sol-mem-gen/quotes-service.ts

import assert from "assert";
import BN from "bn.js";
import fetch from 'node-fetch';
import Big from 'big.js';

assert(process.env.NEXT_PUBLIC_USDC_MINT, 'USDC_MINT is required');
assert(process.env.NEXT_PUBLIC_MTM_TOKEN_MINT, 'MTM_TOKEN_MINT is required');

const MTM_TOKEN_MINT = process.env.NEXT_PUBLIC_MTM_TOKEN_MINT;
const USDC_MINT = process.env.NEXT_PUBLIC_USDC_MINT;

class QuotesService {
  //  Stores the MTM amount for 1 USDC
  private cachedMTMAmounts: BN[] = [];

  async fetchAndCacheQuotes(): Promise<void> {
    try {
      const url = `https://api.jup.ag/price/v2?ids=${USDC_MINT}&vsToken=${MTM_TOKEN_MINT}`;
      const response = await fetch(url);

      if (!response.ok) {
        throw new Error(`Failed to fetch quote: ${response.statusText}`);
      }

      const quoteResponse = await response.json();

      // Handle price with big.js, then convert to bn.js instance
      const priceMTMFor1USDC = new Big(quoteResponse['data'][USDC_MINT]['price']).toFixed(6);
      const priceMTMFor1USDCInBaseUnits = new BN(new Big(priceMTMFor1USDC).times(new Big(10).pow(6)).toString());

      this.cachedMTMAmounts.push(priceMTMFor1USDCInBaseUnits);
      if (this.cachedMTMAmounts.length > 3) {
        this.cachedMTMAmounts.shift();
      }
    } catch (error) {
      console.error('Error fetching quotes:', error);
    }
  }

  getMTMAmountsFor1USDC(): BN[] {
    return this.cachedMTMAmounts;
  }
}

export { QuotesService };