Ksm fee

node/primitives/src/currency.rs

@@ -75,9 +75,9 @@ macro_rules! create_currency_id {
 			type Error = ();
 			fn try_from(id: CurrencyId) -> Result<AssetId, ()> {
 				let _index = match id {
-					$(CurrencyId::Token(TokenSymbol::$symbol) => Ok((0_u32, TokenSymbol::$symbol as u32)),)*
+					$(CurrencyId::Native(TokenSymbol::$symbol) => Ok((0_u32, TokenSymbol::$symbol as u32)),)*
 					$(CurrencyId::VToken(TokenSymbol::$symbol) => Ok((1_u32, TokenSymbol::$symbol as u32)),)*
-					$(CurrencyId::Native(TokenSymbol::$symbol) => Ok((2_u32, TokenSymbol::$symbol as u32)),)*
+					$(CurrencyId::Token(TokenSymbol::$symbol) => Ok((2_u32, TokenSymbol::$symbol as u32)),)*
 					$(CurrencyId::Stable(TokenSymbol::$symbol) => Ok((3_u32, TokenSymbol::$symbol as u32)),)*
 					$(CurrencyId::VSToken(TokenSymbol::$symbol) => Ok((4_u32, TokenSymbol::$symbol as u32)),)*
 					_ => Err(()),
@@ -110,9 +110,9 @@ macro_rules! create_currency_id {
 					_ => Err(()),
 				};
 				match c_discr {
-					0 => Ok(CurrencyId::Token(token_symbol?)),
+					0 => Ok(CurrencyId::Native(token_symbol?)),
 					1 => Ok(CurrencyId::VToken(token_symbol?)),
-					2 => Ok(CurrencyId::Native(token_symbol?)),
+					2 => Ok(CurrencyId::Token(token_symbol?)),
 					3 => Ok(CurrencyId::Stable(token_symbol?)),
 					4 => Ok(CurrencyId::VSToken(token_symbol?)),
 					_ => Err(()),
@@ -245,9 +245,9 @@ impl Default for TokenSymbol {
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
 #[non_exhaustive]
 pub enum CurrencyId {
-	Token(TokenSymbol),
-	VToken(TokenSymbol),
 	Native(TokenSymbol),
+	VToken(TokenSymbol),
+	Token(TokenSymbol),
 	Stable(TokenSymbol),
 	VSToken(TokenSymbol),
 	VSBond(TokenSymbol, ParaId, LeasePeriod, LeasePeriod),
@@ -289,9 +289,9 @@ impl CurrencyId {
 
 	pub fn discriminant(&self) -> u8 {
 		match *self {
-			Self::Token(..) => 0,
+			Self::Native(..) => 0,
 			Self::VToken(..) => 1,
-			Self::Native(..) => 2,
+			Self::Token(..) => 2,
 			Self::Stable(..) => 3,
 			Self::VSToken(..) => 4,
 			Self::VSBond(..) => 5,
@@ -361,9 +361,9 @@ impl TryFrom<u64> for CurrencyId {
 		let token_symbol = TokenSymbol::try_from(t_discr)?;
 
 		match c_discr {
-			0 => Ok(Self::Token(token_symbol)),
+			0 => Ok(Self::Native(token_symbol)),
 			1 => Ok(Self::VToken(token_symbol)),
-			2 => Ok(Self::Native(token_symbol)),
+			2 => Ok(Self::Token(token_symbol)),
 			3 => Ok(Self::Stable(token_symbol)),
 			4 => Ok(Self::VSToken(token_symbol)),
 			5 => Ok(Self::VSBond(token_symbol, pid, lp1, lp2)),

node/primitives/src/tests.rs

@@ -30,12 +30,12 @@ fn currency_id_from_string_should_work() {
 
 #[test]
 fn currency_id_to_u64_should_work() {
-	let e00 = CurrencyId::Token(TokenSymbol::ASG);
-	let e01 = CurrencyId::Token(TokenSymbol::BNC);
-	let e02 = CurrencyId::Token(TokenSymbol::AUSD);
-	let e03 = CurrencyId::Token(TokenSymbol::DOT);
-	let e04 = CurrencyId::Token(TokenSymbol::KSM);
-	let e05 = CurrencyId::Token(TokenSymbol::ETH);
+	let e00 = CurrencyId::Native(TokenSymbol::ASG);
+	let e01 = CurrencyId::Native(TokenSymbol::BNC);
+	let e02 = CurrencyId::Native(TokenSymbol::AUSD);
+	let e03 = CurrencyId::Native(TokenSymbol::DOT);
+	let e04 = CurrencyId::Native(TokenSymbol::KSM);
+	let e05 = CurrencyId::Native(TokenSymbol::ETH);
 
 	assert_eq!(0x0000_0000_0000_0000, e00.currency_id());
 	assert_eq!(0x0001_0000_0000_0000, e01.currency_id());
@@ -58,12 +58,12 @@ fn currency_id_to_u64_should_work() {
 	assert_eq!(0x0104_0000_0000_0000, e14.currency_id());
 	assert_eq!(0x0105_0000_0000_0000, e15.currency_id());
 
-	let e20 = CurrencyId::Native(TokenSymbol::ASG);
-	let e21 = CurrencyId::Native(TokenSymbol::BNC);
-	let e22 = CurrencyId::Native(TokenSymbol::AUSD);
-	let e23 = CurrencyId::Native(TokenSymbol::DOT);
-	let e24 = CurrencyId::Native(TokenSymbol::KSM);
-	let e25 = CurrencyId::Native(TokenSymbol::ETH);
+	let e20 = CurrencyId::Token(TokenSymbol::ASG);
+	let e21 = CurrencyId::Token(TokenSymbol::BNC);
+	let e22 = CurrencyId::Token(TokenSymbol::AUSD);
+	let e23 = CurrencyId::Token(TokenSymbol::DOT);
+	let e24 = CurrencyId::Token(TokenSymbol::KSM);
+	let e25 = CurrencyId::Token(TokenSymbol::ETH);
 
 	assert_eq!(0x0200_0000_0000_0000, e20.currency_id());
 	assert_eq!(0x0201_0000_0000_0000, e21.currency_id());
@@ -117,12 +117,12 @@ fn currency_id_to_u64_should_work() {
 
