using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Linq;
using NUnit.Framework;

namespace Xamarin.Forms.Core.UnitTests
{
	[TestFixture]
	public class TemplatedItemsListTests : BaseTestFixture
	{
		class MockItemsView
			: ItemsView<BindableObject>
		{
			public MockItemsView()
			{
				TemplatedItems.IsGroupingEnabledProperty = IsGroupingEnabledProperty;
			}

			public event Action<BindableObject> Hooked;
			public event Action<BindableObject> Unhooked;

			public static readonly BindableProperty IsGroupingEnabledProperty =
				BindableProperty.Create<MockItemsView, bool> (lv => lv.IsGroupingEnabled, false);

			public bool IsGroupingEnabled
			{
				get { return (bool)GetValue (IsGroupingEnabledProperty); }
				set { SetValue (IsGroupingEnabledProperty, value); }
			}

			protected override BindableObject CreateDefault (object item)
			{
				return new TextCell { Text = item.ToString () };
			}

			public new TemplatedItemsList<ItemsView<BindableObject>, BindableObject> TemplatedItems
			{
				get { return base.TemplatedItems; }
			}
			
			BindingBase groupShortNameBinding;
			public BindingBase GroupShortNameBinding
			{
				get { return groupShortNameBinding; }
				set {
					if (groupShortNameBinding == value)
						return;
					OnPropertyChanging ();
					groupShortNameBinding = value;
					TemplatedItems.GroupShortNameBinding = value;
					OnPropertyChanged ();
				}
			}

			BindingBase groupDisplayBinding;
			public BindingBase GroupDisplayBinding
			{
				get { return groupDisplayBinding; }
				set {
					if (groupDisplayBinding == value)
						return;

					OnPropertyChanging ();
					groupDisplayBinding = value;
					TemplatedItems.GroupDisplayBinding = value;
					OnPropertyChanged ();
				}
			}

			protected override void SetupContent (BindableObject content, int index)
			{
				base.SetupContent (content, index);

				if (Hooked != null)
					Hooked (content);
			}

			protected override void UnhookContent (BindableObject content)
			{
				base.UnhookContent (content);

				if (Unhooked != null)
					Unhooked (content);
			}
		}

		[SetUp]
		public override void Setup()
		{
			base.Setup ();
			bindable = new MockItemsView();

			Device.PlatformServices = new MockPlatformServices ();
		}

		[TearDown]
		public override void TearDown()
		{
			base.TearDown ();
			Device.PlatformServices = null;
		}

		MockItemsView bindable;

		[Test]
		public void ListProxyNotNullWithNullItemsSource()
		{
			Assert.IsNotNull (bindable.TemplatedItems.ListProxy);
		}

		[Test]
		public void ResetOnItemsSourceChanged()
		{
			bool raised = false;
			NotifyCollectionChangedAction action = default(NotifyCollectionChangedAction);
			bindable.TemplatedItems.CollectionChanged += (sender, args) => {
				raised = true;
				action = args.Action;
			};

			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, Enumerable.Empty<string>());

			Assert.IsTrue (raised, "CollectionChanged was not raised");
			Assert.AreEqual (NotifyCollectionChangedAction.Reset, action);
		}
		/*
		[Test]
		public void ResetOnInfiniteScrollingChanged()
		{
			bool raised = false;
			NotifyCollectionChangedAction action = default(NotifyCollectionChangedAction);
			bindable.TemplatedItems.CollectionChanged += (sender, args) => {
				raised = true;
				action = args.Action;
			};

			bindable.SetValue (ItemsView.InfiniteScrollingProperty, true);

			Assert.IsTrue (raised, "CollectionChanged was not raised");
			Assert.AreEqual (NotifyCollectionChangedAction.Reset, action);
		}*/

		[Test]
		public void ResetOnTemplateChanged()
		{
			// Template changes won't trigger a reset if there's no items.
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, new[] { "Foo" });

			bool raised = false;
			NotifyCollectionChangedAction action = default(NotifyCollectionChangedAction);
			bindable.TemplatedItems.CollectionChanged += (sender, args) => {
				raised = true;
				action = args.Action;
			};

			bindable.SetValue (ItemsView<BindableObject>.ItemTemplateProperty, new DataTemplate());

