📡 Add XCM Runtime APIs (#414)

## What?
Add XCM payment apis to the runtime

## How?
Most are just a simple copy paste to the pallet function, but a couple of them need some specific config due to asset payment.

## Testing?
integration tests in `runtime_apis.rs`

Cargo.toml

@@ -187,6 +187,7 @@ xcm-builder = { version = "14.0.0", package = 'staging-xcm-builder', default-fea
 xcm-executor = { version = "14.0.0", package = 'staging-xcm-executor', default-features = false }
 polkadot-runtime-common = { version = "14.0.0", default-features = false }
 polkadot-primitives = { version = "14.0.0", default-features = false }
+xcm-fee-payment-runtime-api = { version = "0.4.0", default-features = false }
 
 # Cumulus (with default disabled)
 cumulus-pallet-aura-ext = { version = "0.14.0", default-features = false }

integration-tests/Cargo.toml

@@ -81,6 +81,7 @@ pallet-aura.workspace = true
 pallet-session.workspace = true
 pallet-proxy-bonding.workspace = true
 pallet-skip-feeless-payment.workspace = true
+xcm-fee-payment-runtime-api.workspace = true
 
 # Runtimes
 polkadot-runtime.workspace = true

integration-tests/src/tests/mod.rs

@@ -23,6 +23,7 @@ mod governance;
 mod oracle;
 mod otm_edge_cases;
 mod reserve_backed_transfers;
+mod runtime_apis;
 mod transaction_payment;
 mod vest;
 mod xcm_config;

integration-tests/src/tests/runtime_apis.rs

@@ -0,0 +1,75 @@
+use crate::{constants::*, *};
+
+mod xcm_payment_api {
+	use super::*;
+	use sp_arithmetic::FixedU128;
+	use xcm::v4::Junctions::X3;
+	use xcm_fee_payment_runtime_api::fees::runtime_decl_for_xcm_payment_api::XcmPaymentApiV1;
+
+	#[test]
+	fn query_acceptable_payment_assets() {
+		PolimecNet::execute_with(|| {
+			let accepted_payment_assets = PolimecRuntime::query_acceptable_payment_assets(4u32).unwrap();
+			assert_eq!(
+				accepted_payment_assets,
+				vec![
+					VersionedAssetId::V4(AssetId(Location { parents: 0, interior: Here },),),
+					VersionedAssetId::V4(AssetId(Location { parents: 1, interior: Here },),),
+					VersionedAssetId::V4(AssetId(Location {
+						parents: 1,
+						interior: X3([Parachain(1000,), PalletInstance(50,), GeneralIndex(1984,),].into(),),
+					},),),
+					VersionedAssetId::V4(AssetId(Location {
+						parents: 1,
+						interior: X3([Parachain(1000,), PalletInstance(50,), GeneralIndex(1337,),].into(),),
+					},),),
+				]
+			);
+		});
+	}
+
+	#[test]
+	fn query_weight_to_asset_fee() {
+		polimec::set_prices(
+			PricesBuilder::new()
+				.usdt(FixedU128::from_float(1.0f64))
+				.plmc(FixedU128::from_float(0.5f64))
+				.dot(FixedU128::from_float(10.0f64))
+				.build(),
+		);
+
+		let compute_weight = Weight::from_parts(100_000_000, 20_000);
+
+		// Native Asset
+		PolimecNet::execute_with(|| {
+			let plmc_fee = PolimecRuntime::query_weight_to_asset_fee(
+				compute_weight,
+				VersionedAssetId::V4(AssetId(Location { parents: 0, interior: Here })),
+			)
+			.unwrap();
+			dbg!(plmc_fee);
+
+			let dot_fee = PolimecRuntime::query_weight_to_asset_fee(
+				compute_weight,
+				VersionedAssetId::V4(AssetId(Location { parents: 1, interior: Here })),
+			)
+			.unwrap();
+			dbg!(dot_fee);
+
+			let usdt_fee = PolimecRuntime::query_weight_to_asset_fee(
+				compute_weight,
+				VersionedAssetId::V4(AssetId(Location {
+					parents: 1,
+					interior: X3([Parachain(1000), PalletInstance(50), GeneralIndex(1984)].into()),
+				})),
+			)
+			.unwrap();
+			dbg!(usdt_fee);
+
+			// PLMC and dot have the same decimals, so a simple conversion is enough
+			assert_eq!(dot_fee, plmc_fee / 20);
+			// USDT has 6 decimals, so we need to divide by 10^(10-6)= 10_000
+			assert_eq!(usdt_fee, plmc_fee / 2 / 10_000);
+		});
+	}
+}

polimec-common/common/Cargo.toml

@@ -27,6 +27,7 @@ sp-std.workspace = true
 sp-runtime.workspace = true
 itertools.workspace = true
 xcm.workspace = true
+xcm-builder.workspace = true
 
