// 定义一个询价处理器对象
const priceProcessor = {
  pre (originPrice) {
    if (originPrice >= 100) {
      return originPrice - 20;
    }
    return originPrice * 0.9;
  },
  onSale (originPrice) {
    if (originPrice >= 100) {
      return originPrice - 30;
    }
    return originPrice * 0.8;
  },
  back (originPrice) {
    if (originPrice >= 200) {
      return originPrice - 50;
    }
    return originPrice;
  },
  fresh (originPrice) {
    return originPrice * 0.5;
  },
};

// 询价函数
function askPrice (tag, originPrice) {
  return priceProcessor[tag](originPrice)
}

console.log(askPrice('onSale', 90));