// 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.Collections.Generic;
using System.Composition;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Editing;
using Microsoft.CodeAnalysis.Host.Mef;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Shared.Utilities;
using Microsoft.CodeAnalysis.Snippets;
using Microsoft.CodeAnalysis.Snippets.SnippetProviders;
 
namespace Microsoft.CodeAnalysis.CSharp.Snippets;
 
[ExportSnippetProvider(nameof(ISnippetProvider), LanguageNames.CSharp), Shared]
[method: ImportingConstructor]
[method: Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
internal sealed class CSharpStructSnippetProvider() : AbstractCSharpTypeSnippetProvider<StructDeclarationSyntax>
{
    private static readonly ISet<SyntaxKind> s_validModifiers = new HashSet<SyntaxKind>(SyntaxFacts.EqualityComparer)
    {
        SyntaxKind.InternalKeyword,
        SyntaxKind.PublicKeyword,
        SyntaxKind.PrivateKeyword,
        SyntaxKind.ProtectedKeyword,
        SyntaxKind.UnsafeKeyword,
        SyntaxKind.RefKeyword,
        SyntaxKind.ReadOnlyKeyword,
        SyntaxKind.FileKeyword,
    };
 
    public override string Identifier => CSharpSnippetIdentifiers.Struct;
 
    public override string Description => FeaturesResources.struct_;
 
    protected override ISet<SyntaxKind> ValidModifiers => s_validModifiers;
 
    protected override async Task<StructDeclarationSyntax> GenerateTypeDeclarationAsync(Document document, int position, CancellationToken cancellationToken)
    {
        var generator = SyntaxGenerator.GetGenerator(document);
        var semanticModel = await document.GetRequiredSemanticModelAsync(cancellationToken).ConfigureAwait(false);
 
        var name = NameGenerator.GenerateUniqueName("MyStruct", name => semanticModel.LookupSymbols(position, name: name).IsEmpty);
        return (StructDeclarationSyntax)generator.StructDeclaration(name);
    }
}