm_sender::ExponentialPrice<
	FeeAssetId,
	BaseDeliveryFee,
	ByteFee,
	XcmpQueue,
>;

impl Config for Test {
	type RuntimeEvent = RuntimeEvent;
	type ChannelInfo = MockedChannelInfo;
	type VersionWrapper = ();
	type XcmpQueue = EnqueueToLocalStorage<Pallet<Test>>;
	type MaxInboundSuspended = ConstU32<1_000>;
	type MaxActiveOutboundChannels = ConstU32<128>;
	// Most on-chain HRMP channels are configured to use 102400 bytes of max message size, so we
	// need to set the page size larger than that until we reduce the channel size on-chain.
	type MaxPageSize = ConstU32<{ 103 * 1024 }>;
	type ControllerOrigin = EnsureRoot<AccountId>;
	type ControllerOriginConverter = SystemParachainAsSuperuser<RuntimeOrigin>;
	type WeightInfo = ();
	type PriceForSiblingDelivery = PriceForSiblingParachainDelivery;
}

pub fn new_test_ext() -> sp_io::TestExternalities {
	frame_system::GenesisConfig::<Test>::default().build_storage().unwrap().into()
}

/// A para that we have an HRMP channel with.
pub const HRMP_PARA_ID: u32 = 7777;

pub struct MockedChannelInfo;
impl GetChannelInfo for MockedChannelInfo {
	fn get_channel_status(id: ParaId) -> ChannelStatus {
		if id == HRMP_PARA_ID.into() {
			return ChannelStatus::Ready(usize::MAX, usize::MAX);
		}

		ParachainSystem::get_channel_status(id)
	}

	fn get_channel_info(id: ParaId) -> Option<ChannelInfo> {
		if id == HRMP_PARA_ID.into() {
			return Some(ChannelInfo {
				max_capacity: u32::MAX,
				max_total_size: u32::MAX,
				max_message_size: u32::MAX,
				msg_count: 0,
				total_size: 0,
			});
		}

		ParachainSystem::get_channel_info(id)
	}
}

pub(crate) fn mk_page() -> Vec<u8> {
	let mut page = Vec::<u8>::new();

	let newer_xcm_version = xcm::prelude::XCM_VERSION;
	let older_xcm_version = newer_xcm_version - 1;

	for i in 0..100 {
		page.extend(match i % 2 {
			0 => versioned_xcm(older_xcm_version).encode(),
			1 => versioned_xcm(newer_xcm_version).encode(),
			// We cannot push an undecodable XCM here since it would break the decode stream.
			_ => unreachable!(),
		});
	}

	page
}

pub(crate) fn versioned_xcm(version: XcmVersion) -> VersionedXcm<()> {
	let instr = Instruction::<()>::Trap(1);
	VersionedXcm::from(Xcm::<()>(vec![instr; 3]))
		.into_version(version)
		.expect("Version conversion should work")
}
