using NUnit.Framework;
using System.Threading.Tasks;

namespace Xamarin.Forms.Core.UnitTests
{
	[TestFixture]
	public class DataTriggerTests : BaseTestFixture
	{
		[SetUp]
		public override void Setup()
		{
			Device.PlatformServices = new MockPlatformServices();
			base.Setup();
		}

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

		class MockElement : VisualElement
		{
		}

		[Test]
		public void SettersAppliedOnAttachIfConditionIsTrue ()
		{
			var setterbp = BindableProperty.Create ("bar", typeof(string), typeof(BindableObject), null);
			var element = new MockElement ();
			var datatrigger = new DataTrigger (typeof(VisualElement)) {
				Binding = new Binding ("foo"),
				Value = "foobar",
				Setters = {
					new Setter { Property = setterbp, Value = "qux" },
				}
			};

			element.SetValue (setterbp, "default");
			element.BindingContext = new {foo = "foobar"};
			Assert.AreEqual ("default", element.GetValue (setterbp));
			element.Triggers.Add (datatrigger);
			Assert.AreEqual ("qux", element.GetValue (setterbp));
		}

		[Test]
		public void SettersUnappliedOnDetach ()
		{
			var setterbp = BindableProperty.Create ("bar", typeof(string), typeof(BindableObject), null);
			var element = new MockElement ();
			var datatrigger = new DataTrigger (typeof(VisualElement)) {
				Binding = new Binding ("foo"),
				Value = "foobar",
				Setters = {
					new Setter { Property = setterbp, Value = "qux" },
				}
			};

			element.SetValue (setterbp, "default");
			element.Triggers.Add (datatrigger);

			Assert.AreEqual ("default", element.GetValue (setterbp));
			element.BindingContext = new {foo = "foobar"};
			Assert.AreEqual ("qux", element.GetValue (setterbp));
			element.Triggers.Remove (datatrigger);
			Assert.AreEqual ("default", element.GetValue (setterbp));
		}

		[Test]
		public void SettersAppliedOnConditionChanged ()
		{
			var setterbp = BindableProperty.Create ("bar", typeof(string), typeof(BindableObject), null);
			var element = new MockElement ();
			var trigger = new DataTrigger (typeof (VisualElement)){
				Binding = new Binding ("foo"),
				Value = "foobar",
				Setters = {
					new Setter { Property = setterbp, Value = "qux" },
				}
			};

			element.SetValue (setterbp, "default");
			element.Triggers.Add (trigger);

			Assert.AreEqual ("default", element.GetValue (setterbp));
			element.BindingContext = new {foo = "foobar"};
			Assert.AreEqual ("qux", element.GetValue (setterbp));
			element.BindingContext = new {foo = ""};
			Assert.AreEqual ("default", element.GetValue (setterbp));
		}

		[Test]
		public void TriggersAppliedOnMultipleElements ()
		{
			var setterbp = BindableProperty.Create ("bar", typeof(string), typeof(BindableObject), null);
			var trigger = new DataTrigger (typeof(VisualElement)) {
				Binding = new Binding ("foo"),
				Value = "foobar",
				Setters = {
					new Setter { Property = setterbp, Value = "qux" },
				}
			};
			var element0 = new MockElement { Triggers = { trigger } };
			var element1 = new MockElement { Triggers = { trigger } };

			element0.BindingContext = element1.BindingContext = new {foo = "foobar"};
			Assert.AreEqual ("qux", element0.GetValue (setterbp));
			Assert.AreEqual ("qux", element1.GetValue (setterbp));
		}

		[Test]
		//https://bugzilla.xamarin.com/show_bug.cgi?id=30074
		public void AllTriggersUnappliedBeforeApplying ()
		{
			var boxview = new BoxView {
				Triggers = {
					new DataTrigger (typeof(BoxView)) {
						Binding = new Binding ("."),
						Value = "Complete",
						Setters = {
							new Setter { Property = BoxView.ColorProperty, Value = Color.Green },
							new Setter { Property = VisualElement.OpacityProperty, Value = .5 },
						}
					},
					new DataTrigger (typeof(BoxView)) {
						Binding = new Binding ("."),
						Value = "MissingInfo",
						Setters = {
							new Setter { Property = BoxView.ColorProperty, Value = Color.Yellow },
						}
					},
					new DataTrigger (typeof(BoxView)) {
						Binding = new Binding ("."),
						Value = "Error",
						Setters = {
							new Setter { Property = BoxView.ColorProperty, Value = Color.Red },
						}
					},
				}
			};

			boxview.BindingContext = "Complete";
			Assert.AreEqual (Color.Green, boxview.Color);
			Assert.AreEqual (.5, boxview.Opacity);

			boxview.BindingContext = "MissingInfo";
			Assert.AreEqual (Color.Yellow, boxview.Color);
			Assert.AreEqual (1, boxview.Opacity);

			boxview.BindingContext = "Error";
			Assert.AreEqual (Color.Red, boxview.Color);
			Assert.AreEqual (1, boxview.Opacity);

			boxview.BindingContext = "Complete";
			Assert.AreEqual (Color.Green, boxview.Color);
			Assert.AreEqual (.5, boxview.Opacity);
		}
	}
}