refactor: liquidity_amounts

position/_GET_position.gno

@@ -37,5 +37,5 @@ func PositionGetPositionTokensOwed1(tokenId uint64) bigint {
 }
 
 func PositionGetAmountsForLiquidity(sqrtRatioX96, sqrtRatioAX96, sqrtRatioBX96, liquidity bigint) (bigint, bigint) {
-	return liquidityAmountsGetAmountsForLiquidity(sqrtRatioX96, sqrtRatioAX96, sqrtRatioBX96, liquidity)
+	return GetAmountsForLiquidity(sqrtRatioX96, sqrtRatioAX96, sqrtRatioBX96, liquidity)
 }

position/_RPC_api.gno

@@ -70,7 +70,7 @@ func rpcMakePosition(lpTokenId uint64) RpcPosition {
 	lowerX96 := p.TickMathGetSqrtRatioAtTick(position.tickLower)
 	upperX96 := p.TickMathGetSqrtRatioAtTick(position.tickUpper)
 
-	token0Balance, token1Balance := liquidityAmountsGetAmountsForLiquidity(
+	token0Balance, token1Balance := GetAmountsForLiquidity(
 		currentX96,
 		lowerX96,
 		upperX96,

position/_RPC_dry.gno

@@ -15,7 +15,7 @@ func DryMint(
 	sqrtLowerX96 := p.TickMathGetSqrtRatioAtTick(tickLower)
 	sqrtUpperX96 := p.TickMathGetSqrtRatioAtTick(tickUpper)
 
-	liquidity := liquidityAmountsGetLiquidityForAmounts(
+	liquidity := GetLiquidityForAmounts(
 		sqrtRatioX96,
 		sqrtLowerX96,
 		sqrtUpperX96,

position/liquidity_amounts.gno

@@ -1,49 +1,53 @@
 package position
 
-func liquidityAmountsGetLiquidityForAmount0(
-	sqrtRatioAX96 bigint,
-	sqrtRatioBX96 bigint,
-	amount0 bigint,
-) bigint {
-	if sqrtRatioAX96 > sqrtRatioBX96 {
-		sqrtRatioAX96, sqrtRatioBX96 = sqrtRatioBX96, sqrtRatioAX96
+import (
+	"gno.land/r/demo/consts"
+)
+
+// swapIfGreater checkes if the first value is greater than
+// the second then swaps two values.
+func swapIfGreater(a, b bigint) (bigint, bigint) {
+	if a > b {
+		return b, a
 	}
 
-	intermediate := (sqrtRatioAX96 * sqrtRatioBX96) / Q96
+	return a, b
+}
 
-	return amount0 * intermediate / (sqrtRatioBX96 - sqrtRatioAX96)
+// calcIntermediateValue computes the intermediate value
+// used in liquidity calculations.
+func calcIntermediateValue(sqrtRatioA, sqrtRatioB bigint) bigint {
+	return (sqrtRatioA * sqrtRatioB) / consts.Q96
 }
 
-func liquidityAmountsGetLiquidityForAmount1(
-	sqrtRatioAX96 bigint,
-	sqrtRatioBX96 bigint,
-	amount1 bigint,
-) bigint {
-	if sqrtRatioAX96 > sqrtRatioBX96 {
-		sqrtRatioAX96, sqrtRatioBX96 = sqrtRatioBX96, sqrtRatioAX96
-	}
+// GetLiquidityForAmount0 calculates liquidity for a given amount of token 0.
+func computeLiquidityForAmount0(sqrtRatioA, sqrtRatioB, amount0 bigint) bigint {
+	sqrtRatioA, sqrtRatioB = swapIfGreater(sqrtRatioA, sqrtRatioB)
+	intermediate := calcIntermediateValue(sqrtRatioA, sqrtRatioB)
+	diff := sqrtRatioB - sqrtRatioA
 
-	return amount1 * Q96 / (sqrtRatioBX96 - sqrtRatioAX96)
+	// we don't need to care about division by zero here.
+	return amount0 * intermediate / diff
 }
 
-func liquidityAmountsGetLiquidityForAmounts(
-	sqrtRatioX96 bigint,
-	sqrtRatioAX96 bigint,
-	sqrtRatioBX96 bigint,
-	amount0 bigint,
-	amount1 bigint,
-) bigint {
-	var liquidity bigint
+// computeLiquidityForAmount1 calculates liquidity for a given amount of token 1.
+func computeLiquidityForAmount1(sqrtRatioA, sqrtRatioB, amount1 bigint) bigint {
+	sqrtRatioA, sqrtRatioB = swapIfGreater(sqrtRatioA, sqrtRatioB)
+	diff := sqrtRatioB - sqrtRatioA
 
-	if sqrtRatioAX96 > sqrtRatioBX96 {
-		sqrtRatioAX96, sqrtRatioBX96 = sqrtRatioBX96, sqrtRatioAX96
-	}
+	return (amount1 * consts.Q96) / diff
+}
 
