// 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.Diagnostics;
using System.Reflection;
using System.Text.Encodings.Web;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.Razor.Internal;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.Routing;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using Moq;
using Xunit;

namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure
{
    public class DefaultPageFactoryProviderTest
    {
        [Fact]
        public void CreatePage_ThrowsIfActivatedInstanceIsNotAnInstanceOfRazorPage()
        {
            // Arrange
            var descriptor = new CompiledPageActionDescriptor
            {
                PageTypeInfo = typeof(object).GetTypeInfo(),
            };

            var pageActivator = CreateActivator();
            var factoryProvider = CreatePageFactory();

            // Act & Assert
            var ex = Assert.Throws<InvalidOperationException>(() => factoryProvider.CreatePageFactory(descriptor));
            Assert.Equal(
                $"Page created by '{pageActivator.GetType()}' must be an instance of '{typeof(Page)}'.",
                ex.Message);
        }

        [Fact]
        public void PageFactorySetsPageContext()
        {
            // Arrange
            var descriptor = new CompiledPageActionDescriptor
            {
                PageTypeInfo = typeof(TestPage).GetTypeInfo(),
            };
            var pageContext = new PageContext
            {
                ActionDescriptor = descriptor
            };
            var viewContext = new ViewContext();
            var factoryProvider = CreatePageFactory();

            // Act
            var factory = factoryProvider.CreatePageFactory(descriptor);
            var instance = factory(pageContext, viewContext);

            // Assert
            var testPage = Assert.IsType<TestPage>(instance);
            Assert.Same(pageContext, testPage.PageContext);
        }

        [Fact]
        public void PageFactorySetsPropertiesWithRazorInject()
        {
            // Arrange
            var pageContext = new PageContext
            {
                ActionDescriptor = new CompiledPageActionDescriptor
                {
                    PageTypeInfo = typeof(TestPage).GetTypeInfo(),
                }
            };

            var viewContext = new ViewContext();

            var urlHelperFactory = new Mock<IUrlHelperFactory>();
            var urlHelper = Mock.Of<IUrlHelper>();
            urlHelperFactory
                .Setup(f => f.GetUrlHelper(viewContext))
                .Returns(urlHelper)
                .Verifiable();

            var htmlEncoder = HtmlEncoder.Create();

            var factoryProvider = CreatePageFactory(
                urlHelperFactory: urlHelperFactory.Object,
                htmlEncoder: htmlEncoder);

            // Act
            var factory = factoryProvider.CreatePageFactory(pageContext.ActionDescriptor);
            var instance = factory(pageContext, viewContext);

            // Assert
            var testPage = Assert.IsType<TestPage>(instance);
            Assert.Same(urlHelper, testPage.UrlHelper);
            Assert.Same(htmlEncoder, testPage.HtmlEncoder);
            Assert.NotNull(testPage.ViewData);
        }

        [Fact]
        public void PageFactorySetsPath()
        {
            // Arrange
            var descriptor = new CompiledPageActionDescriptor
            {
                PageTypeInfo = typeof(ViewDataTestPage).GetTypeInfo(),
                ModelTypeInfo = typeof(ViewDataTestPageModel).GetTypeInfo()
            };
            descriptor.RelativePath = "/this/is/a/path.cshtml";

            var pageContext = new PageContext
            {
                ActionDescriptor = descriptor
            };
            
            var viewContext = new ViewContext();

            // Act
            var factory = CreatePageFactory().CreatePageFactory(descriptor);
            var instance = factory(pageContext, viewContext);

            // Assert
            var testPage = Assert.IsType<ViewDataTestPage>(instance);
            Assert.Equal("/this/is/a/path.cshtml", testPage.Path);
        }

        [Fact]
        public void PageFactorySetViewDataWithModelTypeWhenNotNull()
        {
            // Arrange
            var pageContext = new PageContext
            {
                ActionDescriptor = new CompiledPageActionDescriptor
                {
                    PageTypeInfo = typeof(ViewDataTestPage).GetTypeInfo(),
                    ModelTypeInfo = typeof(ViewDataTestPageModel).GetTypeInfo(),
                },
            };

            var viewContext = new ViewContext();

            var factoryProvider = CreatePageFactory();

            // Act
            var factory = factoryProvider.CreatePageFactory(pageContext.ActionDescriptor);
            var instance = factory(pageContext, viewContext);

            // Assert
            var testPage = Assert.IsType<ViewDataTestPage>(instance);
            Assert.NotNull(testPage.ViewData);
        }

        [Fact]
        public void PageFactorySetsNonGenericViewDataDictionary()
        {
            // Arrange
            var pageContext = new PageContext
            {
                ActionDescriptor = new CompiledPageActionDescriptor
                {
                    PageTypeInfo = typeof(NonGenericViewDataTestPage).GetTypeInfo()
                },
            };

            var viewContext = new ViewContext();

            var factoryProvider = CreatePageFactory();

            // Act
            var factory = factoryProvider.CreatePageFactory(pageContext.ActionDescriptor);
            var instance = factory(pageContext, viewContext);

            // Assert
            var testPage = Assert.IsType<NonGenericViewDataTestPage>(instance);
            Assert.NotNull(testPage.ViewData);
        }

