getQuote.ts

import V4QuoterAbi from "@/constants/abis/V4Quoter";
import type { UniDevKitV4Instance } from "@/types/core";
import type { QuoteParams, QuoteResponse } from "@/types/utils/getQuote";

/**
 * Fetches a quote for a token swap using the V4 Quoter contract.
 * This function uses the provided pool instance to simulate the quote.
 *
 * @param params - The parameters required for the quote, including pool and amount.
 * @param instance - UniDevKitV4 instance for contract interaction
 * @returns A Promise that resolves to the quote result, including the amount out and gas estimate.
 * @throws Will throw an error if:
 * - Simulation fails (e.g., insufficient liquidity, invalid parameters)
 * - Contract call reverts
 */
export async function getQuote(
	params: QuoteParams,
	instance: UniDevKitV4Instance,
): Promise<QuoteResponse> {
	const { client, contracts } = instance;
	const { quoter } = contracts;
	const {
		pool: { poolKey },
	} = params;

	try {
		// Build the parameters for quoteExactInputSingle
		const quoteParams = {
			poolKey: {
				currency0: poolKey.currency0 as `0x${string}`,
				currency1: poolKey.currency1 as `0x${string}`,
				fee: poolKey.fee,
				tickSpacing: poolKey.tickSpacing,
				hooks: poolKey.hooks as `0x${string}`,
			},
			zeroForOne: params.zeroForOne,
			exactAmount: params.amountIn,
			hookData: params.hookData || "0x",
		};

		// Simulate the quote to estimate the amount out
		const simulation = await client.simulateContract({
			address: quoter,
			abi: V4QuoterAbi,
			functionName: "quoteExactInputSingle",
			args: [quoteParams],
		});

		// Extract the results
		const [amountOut, gasEstimate] = simulation.result as [bigint, bigint];

		return {
			amountOut,
			estimatedGasUsed: gasEstimate,
			timestamp: Date.now(),
		};
	} catch (error) {
		console.error("Error simulating quote:", error);
		throw new Error(`Failed to fetch quote: ${(error as Error).message}`);
	}
}