feat: add getExpectedInput function

src/index.ts

@@ -52,7 +52,7 @@ export const getMarket = async (
  * @param chainId The chain ID of the blockchain.
  * @param inputToken The address of the input token.
  * @param outputToken The address of the output token.
- * @param amountIn The amount of input token. (ex 1.2 ETH -> 1.2)
+ * @param amountIn The amount of expected input amount. (ex 1.2 ETH -> 1.2)
  * @param limitPrice The maximum limit price to spend.
  * @returns A Promise resolving to an object containing the taken amount and spend amount.
  * @example
@@ -105,3 +105,63 @@ export const getExpectedOutput = async (
     ),
   }
 }
+
+/**
+ * Calculates the expected input for a given output amount, based on the provided market data.
+ *
+ * @param chainId The chain ID of the blockchain.
+ * @param inputToken The address of the input token.
+ * @param outputToken The address of the output token.
+ * @param amountOut The amount of expected output amount. (ex 1.2 ETH -> 1.2)
+ * @param limitPrice The maximum limit price to take.
+ * @returns A Promise resolving to an object containing the taken amount and spend amount.
+ * @example
+ * import { getExpectedInput } from '@clober-dex/v2-sdk'
+ * import { arbitrumSepolia } from 'viem/chains'
+ *
+ * const { takenAmount, spendAmount } = await getExpectedInput(
+ *   arbitrumSepolia.id,
+ *  '0x00bfd44e79fb7f6dd5887a9426c8ef85a0cd23e0', // USDC
+ *  '0x0000000000000000000000000000000000000000', // ETH
+ *  '0.1', // take 0.1 ETH
+ * )
+ */
+export const getExpectedInput = async (
+  chainId: CHAIN_IDS,
+  inputToken: `0x${string}`,
+  outputToken: `0x${string}`,
+  amountOut: string,
+  limitPrice?: string,
+): Promise<{ takenAmount: string; spendAmount: string }> => {
+  const market = await fetchMarket(chainId, [inputToken, outputToken])
+  const isBid = isAddressEqual(market.quote.address, inputToken)
+  limitPrice = limitPrice ?? (isBid ? (Math.pow(2, 256) - 1).toFixed(0) : '0')
+  const outputCurrency = isBid ? market.base : market.quote
+  const { takenAmount, spendAmount } = Object.values(
+    market.take({
+      takeQuote: !isBid,
+      limitPrice: parsePrice(
+        Number(limitPrice),
+        market.quote.decimals,
+        market.base.decimals,
+      ),
+      amountOut: parseUnits(amountOut, outputCurrency.decimals),
+    }),
+  ).reduce(
+    (acc, { takenAmount, spendAmount }) => ({
+      takenAmount: acc.takenAmount + takenAmount,
+      spendAmount: acc.spendAmount + spendAmount,
+    }),
+    { takenAmount: 0n, spendAmount: 0n },
+  )
+  return {
+    takenAmount: formatUnits(
+      takenAmount,
+      isBid ? market.base.decimals : market.quote.decimals,
+    ),
+    spendAmount: formatUnits(
+      spendAmount,
+      isBid ? market.quote.decimals : market.base.decimals,
+    ),
+  }
+}

