milk and egg

milkAndEgg.js

var developer = objInit({
    info: {
        name        : '개발자',
        state       : 'go home'
    }
});
var wife = objInit({
    info: {
        name    : '아내'
    }
});
var market = objInit({
    info: {
        name    : '마트'
    },
    items: {
        egg     : 100,
        milk    : 100
    }
});

if(developer.info.state == 'go home'){
    developer.purchase(market, 'milk', 2);
    if(market.hasItem('egg')){
        developer.purchase(market, 'milk', 6)
    }
}

developer.state = 'stay home';
developer.allGive(wife, 'milk');

market.print();
developer.print();
wife.print();


//util


function simpleExtend(object, target){
    for(key in object){
        target[key] = object[key];
    }
}

function objInit(obj){
    var methods = {
        print       : print,
        allGive     : allGive,
        give        : give,
        purchase    : purchase,
        removeItem  : removeItem,
        addItem     : addItem,
        hasItem     : hasItem,
        getNum      : getNum,
        setNum      : setNum
    }
    
    simpleExtend(methods, obj);
    obj.info = obj.info ? obj.info : {};
    obj.info.name = obj.info.name ? obj.info.name : 'undefined';
    obj.items = obj.items ? obj.items : {};

    return obj;
}


// methods

function print(){
    console.log('%s은(는)...', this.info.name);

    var has = false;
    for(item in this.items){
        var num = getNum.call(this, item);
        if(num > 0){
            console.log('%s을(를) %i개', item, num);
            has = true;
        }
    }

    if(has){
        console.log('갖고있습니다.');
    }else{
        console.log('아무것도 갖고있지 않습니다.');
    }
    
}

function allGive(other){
    console.log('%s은(는) 갖고있는 것을 %s에(에게) 모두 주는것을 시도.', this.info.name, other.info.name);
    for(item in this.items){
        var num = getNum.call(this, item);
        give.call(this, other, item, num);
    }
    console.log('성공적');
}

function give(other, item, num){
    console.log('%s은(는) %s %i개를 %s에(에게) 주는것을 시도.', this.info.name, item, num, other.info.name);
    removeItem.call(this, item, num);
    addItem.call(other, item, num);
    console.log('성공적');
}

function purchase(other, item, num){
    console.log('%s은(는) %s에서 %s %i개를 구매 시도.', this.info.name, other.info.name, item, num);
    removeItem.call(other, item, num);
    addItem.call(this, item, num);
    console.log('성공적');
}

function addItem(item, num){
    this.items[item] = this.items[item] ? this.items[item] + num : num;
}

function removeItem(item, num){
    if(num <= 0){
        return;
    }

    if(!hasItem.call(this, item)){
        throw Error(this.info.name +'에게 '+item+'이(가) 없어서 제거 실패');
    }

    if(this.items[item] < num){
        throw Error(this.info.name +'에게 '+item+'이(가) '+this.getNum(item)+'개 밖에 없어서 '+num+'개 제거 실패');
    }

    this.items[item] = this.getNum(item) - num;
}

function hasItem(item){
    if(!this.items[item] || this.items[item] <= 0){
        return false;
    }
    return true;
}

function getNum(item){
    if(hasItem.call(this, item)){
        return this.items[item];
    }
    return 0;
}

function setNum(item, num){
    this.items[item] = num;
}