// 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;
using System.Diagnostics;
using System.Runtime.InteropServices;
using EnvDTE;
using Microsoft.CodeAnalysis.CodeGeneration;
using Microsoft.CodeAnalysis.LanguageService;
using Microsoft.VisualStudio.LanguageServices.Implementation.CodeModel.Interop;
using Microsoft.VisualStudio.LanguageServices.Implementation.Interop;
using Microsoft.VisualStudio.LanguageServices.Implementation.Utilities;
using Microsoft.VisualStudio.Shell.Interop;
 
namespace Microsoft.VisualStudio.LanguageServices.Implementation.CodeModel;
 
/// <summary>
/// This is the root class for all code model objects. It contains methods that
/// are common to everything.
/// </summary>
public abstract partial class AbstractCodeModelObject : ApartmentSensitiveComObject
{
    private CodeModelState _state;
 
    internal AbstractCodeModelObject(CodeModelState state)
    {
        Debug.Assert(state != null);
 
        _state = state;
    }
 
    protected bool IsZombied { get; private set; }
 
    internal CodeModelState State
    {
        get
        {
            if (IsZombied)
            {
                Debug.Fail("Cannot access " + this.GetType().FullName + " after it has been ShutDown!");
                throw Exceptions.ThrowEUnexpected();
            }
 
            return _state;
        }
    }
 
    internal ICodeGenerationService CodeGenerationService
    {
        get { return this.State.CodeGenerator; }
    }
 
    internal ICodeModelService CodeModelService
    {
        get { return this.State.CodeModelService; }
    }
 
    internal IServiceProvider ServiceProvider
    {
        get { return this.State.ServiceProvider; }
    }
 
    internal ISyntaxFactsService SyntaxFactsService
    {
        get { return this.State.SyntaxFactsService; }
    }
 
    internal VisualStudioWorkspace Workspace
    {
        get { return this.State.Workspace; }
    }
 
    internal virtual void Shutdown()
    {
        _state = null;
        IsZombied = true;
    }
 
    public DTE DTE
    {
        get { return (DTE)this.ServiceProvider.GetService(typeof(SDTE)); }
    }
 
    public string Language
    {
        get { return this.CodeModelService.Language; }
    }
 
    protected EnvDTE.CodeElements GetCollection<T>(object parentObject)
    {
        var parentInstance = ComAggregate.GetManagedObject<object>(parentObject);
        Debug.Assert(!Marshal.IsComObject(parentInstance), "We should have a pure managed object!");
 
        if (parentInstance is ICodeElementContainer<T> container)
        {
            return container.GetCollection();
        }
 
        throw Exceptions.ThrowEFail();
    }
}