namespace MyApp.Tests
{
    using MyTested.AspNetCore.Mvc;
    
    using Microsoft.Extensions.DependencyInjection;

    public class TestStartup : Startup
    {
        public void ConfigureTestServices(IServiceCollection services)
        {
            base.ConfigureServices(services);
            
            // Replace only your own custom services. The ASP.NET Core ones 
            // are already replaced by MyTested.AspNetCore.Mvc. 
            services.Replace<IService, MockedService>();
        }
    }
}

namespace MyApp.Tests.Controllers
{
    using MyTested.AspNetCore.Mvc;
    
    using MyApp.Controllers;
    using Xunit;

    public class HomeControllerShould
    {
        [Fact]
        public void ReturnOkWithCorrectModelWhenCallingAuthenticatedIndexAction()
            => MyMvc                                             // Start a test case.
                .Controller<HomeController>(instance => instance // Arrange the controller under test.
                    .WithUser("TestUser")                        // Set an authenticated user to the request.
                    .WithData(MyTestData.GetData()))             // Populate the application DbContext.
                .Calling(c => c.Index())                         // Act - invoke the action under test.
                .ShouldReturn()                                  // Assert action behavior.
                .Ok(result => result                             // Validate the action result type.
                    .WithModelOfType<List<MyResponseModel>>()    // Check the response model type.
                    .Passing(model => model.Count == 10));       // Assert specific model properties. 
    }
}

// Instantiates controller with the registered global services,
// and mocks authenticated user,
// and tests for valid model state,
// and tests for added by the action view bag entry,
// and tests for view result and model with specific assertions.
MyController<MyMvcController>
    .Instance(instance => instance
        .WithUser(user => user
            .WithUsername("MyUserName")))
    .Calling(c => c.MyAction(myRequestModel))
    .ShouldHave()
    .ValidModelState()
    .AndAlso()
    .ShouldHave()
    .ViewBag(viewBag => viewBag
        .ContainingEntry("MyViewBagProperty", "MyViewBagValue"))
    .AndAlso()
    .ShouldReturn()
    .View(result => result
        .WithModelOfType<MyResponseModel>()
        .Passing(model =>
        {
            Assert.AreEqual(1, model.Id);
            Assert.AreEqual("My property value", model.MyProperty);
        }));

// Instantiates controller with the registered global services,
// and sets options for the current test,
// and sets session for the current test,
// and sets DbContext data for the current test,
// and tests for added by the action cache entry,
// and tests for view result with specific model type.
MyController<MyMvcController>
    .Instance(instance => instance
        .WithOptions(options => options
            .For<MyAppSettings>(settings => settings.Cache = true))
        .WithSession(session => session
            .WithEntry("MySession", "MySessionValue"))
        .WithData(data => data
            .WithEntities(entities => entities
                .AddRange(MyDataProvider.GetMyModels()))))
    .Calling(c => c.MyAction())
    .ShouldHave()
    .MemoryCache(cache => cache
        .ContainingEntry(entry => entry
            .WithKey("MyCacheEntry")
            .WithSlidingExpiration(TimeSpan.FromMinutes(10))
            .WithValueOfType<MyCachedModel>()
            .Passing(cacheModel => cacheModel.Id == 1)))
    .AndAlso()
    .ShouldReturn()
    .Ok(result => result
        .WithModelOfType<MyResponseModel>());

// Instantiates controller with the registered global services,
// and tests for valid model state,
// and tests for saved data in the DbContext after the action call,
// and tests for added by the action temp data entry with а specific key,
// and tests for redirect result to a specific action. 
MyController<MyMvcController>
    .Calling(c => c.MyAction(new MyFormModel
    {
        Title = title,
        Content = content
    }))
    .ShouldHave()
    .ValidModelState()
    .AndAlso()
    .ShouldHave()
    .Data(data => data
        .WithSet<MyModel>(set => set 
            .Should() // Uses FluentAssertions.
            .NotBeEmpty()
            .And
            .ContainSingle(model => model.Title == title)))
    .AndAlso()
    .ShouldHave()
    .TempData(tempData => tempData
        .ContainingEntryWithKey(ControllerConstants.SuccessMessage))
    .AndAlso()
    .ShouldReturn()
    .Redirect(result => result
        .To<AnotherController>(c => c.AnotherAction()));

