' 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.Globalization
Imports System.Threading
Imports Microsoft.CodeAnalysis.PooledObjects
Imports Microsoft.CodeAnalysis.Text
Imports Microsoft.CodeAnalysis.VisualBasic.Emit
Imports Microsoft.CodeAnalysis.VisualBasic.Symbols
Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols.Retargeting
    Friend NotInheritable Class RetargetingEventSymbol
        Inherits EventSymbol

        ''' <summary>
        ''' Owning RetargetingModuleSymbol.
        ''' </summary>
        Private ReadOnly _retargetingModule As RetargetingModuleSymbol

        ''' <summary>
        ''' The underlying EventSymbol, cannot be another RetargetingEventSymbol.
        ''' </summary>
        Private ReadOnly _underlyingEvent As EventSymbol

        ''' <summary>
        ''' Retargeted custom attributes
        ''' </summary>
        ''' <remarks></remarks>
        Private _lazyCustomAttributes As ImmutableArray(Of VisualBasicAttributeData)

        Private _lazyExplicitInterfaceImplementations As ImmutableArray(Of EventSymbol)

        Private _lazyCachedUseSiteInfo As CachedUseSiteInfo(Of AssemblySymbol) = CachedUseSiteInfo(Of AssemblySymbol).Uninitialized ' Indicates unknown state. 

        Public Sub New(retargetingModule As RetargetingModuleSymbol, underlyingEvent As EventSymbol)
            Debug.Assert(retargetingModule IsNot Nothing)
            Debug.Assert(underlyingEvent IsNot Nothing)

            If TypeOf underlyingEvent Is RetargetingEventSymbol Then
                Throw New ArgumentException()
            End If

            _retargetingModule = retargetingModule
            _underlyingEvent = underlyingEvent
        End Sub

        Private ReadOnly Property RetargetingTranslator As RetargetingModuleSymbol.RetargetingSymbolTranslator
            Get
                Return _retargetingModule.RetargetingTranslator
            End Get
        End Property

        Public ReadOnly Property UnderlyingEvent As EventSymbol
            Get
                Return _underlyingEvent
            End Get
        End Property

        Public ReadOnly Property RetargetingModule As RetargetingModuleSymbol
            Get
                Return _retargetingModule
            End Get
        End Property

        Public Overrides ReadOnly Property ContainingSymbol As Symbol
            Get
                Return RetargetingTranslator.Retarget(_underlyingEvent.ContainingSymbol)
            End Get
        End Property

        Public Overrides ReadOnly Property DeclaredAccessibility As Accessibility
            Get
                Return _underlyingEvent.DeclaredAccessibility
            End Get
        End Property

        Public Overrides Function GetAttributes() As ImmutableArray(Of VisualBasicAttributeData)
            Return RetargetingTranslator.GetRetargetedAttributes(_underlyingEvent, _lazyCustomAttributes)
        End Function

        Friend Overrides Function GetCustomAttributesToEmit(moduleBuilder As PEModuleBuilder) As IEnumerable(Of VisualBasicAttributeData)
            Return RetargetingTranslator.RetargetAttributes(_underlyingEvent.GetCustomAttributesToEmit(moduleBuilder))
        End Function

        Public Overrides ReadOnly Property AddMethod As MethodSymbol
            Get
                Return If(_underlyingEvent.AddMethod Is Nothing, Nothing, RetargetingTranslator.Retarget(_underlyingEvent.AddMethod))
            End Get
        End Property

        Friend Overrides ReadOnly Property AssociatedField As FieldSymbol
            Get
                Return If(_underlyingEvent.AssociatedField Is Nothing, Nothing, RetargetingTranslator.Retarget(_underlyingEvent.AssociatedField))
            End Get
        End Property

        Public Overrides ReadOnly Property ExplicitInterfaceImplementations As ImmutableArray(Of EventSymbol)
            Get
                If _lazyExplicitInterfaceImplementations.IsDefault Then
                    ImmutableInterlocked.InterlockedCompareExchange(
                        _lazyExplicitInterfaceImplementations,
                        Me.RetargetExplicitInterfaceImplementations(),
                        Nothing)
                End If

                Return _lazyExplicitInterfaceImplementations
            End Get
        End Property

        Private Function RetargetExplicitInterfaceImplementations() As ImmutableArray(Of EventSymbol)
            Dim impls = Me.UnderlyingEvent.ExplicitInterfaceImplementations
            If impls.IsEmpty Then
                Return impls
            End If

