// 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.
 
using System.Collections.Immutable;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.DocumentHighlighting;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Remote;
 
internal sealed class RemoteDocumentHighlightsService : BrokeredServiceBase, IRemoteDocumentHighlightsService
{
    internal sealed class Factory : FactoryBase<IRemoteDocumentHighlightsService>
    {
        protected override IRemoteDocumentHighlightsService CreateService(in ServiceConstructionArguments arguments)
            => new RemoteDocumentHighlightsService(arguments);
    }
 
    public RemoteDocumentHighlightsService(in ServiceConstructionArguments arguments)
        : base(arguments)
    {
    }
 
    public ValueTask<ImmutableArray<SerializableDocumentHighlights>> GetDocumentHighlightsAsync(
        Checksum solutionChecksum, DocumentId documentId, int position, ImmutableArray<DocumentId> documentIdsToSearch, HighlightingOptions options, CancellationToken cancellationToken)
    {
        // NOTE: In projection scenarios, we might get a set of documents to search
        // that are not all the same language and might not exist in the OOP process
        // (like the JS parts of a .cshtml file). Filter them out here.  This will
        // need to be revisited if we someday support FAR between these languages.
        return RunServiceAsync(solutionChecksum, async solution =>
        {
            var document = await solution.GetRequiredDocumentAsync(documentId, includeSourceGenerated: true, cancellationToken).ConfigureAwait(false);
            document = options.FrozenPartialSemantics ? document.WithFrozenPartialSemantics(cancellationToken) : document;
            solution = document.Project.Solution;
 
            var documentsToSearch = await documentIdsToSearch.SelectAsArrayAsync(id => solution.GetDocumentAsync(id, includeSourceGenerated: true, cancellationToken)).ConfigureAwait(false);
            var documentsToSearchSet = ImmutableHashSet.CreateRange(documentsToSearch.WhereNotNull());
 
            var service = document.GetRequiredLanguageService<IDocumentHighlightsService>();
            var result = await service.GetDocumentHighlightsAsync(
                document, position, documentsToSearchSet, options, cancellationToken).ConfigureAwait(false);
 
            return result.SelectAsArray(SerializableDocumentHighlights.Dehydrate);
        }, cancellationToken);
    }
}