			Assert.IsTrue (raised, "CollectionChanged was not raised");
			Assert.AreEqual (NotifyCollectionChangedAction.Reset, action);
		}

		[Test]
		public void PassThroughChanges()
		{
			var collection = new ObservableCollection<string>();
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			bool raised = false;
			NotifyCollectionChangedEventArgs args = null;
			bindable.TemplatedItems.CollectionChanged += (sender, eventArgs) => {
				raised = true;
				args = eventArgs;
			};

			string str = "foo bar";
			collection.Add (str);

			Assert.IsTrue (raised, "CollectionChanged was not raised");
			Assert.AreEqual (NotifyCollectionChangedAction.Add, args.Action);
			Assert.AreEqual (0, args.NewStartingIndex);
			Assert.IsNotNull (args.NewItems);
			Assert.AreEqual (1, args.NewItems.Count);
			Assert.AreSame (str, ((Cell)args.NewItems[0]).BindingContext);
		}

		[Test]
		public void ListProxyUpdatesWithItemsSource()
		{
			var collection = new List<string> { "foo bar" };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			Assert.IsNotNull (bindable.TemplatedItems.ListProxy);
			Assert.AreEqual (collection.Count, bindable.TemplatedItems.ListProxy.Count);
		}

		[Test]
		public void GetOrCreateContent ([Values (0, 1, 2)] int index)
		{
			var collection = new List<string> { "foo", "bar", "baz" };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			DataTemplate template = new DataTemplate (typeof (TextCell));
			template.SetBinding (TextCell.TextProperty, new Binding ("."));
			bindable.SetValue (ItemsView<BindableObject>.ItemTemplateProperty, template);

			BindableObject content = bindable.TemplatedItems.GetOrCreateContent (index, collection[index]);
			Assert.IsNotNull (content);

			TextCell textCell = content as TextCell;
			Assert.IsNotNull (textCell, "Content was did not match the template type, expected {0} but got {1}", typeof(TextCell), content.GetType());

			Assert.AreSame (collection[index], textCell.BindingContext);
			Assert.AreSame (collection[index], textCell.Text);

			BindableObject content2 = bindable.TemplatedItems.GetOrCreateContent (index, collection[index]);
			Assert.AreSame (content, content2);
		}

		[Test]
		public void GetOrCreateContentDefault()
		{
			Assert.IsNull (bindable.GetValue (ItemsView<BindableObject>.ItemTemplateProperty));

			var collection = new List<string> { "foo", "bar", "baz" };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			const int index = 0;
			BindableObject content = bindable.TemplatedItems.GetOrCreateContent (index, collection[index]);
			Assert.IsNotNull (content);

			TextCell textCell = content as TextCell;
			Assert.IsNotNull (textCell, "Content was did not match the template type, expected {0} but got {1}", typeof(TextCell), content.GetType());

			Assert.AreSame (collection[index], textCell.BindingContext);
			Assert.AreSame (collection[index], textCell.Text);

			BindableObject content2 = bindable.TemplatedItems.GetOrCreateContent (index, collection[index]);
			Assert.AreSame (content, content2);
		}

		[Test]
		public void GetOrCreateContentAfterTemplateChange()
		{
			var collection = new List<string> { "foo", "bar", "baz" };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			const int index = 0;

			DataTemplate template = new DataTemplate (typeof (TextCell));
			template.SetBinding (TextCell.TextProperty, new Binding ("."));
			bindable.SetValue (ItemsView<BindableObject>.ItemTemplateProperty, template);

			BindableObject content = bindable.TemplatedItems.GetOrCreateContent (index, collection[index]);
			Assert.That (content, Is.InstanceOf<TextCell>());

			template = new DataTemplate (typeof (SwitchCell));
			template.SetBinding (SwitchCell.TextProperty, new Binding ("."));

			bindable.SetValue (ItemsView<BindableObject>.ItemTemplateProperty, template);

