using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using NUnit.Framework;
using Xamarin.Forms;
using Xamarin.Forms.Core.UnitTests;

[assembly: Dependency(typeof (DependencyTestImpl))]

namespace Xamarin.Forms.Core.UnitTests
{
	public interface IDependencyTest
	{
		bool Works { get; }
	}

	public interface IDependencyTestRegister
	{
		bool Works { get; }
	}

	public interface IUnsatisfied
	{
		bool Broken { get; }
	}

	public class DependencyTestImpl : IDependencyTest
	{
		public bool Works { get { return true; } }
	}

	public class DependencyTestRegisterImpl : IDependencyTestRegister
	{
		public bool Works { get { return true; } }
	}

	public class DependencyTestRegisterImpl2 : IDependencyTestRegister
	{
		public bool Works { get { return false; } }
	}

	public class DependencyServiceTests : BaseTestFixture
	{
		[SetUp]
		public override void Setup()
		{
			base.Setup ();
			Device.PlatformServices = new MockPlatformServices ();
		}

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

		[Test]
		public void GetGlobalInstance ()
		{
			var global = DependencyService.Get<IDependencyTest> ();

			Assert.NotNull (global);

			var secondFetch = DependencyService.Get<IDependencyTest> ();

			Assert.True (ReferenceEquals (global, secondFetch));
		}

		[Test]
		public void NewInstanceIsNotGlobalInstance ()
		{
			var global = DependencyService.Get<IDependencyTest> ();

			Assert.NotNull (global);

			var secondFetch = DependencyService.Get<IDependencyTest> (DependencyFetchTarget.NewInstance);

			Assert.False (ReferenceEquals (global, secondFetch));
		}

		[Test]
		public void NewInstanceIsAlwaysNew ()
		{
			var firstFetch = DependencyService.Get<IDependencyTest> (DependencyFetchTarget.NewInstance);

			Assert.NotNull (firstFetch);

			var secondFetch = DependencyService.Get<IDependencyTest> (DependencyFetchTarget.NewInstance);

			Assert.False (ReferenceEquals (firstFetch, secondFetch));
		}

		[Test]
		public void UnsatisfiedReturnsNull ()
		{
			Assert.Null (DependencyService.Get<IUnsatisfied> ());
		}

		[Test]
		public void RegisterTypeImplementation ()
		{
			DependencyService.Register<DependencyTestRegisterImpl> ();
			var global = DependencyService.Get<DependencyTestRegisterImpl> ();
			Assert.NotNull (global);
		}


		[Test]
		public void RegisterInterfaceAndImplementations ()
		{
			DependencyService.Register<IDependencyTestRegister, DependencyTestRegisterImpl2> ();
			var global = DependencyService.Get<IDependencyTestRegister> ();
			Assert.IsInstanceOf<DependencyTestRegisterImpl2> (global);
		}

		[Test]
		public void RegisterInterfaceAndOverrideImplementations ()
		{
			DependencyService.Register<IDependencyTestRegister, DependencyTestRegisterImpl> ();
			DependencyService.Register<IDependencyTestRegister, DependencyTestRegisterImpl2> ();
			var global = DependencyService.Get<IDependencyTestRegister> ();
			Assert.IsInstanceOf<DependencyTestRegisterImpl2> (global);
		}
	}
}