Challenge: Solution Review

class Inventory{
  constructor(){
    this.shampoosAmount = 20
    this.conditionersAmount = 20
    this.hairSerumsAmount = 1000
  }
  checkInventory(product){
    let available = true;
    if(product.productName == "shampoo" && product.amount > this.shampoosAmount){
      available = false
      return available
    }
    else if(product.productName == "conditioner" && product.amount > this.conditionersAmount){
      available = false
      return available
    }
    else if(product.productName == "hair serum" && product.amount > this.hairSerumsAmount){
      available = false
      return available
  }
  return available
}
}
class BuyingProduct extends Inventory {
  buyProduct(product) {
    let order;
    if(this.checkInventory(product)){
      order = new BuyProduct()
    }else{
      order = new PreOrderProduct()
    }
    return order.showDetails(product)
}
}
class BuyProduct{
  showDetails(product){
    console.log(`${product.amount} bottles of ${product.productName} are available. Click on "buy" to purchase them.`)
  }
}
class PreOrderProduct{
  showDetails(product){
    console.log(`${product.amount} bottles of ${product.productName} are not available. You can Pre-order them on the next page.`)
  }
}
var customer = new BuyingProduct()
customer.buyProduct({productName: "shampoo", amount: 2})
customer.buyProduct({productName: "hair serum", amount: 2000})