// 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.Configuration.Assemblies;
using System.Linq;
using System.Numerics;
using BasicTestApp;
using BasicTestApp.HierarchicalImportsTest.Subdir;
using Microsoft.AspNetCore.Blazor.E2ETest.Infrastructure;
using Microsoft.AspNetCore.Blazor.E2ETest.Infrastructure.ServerFixtures;
using OpenQA.Selenium;
using Xunit;

namespace Microsoft.AspNetCore.Blazor.E2ETest.Tests
{
    public class ComponentRenderingTest : BasicTestAppTestBase
    {
        public ComponentRenderingTest(BrowserFixture browserFixture, DevHostServerFixture<Program> serverFixture)
            : base(browserFixture, serverFixture)
        {
            Navigate(ServerPathBase, noReload: true);
        }

        [Fact]
        public void BasicTestAppCanBeServed()
        {
            Assert.Equal("Basic test app", Browser.Title);
        }

        [Fact]
        public void CanRenderTextOnlyComponent()
        {
            var appElement = MountTestComponent<TextOnlyComponent>();
            Assert.Equal("Hello from TextOnlyComponent", appElement.Text);
        }

        [Fact]
        public void CanRenderComponentWithAttributes()
        {
            var appElement = MountTestComponent<RedTextComponent>();
            var styledElement = appElement.FindElement(By.TagName("h1"));
            Assert.Equal("Hello, world!", styledElement.Text);
            Assert.Equal("color: red;", styledElement.GetAttribute("style"));
            Assert.Equal("somevalue", styledElement.GetAttribute("customattribute"));
        }

        [Fact]
        public void CanTriggerEvents()
        {
            // Initial count is zero
            var appElement = MountTestComponent<CounterComponent>();
            var countDisplayElement = appElement.FindElement(By.TagName("p"));
            Assert.Equal("Current count: 0", countDisplayElement.Text);

            // Clicking button increments count
            appElement.FindElement(By.TagName("button")).Click();
            Assert.Equal("Current count: 1", countDisplayElement.Text);
        }

        [Fact]
        public void CanTriggerKeyPressEvents()
        {
            // List is initially empty
            var appElement = MountTestComponent<KeyPressEventComponent>();
            var inputElement = appElement.FindElement(By.TagName("input"));
            Func<IEnumerable<IWebElement>> liElements =
                () => appElement.FindElements(By.TagName("li"));
            Assert.Empty(liElements());

            // Typing adds element
            inputElement.SendKeys("a");
            Assert.Collection(liElements(),
                li => Assert.Equal("a", li.Text));

            // Typing again adds another element
            inputElement.SendKeys("b");
            Assert.Collection(liElements(),
                li => Assert.Equal("a", li.Text),
                li => Assert.Equal("b", li.Text));
        }

        [Fact]
        public void CanRenderChildComponents()
        {
            var appElement = MountTestComponent<ParentChildComponent>();
            Assert.Equal("Parent component",
                appElement.FindElement(By.CssSelector("fieldset > legend")).Text);

            // TODO: Once we remove the wrapper elements from around child components,
            // assert that the child component text node is directly inside the <fieldset>
            var childComponentWrapper = appElement.FindElement(By.CssSelector("fieldset > blazor-component"));
            Assert.Single(childComponentWrapper.FindElements(By.CssSelector("*")));

            var styledElement = childComponentWrapper.FindElement(By.TagName("h1"));
            Assert.Equal("Hello, world!", styledElement.Text);
            Assert.Equal("color: red;", styledElement.GetAttribute("style"));
            Assert.Equal("somevalue", styledElement.GetAttribute("customattribute"));
        }

        [Fact]
        public void CanTriggerEventsOnChildComponents()
        {
            // Counter is displayed as child component. Initial count is zero.
            var childComponentWrapper = MountTestComponent<CounterComponentWrapper>()
                .FindElements(By.CssSelector("blazor-component")).Single();
            var counterDisplay = childComponentWrapper.FindElement(By.TagName("p"));
            Assert.Equal("Current count: 0", counterDisplay.Text);

            // Clicking increments count in child component
            childComponentWrapper.FindElement(By.TagName("button")).Click();
            Assert.Equal("Current count: 1", counterDisplay.Text);
        }

        [Fact]
        public void ChildComponentsRerenderWhenPropertiesChanged()
        {
            // Count value is displayed in child component with initial value zero
            var appElement = MountTestComponent<CounterComponentUsingChild>();
            var wholeCounterElement = appElement.FindElement(By.TagName("p"));
            var messageElementInChild = wholeCounterElement.FindElement(By.ClassName("message"));
            Assert.Equal("Current count: 0", wholeCounterElement.Text);
            Assert.Equal("0", messageElementInChild.Text);

            // Clicking increments count in child element
            appElement.FindElement(By.TagName("button")).Click();
            Assert.Equal("1", messageElementInChild.Text);
        }

        [Fact]
        public void CanAddAndRemoveChildComponentsDynamically()
        {
            // Initially there are zero child components
            var appElement = MountTestComponent<AddRemoveChildComponents>();
            var addButton = appElement.FindElement(By.ClassName("addChild"));
            var removeButton = appElement.FindElement(By.ClassName("removeChild"));
            Func<IEnumerable<IWebElement>> childComponentWrappers = () => appElement.FindElements(By.TagName("p"));
            Assert.Empty(childComponentWrappers());

