// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
#nullable disable
 
using System;
using System.Collections.Immutable;
using System.Composition;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CodeActions;
using Microsoft.CodeAnalysis.CodeFixes;
using Microsoft.CodeAnalysis.Editor.Xaml.Diagnostics;
using Microsoft.CodeAnalysis.Host.Mef;
using Microsoft.CodeAnalysis.RemoveUnnecessaryImports;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.VisualStudio.LanguageServices.Xaml;
 
namespace Microsoft.CodeAnalysis.Editor.Xaml.CodeFixes.RemoveUnusedUsings;
 
[ExportCodeFixProvider(StringConstants.XamlLanguageName, Name = PredefinedCodeFixProviderNames.RemoveUnnecessaryImports), Shared]
[ExtensionOrder(After = PredefinedCodeFixProviderNames.AddMissingReference)]
internal sealed class RemoveUnnecessaryUsingsCodeFixProvider : CodeFixProvider
{
    [ImportingConstructor]
    [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
    public RemoveUnnecessaryUsingsCodeFixProvider()
    {
    }
 
    public sealed override ImmutableArray<string> FixableDiagnosticIds
    {
        get { return [XamlDiagnosticIds.UnnecessaryNamespacesId]; }
    }
 
    public override FixAllProvider GetFixAllProvider()
    {
        // Fix All is not supported by this code fix, because the action already applies to one document at a time
        return null;
    }
 
    public sealed override Task RegisterCodeFixesAsync(CodeFixContext context)
    {
        context.RegisterCodeFix(
            CodeAction.Create(
                Resources.RemoveUnnecessaryNamespaces,
                c => RemoveUnnecessaryImportsAsync(context.Document, c),
                nameof(Resources.RemoveUnnecessaryNamespaces)),
            context.Diagnostics);
        return Task.CompletedTask;
    }
 
    private static async Task<Document> RemoveUnnecessaryImportsAsync(
        Document document, CancellationToken cancellationToken)
    {
        var service = document.GetLanguageService<IRemoveUnnecessaryImportsService>();
        return await service.RemoveUnnecessaryImportsAsync(document, cancellationToken).ConfigureAwait(false);
    }
}