feat: initialize Kurdistan SDK - independent fork of Polkadot SDK

pezkuwi/xcm/xcm-executor/src/traits/asset_transfer.rs

@@ -0,0 +1,94 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+use crate::traits::TransactAsset;
+use frame_support::traits::ContainsPair;
+use scale_info::TypeInfo;
+use sp_runtime::codec::{Decode, DecodeWithMemTracking, Encode};
+use xcm::prelude::*;
+
+/// Errors related to determining asset transfer support.
+#[derive(Copy, Clone, Encode, Decode, Eq, PartialEq, Debug, TypeInfo)]
+pub enum Error {
+	/// Reserve chain could not be determined for assets.
+	UnknownReserve,
+}
+
+/// Specify which type of asset transfer is required for a particular `(asset, dest)` combination.
+#[derive(Clone, Encode, Decode, DecodeWithMemTracking, PartialEq, Debug, TypeInfo)]
+pub enum TransferType {
+	/// should teleport `asset` to `dest`
+	Teleport,
+	/// should reserve-transfer `asset` to `dest`, using local chain as reserve
+	LocalReserve,
+	/// should reserve-transfer `asset` to `dest`, using `dest` as reserve
+	DestinationReserve,
+	/// should reserve-transfer `asset` to `dest`, using remote chain `Location` as reserve
+	RemoteReserve(VersionedLocation),
+}
+
+/// A trait for identifying asset transfer type based on `IsTeleporter` and `IsReserve`
+/// configurations.
+pub trait XcmAssetTransfers {
+	/// Combinations of (Asset, Location) pairs which we trust as reserves. Meaning
+	/// reserve-based-transfers are to be used for assets matching this filter.
+	type IsReserve: ContainsPair<Asset, Location>;
+
+	/// Combinations of (Asset, Location) pairs which we trust as teleporters. Meaning teleports are
+	/// to be used for assets matching this filter.
+	type IsTeleporter: ContainsPair<Asset, Location>;
+
+	/// How to withdraw and deposit an asset.
+	type AssetTransactor: TransactAsset;
+
+	/// Determine transfer type to be used for transferring `asset` from local chain to `dest`.
+	fn determine_for(asset: &Asset, dest: &Location) -> Result<TransferType, Error> {
+		if Self::IsTeleporter::contains(asset, dest) {
+			// we trust destination for teleporting asset
+			return Ok(TransferType::Teleport);
+		} else if Self::IsReserve::contains(asset, dest) {
+			// we trust destination as asset reserve location
+			return Ok(TransferType::DestinationReserve);
+		}
+
+		// try to determine reserve location based on asset id/location
+		let asset_location = asset.id.0.chain_location();
+		if asset_location == Location::here() ||
+			Self::IsTeleporter::contains(asset, &asset_location)
+		{
+			// if the asset is local, then it's a local reserve
+			// it's also a local reserve if the asset's location is not `here` but it's a location
+			// where it can be teleported to `here` => local reserve
+			Ok(TransferType::LocalReserve)
+		} else if Self::IsReserve::contains(asset, &asset_location) {
+			// remote location that is recognized as reserve location for asset
+			Ok(TransferType::RemoteReserve(asset_location.into()))
+		} else {
+			// remote location that is not configured either as teleporter or reserve => cannot
+			// determine asset reserve
+			Err(Error::UnknownReserve)
+		}
+	}
+}
+
+impl XcmAssetTransfers for () {
+	type IsReserve = ();
+	type IsTeleporter = ();
+	type AssetTransactor = ();
+	fn determine_for(_: &Asset, _: &Location) -> Result<TransferType, Error> {
+		return Err(Error::UnknownReserve);
+	}
+}