			BindableObject content2 = bindable.TemplatedItems.GetOrCreateContent (index, collection[index]);
			Assert.IsNotNull (content2);
			Assert.That (content2, Is.InstanceOf<SwitchCell>());

			var switchCell = (SwitchCell) content2;
			Assert.AreSame (collection[index], switchCell.BindingContext);
		}

		[Test]
		public void GetOrCreateContentAfterItemsSourceChanged()
		{
			var collection = new List<string> { "foo", "bar", "baz" };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			const int index = 0;

			DataTemplate template = new DataTemplate (typeof (TextCell));
			template.SetBinding (TextCell.TextProperty, new Binding ("."));
			bindable.SetValue (ItemsView<BindableObject>.ItemTemplateProperty, template);

			BindableObject content = bindable.TemplatedItems.GetOrCreateContent (index, collection[index]);
			Assert.IsNotNull (content);

			collection = new List<string> { "we", "wee", "weee" };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			var content2 = (TextCell)bindable.TemplatedItems.GetOrCreateContent (index, collection[index]);

			Assert.AreNotSame (content, content2);
			Assert.AreSame (collection[index], content2.BindingContext);
			Assert.AreSame (collection[index], content2.Text);
		}

		/*[Test]
		public void GetOrCreateContentAfterInfiniteScrollingChanged()
		{
			var collection = new List<string> { "foo", "bar", "baz" };
			bindable.SetValue (ItemsView.ItemsSourceProperty, collection);

			const int index = 0;

			DataTemplate template = new DataTemplate (typeof (TextCell));
			template.SetBinding (TextCell.TextProperty, new Binding ("."));
			bindable.SetValue (ItemsView.ItemTemplateProperty, template);

			BindableObject content = bindable.TemplatedItems.GetOrCreateContent (index, collection[index], o => new TextCell (o.ToString()));
			Assert.IsNotNull (content);

			bindable.SetValue (ItemsView.InfiniteScrollingProperty, true);

			var content2 = (TextCell)bindable.TemplatedItems.GetOrCreateContent (index, collection[index], o => new TextCell (o.ToString()));

			Assert.AreNotSame (content, content2);
			Assert.AreSame (collection[index], content2.BindingContext);
			Assert.AreSame (collection[index], content2.Text);
		}*/

		[Test]
		[Description ("Make sure we're not duplicate cell instances for an equal item if it's a different index")]
		public void GetOrCreateContentEqualItemDifferentItemDifferentIndex()
		{
			Assert.IsNull (bindable.GetValue (ItemsView<BindableObject>.ItemTemplateProperty));

			var collection = new List<string> { "foo", "foo" };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			BindableObject content = bindable.TemplatedItems.GetOrCreateContent (0, collection[0]);
			Assert.IsNotNull (content);

			TextCell textCell = content as TextCell;
			Assert.IsNotNull (textCell, "Content was did not match the template type, expected {0} but got {1}", typeof(TextCell), content.GetType());

			Assert.AreSame (collection[0], textCell.BindingContext);
			Assert.AreSame (collection[0], textCell.Text);

			BindableObject content2 = bindable.TemplatedItems.GetOrCreateContent (1, collection[1]);
			Assert.AreNotSame (content, content2);

			Assert.AreSame (collection[1], textCell.BindingContext);
			Assert.AreSame (collection[1], textCell.Text);
		}

		[Test]
		[Description ("Make sure we're not duplicate cell instances for the same item if it's a different index")]
		public void GetOrCreateContentEqualItemSameItemDifferentIndex()
		{
			Assert.IsNull (bindable.GetValue (ItemsView<BindableObject>.ItemTemplateProperty));

			string item = "foo";

			var collection = new List<string> { item, item };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			BindableObject content = bindable.TemplatedItems.GetOrCreateContent (0, item);
			Assert.IsNotNull (content);

			TextCell textCell = content as TextCell;
			Assert.IsNotNull (textCell, "Content was did not match the template type, expected {0} but got {1}", typeof(TextCell), content.GetType());

