bicycleTransformer.js

var bicycleTransformer = (function() {
  "use strict";

  var getBicycles = function() {
    return [{
      id: 1,
      name: "A fast bike",
      type: "Road Bike",
      quantity: 10,
      rentPrice: 20,
      dateAdded: new Date(2015, 1, 2)
    }, {
      id: 2,
      name: "An even faster bike",
      type: "Road Bike",
      quantity: 4,
      rentPrice: 25,
      dateAdded: new Date(2015, 2, 25)
    }, {
      id: 3,
      name: "A springy bike",
      type: "Mountain Bike",
      quantity: 20,
      rentPrice: 18,
      dateAdded: new Date(2014, 10, 1)
    }, {
      id: 4,
      name: "A springier bike",
      type: "Mountain Bike",
      quantity: 10,
      rentPrice: 22,
      dateAdded: new Date(2014, 4, 1)
    }, {
      id: 5,
      name: "An all-terain bike",
      type: "Mountain Bike",
      quantity: 5,
      rentPrice: 27,
      dateAdded: new Date(2014, 8, 14)
    }, {
      id: 6,
      name: "A classy bike",
      type: "Urban Bike",
      quantity: 30,
      rentPrice: 15,
      dateAdded: new Date(2014, 6, 27)
    }, {
      id: 7,
      name: "A modern bike",
      type: "Urban Bike",
      quantity: 20,
      rentPrice: 17,
      dateAdded: new Date(2015, 1, 19)
    }, {
      id: 8,
      name: "A commuter bike",
      type: "Urban Bike",
      quantity: 12,
      rentPrice: 14,
      dateAdded: new Date(2014, 8, 2)
    }, {
      id: 9,
      name: "A blue bike",
      type: "Children Bike",
      quantity: 25,
      rentPrice: 10,
      dateAdded: new Date(2014, 10, 20)
    }, {
      id: 10,
      name: "A pink bike",
      type: "Children Bike",
      quantity: 25,
      rentPrice: 10,
      dateAdded: new Date(2015, 2, 5)
    }, {
      id: 11,
      name: "A noisy bike",
      type: "Children Bike",
      quantity: 3,
      rentPrice: 12,
      dateAdded: new Date(2014, 8, 23)
    }, {
      id: 12,
      name: "A clown bike",
      type: "Children Bike",
      quantity: 2,
      rentPrice: 12,
      dateAdded: new Date(2014, 11, 1)
    }];
  };

  var filterBicyclesByType = function(bicycles, type) {
    if (!type) {
      return bicycles;
    }

    return _.where(bicycles, {
      type: type
    });
  };

  return {
    getBicyclesSortedByRentPrice: function(type) {
      var filteredBicycles = filterBicyclesByType(getBicycles(), type);

      var sortedBicycles = _.sortBy(filteredBicycles, 'rentPrice');
      return _.map(sortedBicycles, function(bicycle) {
        return bicycle.name + " - " + bicycle.type + " : " + bicycle.rentPrice;
      });
    },
    getBicyclesGroupedByYear: function(type) {
      var filteredBicycles = filterBicyclesByType(getBicycles(), type);

      return _.groupBy(filteredBicycles, function(bicycle) {
        return bicycle.dateAdded.getFullYear();
      });
    },
    getBicyclesGroupedByPrice: function(type) {
      var filteredBicycles = filterBicyclesByType(getBicycles(), type);

      return _.groupBy(filteredBicycles, 'rentPrice');
    },
    getBicyclesIndexedById: function() {
      var bicycles = getBicycles();

      return _.indexBy(bicycles, 'id');
    },
    getBicyclesCountByType: function() {
      var bicycles = getBicycles();

      return _.countBy(bicycles, 'type');
    }
  };

}());