// 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.IO;
using Microsoft.VisualStudio.Shell.Interop;
 
namespace Microsoft.VisualStudio.LanguageServices.Implementation.ProjectSystem.Legacy
{
    internal partial class AbstractLegacyProject : IVsHierarchyEvents
    {
        private uint _hierarchyEventsCookie;
 
        private void ConnectHierarchyEvents()
        {
            Debug.Assert(!this.AreHierarchyEventsConnected, "IVsHierarchyEvents are already connected!");
 
            if (ErrorHandler.Failed(Hierarchy.AdviseHierarchyEvents(this, out _hierarchyEventsCookie)))
            {
                Debug.Fail("Failed to connect IVsHierarchyEvents");
                _hierarchyEventsCookie = 0;
            }
        }
 
        private void DisconnectHierarchyEvents()
        {
            if (this.AreHierarchyEventsConnected)
            {
                Hierarchy.UnadviseHierarchyEvents(_hierarchyEventsCookie);
                _hierarchyEventsCookie = 0;
            }
        }
 
        private bool AreHierarchyEventsConnected
        {
            get { return _hierarchyEventsCookie != 0; }
        }
 
        int IVsHierarchyEvents.OnInvalidateIcon(IntPtr hicon)
            => VSConstants.E_NOTIMPL;
 
        int IVsHierarchyEvents.OnInvalidateItems(uint itemidParent)
            => VSConstants.E_NOTIMPL;
 
        int IVsHierarchyEvents.OnItemAdded(uint itemidParent, uint itemidSiblingPrev, uint itemidAdded)
            => VSConstants.E_NOTIMPL;
 
        int IVsHierarchyEvents.OnItemDeleted(uint itemid)
            => VSConstants.E_NOTIMPL;
 
        int IVsHierarchyEvents.OnItemsAppended(uint itemidParent)
            => VSConstants.E_NOTIMPL;
 
        int IVsHierarchyEvents.OnPropertyChanged(uint itemid, int propid, uint flags)
        {
            if ((propid == (int)__VSHPROPID.VSHPROPID_Caption ||
                 propid == (int)__VSHPROPID.VSHPROPID_Name) &&
                itemid == (uint)VSConstants.VSITEMID.Root)
            {
                var filePath = Hierarchy.TryGetProjectFilePath();
 
                if (filePath != null && File.Exists(filePath))
                {
                    ProjectSystemProject.FilePath = filePath;
                }
 
                if (Hierarchy.TryGetName(out var name))
                {
                    ProjectSystemProject.DisplayName = name;
                }
            }
 
            return VSConstants.S_OK;
        }
    }
}