' 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.Syntax
 
Namespace Microsoft.CodeAnalysis.VisualBasic.Completion.KeywordRecommenders.Queries
    ''' <summary>
    ''' Recommends the Equals keyword when in a join syntax.
    ''' </summary>
    Friend Class EqualsKeywordRecommender
        Inherits AbstractKeywordRecommender
 
        Private Shared ReadOnly s_keywords As ImmutableArray(Of RecommendedKeyword) =
            ImmutableArray.Create(New RecommendedKeyword("Equals", VBFeaturesResources.Specifies_the_relationship_between_element_keys_to_use_as_the_basis_of_a_join_operation))
 
        Protected Overrides Function RecommendKeywords(context As VisualBasicSyntaxContext, cancellationToken As CancellationToken) As ImmutableArray(Of RecommendedKeyword)
            Return If(context.SyntaxTree.IsFollowingCompleteExpression(Of JoinConditionSyntax)(context.Position, context.TargetToken, Function(joinCondition) joinCondition.Left, cancellationToken),
                s_keywords,
                ImmutableArray(Of RecommendedKeyword).Empty)
        End Function
    End Class
End Namespace