// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Abstractions;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Mvc.ViewFeatures.Filters;
using Microsoft.AspNetCore.Routing;
using Xunit;

namespace Microsoft.AspNetCore.Mvc.Filters
{
    public class PageViewDataAttributeFilterTest
    {
        [Fact]
        public void OnPageHandlerExecuting_AddsFeature()
        {
            // Arrange
            var filter = new PageViewDataAttributeFilter(Array.Empty<LifecycleProperty>());
            var handler = new object();
            var httpContext = new DefaultHttpContext();
            var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
            var pageContext = new PageContext(actionContext);
            var context = new PageHandlerExecutingContext(pageContext, new IFilterMetadata[0], new HandlerMethodDescriptor(), new Dictionary<string, object>(), handler);

            // Act
            filter.OnPageHandlerExecuting(context);

            // Assert
            var feature = Assert.Single(httpContext.Features, f => f.Key == typeof(IViewDataValuesProviderFeature));
            Assert.Same(filter, feature.Value);
        }

        [Fact]
        public void OnPageHandlerExecuting_SetsSubject()
        {
            // Arrange
            var filter = new PageViewDataAttributeFilter(Array.Empty<LifecycleProperty>());
            var handler = new object();
            var httpContext = new DefaultHttpContext();
            var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
            var pageContext = new PageContext(actionContext);
            var context = new PageHandlerExecutingContext(pageContext, new IFilterMetadata[0], new HandlerMethodDescriptor(), new Dictionary<string, object>(), handler);

            // Act
            filter.OnPageHandlerExecuting(context);

            // Assert
            Assert.Same(handler, filter.Subject);
        }

        [Fact]
        public void ProvideValues_AddsNonNullPropertyValuesToViewData()
        {
            // Arrange
            var type = typeof(TestModel);
            var properties = new[]
            {
                new LifecycleProperty(type.GetProperty(nameof(TestModel.Prop1)), "Prop1"),
                new LifecycleProperty(type.GetProperty(nameof(TestModel.Prop2)), "Prop2"),
                new LifecycleProperty(type.GetProperty(nameof(TestModel.Prop3)), "Prop3"),
            };

            var controller = new TestModel();
            var filter = new PageViewDataAttributeFilter(properties)
            {
                Subject = controller,
            };
            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider(), new ModelStateDictionary());

            // Act
            controller.Prop1 = "New-Value";
            filter.ProvideViewDataValues(viewData);

            // Assert
            Assert.Collection(
                viewData.OrderBy(kvp => kvp.Key),
                kvp =>
                {
                    Assert.Equal("Prop1", kvp.Key);
                    Assert.Equal("New-Value", kvp.Value);
                },
                kvp =>
                {
                    Assert.Equal("Prop2", kvp.Key);
                    Assert.Equal("Test", kvp.Value);
                });
        }

        public class TestModel
        {
            public string Prop1 { get; set; }

            public string Prop2 => "Test";

            public string Prop3 { get; set; }
        }
    }
}
