// 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.Generic;
using System.Collections.Immutable;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CodeLens;
using Microsoft.VisualStudio.Language.CodeLens;
using Microsoft.VisualStudio.Language.CodeLens.Remoting;
using Microsoft.VisualStudio.LanguageServices.CodeLens;
 
namespace Microsoft.CodeAnalysis.UnitTesting.ExternalAccess;
 
internal class UnitTestingReferencesService
{
    private static readonly IEnumerable<(string MethodFullyQualifedName, string MethodFilePath, string MethodOutputFilePath)> Empty =
        Enumerable.Empty<(string MethodFullyQualifedName, string MethodFilePath, string MethodOutputFilePath)>();
 
    internal static async Task<IEnumerable<(string MethodFullyQualifedName, string MethodFilePath, string MethodOutputFilePath)>> GetCallerMethodsAsync(
        IAsyncCodeLensDataPointProvider provider,
        ICodeLensCallbackService callbackService,
        CodeLensDescriptor descriptor,
        CodeLensDescriptorContext descriptorContext,
        CancellationToken cancellationToken)
    {
        var callerMethods = await callbackService.InvokeAsync<ImmutableArray<ReferenceMethodDescriptor>?>(
            provider,
            nameof(ICodeLensContext.FindReferenceMethodsAsync),
            [descriptor, descriptorContext],
            cancellationToken).ConfigureAwait(false);
 
        if (!callerMethods.HasValue || callerMethods.Value.IsEmpty)
        {
            return Empty;
        }
 
        return callerMethods.Value.SelectAsArray(m => (
            MethodFullyQualifiedName: m.FullName,
            MethodFilePath: m.FilePath,
            MethodOutputFilePath: m.OutputFilePath));
    }
}