feat: quote provider

packages/relayer/src/providers/quote.provider.ts

@@ -0,0 +1,21 @@
+import { Address } from "viem";
+import { uniswapProvider } from "./index.js";
+
+export class QuoteProvider {
+
+  static txCost: bigint = 700_000n;
+
+  constructor(readonly baseFee: bigint) {
+  }
+
+  async quoteNativeTokenInERC20(chainId: number, addressIn: Address, amountIn: bigint): Promise<{ num: bigint, den: bigint }> {
+    const { in: in_, out } = (await uniswapProvider.quoteNativeToken(chainId, addressIn, amountIn))!;
+    return { num: out.amount, den: in_.amount };
+  }
+
+  async quoteFeeBPSNative(balance: bigint, nativeQuote: { num: bigint, den: bigint }, gasPrice: bigint, value: bigint): Promise<bigint> {
+    const nativeCosts = (1n * gasPrice * QuoteProvider.txCost + value)
+    return this.baseFee + nativeQuote.den * 10_000n * nativeCosts / balance / nativeQuote.num;
+  }
+
+}