improve lending pool params

Author: suefay

api/side/lending/lending.pulsar.go

@@ -29,8 +29,13 @@ message AssetMetadata {
 message PoolTrancheConfig {
   // maturity duration in seconds
   int64 maturity = 1;
-  // borrow apr permille
-  uint32 borrow_apr = 2 [(gogoproto.customname) = "BorrowAPR"];
+  // borrow apr
+  string borrow_apr = 2 [
+    (gogoproto.customname) = "BorrowAPR",
+    (cosmos_proto.scalar)  = "cosmos.Dec",
+    (gogoproto.customtype) = "cosmossdk.io/math.LegacyDec",
+    (gogoproto.nullable)   = false
+  ];
 }
 
 // Pool config
@@ -65,14 +70,30 @@ message PoolConfig {
     cosmos.base.v1beta1.Coin request_fee = 8 [
       (gogoproto.nullable) = false
     ];
-    // origination fee factor permille
-    uint32 origination_fee_factor = 9;
-    // reserve factor permille
-    uint32 reserve_factor = 10;
-    // maximum ltv percent
-    uint32 max_ltv = 11;
-    // liquidation ltv percent
-    uint32 liquidation_threshold = 12;
+    // origination fee factor
+    string origination_fee_factor = 9 [
+      (cosmos_proto.scalar)  = "cosmos.Dec",
+      (gogoproto.customtype) = "cosmossdk.io/math.LegacyDec",
+      (gogoproto.nullable)   = false
+    ];
+    // reserve factor
+    string reserve_factor = 10 [
+      (cosmos_proto.scalar)  = "cosmos.Dec",
+      (gogoproto.customtype) = "cosmossdk.io/math.LegacyDec",
+      (gogoproto.nullable)   = false
+    ];
+    // maximum ltv
+    string max_ltv = 11 [
+      (cosmos_proto.scalar)  = "cosmos.Dec",
+      (gogoproto.customtype) = "cosmossdk.io/math.LegacyDec",
+      (gogoproto.nullable)   = false
+    ];
+    // liquidation ltv
+    string liquidation_threshold = 12 [
+      (cosmos_proto.scalar)  = "cosmos.Dec",
+      (gogoproto.customtype) = "cosmossdk.io/math.LegacyDec",
+      (gogoproto.nullable)   = false
+    ];
     // indicates if the pool is paused
     bool paused = 13;
 }
@@ -281,7 +302,12 @@ message Loan {
       (gogoproto.nullable) = false
     ];
     int64 maturity = 14;
-    uint32 borrow_apr = 15 [(gogoproto.customname) = "BorrowAPR"];
+    string borrow_apr = 15 [
+      (gogoproto.customname) = "BorrowAPR",
+      (cosmos_proto.scalar)  = "cosmos.Dec",
+      (gogoproto.customtype) = "cosmossdk.io/math.LegacyDec",
+      (gogoproto.nullable)   = false
+    ];
     string start_borrow_index = 16 [
       (cosmos_proto.scalar)  = "cosmos.Dec",
       (gogoproto.customtype) = "cosmossdk.io/math.LegacyDec",

proto/side/lending/lending.proto

@@ -106,7 +106,7 @@ func (m msgServer) Apply(goCtx context.Context, msg *types.MsgApply) (*types.Msg
 		PoolId:             msg.PoolId,
 		BorrowAmount:       msg.BorrowAmount,
 		RequestFee:         poolConfig.RequestFee,
-		OriginationFee:     msg.BorrowAmount.Amount.Mul(sdkmath.NewInt(int64(poolConfig.OriginationFeeFactor))).Quo(types.Permille),
+		OriginationFee:     msg.BorrowAmount.Amount.ToLegacyDec().Mul(poolConfig.OriginationFeeFactor).TruncateInt(),
 		Maturity:           trancheConfig.Maturity,
 		BorrowAPR:          trancheConfig.BorrowAPR,
 		DlcEventId:         dlcEvent.Id,

x/lending/keeper/msg_server_loan.go

@@ -155,10 +155,10 @@ func (k Keeper) UpdatePoolTranches(ctx sdk.Context, pool *types.LendingPool) {
 	for i, tranche := range pool.Tranches {
 		trancheConfig, _ := types.GetTrancheConfig(pool.Config.Tranches, tranche.Maturity)
 
