// 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 Microsoft.CodeAnalysis.Host;

namespace Microsoft.CodeAnalysis;

/// <summary>
/// <see cref="IDocumentServiceProvider"/> for regular C#/VB files.
/// </summary>
internal sealed class DefaultTextDocumentServiceProvider : IDocumentServiceProvider
{
    public static readonly DefaultTextDocumentServiceProvider Instance = new();

    private DefaultTextDocumentServiceProvider() { }

    public TService GetService<TService>() where TService : class, IDocumentService
    {
        // right now, it doesn't implement much services but we expect it to implements all 
        // document services in future so that we can remove all if branches in feature code
        // but just delegate work to default document services.
        if (DocumentOperationService.Instance is TService documentOperationService)
        {
            return documentOperationService;
        }

        if (DocumentPropertiesService.Default is TService documentPropertiesService)
        {
            return documentPropertiesService;
        }

        return null;
    }

    private sealed class DocumentOperationService : IDocumentOperationService
    {
        public static readonly DocumentOperationService Instance = new();

        // right now, we return CanApplyChange for all C# documents, but we probably want to return
        // false for generated files such as resx files or winform designer files.
        // right now, we have a bug where if user renames Resource.[ResourceName] we actually do the rename
        // but not actually change resx files which in turn, break code since generated file go back to 
        // original next time someone changes resx files but reference left as renamed.
        // with this, we now should be able to say no text changes for such files so that rename fails
        // in those cases.
        public bool CanApplyChange => true;
        public bool SupportDiagnostics => true;
    }
}