// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Reflection;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.AspNetCore.Mvc.RazorPages;
 
namespace Microsoft.AspNetCore.Mvc.ApplicationModels;
 
public class ViewDataAttributePageApplicationModelProviderTest
{
    [Fact]
    public void OnProvidersExecuting_DoesNotAddFilter_IfTypeHasNoViewDataProperties()
    {
        // Arrange
        var type = typeof(TestPageModel_NoViewDataProperties);
        var provider = new ViewDataAttributePageApplicationModelProvider();
        var context = CreateProviderContext(type);
 
        // Act
        provider.OnProvidersExecuting(context);
 
        // Assert
        Assert.Empty(context.PageApplicationModel.Filters);
    }
 
    [Fact]
    public void AddsViewDataPropertyFilter_ForViewDataAttributeProperties()
    {
        // Arrange
        var type = typeof(TestPageModel_ViewDataProperties);
        var provider = new ViewDataAttributePageApplicationModelProvider();
        var context = CreateProviderContext(type);
 
        // Act
        provider.OnProvidersExecuting(context);
 
        // Assert
        var filter = Assert.Single(context.PageApplicationModel.Filters);
        var viewDataFilter = Assert.IsType<PageViewDataAttributeFilterFactory>(filter);
        Assert.Collection(
            viewDataFilter.Properties,
            property => Assert.Equal(nameof(TestPageModel_ViewDataProperties.DateTime), property.PropertyInfo.Name));
    }
 
    private static PageApplicationModelProviderContext CreateProviderContext(Type handlerType)
    {
        var descriptor = new CompiledPageActionDescriptor();
        var context = new PageApplicationModelProviderContext(descriptor, typeof(TestPage).GetTypeInfo())
        {
            PageApplicationModel = new PageApplicationModel(descriptor, handlerType.GetTypeInfo(), Array.Empty<object>()),
        };
 
        return context;
    }
 
    private class TestPage : Page
    {
        public object Model => null;
 
        public override Task ExecuteAsync() => null;
    }
 
    public class TestPageModel_NoViewDataProperties
    {
        public DateTime? DateTime { get; set; }
    }
 
    public class TestPageModel_ViewDataProperties
    {
        [ViewData]
        public DateTime? DateTime { get; set; }
    }
}