// 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.

using System;
using System.Composition;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CodeCleanup;
using Microsoft.CodeAnalysis.CSharp.ConvertProgram;
using Microsoft.CodeAnalysis.Formatting;
using Microsoft.CodeAnalysis.Host.Mef;

namespace Microsoft.CodeAnalysis.CSharp.Formatting;

[ExportNewDocumentFormattingProvider(LanguageNames.CSharp), Shared]
internal sealed class CSharpUseProgramMainNewDocumentFormattingProvider : INewDocumentFormattingProvider
{
    [ImportingConstructor]
    [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
    public CSharpUseProgramMainNewDocumentFormattingProvider()
    {
    }

    public async Task<Document> FormatNewDocumentAsync(Document document, Document? hintDocument, CodeCleanupOptions options, CancellationToken cancellationToken)
    {
        // if the user prefers Program.Main style instead, then attempt to convert a template with
        // top-level-statements to that form.
        var option = ((CSharpSyntaxFormattingOptions)options.FormattingOptions).PreferTopLevelStatements;
        if (option.Value)
            return document;

        return await ConvertProgramTransform.ConvertToProgramMainAsync(document, options.FormattingOptions.AccessibilityModifiersRequired, cancellationToken).ConfigureAwait(false);
    }
}