changing weight breaking fee calculation when there is bonus

elys-network · Dec 3, 2024 · 4f8e193 · 4f8e193
1 parent 7dabb7e
commit 4f8e193
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Showing 5 changed files with 50 additions and 18 deletions.
diff --git a/x/amm/types/calc_exit_pool.go b/x/amm/types/calc_exit_pool.go
@@ -141,9 +141,15 @@ func CalcExitPool(
 		targetWeightIn := sdkmath.LegacyOneDec().Sub(targetWeightOut)
 
 		// weight breaking fee as in Plasma pool
-		weightOut := GetDenomOracleAssetWeight(ctx, pool.PoolId, oracleKeeper, newAssetPools, tokenOutDenom)
-		weightIn := sdkmath.LegacyOneDec().Sub(weightOut)
-		weightBreakingFee := GetWeightBreakingFee(weightIn, weightOut, targetWeightIn, targetWeightOut, distanceDiff, params)
+		finalWeightOut := GetDenomOracleAssetWeight(ctx, pool.PoolId, oracleKeeper, newAssetPools, tokenOutDenom)
+		finalWeightIn := sdkmath.LegacyOneDec().Sub(finalWeightOut)
+		initialAssetPools, err := pool.NewPoolAssetsAfterSwap(ctx,
+			sdk.NewCoins(),
+			sdk.NewCoins(), accountedAssets,
+		)
+		initialWeightOut := GetDenomOracleAssetWeight(ctx, pool.PoolId, oracleKeeper, initialAssetPools, tokenOutDenom)
+		initialWeightIn := sdkmath.LegacyOneDec().Sub(initialWeightOut)
+		weightBreakingFee := GetWeightBreakingFee(finalWeightIn, finalWeightOut, targetWeightIn, targetWeightOut, initialWeightIn, initialWeightOut, distanceDiff, params)
 
 		tokenOutAmount := oracleOutAmount.Mul(sdkmath.LegacyOneDec().Sub(weightBreakingFee)).RoundInt()
 		return sdk.Coins{sdk.NewCoin(tokenOutDenom, tokenOutAmount)}, weightBreakingFee.Neg(), nil

diff --git a/x/amm/types/pool_join_pool.go b/x/amm/types/pool_join_pool.go
@@ -194,9 +194,16 @@ func (p *Pool) JoinPool(
 	targetWeightOut := sdkmath.LegacyOneDec().Sub(targetWeightIn)
 
 	// weight breaking fee as in Plasma pool
-	weightIn := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenInDenom)
-	weightOut := sdkmath.LegacyOneDec().Sub(weightIn)
-	weightBreakingFee := GetWeightBreakingFee(weightIn, weightOut, targetWeightIn, targetWeightOut, distanceDiff, params)
+	finalWeightIn := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenInDenom)
+	finalWeightOut := sdkmath.LegacyOneDec().Sub(finalWeightIn)
+
+	initialAssetPools, err := p.NewPoolAssetsAfterSwap(ctx,
+		sdk.NewCoins(),
+		sdk.NewCoins(), accountedAssets,
+	)
+	initialWeightIn := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, initialAssetPools, tokenInDenom)
+	initialWeightOut := sdkmath.LegacyOneDec().Sub(initialWeightIn)
+	weightBreakingFee := GetWeightBreakingFee(finalWeightIn, finalWeightOut, targetWeightIn, targetWeightOut, initialWeightIn, initialWeightOut, distanceDiff, params)
 
 	// weight recovery reward = weight breaking fee * weight breaking fee portion
 	weightRecoveryReward := weightBreakingFee.Mul(params.WeightBreakingFeePortion)

diff --git a/x/amm/types/swap_in_amt_given_out.go b/x/amm/types/swap_in_amt_given_out.go
@@ -132,9 +132,15 @@ func (p *Pool) SwapInAmtGivenOut(
 	targetWeightOut := GetDenomNormalizedWeight(newAssetPools, tokenOut.Denom)
 
 	// weight breaking fee as in Plasma pool
-	weightIn := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenInDenom)
-	weightOut := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenOut.Denom)
-	weightBreakingFee := GetWeightBreakingFee(weightIn, weightOut, targetWeightIn, targetWeightOut, distanceDiff, params)
+	finalWeightIn := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenInDenom)
+	finalWeightOut := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenOut.Denom)
+	initialAssetPools, err := p.NewPoolAssetsAfterSwap(ctx,
+		sdk.NewCoins(),
+		sdk.NewCoins(), accountedAssets,
+	)
+	initialWeightIn := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, initialAssetPools, tokenInDenom)
+	initialWeightOut := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, initialAssetPools, tokenOut.Denom)
+	weightBreakingFee := GetWeightBreakingFee(finalWeightIn, finalWeightOut, targetWeightIn, targetWeightOut, initialWeightIn, initialWeightOut, distanceDiff, params)
 
