' 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.

Imports System.Collections.Immutable
Imports System.Threading
Imports Microsoft.CodeAnalysis.Completion.Providers
Imports Microsoft.CodeAnalysis.VisualBasic.Extensions.ContextQuery
Imports Microsoft.CodeAnalysis.VisualBasic.Utilities

Namespace Microsoft.CodeAnalysis.VisualBasic.Completion.KeywordRecommenders.Declarations
    ''' <summary>
    ''' Recommends the "Iterator" keyword in member declaration contexts
    ''' </summary>
    Friend Class IteratorKeywordRecommender
        Inherits AbstractKeywordRecommender

        Private Shared ReadOnly s_keywords As ImmutableArray(Of RecommendedKeyword) =
            ImmutableArray.Create(New RecommendedKeyword("Iterator", VBFeaturesResources.Indicates_an_iterator_method_that_can_use_the_Yield_statement))

        Protected Overrides Function RecommendKeywords(context As VisualBasicSyntaxContext, cancellationToken As CancellationToken) As ImmutableArray(Of RecommendedKeyword)
            If context.IsTypeMemberDeclarationKeywordContext Then
                Dim modifiers = context.ModifierCollectionFacts
                If modifiers.CouldApplyToOneOf(PossibleDeclarationTypes.IteratorFunction Or PossibleDeclarationTypes.IteratorProperty) AndAlso
                   modifiers.IteratorKeyword.Kind = SyntaxKind.None Then

                    Return s_keywords
                End If
            End If

            Return ImmutableArray(Of RecommendedKeyword).Empty
        End Function
    End Class
End Namespace