// 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.Diagnostics;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Abstractions;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.AspNetCore.Mvc.ViewComponents;
using Microsoft.AspNetCore.Mvc.ViewEngines;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.WebEncoders.Testing;
using Moq;
using Xunit;

namespace Microsoft.AspNetCore.Mvc
{
    public class ViewViewComponentResultTest
    {
        private readonly ITempDataDictionary _tempDataDictionary =
            new TempDataDictionary(new DefaultHttpContext(), new SessionStateTempDataProvider());

        [Fact]
        public void Execute_RendersPartialViews()
        {
            // Arrange
            var view = new Mock<IView>();
            view.Setup(v => v.RenderAsync(It.IsAny<ViewContext>()))
                .Returns(Task.FromResult(result: true))
                .Verifiable();

            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("some-view", Enumerable.Empty<string>()))
                .Verifiable();
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.Found("Components/Invoke/some-view", view.Object))
                .Verifiable();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewName = "some-view",
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view.Object, viewData);

            // Act
            result.Execute(viewComponentContext);

            // Assert
            viewEngine.Verify();
            view.Verify();
        }

        [Fact]
        public void Execute_ResolvesView_WithDefaultAsViewName()
        {
            // Arrange
            var view = new Mock<IView>(MockBehavior.Strict);
            view.Setup(v => v.RenderAsync(It.IsAny<ViewContext>()))
                .Returns(Task.FromResult(result: true))
                .Verifiable();

            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/Default", /*isMainPage*/ false))
                .Returns(ViewEngineResult.Found("Components/Invoke/Default", view.Object))
                .Verifiable();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view.Object, viewData);

            // Act
            result.Execute(viewComponentContext);

            // Assert
            viewEngine.Verify();
            view.Verify();
        }

        [Fact]
        public void Execute_ResolvesView_AndWritesDiagnosticSource()
        {
            // Arrange
            var view = new Mock<IView>(MockBehavior.Strict);
            view.Setup(v => v.RenderAsync(It.IsAny<ViewContext>()))
                .Returns(Task.FromResult(result: true))
                .Verifiable();

            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/Default", /*isMainPage*/ false))
                .Returns(ViewEngineResult.Found("Components/Invoke/Default", view.Object))
                .Verifiable();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var adapter = new TestDiagnosticListener();

            var viewComponentContext = GetViewComponentContext(view.Object, viewData, adapter);

            // Act
            result.Execute(viewComponentContext);

            // Assert
            viewEngine.Verify();
            view.Verify();

            Assert.NotNull(adapter.ViewComponentBeforeViewExecute?.ActionDescriptor);
            Assert.NotNull(adapter.ViewComponentBeforeViewExecute?.ViewComponentContext);
            Assert.NotNull(adapter.ViewComponentBeforeViewExecute?.View);
            Assert.NotNull(adapter.ViewComponentAfterViewExecute?.ActionDescriptor);
            Assert.NotNull(adapter.ViewComponentAfterViewExecute?.ViewComponentContext);
            Assert.NotNull(adapter.ViewComponentAfterViewExecute?.View);
        }

        [Fact]
        public void Execute_ThrowsIfPartialViewCannotBeFound_MessageUsesGetViewLocations()
        {
            // Arrange
            var expected = string.Join(Environment.NewLine,
                "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
                "location1",
                "location2");

            var view = Mock.Of<IView>();

            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("some-view", new[] { "location1", "location2" }))
                .Verifiable();
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("Components/Invoke/some-view", Enumerable.Empty<string>()))
                .Verifiable();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewName = "some-view",
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view, viewData);

            // Act and Assert
            var ex = Assert.Throws<InvalidOperationException>(() => result.Execute(viewComponentContext));
            Assert.Equal(expected, ex.Message);
        }

        [Fact]
        public void Execute_ThrowsIfPartialViewCannotBeFound_MessageUsesFindViewLocations()
        {
            // Arrange
            var expected = string.Join(Environment.NewLine,
                "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
                "location1",
                "location2");

            var view = Mock.Of<IView>();

            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("some-view", Enumerable.Empty<string>()))
                .Verifiable();
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("Components/Invoke/some-view", new[] { "location1", "location2" }))
                .Verifiable();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewName = "some-view",
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view, viewData);

