// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Threading;
using System.Threading.Tasks;
using Microsoft.VisualStudio.Shell.Interop;
using Microsoft.VisualStudio.Threading;
 
namespace Microsoft.VisualStudio.Razor.Extensions;
 
internal static class IVsHierarchyExtensions
{
    public static async Task<string?> GetProjectFilePathAsync(this IVsHierarchy vsHierarchy, JoinableTaskFactory jtf, CancellationToken cancellationToken)
    {
        await jtf.SwitchToMainThreadAsync(cancellationToken);
 
        return vsHierarchy.GetProjectFilePath(jtf);
    }
 
    public static string? GetProjectFilePath(this IVsHierarchy vsHierarchy, JoinableTaskFactory jtf)
    {
        jtf.AssertUIThread();
 
        if (vsHierarchy is not IVsProject vsProject)
        {
            return null;
        }
 
        var hresult = vsProject.GetMkDocument((uint)VSConstants.VSITEMID.Root, out var projectFilePath);
 
        return ErrorHandler.Succeeded(hresult)
            ? projectFilePath
            : null;
    }
}