Collect product information for products in a Bootic cart

cart-info.js

/* Collect product information for products in the cart

Usage:

Get all products in the cart

  CartInfo.getProducts(function (products) {
     // products is an array of product objects
     console.log(products)
  })

Get an object with aggregated data from products in cart

  CartInfo.getInfo(function (info) {
    // all collections in cart
    console.log('collections', info.collections)
    // all types in cart
    console.log('types', info.types)
    // all tags in cart
    console.log('tags', info.tags)
    // all vendors in cart
    console.log('vendors', info.vendors)
  })
*/

var CartInfo = (function ($){
  function collectProductSlugs (cart) {
    return cart.products.map(function(p){return p.slug});
  }

  function startProductRequests (slugs) {
    return slugs.map(function(s){
      return $.getJSON("/products/"+s+".json")
    })
  }
  
  function waitForAllRequests (promises) {
    return $.when.apply($, promises)
  }

  function mapJsonObjectsFromResponses () {
    var arr = Array.prototype.slice.call(arguments)
    return arr.map(function (a) { return a[0]})  
  }

  function productCollections(memo, prod) {
    return memo.concat(prod.collections)
  }

  function flatten(listName) {
    return function (memo, prod) {
      return memo.concat(prod[listName])
    }
  }

  function pluck(field) {
    return function (memo, prod) {
      if(prod[field])
        memo.push(prod[field]);
      return memo;
    }
  }

  function fetchProductsInCart() {
    return $.getJSON("/cart.json")
      .then(collectProductSlugs)
      .then(startProductRequests)
      .then(waitForAllRequests)
      .then(mapJsonObjectsFromResponses);
  }

  function getProducts (fn) {
    fetchProductsInCart().then(fn)
  }

  function getInfo (fn) {
    fetchProductsInCart().then(function (products) {
      var collections = products.reduce(flatten("collections"), [])
      var types = products.reduce(pluck("product_type"), []);
      var vendors = products.reduce(pluck("vendor_name"), []);
      var tags = products.reduce(flatten("tags"), []);

      fn({
        collections: collections,
        types: types,
        vendors: vendors,
        tags: tags
      })
    });
  }

  return {
    getProducts: getProducts,
    getInfo: getInfo
  }

})(jQuery);