            // Act and Assert
            var ex = Assert.Throws<InvalidOperationException>(() => result.Execute(viewComponentContext));
            Assert.Equal(expected, ex.Message);
        }

        [Fact]
        public void Execute_ThrowsIfPartialViewCannotBeFound_MessageUsesAllLocations()
        {
            // Arrange
            var expected = string.Join(Environment.NewLine,
                "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
                "location1",
                "location2",
                "location3",
                "location4");

            var view = Mock.Of<IView>();

            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("some-view", new[] { "location1", "location2" }))
                .Verifiable();
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("Components/Invoke/some-view", new[] { "location3", "location4" }))
                .Verifiable();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewName = "some-view",
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view, viewData);

            // Act and Assert
            var ex = Assert.Throws<InvalidOperationException>(() => result.Execute(viewComponentContext));
            Assert.Equal(expected, ex.Message);
        }

        [Fact]
        public void Execute_DoesNotWrapThrownExceptionsInAggregateExceptions()
        {
            // Arrange
            var expected = new IndexOutOfRangeException();

            var view = new Mock<IView>();
            view.Setup(v => v.RenderAsync(It.IsAny<ViewContext>()))
                .Throws(expected)
                .Verifiable();

            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("some-view", Enumerable.Empty<string>()))
                .Verifiable();
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.Found("Components/Invoke/some-view", view.Object))
                .Verifiable();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewName = "some-view",
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view.Object, viewData);

            // Act
            var actual = Record.Exception(() => result.Execute(viewComponentContext));

            // Assert
            Assert.Same(expected, actual);
            view.Verify();
        }

        [Fact]
        public async Task ExecuteAsync_RendersPartialViews()
        {
            // Arrange
            var view = Mock.Of<IView>();

            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("some-view", Enumerable.Empty<string>()))
                .Verifiable();
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.Found("Components/Invoke/some-view", view))
                .Verifiable();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewName = "some-view",
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view, viewData);

            // Act
            await result.ExecuteAsync(viewComponentContext);

            // Assert
            viewEngine.Verify();
        }

        [Fact]
        public async Task ExecuteAsync_ResolvesViewEngineFromServiceProvider_IfNoViewEngineIsExplicitlyProvided()
        {
            // Arrange
            var view = Mock.Of<IView>();

            var viewEngine = new Mock<ICompositeViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("some-view", Enumerable.Empty<string>()))
                .Verifiable();
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.Found("Components/Invoke/some-view", view))
                .Verifiable();

            var serviceProvider = new Mock<IServiceProvider>();
            serviceProvider.Setup(p => p.GetService(typeof(ICompositeViewEngine)))
                .Returns(viewEngine.Object);
            serviceProvider.Setup(p => p.GetService(typeof(DiagnosticSource)))
                .Returns(new DiagnosticListener("Test"));

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewName = "some-view",
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view, viewData);
            viewComponentContext.ViewContext.HttpContext.RequestServices = serviceProvider.Object;

            // Act
            await result.ExecuteAsync(viewComponentContext);

            // Assert
            viewEngine.Verify();
            serviceProvider.Verify();
        }

        [Fact]
        public async Task ExecuteAsync_ThrowsIfPartialViewCannotBeFound()
        {
            // Arrange
            var expected = string.Join(Environment.NewLine,
                "The view 'Components/Invoke/some-view' was not found. The following locations were searched:",
                "view-location1",
                "view-location2",
                "view-location3",
                "view-location4");

            var view = Mock.Of<IView>();

            var viewEngine = new Mock<IViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.GetView(/*executingFilePath*/ null, "some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound("some-view", new[] { "view-location1", "view-location2" }))
                .Verifiable();
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), "Components/Invoke/some-view", /*isMainPage*/ false))
                .Returns(ViewEngineResult.NotFound(
                    "Components/Invoke/some-view",
                    new[] { "view-location3", "view-location4" }))
                .Verifiable();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewName = "some-view",
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view, viewData);

            // Act and Assert
            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
                        () => result.ExecuteAsync(viewComponentContext));
            Assert.Equal(expected, ex.Message);
        }

        [Fact]
        public async Task ExecuteAsync_Throws_IfNoViewEngineCanBeResolved()
        {
            // Arrange
            var expected = $"No service for type '{typeof(ICompositeViewEngine).FullName}'" +
                " has been registered.";

            var view = Mock.Of<IView>();

            var serviceProvider = new ServiceCollection().BuildServiceProvider();