            // Click to add some child components
            addButton.Click();
            addButton.Click();
            removeButton.Click();
            addButton.Click();
            Assert.Collection(childComponentWrappers(),
                elem => Assert.Equal("Child 1", elem.FindElement(By.ClassName("message")).Text),
                elem => Assert.Equal("Child 3", elem.FindElement(By.ClassName("message")).Text));
        }

        [Fact]
        public void ChildComponentsNotifiedWhenPropertiesChanged()
        {
            // Child component receives notification that lets it compute a property before first render
            var appElement = MountTestComponent<PropertiesChangedHandlerParent>();
            var suppliedValueElement = appElement.FindElement(By.ClassName("supplied"));
            var computedValueElement = appElement.FindElement(By.ClassName("computed"));
            var incrementButton = appElement.FindElement(By.TagName("button"));
            Assert.Equal("You supplied: 100", suppliedValueElement.Text);
            Assert.Equal("I computed: 200", computedValueElement.Text);

            // When property changes, child is renotified before rerender
            incrementButton.Click();
            Assert.Equal("You supplied: 101", suppliedValueElement.Text);
            Assert.Equal("I computed: 202", computedValueElement.Text);
        }

        [Fact]
        public void CanRenderFragmentsWhilePreservingSurroundingElements()
        {
            // Initially, the region isn't shown
            var appElement = MountTestComponent<RenderFragmentToggler>();
            var originalButton = appElement.FindElement(By.TagName("button"));
            var fragmentElements = appElement.FindElements(By.CssSelector("p[name=fragment-element]"));
            Assert.Empty(fragmentElements);

            // The JS-side DOM builder handles regions correctly, placing elements
            // after the region after the corresponding elements
            Assert.Equal("The end", appElement.FindElements(By.CssSelector("div > *:last-child")).Single().Text);

            // When we click the button, the region is shown
            originalButton.Click();
            fragmentElements = appElement.FindElements(By.CssSelector("p[name=fragment-element]"));
            Assert.Single(fragmentElements);

            // The button itself was preserved, so we can click it again and see the effect
            originalButton.Click();
            fragmentElements = appElement.FindElements(By.CssSelector("p[name=fragment-element]"));
            Assert.Empty(fragmentElements);
        }

        [Fact]
        public void CanUseViewImportsHierarchically()
        {
            // The component is able to compile and output these type names only because
            // of the _ViewImports.cshtml files at the same and ancestor levels
            var appElement = MountTestComponent<ComponentUsingImports>();
            Assert.Collection(appElement.FindElements(By.TagName("p")),
                elem => Assert.Equal(typeof(Complex).FullName, elem.Text),
                elem => Assert.Equal(typeof(AssemblyHashAlgorithm).FullName, elem.Text));
        }

        [Fact]
        public void CanUseComponentAndStaticContentFromExternalNuGetPackage()
        {
            var appElement = MountTestComponent<ExternalContentPackage>();

            // NuGet packages can use Blazor's JS interop features to provide
            // .NET code access to browser APIs
            var showPromptButton = appElement.FindElements(By.TagName("button")).First();
            showPromptButton.Click();
            var modal = Browser.SwitchTo().Alert();
            modal.SendKeys("Some value from test");
            modal.Accept();
            var promptResult = appElement.FindElement(By.TagName("strong"));
            Assert.Equal("Some value from test", promptResult.Text);

            // NuGet packages can also embed entire Blazor components (themselves
            // authored as Razor files), including static content. The CSS value
            // here is in a .css file, so if it's correct we know that static content
            // file was loaded.
            var specialStyleDiv = appElement.FindElement(By.ClassName("special-style"));
            Assert.Equal("50px", specialStyleDiv.GetCssValue("padding"));

            // The external Blazor components are fully functional, not just static HTML
            var externalComponentButton = specialStyleDiv.FindElement(By.TagName("button"));
            Assert.Equal("Click me", externalComponentButton.Text);
            externalComponentButton.Click();
            Assert.Equal("It works", externalComponentButton.Text);
        }

        [Fact]
        public void CanRenderSvgWithCorrectNamespace()
        {
            var appElement = MountTestComponent<SvgComponent>();
            
            var svgElement = appElement.FindElement(By.XPath("//*[local-name()='svg' and namespace-uri()='http://www.w3.org/2000/svg']"));
            Assert.NotNull(svgElement);

            var svgCircleElement = appElement.FindElement(By.XPath("//*[local-name()='circle' and namespace-uri()='http://www.w3.org/2000/svg']"));
            Assert.NotNull(svgCircleElement);
        }

        [Fact]
        public void CanRenderSvgChildComponentWithCorrectNamespace()
        {
            var appElement = MountTestComponent<SvgWithChildComponent>();
            
            var svgElement = appElement.FindElement(By.XPath("//*[local-name()='svg' and namespace-uri()='http://www.w3.org/2000/svg']"));
            Assert.NotNull(svgElement);

            var svgCircleElement = appElement.FindElement(By.XPath("//*[local-name()='circle' and namespace-uri()='http://www.w3.org/2000/svg']"));
            Assert.NotNull(svgCircleElement);
        }
    }
}