fix path calculation

src/functions/fromExactOutputGetExpectedInput.tsx

@@ -9,8 +9,7 @@ export default function fromExactOutputGetExpectedInput(
   reserve0: BigNumber | undefined,
   reserve1: BigNumber | undefined,
 ): BigNumber {
-  if (!amountIn || !reserve0 || !reserve1) return BigNumber(0)
-
+  if (!amountIn || !reserve0 || !reserve1) return BigNumber(0);
   return getExpectedAmountFromReserves(amountIn, reserve0, reserve1);
 }
 

src/functions/generateRoute.ts

@@ -136,7 +136,7 @@ export const useRouterSDK = () => {
         }
 
         // Get amountOut or amountIn from reserves and tradeType
-        let outputAmount = await getExpectedAmount(
+        let quoteAmount = await getExpectedAmount(
           amountAsset.currency,
           quoteAsset,
           new BigNumber(amount),
@@ -145,20 +145,18 @@ export const useRouterSDK = () => {
         );
 
         // Convert from lumens to stroops (multiply by 10^7)
-        outputAmount = outputAmount.integerValue();
-
-        const quoteCurrencyAmount = CurrencyAmount.fromRawAmount(fromAddressToToken(quoteAsset.contract), outputAmount.toString());
+        quoteAmount = quoteAmount.integerValue();
 
         return {
           amountCurrency: amountAsset,
-          quoteCurrency: CurrencyAmount.fromRawAmount(fromAddressToToken(quoteAsset.contract), outputAmount.toString()),
+          quoteCurrency: CurrencyAmount.fromRawAmount(fromAddressToToken(quoteAsset.contract), quoteAmount.toString()),
           tradeType,
           trade: {
-            amountIn: tradeType === TradeType.EXACT_INPUT ? amount : outputAmount.toString(),
-            amountInMax: tradeType === TradeType.EXACT_OUTPUT ? outputAmount.toString() : undefined,
-            amountOut: tradeType === TradeType.EXACT_INPUT ? outputAmount.toString() : amount,
-            amountOutMin: tradeType === TradeType.EXACT_INPUT ? outputAmount.toString() : undefined,
-            path: [amountAsset.currency.contract, quoteAsset.contract],
+            amountIn: tradeType === TradeType.EXACT_INPUT ? amount : quoteAmount.toString(),
+            amountInMax: tradeType === TradeType.EXACT_OUTPUT ? quoteAmount.toString() : undefined,
+            amountOut: tradeType === TradeType.EXACT_INPUT ? quoteAmount.toString() : amount,
+            amountOutMin: tradeType === TradeType.EXACT_INPUT ? quoteAmount.toString() : undefined,
+            path: tradeType === TradeType.EXACT_INPUT ? [amountAsset.currency.contract, quoteAsset.contract] : [quoteAsset.contract, amountAsset.currency.contract],
           },
           priceImpact: new Percent('0'),
           platform: PlatformType.ROUTER,
@@ -168,7 +166,6 @@ export const useRouterSDK = () => {
         throw error;
       }
     }
-
     if (!factory) throw new Error('Factory address not found');
     const currencyAmount = fromAddressAndAmountToCurrencyAmount(
       amountAsset.currency.contract,

src/functions/getExpectedAmount.tsx

@@ -32,23 +32,36 @@ export async function getExpectedAmount(
     );
     const reserves = customReserves ?? (await reservesBNWithTokens(pairAddress, sorobanContext));
 
+    if (!reserves || !reserves.reserve0 || !reserves.reserve1) {
+      throw new Error('Reserves not found or invalid');
+    }
+
+    let reserveIn: BigNumber, reserveOut: BigNumber;
+    if (currencyIn.contract === reserves.token0) {
+      reserveIn = reserves.reserve0;
+      reserveOut = reserves.reserve1;
+    } else if (currencyIn.contract === reserves.token1) {
+      reserveIn = reserves.reserve1;
+      reserveOut = reserves.reserve0;
+    } else {
+      throw new Error('CurrencyIn does not match any token in reserves');
+    }
+
     let expectedOutput;
     if (tradeType === TradeType.EXACT_INPUT) {
       expectedOutput = fromExactInputGetExpectedOutput(
         amountIn,
-        reserves.reserve0,
-        reserves.reserve1,
+        reserveIn,
+        reserveOut,
+        currencyIn.decimals ?? 7,
       );
     } else {
-      expectedOutput = fromExactOutputGetExpectedInput(
-        amountIn,
-        reserves.reserve0,
-        reserves.reserve1,
-      );
+      expectedOutput = fromExactOutputGetExpectedInput(amountIn, reserveOut, reserveIn);
     }
 
     return expectedOutput;
   } catch (error) {
+    console.error('Error in getExpectedAmount:', error);
     return BigNumber(0);
   }
 }