            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());

            var result = new ViewViewComponentResult
            {
                ViewName = "some-view",
                ViewData = viewData,
                TempData = _tempDataDictionary,
            };

            var viewComponentContext = GetViewComponentContext(view, viewData);
            viewComponentContext.ViewContext.HttpContext.RequestServices = serviceProvider;

            // Act and Assert
            var ex = await Assert.ThrowsAsync<InvalidOperationException>(
                        () => result.ExecuteAsync(viewComponentContext));
            Assert.Equal(expected, ex.Message);
        }

        [Theory]
        [InlineData(null)]
        [InlineData("")]
        public void Execute_CallsFindView_WithExpectedPath_WhenViewNameIsNullOrEmpty(string viewName)
        {
            // Arrange
            var shortName = "SomeShortName";
            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
            var componentContext = GetViewComponentContext(new Mock<IView>().Object, viewData);
            componentContext.ViewComponentDescriptor.ShortName = shortName;
            var expectedViewName = $"Components/{shortName}/Default";
            var viewEngine = new Mock<ICompositeViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.FindView(It.IsAny<ActionContext>(), expectedViewName, /*isMainPage*/ false))
                .Returns(ViewEngineResult.Found(expectedViewName, new Mock<IView>().Object))
                .Verifiable();

            var componentResult = new ViewViewComponentResult();
            componentResult.ViewEngine = viewEngine.Object;
            componentResult.ViewData = viewData;
            componentResult.ViewName = viewName;
            componentResult.TempData = _tempDataDictionary;

            // Act & Assert
            componentResult.Execute(componentContext);
            viewEngine.Verify();
        }

        [Theory]
        [InlineData("~/Home/Index/MyViewComponent1.cshtml")]
        [InlineData("~MyViewComponent2.cshtml")]
        [InlineData("/MyViewComponent3.cshtml")]
        public void Execute_CallsFindView_WithExpectedPath_WhenViewNameIsSpecified(string viewName)
        {
            // Arrange
            var viewEngine = new Mock<ICompositeViewEngine>(MockBehavior.Strict);
            viewEngine
                .Setup(v => v.GetView(/*executingFilePath*/ null, viewName, /*isMainPage*/ false))
                .Returns(ViewEngineResult.Found(viewName, new Mock<IView>().Object))
                .Verifiable();
            var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider());
            var componentContext = GetViewComponentContext(new Mock<IView>().Object, viewData);
            var componentResult = new ViewViewComponentResult
            {
                ViewEngine = viewEngine.Object,
                ViewData = viewData,
                ViewName = viewName,
                TempData = _tempDataDictionary,
            };

            // Act & Assert
            componentResult.Execute(componentContext);
            viewEngine.Verify();
        }

        private static ViewComponentContext GetViewComponentContext(
            IView view,
            ViewDataDictionary viewData,
            object diagnosticListener = null)
        {
            var diagnosticSource = new DiagnosticListener("Microsoft.AspNetCore");
            if (diagnosticListener == null)
            {
                diagnosticListener = new TestDiagnosticListener();
            }

            diagnosticSource.SubscribeWithAdapter(diagnosticListener);

            var serviceProvider = new Mock<IServiceProvider>();
            serviceProvider.Setup(s => s.GetService(typeof(DiagnosticSource))).Returns(diagnosticSource);

            var httpContext = new DefaultHttpContext();
            httpContext.RequestServices = serviceProvider.Object;

            var actionContext = new ActionContext(httpContext, new RouteData(), new ActionDescriptor());
            var viewContext = new ViewContext(
                actionContext,
                view,
                viewData,
                new TempDataDictionary(httpContext, new SessionStateTempDataProvider()),
                TextWriter.Null,
                new HtmlHelperOptions());

            var viewComponentDescriptor = new ViewComponentDescriptor()
            {
                ShortName = "Invoke",
                TypeInfo = typeof(object).GetTypeInfo(),
                MethodInfo = typeof(object).GetTypeInfo().DeclaredMethods.First()
            };

            var viewComponentContext = new ViewComponentContext(
                viewComponentDescriptor,
                new Dictionary<string, object>(),
                new HtmlTestEncoder(),
                viewContext,
                TextWriter.Null);

            return viewComponentContext;
        }
    }
}