 #[test]
 fn u64_to_currency_id_should_work() {
-	let e00 = CurrencyId::Token(TokenSymbol::ASG);
-	let e01 = CurrencyId::Token(TokenSymbol::BNC);
-	let e02 = CurrencyId::Token(TokenSymbol::AUSD);
-	let e03 = CurrencyId::Token(TokenSymbol::DOT);
-	let e04 = CurrencyId::Token(TokenSymbol::KSM);
-	let e05 = CurrencyId::Token(TokenSymbol::ETH);
+	let e00 = CurrencyId::Native(TokenSymbol::ASG);
+	let e01 = CurrencyId::Native(TokenSymbol::BNC);
+	let e02 = CurrencyId::Native(TokenSymbol::AUSD);
+	let e03 = CurrencyId::Native(TokenSymbol::DOT);
+	let e04 = CurrencyId::Native(TokenSymbol::KSM);
+	let e05 = CurrencyId::Native(TokenSymbol::ETH);
 
 	assert_eq!(e00, CurrencyId::try_from(0x0000_0000_0000_0000).unwrap());
 	assert_eq!(e01, CurrencyId::try_from(0x0001_0000_0000_0000).unwrap());
@@ -145,12 +145,12 @@ fn u64_to_currency_id_should_work() {
 	assert_eq!(e14, CurrencyId::try_from(0x0104_0000_0000_0000).unwrap());
 	assert_eq!(e15, CurrencyId::try_from(0x0105_0000_0000_0000).unwrap());
 
-	let e20 = CurrencyId::Native(TokenSymbol::ASG);
-	let e21 = CurrencyId::Native(TokenSymbol::BNC);
-	let e22 = CurrencyId::Native(TokenSymbol::AUSD);
-	let e23 = CurrencyId::Native(TokenSymbol::DOT);
-	let e24 = CurrencyId::Native(TokenSymbol::KSM);
-	let e25 = CurrencyId::Native(TokenSymbol::ETH);
+	let e20 = CurrencyId::Token(TokenSymbol::ASG);
+	let e21 = CurrencyId::Token(TokenSymbol::BNC);
+	let e22 = CurrencyId::Token(TokenSymbol::AUSD);
+	let e23 = CurrencyId::Token(TokenSymbol::DOT);
+	let e24 = CurrencyId::Token(TokenSymbol::KSM);
+	let e25 = CurrencyId::Token(TokenSymbol::ETH);
 
 	assert_eq!(e20, CurrencyId::try_from(0x0200_0000_0000_0000).unwrap());
 	assert_eq!(e21, CurrencyId::try_from(0x0201_0000_0000_0000).unwrap());

pallets/flexible-fee/src/fee_dealer.rs

@@ -0,0 +1,77 @@
+// This file is part of Bifrost.
+
+// Copyright (C) 2019-2021 Liebi Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program 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.
+
+// This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
+
+// The swap pool algorithm implements Balancer protocol
+// For more details, refer to https://balancer.finance/whitepaper/
+
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use sp_runtime::traits::UniqueSaturatedFrom;
+
+use super::*;
+use crate::Config;
+
+pub trait FeeDealer<AccountId, Balance> {
+	fn ensure_can_charge_fee(
+		who: &AccountId,
+		fee: Balance,
+		reason: WithdrawReasons,
+	) -> DispatchResult;
+}
+
+pub struct FixedCurrencyFeeRate<T: Config>(PhantomData<T>);
+
+impl<T: Config> FeeDealer<T::AccountId, PalletBalanceOf<T>> for FixedCurrencyFeeRate<T> {
+	/// Make sure there are enough BNC to be deducted if the user has assets in other form of tokens
+	/// rather than BNC.
+	fn ensure_can_charge_fee(
+		who: &T::AccountId,
+		fee: PalletBalanceOf<T>,
+		_reason: WithdrawReasons,
+	) -> DispatchResult {
+		let fee_currency_id: CurrencyId = T::AlternativeFeeCurrencyId::get();
+		let (fee_currency_base, native_currency_base): (u32, u32) =
+			T::AltFeeCurrencyExchangeRate::get();
+
+		let fee_currency_balance = T::MultiCurrency::free_balance(fee_currency_id, who);
+
+		let consume_fee_currency_amount =
+			fee.saturating_mul(fee_currency_base.into()) / native_currency_base.into();
+		ensure!(
+			consume_fee_currency_amount <=
+				PalletBalanceOf::<T>::unique_saturated_from(fee_currency_balance.into()),
+			Error::<T>::NotEnoughBalance
+		);
+
+		// deduct fee currency and increase native currency amount
+		// This withdraw operation allows death. So it will succeed given the remaining amount less
+		// than the existential deposit.
+		T::MultiCurrency::withdraw(
+			fee_currency_id,
+			who,
+			T::Balance::from(consume_fee_currency_amount),
+		)?;
+		T::MultiCurrency::deposit(T::NativeCurrencyId::get(), who, T::Balance::from(fee))?;
+
+		crate::Pallet::<T>::deposit_event(Event::FixedRateFeeExchanged(
+			fee_currency_id,
+			consume_fee_currency_amount,
+		));
+		Ok(())
+	}
+}