function EquipmentComposition(name) {
  this.equipments = [];
  this.name = name;
}

EquipmentComposition.prototype.add = function(equipment) {
  this.equipments.push(equipment);
};

EquipmentComposition.prototype.getPrice = function() {
  return this.equipments.map(function(equipment) {
    return equipment.getPrice();
  }).reduce(function(a, b) {
    return a + b;
  });
};

function Equipment() {}

Equipment.prototype.getPrice = function() {
  return this.price;
};

function Equipment() {}

Equipment.prototype.getPrice = function() {
  return this.price;
};

function FloppyDisk() {
  this.name = "Floppy Disk";
  this.price = 70;
}
FloppyDisk.prototype = Object.create(Equipment.prototype);

function HardDrive() {
  this.name = "Hard Drive";
  this.price = 250;
}
HardDrive.prototype = Object.create(Equipment.prototype);

function Memory() {
  this.name = "8gb memomry";
  this.price = 280;
}
Memory.prototype = Object.create(Equipment.prototype);

// 커피는 에스프레소부타 시작... 슈퍼클래스로 선언
function Espresso() {
  this.cost = 2500;
}


// 아메리카노, 카페라떼.. 서브클래스로 선언
function Americano() {
  Espresso.call(this);
  this.cost = (new Espresso()).cost + 500;
  this.water = 250;
}

function CafeLatte() {
  Americano.call(this);
  this.cost = (new Americano()).cost + 500;
  this.milk = 100;
}


console.log(new Espresso());
// { cost: 2500 }
console.log(new Americano());
// { cost: 3000, water: 250 }
console.log(new CafeLatte());
//{ cost: 3500, water: 250, milk: 100 }

// 에스프레소에 물을 넣자...
function Water (espresso) {
  espresso.cost = espresso.cost + 500;
  espresso.water = 250;
  return espresso; //함수 체이닝
}

// 에스프레소에 우류를 넣자..
function Milk (espresso) {
  espresso.cost = espresso.cost + 500;
  espresso.milk = 100;
  return espresso;
}

var espresso = new Espresso();
// { cost: 2500 }
var americano = Water(new Espresso());
// { cost: 3000, water: 250 }
var cafeLatte = Milk(Water(new Espresso()));
// { cost: 3500, water: 250, milk: 100 }

// 파라매터로 받은 apiMethod 함수를 받는다.
http = function http(apiMethod) {

    return function apiHandler(req, res, next) {
        // request 개체를 통해 넘어온 요청데이터를 정규화 한다. 
        // body, params, query, files 를 object와 options 객체에 모아 담는다.
        var object = req.body,
            options = _.extend({}, req.files, req.query, req.params, {
                context: {
                    user: (req.user && req.user.id) ? req.user.id : null
                }
            });
        if (_.isEmpty(object)) {
            object = options;
            options = {};
        }

        // 정규화된 요청데이터를 파라메터로 넘어온 apiMethod 함수에 넘겨준다.
        return apiMethod(object, options).tap(function onSuccess(response) {
            // 응답 헤더를 설정한다.
            return addHeaders(apiMethod, req, res, (response || {}));
        }).then(function then(response) {
            // 응답 바디를 설정한다.
            res.json(response || {});
        }).catch(function onAPIError(error) {
            // 에러 처리
            next(error);
        });
    };
};

function Product() {
  this.price = 0;
  this.actions = [];
}

Product.prototype.setBasePrice = function(val) {
  this.price = val;
  this.notifyAll();
};

Product.prototype.register = function(observer) {
  this.actions.push(observer);
};

Product.prototype.unregister = function(observer) {
  this.actions = this.actions.filter(function(el) {
    return el != observer;
  });
};

Product.prototype.notifyAll = function() {
  return this.actions.forEach(function(el) {
    el.update(this);
  }.bind(this));
};

var fees = {
  update: function(product) {
    product.price = product.price * 1.2;
  }
};

var proft = {
  update: function(product) {
    product.price = product.price * 2;
  }
};

// discount, shipping, fees 실행
var shopFacade = {
  calc: function(price) {
    price = discount(price);
    price = fees(price);
    price += shipping();
    return price;
  }
};

// 할인
function discount(value) {
  return value * 0.9;
}

// 배송료
function shipping() {
  return 5;
}

// 수수료
function fees(value) {
  return value * 1.05;
}

function TrafficTower() {
  this.airplanes = [];
}

TrafficTower.prototype.requestPositions = function() {
  return this.airplanes.map(function(airplane) {
    return airplane.position;
  });
};

function Airplane(position, trafficTower) {
  this.position = position;
  this.trafficTower = trafficTower;
  this.trafficTower.airplanes.push(this);
}

Airplane.prototype.requestPositions = function() {
  return this.trafficTower.requestPositions();
};