test/get-expected-input.test.ts

@@ -0,0 +1,202 @@
+import { expect, test } from 'vitest'
+import { getExpectedInput } from '@clober-dex/v2-sdk'
+import { arbitrumSepolia } from 'viem/chains'
+import {
+  createPublicClient,
+  formatUnits,
+  http,
+  isAddressEqual,
+  parseUnits,
+  zeroHash,
+} from 'viem'
+
+import { fetchMarket } from '../src/apis/market'
+import { parsePrice } from '../src/utils/prices'
+import { invertPrice } from '../src/utils/tick'
+
+const BOOK_VIEWER_CONTRACT_ADDRESS =
+  '0x8676558Af8D8a4A7fd7fC6A7b435D231393a2A76'
+const publicClient = createPublicClient({
+  chain: arbitrumSepolia,
+  transport: http(),
+})
+
+const _ABI = [
+  {
+    inputs: [
+      {
+        components: [
+          {
+            internalType: 'BookId',
+            name: 'id',
+            type: 'uint192',
+          },
+          {
+            internalType: 'uint256',
+            name: 'limitPrice',
+            type: 'uint256',
+          },
+          {
+            internalType: 'uint256',
+            name: 'quoteAmount',
+            type: 'uint256',
+          },
+          {
+            internalType: 'bytes',
+            name: 'hookData',
+            type: 'bytes',
+          },
+        ],
+        internalType: 'struct IController.TakeOrderParams',
+        name: 'params',
+        type: 'tuple',
+      },
+    ],
+    name: 'getExpectedInput',
+    outputs: [
+      {
+        internalType: 'uint256',
+        name: 'takenQuoteAmount',
+        type: 'uint256',
+      },
+      {
+        internalType: 'uint256',
+        name: 'spendBaseAmount',
+        type: 'uint256',
+      },
+    ],
+    stateMutability: 'view',
+    type: 'function',
+  },
+] as const
+
+const isSpendResultEqual = async (
+  inputToken: `0x${string}`,
+  outputToken: `0x${string}`,
+  amountOut: string,
+  limitPrice: string,
+) => {
+  const market = await fetchMarket(arbitrumSepolia.id, [
+    inputToken,
+    outputToken,
+  ])
+
+  const isBid = isAddressEqual(market.quote.address, inputToken)
+  const outputCurrency = isBid ? market.base : market.quote
+  const [takenQuoteAmount, spendBaseAmount] = await publicClient.readContract({
+    address: BOOK_VIEWER_CONTRACT_ADDRESS,
+    abi: _ABI,
+    functionName: 'getExpectedInput',
+    args: [
+      {
+        id: isBid
+          ? 2753017174304248252793812478093441832431186343406437115611n
+          : 2505799676027433010421416925405481572661563164234992034276n,
+        limitPrice: isBid
+          ? invertPrice(
+              parsePrice(
+                Number(limitPrice),
+                market.quote.decimals,
+                market.base.decimals,
+              ),
+            )
+          : parsePrice(
+              Number(limitPrice),
+              market.quote.decimals,
+              market.base.decimals,
+            ),
+        quoteAmount: parseUnits(amountOut, outputCurrency.decimals),
+        hookData: zeroHash,
+      },
+    ],
+  })
+
+  const { takenAmount, spendAmount } = await getExpectedInput(
+    arbitrumSepolia.id,
+    inputToken,
+    outputToken,
+    amountOut,
+    limitPrice,
+  )
+
+  expect(takenAmount).toBe(
+    formatUnits(
+      takenQuoteAmount,
+      isBid ? market.base.decimals : market.quote.decimals,
+    ),
+  )
+  expect(spendAmount).toBe(
+    formatUnits(
+      spendBaseAmount,
+      isBid ? market.quote.decimals : market.base.decimals,
+    ),
+  )
+  return {
+    takenAmount,
+    spendAmount,
+  }
+}
+
+test('get expected input ask', async () => {
+  const { takenAmount, spendAmount } = await isSpendResultEqual(
+    '0x00bfd44e79fb7f6dd5887a9426c8ef85a0cd23e0',
+    '0x0000000000000000000000000000000000000000',
+    '0.1',
+    '100',
+  )
+  expect(takenAmount).toBe('0')
+  expect(spendAmount).toBe('0')
+
+  await isSpendResultEqual(
+    '0x00bfd44e79fb7f6dd5887a9426c8ef85a0cd23e0',
+    '0x0000000000000000000000000000000000000000',
+    '0.2',
+    '4005',
+  )
+
+  await isSpendResultEqual(
+    '0x00bfd44e79fb7f6dd5887a9426c8ef85a0cd23e0',
+    '0x0000000000000000000000000000000000000000',
+    '0.23',
+    '10000',
+  )
+
+  await isSpendResultEqual(
+    '0x00bfd44e79fb7f6dd5887a9426c8ef85a0cd23e0',
+    '0x0000000000000000000000000000000000000000',
+    '10',
+    (Math.pow(2, 256) - 1).toFixed(0),
+  )
+})
+
+test('get expected input bid', async () => {
+  const { takenAmount, spendAmount } = await isSpendResultEqual(
+    '0x0000000000000000000000000000000000000000',
+    '0x00bfd44e79fb7f6dd5887a9426c8ef85a0cd23e0',
+    '100000',
+    '4010',
+  )
+  expect(takenAmount).toBe('0')
+  expect(spendAmount).toBe('0')
+
+  await isSpendResultEqual(
+    '0x0000000000000000000000000000000000000000',
+    '0x00bfd44e79fb7f6dd5887a9426c8ef85a0cd23e0',
+    '100000',
+    '4005',
+  )
+
+  await isSpendResultEqual(
+    '0x0000000000000000000000000000000000000000',
+    '0x00bfd44e79fb7f6dd5887a9426c8ef85a0cd23e0',
+    '100000',
+    '200',
+  )
+
+  await isSpendResultEqual(
+    '0x0000000000000000000000000000000000000000',
+    '0x00bfd44e79fb7f6dd5887a9426c8ef85a0cd23e0',
+    '200000',
+    '0',
+  )
+})