            Dim builder = ArrayBuilder(Of EventSymbol).GetInstance()

            For i = 0 To impls.Length - 1
                Dim retargeted = Me.RetargetingModule.RetargetingTranslator.RetargetImplementedEvent(impls(i))
                If retargeted IsNot Nothing Then
                    builder.Add(retargeted)
                End If
            Next

            Return builder.ToImmutableAndFree()
        End Function

        Public Overrides ReadOnly Property IsMustOverride As Boolean
            Get
                Return _underlyingEvent.IsMustOverride
            End Get
        End Property

        Public Overrides ReadOnly Property IsNotOverridable As Boolean
            Get
                Return _underlyingEvent.IsNotOverridable
            End Get
        End Property

        Public Overrides ReadOnly Property IsOverridable As Boolean
            Get
                Return _underlyingEvent.IsOverridable
            End Get
        End Property

        Public Overrides ReadOnly Property IsOverrides As Boolean
            Get
                Return _underlyingEvent.IsOverrides
            End Get
        End Property

        Public Overrides ReadOnly Property IsShared As Boolean
            Get
                Return _underlyingEvent.IsShared
            End Get
        End Property

        Public Overrides ReadOnly Property Locations As ImmutableArray(Of Location)
            Get
                Return _underlyingEvent.Locations
            End Get
        End Property

        Public Overrides ReadOnly Property DeclaringSyntaxReferences As ImmutableArray(Of SyntaxReference)
            Get
                Return _underlyingEvent.DeclaringSyntaxReferences
            End Get
        End Property

        Public Overrides ReadOnly Property RaiseMethod As MethodSymbol
            Get
                Return If(_underlyingEvent.RaiseMethod Is Nothing, Nothing, RetargetingTranslator.Retarget(_underlyingEvent.RaiseMethod))
            End Get
        End Property

        Public Overrides ReadOnly Property RemoveMethod As MethodSymbol
            Get
                Return If(_underlyingEvent.RemoveMethod Is Nothing, Nothing, RetargetingTranslator.Retarget(_underlyingEvent.RemoveMethod))
            End Get
        End Property

        Public Overrides ReadOnly Property Type As TypeSymbol
            Get
                Return RetargetingTranslator.Retarget(_underlyingEvent.Type, RetargetOptions.RetargetPrimitiveTypesByTypeCode)
            End Get
        End Property

        Public Overrides ReadOnly Property Name As String
            Get
                Return _underlyingEvent.Name
            End Get
        End Property

        Public Overrides ReadOnly Property MetadataName As String
            Get
                Return _underlyingEvent.MetadataName
            End Get
        End Property

        Friend Overrides ReadOnly Property HasSpecialName As Boolean
            Get
                Return _underlyingEvent.HasSpecialName
            End Get
        End Property

        Friend Overrides ReadOnly Property HasRuntimeSpecialName As Boolean
            Get
                Return _underlyingEvent.HasRuntimeSpecialName
            End Get
        End Property

        Friend Overrides Function GetUseSiteInfo() As UseSiteInfo(Of AssemblySymbol)
            Dim primaryDependency As AssemblySymbol = Me.PrimaryDependency

            If Not _lazyCachedUseSiteInfo.IsInitialized Then
                _lazyCachedUseSiteInfo.Initialize(primaryDependency, CalculateUseSiteInfo())
            End If

            Return _lazyCachedUseSiteInfo.ToUseSiteInfo(primaryDependency)
        End Function

        Friend Overrides ReadOnly Property ObsoleteAttributeData As ObsoleteAttributeData
            Get
                Return _underlyingEvent.ObsoleteAttributeData
            End Get
        End Property

        Public Overrides ReadOnly Property IsWindowsRuntimeEvent As Boolean
            Get
                Return _underlyingEvent.IsWindowsRuntimeEvent
            End Get
        End Property

        ''' <remarks>
        ''' This is for perf, not for correctness.
        ''' </remarks>
        Friend Overrides ReadOnly Property DeclaringCompilation As VisualBasicCompilation
            Get
                Return Nothing
            End Get
        End Property

        Public Overrides Function GetDocumentationCommentXml(Optional preferredCulture As CultureInfo = Nothing, Optional expandIncludes As Boolean = False, Optional cancellationToken As CancellationToken = Nothing) As String
            Return _underlyingEvent.GetDocumentationCommentXml(preferredCulture, expandIncludes, cancellationToken)
        End Function
    End Class
End Namespace