// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

#nullable disable

using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Razor.Language;
using Microsoft.AspNetCore.Razor.Language.Components;
using Xunit;

namespace Microsoft.CodeAnalysis.Razor;

public class EventHandlerTagHelperDescriptorProviderTest : TagHelperDescriptorProviderTestBase
{
    [Fact]
    public void Execute_EventHandler_CreatesDescriptor()
    {
        // Arrange
        var compilation = BaseCompilation.AddSyntaxTrees(Parse(@"
using System;
using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Web;

namespace Test
{
    [EventHandler(""onclick"", typeof(Action<MouseEventArgs>))]
    public class EventHandlers
    {
    }
}
"));

        Assert.Empty(compilation.GetDiagnostics());

        var context = TagHelperDescriptorProviderContext.Create();
        context.SetCompilation(compilation);

        var provider = new EventHandlerTagHelperDescriptorProvider();

        // Act
        provider.Execute(context);

        // Assert
        var matches = GetEventHandlerTagHelpers(context);
        var item = Assert.Single(matches);

        // These are features Event Handler Tag Helpers don't use. Verifying them once here and
        // then ignoring them.
        Assert.Empty(item.AllowedChildTags);
        Assert.Null(item.TagOutputHint);

        // These are features that are invariants of all Event Handler Helpers. Verifying them once
        // here and then ignoring them.
        Assert.Empty(item.Diagnostics);
        Assert.False(item.HasErrors);
        Assert.Equal(ComponentMetadata.EventHandler.TagHelperKind, item.Kind);
        Assert.Equal(bool.TrueString, item.Metadata[TagHelperMetadata.Common.ClassifyAttributesOnly]);
        Assert.Equal(ComponentMetadata.EventHandler.RuntimeName, item.Metadata[TagHelperMetadata.Runtime.Name]);
        Assert.False(item.IsDefaultKind());
        Assert.False(item.KindUsesDefaultTagHelperRuntime());
        Assert.False(item.IsComponentOrChildContentTagHelper());
        Assert.True(item.CaseSensitive);

        Assert.Equal(
            "Sets the '@onclick' attribute to the provided string or delegate value. " +
            "A delegate value should be of type 'System.Action<Microsoft.AspNetCore.Components.Web.MouseEventArgs>'.",
            item.Documentation);

        // These are all trivially derived from the assembly/namespace/type name
        Assert.Equal("Microsoft.AspNetCore.Components", item.AssemblyName);
        Assert.Equal("onclick", item.Name);
        Assert.Equal("Test.EventHandlers", item.DisplayName);
        Assert.Equal("Test.EventHandlers", item.GetTypeName());

        // The tag matching rule for an event handler is just the attribute name
        var rule = Assert.Single(item.TagMatchingRules);
        Assert.Empty(rule.Diagnostics);
        Assert.False(rule.HasErrors);
        Assert.Null(rule.ParentTag);
        Assert.Equal("*", rule.TagName);
        Assert.Equal(TagStructure.Unspecified, rule.TagStructure);

        var requiredAttribute = Assert.Single(rule.Attributes);
        Assert.Empty(requiredAttribute.Diagnostics);
        Assert.Equal("@onclick", requiredAttribute.DisplayName);
        Assert.Equal("@onclick", requiredAttribute.Name);
        Assert.Equal(RequiredAttributeDescriptor.NameComparisonMode.FullMatch, requiredAttribute.NameComparison);
        Assert.Null(requiredAttribute.Value);
        Assert.Equal(RequiredAttributeDescriptor.ValueComparisonMode.None, requiredAttribute.ValueComparison);

        var attribute = Assert.Single(item.BoundAttributes);

        // Invariants
        Assert.Empty(attribute.Diagnostics);
        Assert.False(attribute.HasErrors);
        Assert.Equal(ComponentMetadata.EventHandler.TagHelperKind, attribute.Kind);
        Assert.False(attribute.IsDefaultKind());
        Assert.False(attribute.HasIndexer);
        Assert.Null(attribute.IndexerNamePrefix);
        Assert.Null(attribute.IndexerTypeName);
        Assert.False(attribute.IsIndexerBooleanProperty);
        Assert.False(attribute.IsIndexerStringProperty);

        Assert.Collection(
            attribute.Metadata.OrderBy(kvp => kvp.Key),
            kvp => Assert.Equal(kvp, new KeyValuePair<string, string>(ComponentMetadata.Common.DirectiveAttribute, bool.TrueString)),
            kvp => Assert.Equal(kvp, new KeyValuePair<string, string>("Common.PropertyName", "onclick")),
            kvp => Assert.Equal(kvp, new KeyValuePair<string, string>(ComponentMetadata.Component.WeaklyTypedKey, bool.TrueString)));

        Assert.Equal(
            "Sets the '@onclick' attribute to the provided string or delegate value. " +
            "A delegate value should be of type 'System.Action<Microsoft.AspNetCore.Components.Web.MouseEventArgs>'.",
            attribute.Documentation);

        Assert.Equal("@onclick", attribute.Name);
        Assert.Equal("onclick", attribute.GetPropertyName());
        Assert.Equal("Microsoft.AspNetCore.Components.EventCallback<System.Action<Microsoft.AspNetCore.Components.Web.MouseEventArgs>> Test.EventHandlers.onclick", attribute.DisplayName);

        // Defined from the property type
        Assert.Equal("Microsoft.AspNetCore.Components.EventCallback<System.Action<Microsoft.AspNetCore.Components.Web.MouseEventArgs>>", attribute.TypeName);
        Assert.False(attribute.IsStringProperty);
        Assert.False(attribute.IsBooleanProperty);
        Assert.False(attribute.IsEnum);
    }

    private static TagHelperDescriptor[] GetEventHandlerTagHelpers(TagHelperDescriptorProviderContext context)
    {
        return ExcludeBuiltInComponents(context).Where(t => t.IsEventHandlerTagHelper()).ToArray();
    }
}