-		borrowRatePerBlock := sdkmath.LegacyNewDec(int64(trancheConfig.BorrowAPR)).Quo(sdkmath.LegacyNewDec(1000)).Quo(sdkmath.LegacyNewDec(int64(blocksPerYear)))
+		borrowRatePerBlock := trancheConfig.BorrowAPR.Quo(sdkmath.LegacyNewDec(int64(blocksPerYear)))
 		borrowIndexRatio := sdkmath.LegacyOneDec().Add(borrowRatePerBlock)
 
-		reserveDelta := pool.Tranches[i].TotalBorrowed.ToLegacyDec().Mul(borrowRatePerBlock).MulInt(sdkmath.NewInt(int64(pool.Config.ReserveFactor))).QuoInt(sdkmath.NewInt(1000)).TruncateInt()
+		reserveDelta := pool.Tranches[i].TotalBorrowed.ToLegacyDec().Mul(borrowRatePerBlock).Mul(pool.Config.ReserveFactor).TruncateInt()
 
 		pool.Tranches[i].BorrowIndex = pool.Tranches[i].BorrowIndex.Mul(borrowIndexRatio)
 		pool.Tranches[i].TotalBorrowed = pool.Tranches[i].TotalBorrowed.ToLegacyDec().Mul(borrowIndexRatio).TruncateInt()

x/lending/keeper/pool.go

@@ -68,7 +68,7 @@ func (k Keeper) CompleteRepayment(ctx sdk.Context, loan *types.Loan) error {
 	repayment := k.GetRepayment(ctx, loan.VaultAddress)
 
 	interest := repayment.Amount.Sub(loan.BorrowAmount)
-	protocolFee := sdk.NewCoin(interest.Denom, interest.Amount.Mul(sdkmath.NewInt(int64(pool.Config.ReserveFactor))).Quo(types.Permille))
+	protocolFee := sdk.NewCoin(interest.Denom, interest.Amount.ToLegacyDec().Mul(pool.Config.ReserveFactor).TruncateInt())
 
 	referralFee := sdkmath.ZeroInt()
 	actualProtocolFee := protocolFee

x/lending/keeper/repayment.go

@@ -54,18 +54,18 @@ func GetInterest(borrowAmount sdkmath.Int, startBorrowIndex sdkmath.LegacyDec, b
 }
 
 // GetTotalInterest calculates the total loan interest based on the given params
-func GetTotalInterest(borrowAmount sdkmath.Int, maturity int64, borrowAPR uint32, blocksPerYear uint64) sdkmath.Int {
+func GetTotalInterest(borrowAmount sdkmath.Int, maturity int64, borrowAPR sdkmath.LegacyDec, blocksPerYear uint64) sdkmath.Int {
 	totalBlocks := uint64(maturity) * blocksPerYear / uint64(OneYear)
 
-	borrowRatePerBlock := sdkmath.LegacyNewDec(int64(borrowAPR)).Quo(sdkmath.LegacyNewDec(1000)).Quo(sdkmath.LegacyNewDec(int64(blocksPerYear)))
+	borrowRatePerBlock := borrowAPR.Quo(sdkmath.LegacyNewDec(int64(blocksPerYear)))
 	borrowIndexRatio := sdkmath.LegacyOneDec().Add(borrowRatePerBlock)
 
 	return borrowAmount.ToLegacyDec().Mul(borrowIndexRatio.Power(totalBlocks)).TruncateInt().Sub(borrowAmount)
 }
 
 // GetProtocolFee calculates the protocol fee based on the given interest and reserve factor
-func GetProtocolFee(interest sdkmath.Int, reserveFactor uint32) sdkmath.Int {
-	return interest.Mul(sdkmath.NewInt(int64(reserveFactor))).Quo(Permille)
+func GetProtocolFee(interest sdkmath.Int, reserveFactor sdkmath.LegacyDec) sdkmath.Int {
+	return interest.ToLegacyDec().Mul(reserveFactor).TruncateInt()
 }
 
 // GetLiquidationPrice calculates the liquidation price according to the liquidation LTV
@@ -74,14 +74,14 @@ func GetProtocolFee(interest sdkmath.Int, reserveFactor uint32) sdkmath.Int {
 // liquidation price = (borrow amount + interest) / lltv / collateral amount
 // 2. collateral is NOT the base price asset:
 // liquidation price = collateral amount * lltv / (borrow amount + interest)
-func GetLiquidationPrice(collateralAmount sdkmath.Int, collateralAssetDecimals int, borrowAmount sdkmath.Int, borrowAssetDecimals int, maturity int64, borrowAPR uint32, blocksPerYear uint64, lltv uint32, collateralIsBaseAsset bool) sdkmath.LegacyDec {
+func GetLiquidationPrice(collateralAmount sdkmath.Int, collateralAssetDecimals int, borrowAmount sdkmath.Int, borrowAssetDecimals int, maturity int64, borrowAPR sdkmath.LegacyDec, blocksPerYear uint64, lltv sdkmath.LegacyDec, collateralIsBaseAsset bool) sdkmath.LegacyDec {
 	interest := GetTotalInterest(borrowAmount, maturity, borrowAPR, blocksPerYear)
 
