// 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.Threading;
using Microsoft.CodeAnalysis.CSharp.Extensions.ContextQuery;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Shared.Extensions;
 
namespace Microsoft.CodeAnalysis.CSharp.Completion.KeywordRecommenders
{
    internal class AssemblyKeywordRecommender : AbstractSyntacticSingleKeywordRecommender
    {
        public AssemblyKeywordRecommender()
            : base(SyntaxKind.AssemblyKeyword)
        {
        }
 
        protected override bool IsValidContext(int position, CSharpSyntaxContext context, CancellationToken cancellationToken)
        {
            var token = context.TargetToken;
 
            if (token.Kind() == SyntaxKind.OpenBracketToken &&
                token.GetRequiredParent().Kind() == SyntaxKind.AttributeList)
            {
                var attributeList = token.GetRequiredParent();
                var parentSyntax = attributeList.Parent;
                switch (parentSyntax)
                {
                    case CompilationUnitSyntax:
                    case BaseNamespaceDeclarationSyntax:
                    // The case where the parent of attributeList is (Class/Interface/Enum/Struct)DeclarationSyntax, like:
                    // [$$
                    // class Goo {
                    // for these cases is necessary check if they Parent is CompilationUnitSyntax
                    case BaseTypeDeclarationSyntax baseType when baseType.Parent is CompilationUnitSyntax:
                    // The case where the parent of attributeList is IncompleteMemberSyntax(See test: ), like:
                    // [$$
                    // for that case is necessary check if they Parent is CompilationUnitSyntax
                    case IncompleteMemberSyntax incompleteMember when incompleteMember.Parent is CompilationUnitSyntax:
                        return true;
                }
            }
 
            return false;
        }
    }
}