using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using Xunit;

namespace ReactiveUI.Routing.Tests

{

public class TestViewModel : ReactiveObject, IRoutableViewModel

{

string _SomeProp;

public string SomeProp {

get { return _SomeProp; }

set { this.RaiseAndSetIfChanged(ref _SomeProp, value); }

}

public string UrlPathSegment {

get { return "Test"; }

}

public IScreen HostScreen

{

get { return null; }

}

}

public class TestScreen : ReactiveObject, IScreen

{

IRoutingState _Router;

public IRoutingState Router {

get { return _Router; }

set { this.RaiseAndSetIfChanged(ref _Router, value); }

}

}

public class RoutingStateTests

{

[Fact]

public void NavigationPushPopTest()

{

var input = new TestViewModel() {SomeProp = "Foo"};

var fixture = new RoutingState();

Assert.False(fixture.NavigateBack.CanExecute(input));

fixture.Navigate.Execute(new TestViewModel());

Assert.Equal(1, fixture.NavigationStack.Count);

Assert.False(fixture.NavigateBack.CanExecute(null));

fixture.Navigate.Execute(new TestViewModel());

Assert.Equal(2, fixture.NavigationStack.Count);

Assert.True(fixture.NavigateBack.CanExecute(null));

fixture.NavigateBack.Execute(null);

Assert.Equal(1, fixture.NavigationStack.Count);

}

[Fact]

public void CurrentViewModelObservableIsAccurate()

{

var fixture = new RoutingState();

var output = fixture.CurrentViewModel.CreateCollection();

Assert.Equal(1, output.Count);

fixture.Navigate.Execute(new TestViewModel() { SomeProp = "A" });

Assert.Equal(2, output.Count);

fixture.Navigate.Execute(new TestViewModel() { SomeProp = "B" });

Assert.Equal(3, output.Count);

Assert.Equal("B", ((TestViewModel)output.Last()).SomeProp);

fixture.NavigateBack.Execute(null);

Assert.Equal(4, output.Count);

Assert.Equal("A", ((TestViewModel)output.Last()).SomeProp);

}

[Fact]

public void CurrentViewModelObservableIsAccurateViaWhenAnyObservable()

{

var fixture = new TestScreen();

var output = fixture.WhenAnyObservable(x => x.Router.CurrentViewModel).CreateCollection();

fixture.Router = new RoutingState();

Assert.Equal(1, output.Count);

fixture.Router.Navigate.Execute(new TestViewModel() { SomeProp = "A" });

Assert.Equal(2, output.Count);

fixture.Router.Navigate.Execute(new TestViewModel() { SomeProp = "B" });

Assert.Equal(3, output.Count);

Assert.Equal("B", ((TestViewModel)output.Last()).SomeProp);

fixture.Router.NavigateBack.Execute(null);

Assert.Equal(4, output.Count);

Assert.Equal("A", ((TestViewModel)output.Last()).SomeProp);

}

}

}