WIP: slipage for swapAmounts

EthereumTransactionCall.sh

@@ -0,0 +1,4 @@
+cast call 0x8f98B899F4135408Fe03228cE942Ad6BF8E40f22 \
+  "working(address)" \
+  0x3EDE1eE859A72aEc85ff04d305B6Ffe89f2Cb4eb \
+  --rpc-url https://eth-sepolia.g.alchemy.com/v2/demo

src/hooks/usePartyPlanner.ts

@@ -580,7 +580,8 @@ export function useSwapMintAmounts(
   poolAddress: `0x${string}` | undefined,
   inputTokenIndex: number | undefined,
   maxAmountIn: bigint | undefined,
-  lpTokenPrice?: number // Market price of the LP token in decimal format
+  lpTokenPrice?: number, // Market price of the LP token in decimal format
+  inputTokenDecimals?: number // Decimals of the input token
 ) {
   const publicClient = usePublicClient();
   const [mounted, setMounted] = useState(false);
@@ -629,13 +630,42 @@ export function useSwapMintAmounts(
           args: [poolAddress, BigInt(inputTokenIndex), maxAmountIn],
         }) as readonly [bigint, bigint, bigint];
 
-        // Calculate slippage if LP token price is provided
-        let calculatedSlippage: number | undefined;
-        if (lpTokenPrice !== undefined) {
+        // Fetch the market price if not provided
+        let marketPrice = lpTokenPrice;
+        if (marketPrice === undefined) {
           try {
-            // For swapMint: output is result[0] (amountInUsed), input is maxAmountIn, fee is result[2]
-            calculatedSlippage = calculateSlippage(lpTokenPrice, result[0], maxAmountIn, result[2]);
-            console.log('swapMint calculatedSlippage', calculatedSlippage);
+              console.log('input token index', inputTokenIndex)
+            // Get the pool price (price of the pool in terms of the input token)
+            const poolPriceInt128 = await publicClient.readContract({
+              address: partyInfoAddress as `0x${string}`,
+              abi: IPartyInfoABI,
+              functionName: 'poolPrice',
+              args: [poolAddress, BigInt(inputTokenIndex)],
+            }) as bigint;
+
+            // Convert Q64 format to decimal (price = priceValue / 2^64)
+            // poolPrice returns how much 1 LP token is worth in terms of the input token
+            marketPrice = Number(poolPriceInt128) / 2 ** 64;
+            console.log('swapMintAmounts fetched marketPrice (poolPrice)', marketPrice);
+          } catch (priceErr) {
+            console.error('Error fetching poolPrice:', priceErr);
+          }
+        }
+
+        // Calculate slippage if market price is available
+        let calculatedSlippage: number | undefined;
+        if (marketPrice !== undefined) {
+          try {
+            // For swapMint:
+            // - marketPrice: how much 1 LP token is worth in input tokens (from poolPrice)
+            // - swapOutputAmount: LP tokens minted (result[2])
+            // - swapInputAmount: input token amount used (maxAmountIn)
+            // - inFee: fee charged (result[1])
+              console.log('LP minted', result[1])
+            // Convert result[1] to token price using poolPrice: result[1] * poolPrice
+            const lpMintedInTokenPrice = BigInt(Math.floor(Number(result[1]) * marketPrice));
+            calculatedSlippage = calculateSlippage(marketPrice, lpMintedInTokenPrice, result[0], result[2]);
+            console.log('🎯 swapMint calculatedSlippage: ' + calculatedSlippage.toFixed(4) + '%');
           } catch (slippageErr) {
             console.error(`Error calculating slippage for swapMint:`, slippageErr);
           }

src/hooks/usePartyPool.ts

@@ -29,7 +29,7 @@ export function calculateSlippage(
     const swapPrice = Number(swapOutputAmount) / (Number(swapInputAmount) - Number(swapFee));
 
     // Calculate slippage percentage: ((swapPrice - marketPrice) / marketPrice) * 100
-    const slippage = ((swapPrice - marketPrice) / marketPrice) * 100;
+    const slippage = ((marketPrice - swapPrice) / marketPrice) * 100;
 
     return slippage;
 }