using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;

using GongSolutions.Wpf.DragDrop;

namespace Dominion.NET_WPF.ViewModel
{
	class CardListViewModel : IDropTarget
	{
		public ObservableCollection<CardViewModel> Cards { get; set; }
		public void ShowCards(IEnumerable<DominionBase.Cards.Card> cards, DominionBase.Piles.Visibility visibility)
		{
			Cards = new ObservableCollection<CardViewModel>();
			foreach (DominionBase.Cards.Card card in cards)
				Cards.Add(new CardViewModel { CardName = card.Name, ICard = card, Visibility = visibility });
		}

		public CardListViewModel()
		{
			Cards = new ObservableCollection<CardViewModel>();
		}

		void IDropTarget.DragOver(DropInfo dropInfo)
		{
			CardViewModel sourceItem = dropInfo.Data as CardViewModel;
			CardViewModel targetItem = dropInfo.TargetItem as CardViewModel;

			if (sourceItem != null && (targetItem != null || dropInfo.TargetCollection != null))
			{
				dropInfo.Effects = DragDropEffects.Move;
				dropInfo.DropTargetAdorner = DropTargetAdorners.Insert;
			}
			if (targetItem == null)
			{
			}
		}

		void IDropTarget.Drop(DropInfo dropInfo)
		{
			if (dropInfo.DragInfo == null)
				return;

			int insertIndex = dropInfo.InsertIndex;
			IList destinationList = GetList(dropInfo.TargetCollection);
			IEnumerable data = ExtractData(dropInfo.Data);

			ListBox lbSource = dropInfo.DragInfo.VisualSource as ListBox;
			ListBox lbTarget = dropInfo.VisualTarget as ListBox;
			if (lbSource != null && lbTarget != null && lbSource.DataContext.GetType() == lbTarget.DataContext.GetType())
			{
				IList sourceList = GetList(dropInfo.DragInfo.SourceCollection);

				foreach (object o in data)
				{
					int index = sourceList.IndexOf(o);

					if (index != -1)
					{
						sourceList.RemoveAt(index);

						if (sourceList == destinationList && index < insertIndex)
						{
							--insertIndex;
						}
					}
				}
			}

			foreach (object o in data)
				destinationList.Insert(insertIndex++, o);
		}

		protected static IEnumerable ExtractData(object data)
		{
			if (data is IEnumerable && !(data is string))
				return (IEnumerable)data;
			else
				return Enumerable.Repeat(data, 1);
		}

		protected static IList GetList(IEnumerable enumerable)
		{
			if (enumerable is ICollectionView)
				return ((ICollectionView)enumerable).SourceCollection as IList;
			else
				return enumerable as IList;
		}
	}
}