WeightedRanomExample

SomeClass {
    public class WeightedItem {
        public readonly int weight;
        public readonly Item drop;
        public WeightedItem(Item i, int w) {
            drop = i;
            weight = w;
        }

        public ItemStack GetStackFromDrop() {
            return new ItemStack(drop);
        }
    }

    private List<WeightedItem> bucket = new List<WeightedItem>();
    private totalWeight = 0;

    public void Add (Item item, int count) {
        if(count <= 0) throw new Exception("Invalid random weight");
        bucket.Add(new WeightedItem(item, count));
        totalWeight += count;
    }

    public void Add(WeightedItem item) {
        bucket.Add(item);
        totalWeight += item.weight;
    }

    public ItemStack GetRandom (Random rng) {
        int randomVal = rng.Next(0, totalWeight);
        foreach(WeightedItem item in bucket) {
            randomVal -= item.weight;
            if(randomVal <= 0) {
                return item.GetStackFromDrop();
            }
        }
    }
}