minterjs-util/dist/cjs/coin-math.js

Utils for Minter

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.buyCoin = buyCoin;
exports.buyCoinByCoin = buyCoinByCoin;
exports.sellCoin = sellCoin;
exports.sellCoinByBip = sellCoinByBip;
var _big = _interopRequireDefault(require("./big.js"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
/**
 * Bancor sell COIN, calculate received BIP
 * @param {BancorCoinParams} coin
 * @param {number} coinAmount - sell COIN
 * @return {string} - get BIP
 */
function sellCoin(coin, coinAmount) {
  if (!isCoinValid(coin)) {
    return '0';
  }
  coinAmount = Math.min(coin.supply, coinAmount);
  return new _big["default"](coin.reserve).times(one().minus(Math.pow(one().minus(new _big["default"](coinAmount).div(coin.supply)), one().div(coin.crr)))).toFixed();
  // return coin.reserve * (1 - ((1 - coinAmount / coin.supply) ** (1 / coin.crr)));
}

/**
 * Bancor sell COIN, calculate needed COIN
 * @param {BancorCoinParams} coin
 * @param {number} bipAmount - get BIP
 * @return {string} - sell COIN
 */
function sellCoinByBip(coin, bipAmount) {
  if (!isCoinValid(coin)) {
    return '0';
  }
  bipAmount = Math.min(coin.reserve, bipAmount);
  return new _big["default"](coin.supply).times(one().minus(Math.pow(one().minus(new _big["default"](bipAmount).div(coin.reserve)), coin.crr))).toFixed();
  // return coin.supply * (1 - ((1 - bipAmount / coin.reserve) ** coin.crr));
}

/**
 * Bancor buy COIN, calculate received COIN
 * @param {BancorCoinParams} coin
 * @param {number} bipAmount - pay BIP
 * @return {string} - get COIN
 */
function buyCoin(coin, bipAmount) {
  if (!isCoinValid(coin)) {
    return '0';
  }
  return new _big["default"](coin.supply).times(new _big["default"](Math.pow(one().plus(new _big["default"](bipAmount).div(coin.reserve)), coin.crr)).minus(1)).toFixed();
  // return coin.supply * (((1 + bipAmount / coin.reserve) ** coin.crr) - 1);
}

/**
 * Bancor buy COIN, calculate needed BIP
 * @param {BancorCoinParams} coin
 * @param {number|string} coinAmount - get COIN
 * @return {string} - pay BIP
 */
function buyCoinByCoin(coin, coinAmount) {
  if (!isCoinValid(coin)) {
    return '0';
  }
  return new _big["default"](coin.reserve).times(new _big["default"](Math.pow(one().plus(new _big["default"](coinAmount).div(coin.supply)), one().div(coin.crr))).minus(1)).toString();
  // return coin.reserve * (((1 + coinAmount / coin.supply) ** (1 / coin.crr)) - 1);
}

/**
 * @param {BancorCoinParams} coin
 * @return {boolean}
 */
function isCoinValid(coin) {
  return !!(coin.reserve && coin.supply && coin.crr);
}
function one() {
  return new _big["default"](1);
}

/**
 * @typedef {object} BancorCoinParams
 * @property {number|null} supply
 * @property {number|null} crr
 * @property {number|null} reserve - from 0 to 1
 */