// 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.Runtime.InteropServices;
using Microsoft.CodeAnalysis;
using Microsoft.VisualStudio.LanguageServices.Implementation.Interop;
using Microsoft.VisualStudio.LanguageServices.Implementation.Utilities;
 
namespace Microsoft.VisualStudio.LanguageServices.Implementation.CodeModel.ExternalElements;
 
[ComVisible(true)]
[ComDefaultInterface(typeof(EnvDTE.CodeParameter))]
public sealed class ExternalCodeParameter : AbstractExternalCodeElement, EnvDTE.CodeParameter, EnvDTE80.CodeParameter2
{
    internal static EnvDTE.CodeParameter Create(CodeModelState state, ProjectId projectId, IParameterSymbol symbol, AbstractExternalCodeMember parent)
    {
        var element = new ExternalCodeParameter(state, projectId, symbol, parent);
        return (EnvDTE.CodeParameter)ComAggregate.CreateAggregatedObject(element);
    }
 
    private readonly ParentHandle<AbstractExternalCodeElement> _parentHandle;
 
    private ExternalCodeParameter(CodeModelState state, ProjectId projectId, IParameterSymbol symbol, AbstractExternalCodeElement parent)
        : base(state, projectId, symbol)
    {
        _parentHandle = new ParentHandle<AbstractExternalCodeElement>(parent);
    }
 
    private IParameterSymbol ParameterSymbol
    {
        get { return (IParameterSymbol)LookupSymbol(); }
    }
 
    protected override EnvDTE.CodeElements GetCollection()
        => GetCollection<ExternalCodeParameter>(this.Parent);
 
    public override EnvDTE.vsCMElement Kind
    {
        get { return EnvDTE.vsCMElement.vsCMElementParameter; }
    }
 
    protected override string GetDocComment()
        => string.Empty;
 
    protected override object GetParent()
        => _parentHandle.Value;
 
    public new EnvDTE.CodeElement Parent
    {
        get { return (EnvDTE.CodeElement)GetParent(); }
    }
 
    public EnvDTE.CodeTypeRef Type
    {
        get
        {
            return CodeTypeRef.Create(this.State, this, this.ProjectId, ParameterSymbol.Type);
        }
 
        set
        {
            throw Exceptions.ThrowEFail();
        }
    }
 
    public string DefaultValue
    {
        get
        {
            return ParameterSymbol.HasExplicitDefaultValue && ParameterSymbol.ExplicitDefaultValue != null
                ? ParameterSymbol.ExplicitDefaultValue.ToString()
                : null;
        }
 
        set
        {
            throw Exceptions.ThrowEFail();
        }
    }
 
    public EnvDTE80.vsCMParameterKind ParameterKind
    {
        get
        {
            var result = EnvDTE80.vsCMParameterKind.vsCMParameterKindNone;
 
            if (ParameterSymbol.RefKind == RefKind.Ref)
            {
                result = EnvDTE80.vsCMParameterKind.vsCMParameterKindRef;
            }
            else if (ParameterSymbol.RefKind == RefKind.Out)
            {
                result = EnvDTE80.vsCMParameterKind.vsCMParameterKindOut;
            }
            else if (ParameterSymbol.IsParams)
            {
                result = EnvDTE80.vsCMParameterKind.vsCMParameterKindParamArray;
            }
 
            if (ParameterSymbol.IsOptional)
            {
                result |= EnvDTE80.vsCMParameterKind.vsCMParameterKindOptional;
            }
 
            return result;
        }
 
        set
        {
            throw Exceptions.ThrowEFail();
        }
    }
}