Calculate Token Amount

CalculateAmountOptions

export interface CalculateAmountOptions {
  coinType: string;
  amount: string;
  threshold: string;
  atob: boolean;
  isExact: boolean;
  isInit?: boolean;
}

async calculateTokenAndThresholdAmount(options: CalculateAmountOptions) {
    const { coinType, atob, isExact, threshold, isInit = false } = options;
    const poolInfo = !isInit ? await this.getPoolInfo(coinType) : undefined;

    const virtual_token_reserves = new Decimal(
      poolInfo ? poolInfo.virtual_token_reserves : this.initial_virtual_token_reserves,
    );
    const virtual_sui_reserves = new Decimal(
      poolInfo ? poolInfo.virtual_sui_reserves : this.initial_virtual_sui_reserves,
    );
    const amount = new Decimal(options.amount);

    let _amount: Decimal;
    let _amountThreshold: Decimal;

    if (atob) {
      if (isExact) {
        const _fee = new Decimal(1).sub(this.platform_fee); // 0.005 fee
        _amount = virtual_token_reserves.sub(
          virtual_sui_reserves
            .mul(virtual_token_reserves)
            .div(virtual_sui_reserves.add(amount.mul(_fee))),
        );
        _amountThreshold = new Decimal(100).sub(threshold).div(100).mul(_amount);
      } else {
        const _fee = new Decimal(1).add(this.platform_fee); // 0.005 fee
        const _threshold = new Decimal(100).add(threshold).div(100);
        _amount = virtual_sui_reserves
          .mul(virtual_token_reserves)
          .div(virtual_token_reserves.sub(amount))
          .sub(virtual_sui_reserves)
          .mul(_fee)
          .mul(_threshold);

        _amountThreshold = _amount;
      }
    } else {
      if (isExact) {
        const _fee = new Decimal(1).sub(this.platform_fee); // 0.005 fee
        _amount = virtual_sui_reserves
          .sub(
            virtual_sui_reserves
              .mul(virtual_token_reserves)
              .div(virtual_token_reserves.add(amount)),
          )
          .mul(_fee);

        _amountThreshold = new Decimal(100).sub(threshold).div(100).mul(_amount);
      } else {
        const _fee = new Decimal(1).add(this.platform_fee); // 0.005 fee
        _amount = virtual_token_reserves.sub(
          virtual_sui_reserves
            .mul(virtual_token_reserves)
            .div(virtual_sui_reserves.add(amount.mul(_fee))),
        );

        _amountThreshold = new Decimal(100).add(threshold).div(100).mul(_amount);
      }
    }

    return {
      tokenAmount: _amount.toFixed(0),
      thresholdAmount: _amountThreshold.toFixed(0),
    };
  }