// Instantiates controller with the provided service mocks,
// and tests for view result.
MyController<MyMvcController>
    .Instance(instance => instance
        .WithDependencies(
            serviceMock,
            anotherServiceMock,
            From.Services<IYetAnotherService>())) // Provides a global service.
    .Calling(c => c.MyAction())
    .ShouldReturn()
    .Accepted();
    
// Instantiates controller with the provided service mocks,
// and tests for view result.
MyController<MyMvcController>
    .Instance(instance => instance
        .WithDependencies(dependencies => dependencies
            .With<IService>(serviceMock)
            .WithNo<IAnotherService>())) // Provides null for IAnotherService.
    .Calling(c => c.MyAction(From.Services<IYetAnotherService>())) // Provides a global service.
    .ShouldReturn()
    .View();

// Tests a route for correct controller, action, and resolved route values.
MyRouting
    .Configuration()
    .ShouldMap("/My/Action/1")
    .To<MyController>(c => c.Action(1));

// Tests a route for correct controller, action, and resolved route values
// with post request and submitted form.
MyRouting
    .Configuration()
    .ShouldMap(request => request
        .WithMethod(HttpMethod.Post)
        .WithLocation("/My/Action")
        .WithFormFields(new
        {
            Title = title,
            Content = content
        }))
    .To<MyController>(c => c.Action(new MyFormModel
    {
        Title = title,
        Content = content
    }))
    .AndAlso()
    .ToValidModelState();

// Tests a route for correct controller, action, and resolved route values
// with post request and JSON body.
MyRouting
    .Configuration()
    .ShouldMap(request => request
        .WithLocation("/My/Action/1")
        .WithMethod(HttpMethod.Post)
        .WithJsonBody(new
        {
            Integer = 1,
            String = "Text"
        }))
    .To<MyController>(c => c.Action(1, new MyJsonModel
    {
        Integer = 1,
        String = "Text"
    }))
    .AndAlso()
    .ToValidModelState();

// Tests a route for correct route values, 
// and validates whether the controller action 
// with an authenticated user and the provided data
// returns redirect result to a specific action,
// while resolving services from the `TestStartup` class.
MyMvc
    .Pipeline()
    .ShouldMap(request => request
        .WithLocation("/My/Action/1")
        .WithMethod(HttpMethod.Post)
        .WithUser()
        .WithAntiForgeryToken()
        .WithJsonBody(new
        {
            Integer = 1,
            String = "Text"
        }))
    .To<MyController>(c => c.Action(1))
    .Which(controller => controller
        .WithData(MyDataProvider.GetMyModels()))
    .ShouldReturn()
    .Redirect(redirect => redirect
        .To<AnotherController>(c => c.AnotherAction()));

// Tests a route for correct route values, 
// and validates whether the controller action 
// with the provided data
// returns view result with a specific model,
// while resolving services from the provided mocks.
MyMvc
    .Pipeline()
    .ShouldMap("/My/Action/1")
    .To<MyController>(c => c.Action(1))
    .Which(controller => controller
        .WithData(MyDataProvider.GetMyModels())
        .WithDependencies(
            serviceMock,
            anotherServiceMock))
    .ShouldReturn()
    .View(result => result
        .WithModelOfType<MyResponseModel>());

// Tests for specific controller attributes - Area and Authorize.
MyController<MyMvcController>
    .ShouldHave()
    .Attributes(attributes => attributes
        .SpecifyingArea(ControllerConstants.AdministratorArea)
        .RestrictingForAuthorizedRequests(ControllerConstants.AdministratorRole));

// Tests for specific action attributes - HttpGet, AllowAnonymous, ValidateAntiForgeryToken, and ActionName.
MyController<MyMvcController>
    .Calling(c => c.MyAction(With.Empty<int>())) // Provides no value for the action parameter.
    .ShouldHave()
    .ActionAttributes(attributes => attributes
        .RestrictingForHttpMethod(HttpMethod.Get)
        .AllowingAnonymousRequests()
        .ValidatingAntiForgeryToken()
        .ChangingActionNameTo("AnotherAction"));