			Assert.AreSame (item, textCell.BindingContext);
			Assert.AreSame (item, textCell.Text);

			BindableObject content2 = bindable.TemplatedItems.GetOrCreateContent (1, item);
			Assert.AreNotSame (content, content2);

			Assert.AreSame (item, textCell.BindingContext);
			Assert.AreSame (item, textCell.Text);
		}

		[Test]
		public void ItemsSourceInsertPreRealzied()
		{
			var collection = new ObservableCollection<string> { "foo", "bar" };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			collection.Insert (1, "baz");

			Assert.That (bindable.TemplatedItems.Count, Is.EqualTo (3));
			Assert.That (bindable.TemplatedItems.GetOrCreateContent (0, collection[0]).BindingContext, Is.SameAs (collection[0]));
			Assert.That (bindable.TemplatedItems.GetOrCreateContent (1, collection[1]).BindingContext, Is.SameAs (collection[1]));
			Assert.That (bindable.TemplatedItems.GetOrCreateContent (2, collection[2]).BindingContext, Is.SameAs (collection[2]));
		}

		[Test]
		public void ItemsSourceInsertPostRealized()
		{
			var collection = new ObservableCollection<string> { "foo", "bar" };
			bindable.SetValue (ItemsView<BindableObject>.ItemsSourceProperty, collection);

			// Force the handler to realize/create the content
			bindable.TemplatedItems.GetOrCreateContent (0, collection[0]);
			bindable.TemplatedItems.GetOrCreateContent (1, collection[1]);

			collection.Insert (1, "baz");

			Assert.That (bindable.TemplatedItems.Count, Is.EqualTo (3));
			Assert.That (bindable.TemplatedItems.GetOrCreateContent (0, collection[0]).BindingContext, Is.SameAs (collection[0]));
			Assert.That (bindable.TemplatedItems.GetOrCreateContent (1, collection[1]).BindingContext, Is.SameAs (collection[1]));
			Assert.That (bindable.TemplatedItems.GetOrCreateContent (2, collection[2]).BindingContext, Is.SameAs (collection[2]));
		}

		[TestCase (0, 0, 0)]
		[TestCase (3, 1, 0)]
		public void GetGroupIndexFromGlobalGroupIndex (int globalIndex, int expectedIndex, int expectedLeftOver)
		{
			var collection = new[] {
				new[] { "foo", "fad" },
				new[] { "bar", "baz" }
			};
			bindable.ItemsSource = collection;
			bindable.IsGroupingEnabled = true;

			int leftOver;
			int index = bindable.TemplatedItems.GetGroupIndexFromGlobal (globalIndex, out leftOver);
			Assert.That (index, Is.EqualTo (expectedIndex));
			Assert.That (leftOver, Is.EqualTo (expectedLeftOver));
		}

		[TestCase (1, 0, 1)]
		[TestCase (2, 0, 2)]
		[TestCase (4, 1, 1)]
		[TestCase (5, 1, 2)]
		public void GetGroupIndexFromGlobalItemIndex (int globalIndex, int expectedIndex, int expectedLeftOver)
		{
			var collection = new[] {
				new[] { "foo", "fad" },
				new[] { "bar", "baz" }
			};
			bindable.ItemsSource = collection;
			bindable.IsGroupingEnabled = true;

			int leftOver;
			int index = bindable.TemplatedItems.GetGroupIndexFromGlobal (globalIndex, out leftOver);
			Assert.That (index, Is.EqualTo (expectedIndex));
			Assert.That (leftOver, Is.EqualTo (expectedLeftOver));
		}

		[Test]
		public void GetGroupAndIndexOfItem ([Values (0, 1, 2)] int group, [Values (0, 1, 2)] int index)
		{
			var collection = new[] {
				new[] { "foo", "fad" },
				new[] { "bar", "baz" }
			};
			bindable.ItemsSource = collection;
			bindable.IsGroupingEnabled = true;

			object item = null;
			if (group < collection.Length) {
				if (index < collection[group].Length)
					item = collection[group][index];
			}

			if (item == null) {
				item = "not in here";
				group = index = -1;
			}

			var location = bindable.TemplatedItems.GetGroupAndIndexOfItem (item);
			Assert.That (location.Item1, Is.EqualTo (group), "Group index was incorrect");
			Assert.That (location.Item2, Is.EqualTo (index), "Item index was incorrect");
		}

