wip

libs/types/src/tokens.rs

@@ -21,15 +21,21 @@ use orml_traits::asset_registry;
 use parity_scale_codec::{Decode, Encode, MaxEncodedLen};
 use scale_info::TypeInfo;
 use serde::{Deserialize, Serialize};
+use sp_core::{bounded::BoundedBTreeSet, bounded_vec::BoundedVec};
 use sp_runtime::{traits::Get, DispatchError, TokenError};
 
 use crate::{xcm::XcmMetadata, EVMChainId};
 
 pub const MAX_ASSET_STRING_LIMIT: u32 = 128;
 
+pub const MAX_LOCAL_VARIANTS: u32 = 10;
+
 frame_support::parameter_types! {
 	#[derive(TypeInfo, Eq, PartialEq, Debug, Clone, Copy )]
 	pub const AssetStringLimit: u32 = MAX_ASSET_STRING_LIMIT;
+
+	#[derive(TypeInfo, Eq, PartialEq, Debug, Clone, Copy )]
+	pub const VariantsLimit: u32 = MAX_LOCAL_VARIANTS;
 }
 
 pub type AssetMetadata = asset_registry::AssetMetadata<Balance, CustomMetadata, AssetStringLimit>;
@@ -109,12 +115,12 @@ impl From<LocalAssetId> for CurrencyId {
 	}
 }
 
-impl TryFrom<CurrencyId> for LocalAssetId {
+impl TryFrom<&CurrencyId> for LocalAssetId {
 	type Error = ();
 
-	fn try_from(value: CurrencyId) -> Result<Self, Self::Error> {
+	fn try_from(value: &CurrencyId) -> Result<Self, Self::Error> {
 		if let CurrencyId::LocalAsset(local) = value {
-			Ok(local)
+			Ok(*local)
 		} else {
 			Err(())
 		}
@@ -275,7 +281,8 @@ pub struct CustomMetadata {
 	/// Whether an asset has a local representation. Usually, this means that we
 	/// are receiving the same asset from multiple domains and unify the asset
 	/// under a common local representation.
-	pub local_representation: Option<LocalAssetId>,
+	/// Can be multiple
+	pub local_representations: Option<BoundedBTreeSet<LocalAssetId, VariantsLimit>>,
 }
 
 #[cfg(feature = "std")]
@@ -375,17 +382,13 @@ where
 	>,
 {
 	fn is_local_representation_of(&self, variant_currency: &Self) -> Result<bool, DispatchError> {
-		let meta_local = AssetInspect::metadata(self).ok_or(DispatchError::CannotLookup)?;
+		let variant_local_id = LocalAssetId::try_from(variant_currency)
+			.map_err(DispatchError::Other("Not a local variant"))?;
 		let meta_variant =
 			AssetInspect::metadata(variant_currency).ok_or(DispatchError::CannotLookup)?;
 
-		if let Some(local) = meta_variant.additional.local_representation {
-			frame_support::ensure!(
-				meta_local.decimals == meta_variant.decimals,
-				DispatchError::Other("Mismatching decimals")
-			);
-
-			Ok(self == &local.into())
+		if let Some(local) = meta_variant.additional.local_representations {
+			Ok(local.iter().any(|local_id| local_id == &variant_local_id))
 		} else {
 			Ok(false)
 		}

pallets/token-mux/src/lib.rs

@@ -343,20 +343,19 @@ pub mod pallet {
 			.map(|_| ())
 		}
 
-		pub(crate) fn try_local(currency: &T::CurrencyId) -> Result<T::CurrencyId, DispatchError> {
-			let meta_variant =
-				T::AssetRegistry::metadata(currency).ok_or(Error::<T>::MetadataNotFound)?;
-
-			let local: T::CurrencyId = T::LocalAssetId::from(
-				meta_variant
-					.additional
-					.local_representation
-					.ok_or(Error::<T>::NoLocalRepresentation)?,
-			)
-			.into();
+		pub(crate) fn try_local(
+			variant: &T::CurrencyId,
+			local: &T::CurrencyId,
+		) -> Result<T::CurrencyId, DispatchError> {
+			ensure!(
+				local.is_local_representation_of(variant)?,
+				Error::<T>::NoLocalRepresentation
+			);
 
+			let meta_variant =
+				T::AssetRegistry::metadata(variant).ok_or(Error::<T>::MetadataNotFound)?;
 			let meta_local =
-				T::AssetRegistry::metadata(&local).ok_or(Error::<T>::MetadataNotFound)?;
+				T::AssetRegistry::metadata(local).ok_or(Error::<T>::MetadataNotFound)?;
 
 			// NOTE: We could also think about making conversion between local
 			//       representations and variants but I fear that we then have problems with