// 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.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.FindSymbols;
using Microsoft.CodeAnalysis.Shared.TestHooks;
using Microsoft.VisualStudio.Language.CallHierarchy;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Editor.Implementation.CallHierarchy.Finders;
 
internal class ImplementerFinder : AbstractCallFinder
{
    public ImplementerFinder(ISymbol symbol, ProjectId projectId, IAsynchronousOperationListener asyncListener, CallHierarchyProvider provider)
        : base(symbol, projectId, asyncListener, provider)
    {
    }
 
    public override string DisplayName
    {
        get
        {
            return string.Format(EditorFeaturesResources.Implements_0, SymbolName);
        }
    }
 
    protected override Task<IEnumerable<SymbolCallerInfo>> GetCallersAsync(ISymbol symbol, Project project, IImmutableSet<Document> documents, CancellationToken cancellationToken)
        => throw new NotImplementedException();
 
    protected override async Task SearchWorkerAsync(ISymbol symbol, Project project, ICallHierarchySearchCallback callback, IImmutableSet<Document> documents, CancellationToken cancellationToken)
    {
        var implementations = await SymbolFinder.FindImplementationsAsync(symbol, project.Solution, cancellationToken: cancellationToken).ConfigureAwait(false);
 
        foreach (var implementation in implementations)
        {
            var sourceLocations = implementation.DeclaringSyntaxReferences.Select(d => project.Solution.GetDocument(d.SyntaxTree)).WhereNotNull();
            var bestLocation = sourceLocations.FirstOrDefault(d => documents == null || documents.Contains(d));
            if (bestLocation != null)
            {
                var item = await Provider.CreateItemAsync(implementation, bestLocation.Project, ImmutableArray<Location>.Empty, cancellationToken).ConfigureAwait(false);
                callback.AddResult(item);
                cancellationToken.ThrowIfCancellationRequested();
            }
        }
    }
}