-	if sqrtRatioX96 <= sqrtRatioAX96 {
-		liquidity = liquidityAmountsGetLiquidityForAmount0(sqrtRatioAX96, sqrtRatioBX96, amount0)
-	} else if sqrtRatioX96 < sqrtRatioBX96 {
-		liquidity0 := liquidityAmountsGetLiquidityForAmount0(sqrtRatioX96, sqrtRatioBX96, amount0)
-		liquidity1 := liquidityAmountsGetLiquidityForAmount1(sqrtRatioAX96, sqrtRatioX96, amount1)
+// GetLiquidityForAmounts calculates the liquidity for given amounts od token 0 and token 1.
+func GetLiquidityForAmounts(sqrtRatioX, sqrtRatioA, sqrtRatioB, amount0, amount1 bigint) bigint {
+	sqrtRatioA, sqrtRatioB = swapIfGreater(sqrtRatioA, sqrtRatioB)
+	var liquidity bigint
+
+	if sqrtRatioX <= sqrtRatioA {
+		liquidity = computeLiquidityForAmount0(sqrtRatioA, sqrtRatioB, amount0)
+	} else if sqrtRatioX < sqrtRatioB {
+		liquidity0 := computeLiquidityForAmount0(sqrtRatioX, sqrtRatioB, amount0)
+		liquidity1 := computeLiquidityForAmount1(sqrtRatioA, sqrtRatioX, amount1)
 
 		if liquidity0 < liquidity1 {
 			liquidity = liquidity0
@@ -52,55 +56,43 @@ func liquidityAmountsGetLiquidityForAmounts(
 		}
 
 	} else {
-		liquidity = liquidityAmountsGetLiquidityForAmount1(sqrtRatioAX96, sqrtRatioBX96, amount1)
+		liquidity = computeLiquidityForAmount1(sqrtRatioA, sqrtRatioB, amount1)
 	}
 
 	return liquidity
 }
 
-func liquidityAmountsGetAmount0ForLiquidity(
-	sqrtRatioAX96 bigint,
-	sqrtRatioBX96 bigint,
-	liquidity bigint,
-) bigint {
-	if sqrtRatioAX96 > sqrtRatioBX96 {
-		sqrtRatioAX96, sqrtRatioBX96 = sqrtRatioBX96, sqrtRatioAX96
-	}
+// computeAmount0ForLiquidity calculates the amount of token 0 for a given liquidity.
+func computeAmount0ForLiquidity(sqrtRatioA, sqrtRatioB, liquidity bigint) bigint {
+	sqrtRatioA, sqrtRatioB = swapIfGreater(sqrtRatioA, sqrtRatioB)
+	diff := sqrtRatioB - sqrtRatioA
 
-	return ((liquidity << 96) * (sqrtRatioBX96 - sqrtRatioAX96) / sqrtRatioBX96) / sqrtRatioAX96
+	return (liquidity << 96) * diff / (sqrtRatioB * sqrtRatioA)
 }
 
-func liquidityAmountsGetAmount1ForLiquidity(
-	sqrtRatioAX96 bigint,
-	sqrtRatioBX96 bigint,
-	liquidity bigint,
-) bigint {
-	if sqrtRatioAX96 > sqrtRatioBX96 {
-		sqrtRatioAX96, sqrtRatioBX96 = sqrtRatioBX96, sqrtRatioAX96
-	}
+// computeAmount1ForLiquidity calculates the amount of token 1 for a given liquidity.
+func computeAmount1ForLiquidity(sqrtRatioA, sqrtRatioB, liquidity bigint) bigint {
+	sqrtRatioA, sqrtRatioB = swapIfGreater(sqrtRatioA, sqrtRatioB)
+	diff := sqrtRatioB - sqrtRatioA
 
-	return liquidity * (sqrtRatioBX96 - sqrtRatioAX96) / Q96
+	return liquidity * diff / consts.Q96
 }
 
-func liquidityAmountsGetAmountsForLiquidity(
-	sqrtRatioX96 bigint,
-	sqrtRatioAX96 bigint,
-	sqrtRatioBX96 bigint,
-	liquidity bigint,
-) (bigint, bigint) {
+// GetAmountsForLiquidity calculates the amounts of token 0 and token 1 for a given liquidity.
+func GetAmountsForLiquidity(sqrtRatioX96, sqrtRatioAX96, sqrtRatioBX96, liquidity bigint) (bigint, bigint) {
 	var amount0, amount1 bigint
 
 	if sqrtRatioAX96 > sqrtRatioBX96 {
 		sqrtRatioAX96, sqrtRatioBX96 = sqrtRatioBX96, sqrtRatioAX96
 	}
 
 	if sqrtRatioX96 <= sqrtRatioAX96 {
-		amount0 = liquidityAmountsGetAmount0ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity)
+		amount0 = computeAmount0ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity)
 	} else if sqrtRatioX96 < sqrtRatioBX96 {
-		amount0 = liquidityAmountsGetAmount0ForLiquidity(sqrtRatioX96, sqrtRatioBX96, liquidity)
-		amount1 = liquidityAmountsGetAmount1ForLiquidity(sqrtRatioAX96, sqrtRatioX96, liquidity)
+		amount0 = computeAmount0ForLiquidity(sqrtRatioX96, sqrtRatioBX96, liquidity)
+		amount1 = computeAmount1ForLiquidity(sqrtRatioAX96, sqrtRatioX96, liquidity)
 	} else {
-		amount1 = liquidityAmountsGetAmount1ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity)
+		amount1 = computeAmount1ForLiquidity(sqrtRatioAX96, sqrtRatioBX96, liquidity)
 	}
 
 	return amount0, amount1

position/liquidity_management.gno

@@ -11,7 +11,7 @@ func addLiquidity(params AddLiquidityParams) (bigint, bigint, bigint) {
 	sqrtRatioAX96 := p.TickMathGetSqrtRatioAtTick(params.tickLower)
 	sqrtRatioBX96 := p.TickMathGetSqrtRatioAtTick(params.tickUpper)
 
-	liquidity := liquidityAmountsGetLiquidityForAmounts(
+	liquidity := GetLiquidityForAmounts(
 		sqrtPriceX96,
 		sqrtRatioAX96,
 		sqrtRatioBX96,