 	var liquidationPrice sdkmath.LegacyDec
 	if collateralIsBaseAsset {
-		liquidationPrice = borrowAmount.Add(interest).Mul(sdkmath.NewIntWithDecimal(1, collateralAssetDecimals)).Mul(Percent).ToLegacyDec().QuoInt(sdkmath.NewInt(int64(lltv))).QuoInt(collateralAmount).QuoInt(sdkmath.NewIntWithDecimal(1, borrowAssetDecimals))
+		liquidationPrice = borrowAmount.Add(interest).Mul(sdkmath.NewIntWithDecimal(1, collateralAssetDecimals)).ToLegacyDec().Quo(lltv).QuoInt(collateralAmount).QuoInt(sdkmath.NewIntWithDecimal(1, borrowAssetDecimals))
 	} else {
-		liquidationPrice = collateralAmount.Mul(sdkmath.NewIntWithDecimal(1, borrowAssetDecimals)).Mul(sdkmath.NewInt(int64(lltv))).ToLegacyDec().QuoInt(Percent).QuoInt(borrowAmount.Add(interest)).QuoInt(sdkmath.NewIntWithDecimal(1, collateralAssetDecimals))
+		liquidationPrice = collateralAmount.Mul(sdkmath.NewIntWithDecimal(1, borrowAssetDecimals)).ToLegacyDec().Mul(lltv).QuoInt(borrowAmount.Add(interest)).QuoInt(sdkmath.NewIntWithDecimal(1, collateralAssetDecimals))
 	}
 
 	return NormalizePrice(liquidationPrice, collateralIsBaseAsset)
@@ -97,12 +97,12 @@ func ToBeLiquidated(price sdkmath.LegacyDec, liquidationPrice sdkmath.LegacyDec,
 }
 
 // CheckLTV returns true if the collateral amount and borrow amount satisfy the max LTV limitation by the given price, false otherwise
-func CheckLTV(collateralAmount sdkmath.Int, collateralAssetDecimals int, borrowAmount sdkmath.Int, borrowAssetDecimals int, maxLTV uint32, price sdkmath.LegacyDec, collateralIsBaseAsset bool) bool {
+func CheckLTV(collateralAmount sdkmath.Int, collateralAssetDecimals int, borrowAmount sdkmath.Int, borrowAssetDecimals int, maxLTV sdkmath.LegacyDec, price sdkmath.LegacyDec, collateralIsBaseAsset bool) bool {
 	if collateralIsBaseAsset {
-		return collateralAmount.Mul(sdkmath.NewIntWithDecimal(1, borrowAssetDecimals)).Mul(sdkmath.NewInt(int64(maxLTV))).ToLegacyDec().Mul(price).QuoInt(sdkmath.NewIntWithDecimal(1, collateralAssetDecimals)).QuoInt(Percent).TruncateInt().GTE(borrowAmount)
+		return collateralAmount.Mul(sdkmath.NewIntWithDecimal(1, borrowAssetDecimals)).ToLegacyDec().Mul(maxLTV).Mul(price).QuoInt(sdkmath.NewIntWithDecimal(1, collateralAssetDecimals)).TruncateInt().GTE(borrowAmount)
 	}
 
-	return collateralAmount.Mul(sdkmath.NewIntWithDecimal(1, borrowAssetDecimals)).Mul(sdkmath.NewInt(int64(maxLTV))).ToLegacyDec().Quo(price).QuoInt(sdkmath.NewIntWithDecimal(1, collateralAssetDecimals)).QuoInt(Percent).TruncateInt().GTE(borrowAmount)
+	return collateralAmount.Mul(sdkmath.NewIntWithDecimal(1, borrowAssetDecimals)).ToLegacyDec().Mul(maxLTV).Quo(price).QuoInt(sdkmath.NewIntWithDecimal(1, collateralAssetDecimals)).TruncateInt().GTE(borrowAmount)
 }
 