 	// weightBreakingFeePerpetualFactor is 1 if not send by perpetual
 	weightBreakingFee = weightBreakingFee.Mul(weightBreakingFeePerpetualFactor)

diff --git a/x/amm/types/swap_out_amt_given_in.go b/x/amm/types/swap_out_amt_given_in.go
@@ -302,9 +302,15 @@ func (p *Pool) SwapOutAmtGivenIn(
 	targetWeightOut := GetDenomNormalizedWeight(newAssetPools, tokenOutDenom)
 
 	// weight breaking fee as in Plasma pool
-	weightIn := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenIn.Denom)
-	weightOut := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenOutDenom)
-	weightBreakingFee := GetWeightBreakingFee(weightIn, weightOut, targetWeightIn, targetWeightOut, distanceDiff, params)
+	finalWeightIn := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenIn.Denom)
+	finalWeightOut := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, newAssetPools, tokenOutDenom)
+	initialAssetPools, err := p.NewPoolAssetsAfterSwap(ctx,
+		sdk.NewCoins(),
+		sdk.NewCoins(), accountedAssets,
+	)
+	initialWeightIn := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, initialAssetPools, tokenIn.Denom)
+	initialWeightOut := GetDenomOracleAssetWeight(ctx, p.PoolId, oracleKeeper, initialAssetPools, tokenOutDenom)
+	weightBreakingFee := GetWeightBreakingFee(finalWeightIn, finalWeightOut, targetWeightIn, targetWeightOut, initialWeightIn, initialWeightOut, distanceDiff, params)
 
 	// weightBreakingFeePerpetualFactor is 1 if not send by perpetual
 	weightBreakingFee = weightBreakingFee.Mul(weightBreakingFeePerpetualFactor)

diff --git a/x/amm/types/utils.go b/x/amm/types/utils.go
@@ -60,16 +60,23 @@ func ApplyDiscount(swapFee sdkmath.LegacyDec, discount sdkmath.LegacyDec) sdkmat
 	return swapFee
 }
 
-func GetWeightBreakingFee(weightIn, weightOut, targetWeightIn, targetWeightOut sdkmath.LegacyDec, distanceDiff sdkmath.LegacyDec, params Params) sdkmath.LegacyDec {
+// GetWeightBreakingFee When distanceDiff > 0, pool is getting worse so we calculate WBF based on final weight
+// When distanceDiff < 0, pool is improving, we need to use initial weights. Say target is 50:50, initially pool is 80:20 and now after it is becoming 30:70,
+// this is improving the pool but with finalWeightOut/finalWeightIn it will be 30/70 which doesn't provide enough bonus to user
+func GetWeightBreakingFee(finalWeightIn, finalWeightOut, targetWeightIn, targetWeightOut, initialWeightIn, initialWeightOut sdkmath.LegacyDec, distanceDiff sdkmath.LegacyDec, params Params) sdkmath.LegacyDec {
 	weightBreakingFee := sdkmath.LegacyZeroDec()
-	if !weightOut.IsZero() && !weightIn.IsZero() && !targetWeightOut.IsZero() && !targetWeightIn.IsZero() && !params.WeightBreakingFeeMultiplier.IsZero() {
+	if !params.WeightBreakingFeeMultiplier.IsZero() {
 		// (45/55*60/40) ^ 2.5
 		if distanceDiff.IsPositive() {
-			weightBreakingFee = params.WeightBreakingFeeMultiplier.
-				Mul(Pow(weightIn.Mul(targetWeightOut).Quo(weightOut).Quo(targetWeightIn), params.WeightBreakingFeeExponent))
+			if !finalWeightOut.IsZero() && !finalWeightIn.IsZero() && !targetWeightOut.IsZero() && !targetWeightIn.IsZero() {
+				weightBreakingFee = params.WeightBreakingFeeMultiplier.
+					Mul(Pow(finalWeightIn.Mul(targetWeightOut).Quo(finalWeightOut).Quo(targetWeightIn), params.WeightBreakingFeeExponent))
+			}
 		} else {
-			weightBreakingFee = params.WeightBreakingFeeMultiplier.
-				Mul(Pow(weightOut.Mul(targetWeightIn).Quo(weightIn).Quo(targetWeightOut), params.WeightBreakingFeeExponent))
+			if !initialWeightOut.IsZero() && !initialWeightIn.IsZero() && !targetWeightOut.IsZero() && !targetWeightIn.IsZero() {
+				weightBreakingFee = params.WeightBreakingFeeMultiplier.
+					Mul(Pow(initialWeightOut.Mul(targetWeightIn).Quo(initialWeightIn).Quo(targetWeightOut), params.WeightBreakingFeeExponent))
+			}
 		}
 
 		if weightBreakingFee.GT(sdkmath.LegacyNewDecWithPrec(99, 2)) {