add generic type for XCM asset transactor with forwarder traits

bridge/src/xcm_asset_transactor.rs

@@ -1,11 +1,12 @@
-use xcm::latest::{Junctions, MultiAsset, MultiLocation, XcmContext};
-use xcm::prelude::{GeneralKey, X3};
-use xcm::v3::Junction::Parachain;
+use core::marker::PhantomData;
+use xcm::latest::{Junction, MultiAsset, MultiLocation, XcmContext};
+use sygma_traits::{AssetTypeIdentifier, TransactorForwarder};
+use xcm::prelude::*;
 use xcm_executor::{traits::TransactAsset};
 
-pub struct XCMAssetTransactor;
+pub struct XCMAssetTransactor<CurrencyTransactor, FungiblesTransactor, AssetTypeChecker, Forwarder>(PhantomData<(CurrencyTransactor, FungiblesTransactor, AssetTypeChecker, Forwarder)>);
 
-impl TransactAsset for XCMAssetTransactor{
+impl<CurrencyTransactor: TransactAsset, FungiblesTransactor: TransactAsset, AssetTypeChecker: AssetTypeIdentifier, Forwarder: TransactorForwarder> TransactAsset for XCMAssetTransactor<CurrencyTransactor, FungiblesTransactor, AssetTypeChecker, Forwarder> {
     // deposit_asset implements the TransactAsset deposit_asset method and contains the logic to classify
     // the asset recipient location:
     // 1. recipient is on the local parachain
@@ -15,23 +16,44 @@ impl TransactAsset for XCMAssetTransactor{
         match (who.parents, who.interior) {
             // 1. recipient is the local parachain
             (0, None) => {
-                // TODO: check if the asset is native or foreign, and call the corresponding deposit_asset()
+                // check if the asset is native or foreign, and call the corresponding deposit_asset()
+                if AssetTypeChecker::is_native_asset(what) {
+                    CurrencyTransactor::deposit_asset(what, who, context)?;
+                } else {
+                    FungiblesTransactor::deposit_asset(what, who, context)?
+                }
             }
             // 2. recipient is remote parachain
+            // trying to eliminate the forward logic here by adding the XCM handler pallet as one of the generic type for XCMAssetTransactor
             (1, Some(Parachain(_))) => {
-                // TODO: call the xcm handler pallet to construct the xcm message (evm to remote parachain route)
                 // xcm message must have a sender(origin), so a tmp account derived from pallet would be used
+                let tmp_account = MultiLocation::new(0, X1(GeneralKey {length: 8, data: [2u8; 32]})).into_account();
+
                 // check if the asset is native or foreign, and call the corresponding deposit_asset(), recipient will be the derived tmp account
                 // xcm message execution
+                if AssetTypeChecker::is_native_asset(what) {
+                    CurrencyTransactor::deposit_asset(what, &Junction::AccountId32 { network: None, id: tmp_account }.into(), context)?;
+                } else {
+                    FungiblesTransactor::deposit_asset(what, &Junction::AccountId32 { network: None, id: tmp_account }.into(), context)?
+                }
 
-                // trying to eliminate the forward logic here by adding the XCM handler pallet as one of the generic type for XCMAssetTransactor
+                // TODO: call the xcm handler pallet to construct the xcm message and execute it(to other remote parachain route)
+                Forwarder::xcm_transactor_forwarder()
             }
             // 3. recipient is on non-substrate chain(evm, cosmos, etc.), will forward to sygma bridge pallet
             // TODO: the junctions below is just an temporary example, will change it to proper sygma bridge standard, see the link below:
             // (https://www.notion.so/chainsafe/Sygma-as-an-Independent-pallet-c481f00ccff84ff49ce917c8b2feacda?pvs=4#6e51e6632e254b9b9a01444ef7297969)
             (0, &X3(Parachain(_), GeneralKey{length: 8, data: [1u8, 32]}, GeneralKey {length:8, data: [2u8, 32]})) => {
-                // TODO: check if the asset is native or foreign, and deposit the asset to a tmp account first
-                // TODO: call deposit() extrisic in sygmaBrdige pallet
+                // check if the asset is native or foreign, and deposit the asset to a tmp account first
+                let tmp_account = MultiLocation::new(0, X1(GeneralKey {length: 8, data: [2u8; 32]})).into_account();
+                if AssetTypeChecker::is_native_asset(what) {
+                    CurrencyTransactor::deposit_asset(what, &Junction::AccountId32 { network: None, id: tmp_account }.into(), context)?;
+                } else {
+                    FungiblesTransactor::deposit_asset(what, &Junction::AccountId32 { network: None, id: tmp_account }.into(), context)?
+                }
+
+                // TODO: call deposit() extrisic in sygmaBrdige pallet. Sygma bridge pallet should also be in the PhantomData type
+                Forwarder::other_world_transactor_forwarder()
             }
             // Other destination multilocation not supported, return Err
             _ => {

traits/src/lib.rs

@@ -61,3 +61,15 @@ pub trait DecimalConverter {
 	/// Sygma relayer will always send asset in 18 decimal
 	fn convert_from(asset: &MultiAsset) -> Option<MultiAsset>;
 }
+
+// TODO: implement this method for local mock and standalone use
+// when integrating with parachain, parachain team can implement their own version
+pub trait AssetTypeIdentifier {
+	fn is_native_asset(asset: &MultiAsset) -> bool;
+}
+
+// TODO: implement these methods
+pub trait TransactorForwarder {
+	fn xcm_transactor_forwarder();
+	fn other_world_transactor_forwarder();
+}