		[Test]
		public void GetGroupAndIndexOfItemNotGrouped ()
		{
			var items = Enumerable.Range (0, 10).ToList ();
			bindable.ItemsSource = items;

			var location = bindable.TemplatedItems.GetGroupAndIndexOfItem (null, items[2]);

			Assert.That (location.Item1, Is.EqualTo (0));
			Assert.That (location.Item2, Is.EqualTo (2));
		}

		[Test]
		public void ItemsSourcePropertyChangedWithBindable()
		{
			bool raised = false;
			bindable.TemplatedItems.PropertyChanged += (s, e) => {
				if (e.PropertyName == "ItemsSource")
					raised = true;
			};

			bindable.ItemsSource = new object[0];

			Assert.That (raised, Is.True, "INPC not raised for ItemsSource");
		}

		[Test]
		public void IndexCorrectAfterMovingGroups()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.IsGroupingEnabled = true;

			items.Move (0, 1);

			var til = bindable.TemplatedItems.GetGroup (1);
			int index = GetIndex (til.HeaderContent);

			Assert.That (index, Is.EqualTo (1));
		}

		[Test]
		public void ShortNameSetBeforeGrouping()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupDisplayBinding = new Binding (".[0]");
			bindable.GroupShortNameBinding = new Binding (".[0]");
			bindable.IsGroupingEnabled = true;

			Assert.That (bindable.TemplatedItems.ShortNames[0], Is.EqualTo ("foo"));
		}

		[Test]
		public void ItemAddedWithShortNameSetButUngrouped()
		{
			var items = new ObservableCollection<string> { "foo", "bar" };

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");

			Assert.That (() => items.Add ("baz"), Throws.Nothing);
		}

		[Test]
		public void ItemAddedWithShortNameSetButGroupingDisabled()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;
			bindable.IsGroupingEnabled = false;

			Assert.That (() => items.Add (new ObservableCollection<string>()), Throws.Nothing);
		}

		int GetIndex (BindableObject item)
		{
			return TemplatedItemsList<ItemsView<BindableObject>, BindableObject>.GetIndex (item);
		}

		[Test]
		public void GetIndex()
		{
			var items = new List<string> { "foo", "bar", "baz" };

			bindable.ItemsSource = items;

			BindableObject item = bindable.TemplatedItems.GetOrCreateContent (1, items[1]);
			int index = GetIndex (item);
			Assert.That (index, Is.EqualTo (1));
		}

		[Test]
		public void GetIndexAfterInsert()
		{
			var items = new ObservableCollection<string> { "foo", "bar", "baz" };

			bindable.ItemsSource = items;

			BindableObject originalItem = bindable.TemplatedItems.GetOrCreateContent (1, items[1]);

			items.Insert (1, "fad");

			BindableObject item = bindable.TemplatedItems.GetOrCreateContent (1, items[1]);

			int index = GetIndex (item);
			Assert.That (index, Is.EqualTo (1));

			index = GetIndex (originalItem);
			Assert.That (index, Is.EqualTo (2));
		}

		[Test]
		public void GetIndexAfterMove()
		{
			var items = new ObservableCollection<string> { "foo", "bar", "baz" };

			bindable.ItemsSource = items;

			BindableObject item0 = bindable.TemplatedItems.GetOrCreateContent (0, items[0]);
			BindableObject item1 = bindable.TemplatedItems.GetOrCreateContent (1, items[1]);
			BindableObject item2 = bindable.TemplatedItems.GetOrCreateContent (2, items[2]);

			items.Move (0, 2); // foo, bar, baz becomes bar (1), baz (2), foo (0)