 
 [features]

polimec-common/common/src/lib.rs

@@ -23,6 +23,7 @@ use sp_runtime::{
 };
 use sp_std::prelude::*;
 pub use xcm::v4::{opaque::Xcm, Assets, Location, QueryId, SendError, SendResult, SendXcm, XcmHash};
+use xcm::{VersionedLocation, VersionedXcm};
 
 pub mod credentials;
 
@@ -239,6 +240,11 @@ impl SendXcm for DummyXcmSender {
 		Ok([0u8; 32])
 	}
 }
+impl xcm_builder::InspectMessageQueues for DummyXcmSender {
+	fn get_messages() -> Vec<(VersionedLocation, Vec<VersionedXcm<()>>)> {
+		vec![]
+	}
+}
 
 pub trait ProvideAssetPrice {
 	type AssetId;

runtimes/polimec/Cargo.toml

@@ -93,6 +93,7 @@ polkadot-runtime-common.workspace = true
 xcm.workspace = true
 xcm-builder.workspace = true
 xcm-executor.workspace = true
+xcm-fee-payment-runtime-api.workspace = true
 
 # Cumulus
 cumulus-pallet-aura-ext.workspace = true

runtimes/polimec/src/lib.rs

@@ -71,18 +71,23 @@ use sp_runtime::{
 };
 use sp_std::{cmp::Ordering, prelude::*};
 use sp_version::RuntimeVersion;
+use xcm::{IntoVersion, VersionedAssets, VersionedLocation, VersionedXcm};
 
 // XCM Imports
 use xcm::v3::{
 	Junction::{GeneralIndex, PalletInstance, Parachain},
 	Junctions::{Here, X3},
 	MultiLocation,
 };
-use xcm_config::{PriceForSiblingParachainDelivery, XcmOriginToTransactDispatchOrigin};
-
 #[cfg(not(feature = "runtime-benchmarks"))]
 use xcm_config::XcmConfig;
 
+use xcm_config::{PriceForSiblingParachainDelivery, XcmOriginToTransactDispatchOrigin};
+use xcm_fee_payment_runtime_api::{
+	dry_run::{CallDryRunEffects, Error as XcmDryRunApiError, XcmDryRunEffects},
+	fees::Error as XcmPaymentApiError,
+};
+
 // Polimec Shared Imports
 pub use pallet_parachain_staking;
 pub use shared_configuration::{
@@ -96,6 +101,7 @@ use sp_version::NativeVersion;
 
 #[cfg(any(feature = "std", test))]
 pub use sp_runtime::BuildStorage;
+use xcm::VersionedAssetId;
 
 #[cfg(feature = "runtime-benchmarks")]
 mod benchmark_helpers;
@@ -1084,6 +1090,7 @@ impl pallet_funding::Config for Runtime {
 }
 