 // GetPricePair gets the price pair from the given pool config
@@ -292,23 +292,23 @@ func ValidatePoolConfig(config PoolConfig) error {
 	}
 
 	if config.SupplyCap.IsNil() || config.SupplyCap.IsNegative() {
-		return errorsmod.Wrap(ErrInvalidPoolConfig, "supply cap can not be nil or negative")
+		return errorsmod.Wrap(ErrInvalidPoolConfig, "supply cap cannot be nil or negative")
 	}
 
 	if config.BorrowCap.IsNil() || config.BorrowCap.IsNegative() {
-		return errorsmod.Wrap(ErrInvalidPoolConfig, "borrow cap can not be nil or negative")
+		return errorsmod.Wrap(ErrInvalidPoolConfig, "borrow cap cannot be nil or negative")
 	}
 
 	if config.MinBorrowAmount.IsNil() || config.MinBorrowAmount.IsNegative() {
-		return errorsmod.Wrap(ErrInvalidPoolConfig, "min borrow amount can not be nil or negative")
+		return errorsmod.Wrap(ErrInvalidPoolConfig, "min borrow amount cannot be nil or negative")
 	}
 
 	if config.MaxBorrowAmount.IsNil() || config.MaxBorrowAmount.IsNegative() {
-		return errorsmod.Wrap(ErrInvalidPoolConfig, "max borrow amount can not be nil or negative")
+		return errorsmod.Wrap(ErrInvalidPoolConfig, "max borrow amount cannot be nil or negative")
 	}
 
 	if config.MinBorrowAmount.IsPositive() && config.MaxBorrowAmount.IsPositive() && config.MaxBorrowAmount.LT(config.MinBorrowAmount) {
-		return errorsmod.Wrap(ErrInvalidPoolConfig, "max borrow amount can not be less than min borrow amount")
+		return errorsmod.Wrap(ErrInvalidPoolConfig, "max borrow amount cannot be less than min borrow amount")
 	}
 
 	if err := validatePoolTranches(config.Tranches); err != nil {
@@ -319,19 +319,19 @@ func ValidatePoolConfig(config PoolConfig) error {
 		return errorsmod.Wrap(ErrInvalidPoolConfig, "invalid request fee")
 	}
 
-	if config.OriginationFeeFactor >= 1000 {
+	if config.OriginationFeeFactor.IsNegative() || config.OriginationFeeFactor.GTE(sdkmath.LegacyOneDec()) {
 		return errorsmod.Wrap(ErrInvalidPoolConfig, "invalid origination fee factor")
 	}
 
-	if config.ReserveFactor >= 1000 {
+	if config.ReserveFactor.IsNegative() || config.ReserveFactor.GTE(sdkmath.LegacyOneDec()) {
 		return errorsmod.Wrap(ErrInvalidPoolConfig, "invalid reserve factor")
 	}
 
-	if config.LiquidationThreshold == 0 || config.LiquidationThreshold >= 100 {
+	if !config.LiquidationThreshold.IsPositive() || config.LiquidationThreshold.GTE(sdkmath.LegacyOneDec()) {
 		return errorsmod.Wrap(ErrInvalidPoolConfig, "invalid liquidation threshold")
 	}
 
-	if config.MaxLtv == 0 || config.MaxLtv >= 100 || config.MaxLtv >= config.LiquidationThreshold {
+	if !config.MaxLtv.IsPositive() || config.MaxLtv.GTE(sdkmath.LegacyOneDec()) || config.MaxLtv.GTE(config.LiquidationThreshold) {
 		return errorsmod.Wrap(ErrInvalidPoolConfig, "invalid max ltv")
 	}
 
@@ -379,16 +379,16 @@ func validateAssetMetadata(metadata AssetMetadata) error {
 // validatePoolTrancheConfig validates the given tranche config
 func validatePoolTranches(tranches []PoolTrancheConfig) error {
 	if len(tranches) == 0 {
-		return errorsmod.Wrap(ErrInvalidPoolConfig, "tranches can not be empty")
+		return errorsmod.Wrap(ErrInvalidPoolConfig, "tranches cannot be empty")
 	}
 
 	for _, tranche := range tranches {
 		if tranche.Maturity <= 0 {
 			return errorsmod.Wrap(ErrInvalidPoolConfig, "maturity must be greater than 0")
 		}
 
-		if tranche.BorrowAPR == 0 || tranche.BorrowAPR >= 1000 {
-			return errorsmod.Wrap(ErrInvalidPoolConfig, "borrow apr must be between (0, 1000)")
+		if !tranche.BorrowAPR.IsPositive() || tranche.BorrowAPR.GTE(sdkmath.LegacyOneDec()) {
+			return errorsmod.Wrap(ErrInvalidPoolConfig, "borrow apr must be between (0, 1)")
 		}
 	}