			Assert.That (GetIndex (item0), Is.EqualTo (2));
			Assert.That (GetIndex (item1), Is.EqualTo (0));
			Assert.That (GetIndex (item2), Is.EqualTo (1));
		}

		[Test]
		public void GetIndexAfterRemove()
		{
			var items = new ObservableCollection<string> { "foo", "bar", "baz" };

			bindable.ItemsSource = items;

			BindableObject item1 = bindable.TemplatedItems.GetOrCreateContent (1, items[1]);
			BindableObject item2 = bindable.TemplatedItems.GetOrCreateContent (2, items[2]);

			items.RemoveAt (0);

			Assert.That (GetIndex (item1), Is.EqualTo (0));
			Assert.That (GetIndex (item2), Is.EqualTo (1));
		}

		[Test]
		public void GetGroup()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			var til = bindable.TemplatedItems.GetGroup (1);
			var item = til[1];

			var group = TemplatedItemsList<ItemsView<BindableObject>, BindableObject>.GetGroup (item);

			Assert.That (group, Is.SameAs (til));
		}

		[Test]
		public void GetIndexGrouped()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			var til = bindable.TemplatedItems.GetGroup (1);
			var item = til[1];

			int index = GetIndex (item);
			Assert.That (index, Is.EqualTo (1));
		}

		[Test]
		public void GetGroupAndIndexOfItem()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			var result = bindable.TemplatedItems.GetGroupAndIndexOfItem (items[1], items[1][1]);

			Assert.That (result.Item1, Is.EqualTo (1));
			Assert.That (result.Item2, Is.EqualTo (1));
		}

		[Test]
		public void GetGroupAndIndexOfItemNoGroup()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			var result = bindable.TemplatedItems.GetGroupAndIndexOfItem (null, items[1][1]);

			Assert.That (result.Item1, Is.EqualTo (1));
			Assert.That (result.Item2, Is.EqualTo (1));
		}

		[Test]
		public void GetGroupAndIndexOfItemNotFound()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			var group = new ObservableCollection<string> { "bam" };

			var result = bindable.TemplatedItems.GetGroupAndIndexOfItem (group, group[0]);

			Assert.That (result.Item1, Is.EqualTo (-1));
			Assert.That (result.Item2, Is.EqualTo (-1));
		}

		[Test]
		public void GetGroupAndIndexOfItemItemNotFound()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			var result = bindable.TemplatedItems.GetGroupAndIndexOfItem (items[1], "bam");

			Assert.That (result.Item1, Is.EqualTo (1));
			Assert.That (result.Item2, Is.EqualTo (-1));
		}

		[Test]
		[Description ("Issue #2464: ANE thrown when moving items in a ListView")]
		public void MovingPastRealizedWindowAndBackDoesntThrow()
		{
			var items = new ObservableCollection<string> (Enumerable.Range (0, 100).Select (i => i.ToString()));

			bindable.ItemsSource = items;

			bindable.TemplatedItems.GetOrCreateContent (0, items[0]);
			bindable.TemplatedItems.GetOrCreateContent (1, items[1]);

			items.Move (0, 3);
			Assert.That (() => items.Move (3, 2), Throws.Nothing);

			Assert.That (GetIndex (bindable.TemplatedItems[0]), Is.EqualTo (0));
			Assert.That (GetIndex (bindable.TemplatedItems[1]), Is.EqualTo (1));
			Assert.That (GetIndex (bindable.TemplatedItems[2]), Is.EqualTo (2));
			Assert.That (GetIndex (bindable.TemplatedItems[3]), Is.EqualTo (3));
		}

		[Test]
		public void GetGlobalIndexOfItem ()
		{
			var items = new ObservableCollection<string> (Enumerable.Range (0, 100).Select (i => i.ToString()));
			bindable.ItemsSource = items;

			int global = bindable.TemplatedItems.GetGlobalIndexOfItem ("50");
			Assert.That (global, Is.EqualTo (50));
		}