 use polimec_common::{PLMC_DECIMALS, PLMC_FOREIGN_ID, USD_DECIMALS};
+
 parameter_types! {
 	// Fee is defined as 1.5% of the usd_amount. Since fee is applied to the plmc amount, and that is always 5 times
 	// less than the usd_amount (multiplier of 5), we multiply the 1.5 by 5 to get 7.5%
@@ -1155,6 +1162,7 @@ impl Convert<MultiLocation, AssetId> for ConvertMultilocationToAssetId {
 			MultiLocation { parents: 1, interior: Here } => 10,
 			MultiLocation { parents: 1, interior: X3(Parachain(1000), PalletInstance(50), GeneralIndex(1337)) } => 1337,
 			MultiLocation { parents: 1, interior: X3(Parachain(1000), PalletInstance(50), GeneralIndex(1984)) } => 1984,
+			// asset 0 should be invalid.
 			_ => 0,
 		}
 	}
@@ -1673,6 +1681,54 @@ impl_runtime_apis! {
 			Default::default()
 		}
 	}
+
+	impl xcm_fee_payment_runtime_api::fees::XcmPaymentApi<Block> for Runtime {
+		fn query_acceptable_payment_assets(xcm_version: xcm::Version) -> Result<Vec<VersionedAssetId>, XcmPaymentApiError> {
+			let acceptable_assets = vec![
+				xcm_config::HereLocation::get().into(),
+				xcm_config::DotLocation::get().into(),
+				xcm_config::UsdtLocation::get().into(),
+				xcm_config::UsdcLocation::get().into()
+			];
+
+			PolkadotXcm::query_acceptable_payment_assets(xcm_version, acceptable_assets)
+		}
+
+		fn query_weight_to_asset_fee(weight: Weight, asset: VersionedAssetId) -> Result<u128, XcmPaymentApiError> {
+			match xcm::v3::AssetId::try_from(asset) {
+				Ok(xcm::v3::AssetId::Concrete(multilocation)) if multilocation == MultiLocation::here() => {
+					// for native token
+					Ok(TransactionPayment::weight_to_fee(weight))
+				},
+				Ok(xcm::v3::AssetId::Concrete(multilocation)) => {
+					let native_fee = TransactionPayment::weight_to_fee(weight);
+					let converted_asset_id = ConvertMultilocationToAssetId::convert(multilocation);
+					PLMCToFundingAssetBalance::to_asset_balance(native_fee, converted_asset_id).map_err(|_| XcmPaymentApiError::AssetNotFound)
+				},
+				_ => {
+					Err(XcmPaymentApiError::VersionedConversionFailed)
+				}
+			}
+		}
+
+		fn query_xcm_weight(message: VersionedXcm<()>) -> Result<Weight, XcmPaymentApiError> {
+			PolkadotXcm::query_xcm_weight(message)
+		}
+
+		fn query_delivery_fees(destination: VersionedLocation, message: VersionedXcm<()>) -> Result<VersionedAssets, XcmPaymentApiError> {
+			PolkadotXcm::query_delivery_fees(destination, message)
+		}
+	}
+
+	impl xcm_fee_payment_runtime_api::dry_run::DryRunApi<Block, RuntimeCall, RuntimeEvent, OriginCaller> for Runtime {
+		fn dry_run_call(origin: OriginCaller, call: RuntimeCall) -> Result<CallDryRunEffects<RuntimeEvent>, XcmDryRunApiError> {
+			PolkadotXcm::dry_run_call::<Runtime, xcm_config::XcmRouter, OriginCaller, RuntimeCall>(origin, call)
+		}
+
+		fn dry_run_xcm(origin_location: VersionedLocation, xcm: VersionedXcm<RuntimeCall>) -> Result<XcmDryRunEffects<RuntimeEvent>, XcmDryRunApiError> {
+			PolkadotXcm::dry_run_xcm::<Runtime, xcm_config::XcmRouter, RuntimeCall, xcm_config::XcmConfig>(origin_location, xcm)
+		}
+	}
 }
 
 cumulus_pallet_parachain_system::register_validate_block! {

runtimes/polimec/src/xcm_config.rs

@@ -55,12 +55,12 @@ const DOT_PER_MB_PROOF: u128 = 0_2_000_000_000; // 0.0000001 DOT per Megabyte of
 // USDT from Polkadot Asset Hub
 const USDT_PER_SECOND_EXECUTION: u128 = 1_000_000; // 1 USDT per second of execution time
 const USDT_PER_MB_PROOF: u128 = 1_000_000; // 1 USDT per Megabyte of proof size
-const USDT_JUNCTION: &[Junction] = &[Parachain(1000), PalletInstance(50), GeneralIndex(1984)];
+pub const USDT_JUNCTION: &[Junction] = &[Parachain(1000), PalletInstance(50), GeneralIndex(1984)];
 
 // USDC from Polkadot Asset Hub
 const USDC_PER_SECOND_EXECUTION: u128 = 1_000_000; // 1 USDC per second of execution time
 const USDC_PER_MB_PROOF: u128 = 1_000_000; // 1 USDC per Megabyte of proof size
-const USDC_JUNCTION: &[Junction] = &[Parachain(1000), PalletInstance(50), GeneralIndex(1337)];
+pub const USDC_JUNCTION: &[Junction] = &[Parachain(1000), PalletInstance(50), GeneralIndex(1337)];
 
 parameter_types! {
 	pub const RelayLocation: Location = Location::parent();

scripts/zombienet/polimec-paseo-local.toml

@@ -1,3 +1,4 @@
+
 [settings]
 timeout = 1000
 provider = "native"