// 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.
 
#nullable disable
 
using System.Collections.Immutable;
using System.Runtime.InteropServices;
using Microsoft.CodeAnalysis;
using Microsoft.VisualStudio.LanguageServices.Implementation.Interop;
 
namespace Microsoft.VisualStudio.LanguageServices.Implementation.CodeModel.InternalElements;
 
[ComVisible(true)]
[ComDefaultInterface(typeof(EnvDTE80.CodeDelegate2))]
public sealed partial class CodeDelegate : AbstractCodeType, ICodeElementContainer<CodeParameter>, EnvDTE.CodeDelegate, EnvDTE80.CodeDelegate2
{
    internal static EnvDTE.CodeDelegate Create(
        CodeModelState state,
        FileCodeModel fileCodeModel,
        SyntaxNodeKey nodeKey,
        int? nodeKind)
    {
        var element = new CodeDelegate(state, fileCodeModel, nodeKey, nodeKind);
        var result = (EnvDTE.CodeDelegate)ComAggregate.CreateAggregatedObject(element);
 
        fileCodeModel.OnCodeElementCreated(nodeKey, (EnvDTE.CodeElement)result);
 
        return result;
    }
 
    internal static EnvDTE.CodeDelegate CreateUnknown(
        CodeModelState state,
        FileCodeModel fileCodeModel,
        int nodeKind,
        string name)
    {
        var element = new CodeDelegate(state, fileCodeModel, nodeKind, name);
        return (EnvDTE.CodeDelegate)ComAggregate.CreateAggregatedObject(element);
    }
 
    private CodeDelegate(
        CodeModelState state,
        FileCodeModel fileCodeModel,
        SyntaxNodeKey nodeKey,
        int? nodeKind)
        : base(state, fileCodeModel, nodeKey, nodeKind)
    {
    }
 
    private CodeDelegate(
        CodeModelState state,
        FileCodeModel fileCodeModel,
        int nodeKind,
        string name)
        : base(state, fileCodeModel, nodeKind, name)
    {
    }
 
    EnvDTE.CodeElements ICodeElementContainer<CodeParameter>.GetCollection()
        => this.Parameters;
 
    private IMethodSymbol LookupInvokeMethod()
    {
        var typeSymbol = (INamedTypeSymbol)LookupSymbol();
        return typeSymbol.DelegateInvokeMethod;
    }
 
    internal override ImmutableArray<SyntaxNode> GetParameters()
        => [.. CodeModelService.GetParameterNodes(LookupNode())];
 
    public override EnvDTE.vsCMElement Kind
    {
        get { return EnvDTE.vsCMElement.vsCMElementDelegate; }
    }
 
    public EnvDTE.CodeClass BaseClass
    {
        get
        {
            return (EnvDTE.CodeClass)this.CodeModelService.CreateCodeType(
                this.State,
                this.FileCodeModel.GetProjectId(),
                this.FileCodeModel.GetCompilation().GetSpecialType(SpecialType.System_Delegate));
        }
    }
 
    public EnvDTE.CodeTypeRef Type
    {
        get
        {
            return CodeTypeRef.Create(this.State, this, GetProjectId(), LookupInvokeMethod().ReturnType);
        }
 
        set
        {
            // The type is sometimes part of the node key, so we should be sure to reacquire
            // it after updating it. Note that we pass trackKinds: false because it's possible
            // that UpdateType might change the kind of a node (e.g. change a VB Sub to a Function).
 
            UpdateNodeAndReacquireNodeKey(FileCodeModel.UpdateType, value, trackKinds: false);
        }
    }
}