Buecherwurm/Inventory.cs

using System.Collections.Generic;

namespace Bücherwurm
{
    class Inventory
    {
        private List<Item> InventoryList {get; set;}

        private int NextId {get; set;}

        public Inventory(){
            InventoryList = new List<Item>();
            NextId = 1;
        }

        public void Add(IProduct Book)
        {
            InventoryList.Add(new Item(NextId, Book.ProductId));
            NextId = NextId + 1;
        }

        public void Add(int BookId)
        {
            InventoryList.Add(new Item(NextId, BookId));
            NextId = NextId + 1;
        }

        public void Remove(int Id)
        {
            InventoryList.RemoveAll(item => item.ItemId == Id);
        }

        public void ProductRemove(int ProdId)
        {
            InventoryList.RemoveAll(item => item.ProdId == ProdId);
        }

        public List<Item> GetInventory()
        {
            return InventoryList;
        }

        public bool IsInInventory(int Id)
        {
            return (InventoryList.Find(item => item.ItemId == Id) != null);
        }

        public bool IsAvailable(int ItemId)
        {
            return (InventoryList.Find(item => item.ItemId == ItemId && item.Status == StatusEnum.Available) != null);
        }

        public List<int> IsProductAvailable(int ProdId)
        {
            var items = InventoryList.FindAll(item => item.ProdId == ProdId && item.Status == StatusEnum.Available);
            var ret = new List<int>();
            foreach (var item in items)
            {
                ret.Add(item.ItemId);
            }
            if (ret.Count == 0)
            {
                return null;
            } else
            {
                return ret;
            }
        }

        public Item LookupItem(int ItemId)
        {
            return InventoryList.Find(item => ItemId == item.ItemId);
        }

        public void MarkAsLended(int ItemId)
        {
            InventoryList[InventoryList.FindIndex(item => item.ItemId == ItemId)].Status = StatusEnum.Lended;
        }

        public void MarkAsAvailable(int ItemId)
        {
            InventoryList[InventoryList.FindIndex(item => item.ItemId == ItemId)].Status = StatusEnum.Available;
        }
    }
}