        [Fact]
        public void PageFactory_SetsViewDataOnPage_FromPageContext()
        {
            // Arrange
            var modelMetadataProvider = new EmptyModelMetadataProvider();
            var pageContext = new PageContext
            {
                ActionDescriptor = new CompiledPageActionDescriptor
                {
                    PageTypeInfo = typeof(TestPage).GetTypeInfo()
                },
                ViewData = new ViewDataDictionary<TestPage>(modelMetadataProvider, new ModelStateDictionary())
                {
                    { "test-key", "test-value" },
                }
            };

            var viewContext = new ViewContext()
            {
                HttpContext = pageContext.HttpContext,
                ViewData = pageContext.ViewData,
            };

            var factoryProvider = CreatePageFactory();

            // Act
            var factory = factoryProvider.CreatePageFactory(pageContext.ActionDescriptor);
            var instance = factory(pageContext, viewContext);

            // Assert
            var testPage = Assert.IsType<TestPage>(instance);
            Assert.NotNull(testPage.ViewData);
            Assert.Same(pageContext.ViewData, testPage.ViewData);
            Assert.Equal("test-value", testPage.ViewData["test-key"]);
        }

        [Fact]
        public void PageFactoryDoesNotBindPropertiesWithNoRazorInjectAttribute()
        {
            // Arrange
            var serviceProvider = new ServiceCollection()
                .AddSingleton<ILogger>(NullLogger.Instance)
                .BuildServiceProvider();

            var pageContext = new PageContext
            {
                ActionDescriptor = new CompiledPageActionDescriptor
                {
                    PageTypeInfo = typeof(PropertiesWithoutRazorInject).GetTypeInfo()
                },
                HttpContext = new DefaultHttpContext
                {
                    RequestServices = serviceProvider,
                },
            };

            var viewContext = new ViewContext()
            {
                HttpContext = pageContext.HttpContext,
            };

            var factoryProvider = CreatePageFactory();

            // Act
            var factory = factoryProvider.CreatePageFactory(pageContext.ActionDescriptor);
            var instance = factory(pageContext, viewContext);

            // Assert
            var testPage = Assert.IsType<PropertiesWithoutRazorInject>(instance);
            Assert.Null(testPage.DiagnosticSourceWithoutInject);
            Assert.NotNull(testPage.DiagnosticSourceWithInject);

            Assert.Null(testPage.LoggerWithoutInject);
            Assert.NotNull(testPage.LoggerWithInject);

            Assert.Null(testPage.ModelExpressionProviderWithoutInject);
            Assert.NotNull(testPage.ModelExpressionProviderWithInject);
        }

        private static DefaultPageFactoryProvider CreatePageFactory(
            IPageActivatorProvider pageActivator = null,
            IModelMetadataProvider provider = null,
            IUrlHelperFactory urlHelperFactory = null,
            IJsonHelper jsonHelper = null,
            DiagnosticSource diagnosticSource = null,
            HtmlEncoder htmlEncoder = null,
            IModelExpressionProvider modelExpressionProvider = null)
        {
            return new DefaultPageFactoryProvider(
                pageActivator ?? CreateActivator(),
                provider ?? Mock.Of<IModelMetadataProvider>(),
                urlHelperFactory ?? Mock.Of<IUrlHelperFactory>(),
                jsonHelper ?? Mock.Of<IJsonHelper>(),
                diagnosticSource ?? new DiagnosticListener("Microsoft.AspNetCore.Mvc.RazorPages"),
                htmlEncoder ?? HtmlEncoder.Default,
                modelExpressionProvider ?? Mock.Of<IModelExpressionProvider>());
        }

        private static IPageActivatorProvider CreateActivator()
        {
            var activator = new Mock<IPageActivatorProvider>();
            activator
                .Setup(a => a.CreateActivator(It.IsAny<CompiledPageActionDescriptor>()))
                .Returns((CompiledPageActionDescriptor descriptor) =>
                {
                    return (context, viewContext) => Activator.CreateInstance(descriptor.PageTypeInfo.AsType());
                });
            return activator.Object;
        }

        private class TestPage : Page
        {
            [RazorInject]
            public IUrlHelper UrlHelper { get; set; }

            [RazorInject]
            public new HtmlEncoder HtmlEncoder { get; set; }

            [RazorInject]
            public ViewDataDictionary<TestPage> ViewData { get; set; }

            public override Task ExecuteAsync()
            {
                throw new NotImplementedException();
            }
        }

        private class NonGenericViewDataTestPage : Page
        {
            [RazorInject]
            public ViewDataDictionary ViewData { get; set; }

            public override Task ExecuteAsync()
            {
                throw new NotImplementedException();
            }
        }

        private class ViewDataTestPage : Page
        {
            [RazorInject]
            public ViewDataDictionary<ViewDataTestPageModel> ViewData { get; set; }

            public override Task ExecuteAsync()
            {
                throw new NotImplementedException();
            }
        }

        private class ViewDataTestPageModel
        {
        }

        private class PropertiesWithoutRazorInject : Page
        {
            public IModelExpressionProvider ModelExpressionProviderWithoutInject { get; set; }

            [RazorInject]
            public IModelExpressionProvider ModelExpressionProviderWithInject { get; set; }

            public DiagnosticSource DiagnosticSourceWithoutInject { get; set; }

            [RazorInject]
            public DiagnosticSource DiagnosticSourceWithInject { get; set; }

            public ILogger LoggerWithoutInject { get; set; }

            [RazorInject]
            public ILogger LoggerWithInject { get; set; }

            public override Task ExecuteAsync()
            {
                throw new NotImplementedException();
            }
        }
    }
}
