// WARNING: DO NOT modify the Item class - the goblin in the corner will insta-rage!

class Item {
  String name;
  int sellIn;
  int quality;

  Item(this.name, this.sellIn, this.quality);

  @override
  String toString() => '$name, $sellIn, $quality';
}

class GildedRose {
  List<Item> items;

  GildedRose(this.items);

  void updateQuality() {
    for (var i = 0; i < items.length; i++) {
      if (items[i].name != 'Aged Brie' &&
          items[i].name != 'Backstage passes to a TAFKAL80ETC concert') {
        if (items[i].quality > 0) {
          if (items[i].name != 'Sulfuras, Hand of Ragnaros') {
            items[i].quality = items[i].quality - 1;
          }
        }
      } else {
        if (items[i].quality < 50) {
          items[i].quality = items[i].quality + 1;

          if (items[i].name == 'Backstage passes to a TAFKAL80ETC concert') {
            if (items[i].sellIn < 11) {
              if (items[i].quality < 50) {
                items[i].quality = items[i].quality + 1;
              }
            }

            if (items[i].sellIn < 6) {
              if (items[i].quality < 50) {
                items[i].quality = items[i].quality + 1;
              }
            }
          }
        }
      }

      if (items[i].name != 'Sulfuras, Hand of Ragnaros') {
        items[i].sellIn = items[i].sellIn - 1;
      } 

      if (items[i].sellIn < 0) {
        if (items[i].name != 'Aged Brie') {
          if (items[i].name != 'Backstage passes to a TAFKAL80ETC concert') {
            if (items[i].quality > 0) {
              if (items[i].name != 'Sulfuras, Hand of Ragnaros') {
                items[i].quality = items[i].quality - 1;
              }
            }
          } else {
            items[i].quality = items[i].quality - items[i].quality;
          }
        } else {
          if (items[i].quality < 50) {
            items[i].quality = items[i].quality + 1;
          }
        }
      }
    }
  }
}