		[Test]
		public void GetGlobalIndexOfItemNotFound ()
		{
			var items = new ObservableCollection<string> (Enumerable.Range (0, 100).Select (i => i.ToString()));
			bindable.ItemsSource = items;

			int global = bindable.TemplatedItems.GetGlobalIndexOfItem ("101");
			Assert.That (global, Is.EqualTo (-1));
		}

		[Test]
		public void GetGlobalIndexOfItemGrouped ()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			int global = bindable.TemplatedItems.GetGlobalIndexOfItem ("baz");
			Assert.That (global, Is.EqualTo (5));
		}

		[Test]
		public void GetGlobalIndexOfItemGroupedNotFound ()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			int global = bindable.TemplatedItems.GetGlobalIndexOfItem ("101");
			Assert.That (global, Is.EqualTo (-1));
		}

		[Test]
		public void GetGlobalIndexOfGroupItemGrouped ()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "baz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			int global = bindable.TemplatedItems.GetGlobalIndexOfItem (items[1], "baz");
			Assert.That (global, Is.EqualTo (5));
		}

		[Test]
		public void GetGlobalIndexOfGroupItemGroupedNotFound ()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "foo", "faz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			int global = bindable.TemplatedItems.GetGlobalIndexOfItem (items[1], "bar");
			Assert.That (global, Is.EqualTo (-1));
		}

		[Test]
		public void GetGlobalIndexOfGroupItemGroupedGroupNotFound ()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "foo", "faz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			int global = bindable.TemplatedItems.GetGlobalIndexOfItem (new object(), "foo");
			Assert.That (global, Is.EqualTo (-1));
		}

		[Test]
		public void SetupContentOnCreation()
		{
			var items = new ObservableCollection<string> {
				"Foo",
				"Bar"
			};

			bindable.ItemTemplate = new DataTemplate (typeof (TextCell)) {
				Bindings = {
					{ TextCell.TextProperty, new Binding (".") }
				}
			};

			int count = 0;
			bindable.Hooked += obj => {
				count++;
				Assert.That (obj, Is.InstanceOf (typeof (TextCell)));
				Assert.That (items, Contains.Item (obj.BindingContext));
			};

			bindable.ItemsSource = items;

			bindable.TemplatedItems.GetOrCreateContent (0, items[0]);
			bindable.TemplatedItems.GetOrCreateContent (1, items[1]);

			Assert.That (count, Is.EqualTo (2));
		}

		[Test]
		public void UnhookGroupOnRemoval()
		{
			var inner = new ObservableCollection<string> {
				"Foo",
			};

			var items = new ObservableCollection<ObservableCollection<string>> {
				inner
			};

			bindable.IsGroupingEnabled = true;
			bindable.GroupDisplayBinding = new Binding (".[0]");

			bindable.ItemTemplate = new DataTemplate (typeof (TextCell)) {
				Bindings = {
					{ TextCell.TextProperty, new Binding (".") }
				}
			};

			int count = 0;
			bindable.Unhooked += obj => {
				if (count == 0) {
					Assert.That (obj.BindingContext, Is.InstanceOf (typeof (TemplatedItemsList<ItemsView<BindableObject>, BindableObject>)));
					Assert.That (((TemplatedItemsList<ItemsView<BindableObject>, BindableObject>) obj.BindingContext).ListProxy.ProxiedEnumerable, Is.SameAs (inner));
				} else {
					Assert.That (obj.BindingContext, Is.SameAs (inner[0]));
				}

				count++;
			};

			bindable.ItemsSource = items;

			var til = bindable.TemplatedItems.GetGroup (0);
			til.GetOrCreateContent (0, inner[0]);

			Assume.That (til, Is.Not.Null);
			Assume.That (til.HeaderContent, Is.Not.Null);
			Assume.That (count, Is.EqualTo (0));

			items.RemoveAt (0);

			Assert.That (count, Is.EqualTo (2));
		}

		[Test]
		public void HookAndUnhookGroupOnReplace()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> {
					"Foo",
				}
			};

			bindable.IsGroupingEnabled = true;
			bindable.GroupDisplayBinding = new Binding (".[0]");
			bindable.ItemTemplate = new DataTemplate (typeof (TextCell)) {
				Bindings = {
					{ TextCell.TextProperty, new Binding (".") }
				}
			};

			bindable.ItemsSource = items;

			var til = bindable.TemplatedItems.GetGroup (0);
			til.GetOrCreateContent (0, items[0][0]);

