public class Inventory {
    private Item[] items;

    public Inventory(Item[] items) {
        super();
        this.items = items;
    }

    public void updateQuality() {
        for (int i = 0; i < items.length; i++) {
            if(items[i].getName().equals("Backstage passes to a TAFKAL80ETC concert")){                
                updateQualityForBackstagePasses(i);
            }else if(items[i].getName().equals("Aged Brie")){
                updateQualityForBrie(i);
            }else if(items[i].getName().equals("Sulfuras, Hand of Ragnaros")){
                continue;
            }else if(items[i].getName().equals("Conjured Item: Thori'dal, the Stars' Fury")){
                updateQualityConjuredItems(i);
            }else if((items[i].getQuality() > 0)){              
                updateQualityForOtherItems(i);               
            }
        }
    }

    public void increaseQualityByOne(int i){
        if(items[i].getQuality() < 50){
            items[i].setQuality(items[i].getQuality() + 1);
        }
    }

    public void decreaseQualityByOne(int i){
        items[i].setQuality(items[i].getQuality() - 1);
    }

    public void decreaseSellInByOne(int i){
        items[i].setSellIn(items[i].getSellIn() - 1);
    }

    public void updateQualityForBackstagePasses(int i){
        if (items[i].getSellIn() < 0){
            items[i].setQuality(0);
            if(items[i].getQuality() > 0){
                decreaseQualityByOne(i);
            }
        }else{
            increaseQualityByOne(i);
            if(items[i].getSellIn() < 11) {
                increaseQualityByOne(i);
            } 
            if(items[i].getSellIn() < 6){
                increaseQualityByOne(i);
            }
        }
    }

    public void updateQualityForBrie(int i){
        increaseQualityByOne(i);
        decreaseSellInByOne(i);       
        if (items[i].getSellIn() < 0){
            increaseQualityByOne(i);
        }
    }

    public void updateQualityForOtherItems(int i){
        decreaseQualityByOne(i); 
        decreaseSellInByOne(i);
        if ((items[i].getSellIn() < 0) && (items[i].getQuality() > 0)) {
            decreaseQualityByOne(i);
        }
        
    }
    
    public void updateQualityConjuredItems(int i){
        decreaseQualityByOne(i);
        decreaseQualityByOne(i); 
        decreaseSellInByOne(i);
        if ((items[i].getSellIn() < 0) && (items[i].getQuality() > 0)) {
            decreaseQualityByOne(i);
            decreaseQualityByOne(i); 
        }
        
    }
}