// View component integration test.
MyViewComponent<MyMvcController>
    .Instance(instance => instance
        .WithSession(session => session
            .WithEntry("MySession", "MySessionValue"))
        .WithData(data => data
            .WithEntities(entities => entities
                .AddRange(MyDataProvider.GetMyModels()))))
    .InvokedWith(c => c.InvokeAsync(1))
    .ShouldHave()
    .ViewBag(viewBag => viewBag
        .ContainingEntry("MyItems", 10)
        .ContainingEntry("MyViewBagName", "MyViewBagValue"))
    .AndAlso()
    .ShouldReturn()
    .View()
    .WithModelOfType<MyResponseModel>();
    
// View component unit test.
MyViewComponent<MyMvcController>
    .Instance(instance => instance
        .WithDependencies(
            serviceMock,
            anotherServiceMock,
            From.Services<IYetAnotherService>())) // Provides a global service.
    .InvokedWith(c => c.InvokeAsync(1))
    .ShouldReturn()
    .View();

// Without breaking the fluent API.

MyMvc

    // Arrange
    .Controller<MyMvcController>()
    .WithHttpRequest(request => request
        .WithFormField("MyFormField", "MyFormFieldValue"))
    .WithSession(session => session
        .WithEntry("MySession", sessionId))
    .WithUser()
    .WithRouteData() // Populates the controller route data.
    .WithData(data => data
        .WithEntities(entities => 
            AddData(sessionId, entities)))
            
    // Act
    .Calling(c => c.MyAction(
        From.Services<MyDataContext>(), // Action injected services can be populated with this call.
        new MyModel { Id = id },
        CancellationToken.None))
            
    // Assert
    .ShouldReturn()
    .Redirect(result => result
        .To<AnotherController>(c => c.AnotherAction(
            With.No<MyDataContext>(),
            id)));
            
// With variables.

// Arrange
var controller = MyController<MyMvcController>
    .Instance()
    .WithUser(username, new[] { role })
    .WithData(MyTestData.GetData());
    
// Act
var call = controller.Calling(c => c.MyAction(id));
    
// Assert
call
    .ShouldReturn()
    .Json(result => result
        .WithModelOfType<MyModel>()
        .Passing(model => model.Id == id));

// Tests whether model state error exists by using a lambda expression
// with specific tests for the error messages,
// and tests whether the action returns view with the same request model.
MyMvc
    .Controller<MyMvcController>()
    .Calling(c => c.MyAction(myRequestWithErrors))
    .ShouldHave()
    .ModelState(modelState => modelState
        .For<MyRequestModel>()
        .ContainingNoErrorFor(m => m.NonRequiredProperty)
        .AndAlso()
        .ContainingErrorFor(m => m.RequiredProperty)
        .ThatEquals("The RequiredProperty field is required."))
    .AndAlso()
    .ShouldReturn()
    .View(myRequestWithErrors);

// Tests whether the action throws an exception 
// of a particular type and with a particular error message.
MyMvc
    .Controller<MyMvcController>()
    .Calling(c => c.MyActionWithException())
    .ShouldThrow()
    .Exception()
    .OfType<MyException>()
    .AndAlso()
    .WithMessage()
    .ThatEquals("My exception message");

// Tests whether the action return OK result
// and writes to the response specific content type,
// custom header, and custom cookie.
MyMvc
    .Controller<MyMvcController>()
    .Calling(c => c.MyAction())
    .ShouldHave()
    .HttpResponse(response => response
        .WithContentType(ContentType.ApplicationJson)
        .ContainingHeader("MyHeader", "MyHeaderValue")
        .ContainingCookie(cookie => cookie
            .WithName("MyCookie")
            .WithValue("MyCookieValue")
            .WithSecurity(true)
            .WithHttpOnly(true)
            .WithDomain("mydomain.com")
            .WithExpiration(myDateTimeOffset)
            .WithPath("/")))
    .AndAlso()
    .ShouldReturn()
    .BadRequest();

using MyTested.AspNetCore.Mvc;