// 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.Collections.Generic;
using System.Linq;
using System.Threading;
using Microsoft.CodeAnalysis.CSharp.Extensions.ContextQuery;
using Microsoft.CodeAnalysis.CSharp.Utilities;
using Roslyn.Utilities;

namespace Microsoft.CodeAnalysis.CSharp.Completion.KeywordRecommenders;

internal sealed class ClosedKeywordRecommender() : AbstractSyntacticSingleKeywordRecommender(SyntaxKind.ClosedKeyword)
{
    private static readonly ISet<SyntaxKind> s_validModifiers = SyntaxKindSet.AllTypeModifiers
        .Where(s => s is not (SyntaxKind.ClosedKeyword or SyntaxKind.AbstractKeyword or SyntaxKind.SealedKeyword or SyntaxKind.StaticKeyword or SyntaxKind.ReadOnlyKeyword or SyntaxKind.RefKeyword))
        .ToSet();

    protected override bool IsValidContext(int position, CSharpSyntaxContext context, CancellationToken cancellationToken)
    {
        return context.IsGlobalStatementContext ||
            context.IsTypeDeclarationContext(
                validModifiers: s_validModifiers,
                validTypeDeclarations: SyntaxKindSet.ClassRecordTypeDeclarations,
                canBePartial: true,
                cancellationToken: cancellationToken) ||
            context.IsMemberDeclarationContext(
                validModifiers: s_validModifiers,
                validTypeDeclarations: SyntaxKindSet.ClassInterfaceStructRecordTypeDeclarations,
                canBePartial: true,
                cancellationToken: cancellationToken);
    }
}