@shogun-sdk/money-legos/src/services/HighSlippageValidationService.ts

Shogun Money Legos: clients and types for quotes, memes, prices, balances, fees, validations, etc.

import { formatUnits } from 'viem';
import { QuoteTypes } from '../types/index.js';

export class HighSlippageValidationService {
  constructor() {}

  getInputUsdValue = (
    weiAmount: bigint | undefined,
    inputDecimals: number,
    inputUsdPrice: number,
  ): number | undefined => {
    if (weiAmount !== undefined) {
      // turn the weiAmount into a normalized number
      const amountNormalized = Number(formatUnits(BigInt(weiAmount), inputDecimals));
      const inputValueUsd = amountNormalized * inputUsdPrice;

      return inputValueUsd;
    }

    return undefined;
  };

  getExpectedSlippage = (
    quotes: QuoteTypes,
    inputValueUsd: number,
    outputTokenData: {
      decimals: number;
      usdPrice: number;
    },
  ): {
    outputValueUsd: number;
    expectedSlippage: number;
  } => {
    const outputAmount = quotes?.outputAmount;

    // NEED TO CALCULATE OUTPUT VALUE USD
    if (outputAmount?.value && BigInt(outputAmount?.value) > BigInt(0) && inputValueUsd > 0) {
      const { decimals: outputTokenDecimals, usdPrice: outputTokenUsdPrice } = outputTokenData;

      const outputAmountFormatted = formatUnits(BigInt(outputAmount?.value), outputTokenDecimals);

      // TODO: this needs to be calculated using the output token usd price
      const outputValueUsd = Number(outputAmountFormatted) * outputTokenUsdPrice;

      const realSlippage = ((inputValueUsd - outputValueUsd) / inputValueUsd) * 100;

      const expectedSlippage = Number(realSlippage.toFixed(2));

      return {
        outputValueUsd,
        expectedSlippage,
      };
    }

    return {
      outputValueUsd: 0,
      expectedSlippage: 0,
    };
  };

  public isSlippageValid = (expectedSlippage: number): boolean => {
    return expectedSlippage <= this.MAX_ALLOWED_OUTPUT_SLIPPAGE;
  };

  MAX_ALLOWED_OUTPUT_SLIPPAGE = 25;
}