pezkuwi-subxt/cumulus/parachains/runtimes/assets/common/src/matching.rs

// Copyright (C) 2023 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 cumulus_primitives_core::ParaId;
use frame_support::{
	pallet_prelude::Get,
	traits::{Contains, ContainsPair},
};
use xcm::{
	latest::prelude::{MultiAsset, MultiLocation},
	prelude::*,
};

pub struct StartsWith<T>(sp_std::marker::PhantomData<T>);
impl<Location: Get<MultiLocation>> Contains<MultiLocation> for StartsWith<Location> {
	fn contains(t: &MultiLocation) -> bool {
		t.starts_with(&Location::get())
	}
}

pub struct Equals<T>(sp_std::marker::PhantomData<T>);
impl<Location: Get<MultiLocation>> Contains<MultiLocation> for Equals<Location> {
	fn contains(t: &MultiLocation) -> bool {
		t == &Location::get()
	}
}

pub struct StartsWithExplicitGlobalConsensus<T>(sp_std::marker::PhantomData<T>);
impl<Network: Get<NetworkId>> Contains<MultiLocation>
	for StartsWithExplicitGlobalConsensus<Network>
{
	fn contains(t: &MultiLocation) -> bool {
		match t.interior.global_consensus() {
			Ok(requested_network) if requested_network.eq(&Network::get()) => true,
			_ => false,
		}
	}
}

frame_support::parameter_types! {
	pub LocalMultiLocationPattern: MultiLocation = MultiLocation::new(0, Here);
	pub ParentLocation: MultiLocation = MultiLocation::parent();
}

/// Accepts an asset if it is from the origin.
pub struct IsForeignConcreteAsset<IsForeign>(sp_std::marker::PhantomData<IsForeign>);
impl<IsForeign: ContainsPair<MultiLocation, MultiLocation>> ContainsPair<MultiAsset, MultiLocation>
	for IsForeignConcreteAsset<IsForeign>
{
	fn contains(asset: &MultiAsset, origin: &MultiLocation) -> bool {
		log::trace!(target: "xcm::contains", "IsForeignConcreteAsset asset: {:?}, origin: {:?}", asset, origin);
		matches!(asset.id, Concrete(ref id) if IsForeign::contains(id, &origin))
	}
}

/// Checks if `a` is from sibling location `b`. Checks that `MultiLocation-a` starts with
/// `MultiLocation-b`, and that the `ParaId` of `b` is not equal to `a`.
pub struct FromSiblingParachain<SelfParaId>(sp_std::marker::PhantomData<SelfParaId>);
impl<SelfParaId: Get<ParaId>> ContainsPair<MultiLocation, MultiLocation>
	for FromSiblingParachain<SelfParaId>
{
	fn contains(&a: &MultiLocation, b: &MultiLocation) -> bool {
		// `a` needs to be from `b` at least
		if !a.starts_with(&b) {
			return false
		}

		// here we check if sibling
		match a {
			MultiLocation { parents: 1, interior } => match interior.first() {
				Some(Parachain(sibling_para_id))
					if sibling_para_id.ne(&u32::from(SelfParaId::get())) =>
					true,
				_ => false,
			},
			_ => false,
		}
	}
}