			Assume.That (til, Is.Not.Null);
			Assume.That (til.HeaderContent, Is.Not.Null);

			int hcount = 0;
			bindable.Hooked += obj => {
				Assert.That (obj.BindingContext, Is.InstanceOf (typeof (TemplatedItemsList<ItemsView<BindableObject>, BindableObject>)));
				hcount++;
			};

			int ucount = 0;
			bindable.Unhooked += obj => {
				Assert.That (obj.BindingContext,
					Is.InstanceOf (typeof (TemplatedItemsList<ItemsView<BindableObject>, BindableObject>))
						.Or.EqualTo ("Foo"));

				ucount++;
			};

			items[0] = new ObservableCollection<string> { "Baz" };

			Assert.That (hcount, Is.EqualTo (1));
			Assert.That (ucount, Is.EqualTo (2));
		}

		[Test]
		public void UnhookContentOnRemoval()
		{
			var items = new ObservableCollection<string> {
				"Foo",
				"Bar"
			};

			bindable.ItemTemplate = new DataTemplate (typeof (TextCell)) {
				Bindings = {
					{ TextCell.TextProperty, new Binding (".") }
				}
			};

			int count = 0;
			bindable.Unhooked += obj => {
				count++;
				Assert.That (obj, Is.InstanceOf (typeof (TextCell)));
				Assert.That (obj.BindingContext, Is.EqualTo ("Foo"));
			};

			bindable.ItemsSource = items;

			bindable.TemplatedItems.GetOrCreateContent (0, items[0]);
			bindable.TemplatedItems.GetOrCreateContent (1, items[1]);

			Assume.That (count, Is.EqualTo (0));

			items.RemoveAt (0);

			Assert.That (count, Is.EqualTo (1));
		}

		[Test]
		public void HookAndUnhookContentOnReplace()
		{
			var items = new ObservableCollection<string> {
				"Foo",
				"Bar"
			};

			bindable.ItemTemplate = new DataTemplate (typeof (TextCell)) {
				Bindings = {
					{ TextCell.TextProperty, new Binding (".") }
				}
			};

			bindable.ItemsSource = items;

			bindable.TemplatedItems.GetOrCreateContent (0, items[0]);
			bindable.TemplatedItems.GetOrCreateContent (1, items[1]);

			int hcount = 0;
			bindable.Hooked += obj => {
				hcount++;
				Assert.That (obj, Is.InstanceOf (typeof (TextCell)));
				Assert.That (obj.BindingContext, Is.EqualTo ("Baz"));
			};

			int ucount = 0;
			bindable.Unhooked += obj => {
				ucount++;
				Assert.That (obj, Is.InstanceOf (typeof (TextCell)));
				Assert.That (obj.BindingContext, Is.EqualTo ("Foo"));
			};

			items[0] = "Baz";

			Assert.That (hcount, Is.EqualTo (1));
			Assert.That (ucount, Is.EqualTo (1));
		}

		[Test (Description = "If the cell exists and has an index, we still need to check if it's in the group asked for")]
		public void IndexOfFailsForCellInAnotherGroup ()
		{
			var items = new ObservableCollection<ObservableCollection<string>> {
				new ObservableCollection<string> { "foo", "faz" },
				new ObservableCollection<string> { "bar", "baz" }
			};

			bindable.ItemsSource = items;
			bindable.GroupShortNameBinding = new Binding (".");
			bindable.IsGroupingEnabled = true;

			var group1 = bindable.TemplatedItems.GetGroup (0);
			var cell = group1[1];

			Assume.That (group1.IndexOf (cell), Is.EqualTo (1));

			var group2 = bindable.TemplatedItems.GetGroup (1);

			Assert.That (group2.IndexOf (cell), Is.EqualTo (-1));
		}
	}
}