// 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;
using System.Collections.Immutable;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.FindSymbols;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Remote
{
    internal sealed class RemoteDependentTypeFinderService : BrokeredServiceBase, IRemoteDependentTypeFinderService
    {
        internal sealed class Factory : FactoryBase<IRemoteDependentTypeFinderService>
        {
            protected override IRemoteDependentTypeFinderService CreateService(in ServiceConstructionArguments arguments)
                => new RemoteDependentTypeFinderService(arguments);
        }
 
        public RemoteDependentTypeFinderService(in ServiceConstructionArguments arguments)
            : base(arguments)
        {
        }
 
        public ValueTask<ImmutableArray<SerializableSymbolAndProjectId>> FindTypesAsync(
            Checksum solutionChecksum,
            SerializableSymbolAndProjectId typeAndProjectId,
            ImmutableArray<ProjectId> projectIdsOpt,
            bool transitive,
            DependentTypesKind kind,
            CancellationToken cancellationToken)
        {
            return RunServiceAsync(solutionChecksum, async solution =>
            {
                var symbol = await typeAndProjectId.TryRehydrateAsync(solution, cancellationToken).ConfigureAwait(false);
 
                if (symbol is not INamedTypeSymbol namedType)
                    return ImmutableArray<SerializableSymbolAndProjectId>.Empty;
 
                var projects = projectIdsOpt.IsDefault ? null : projectIdsOpt.Select(id => solution.GetRequiredProject(id)).ToImmutableHashSet();
 
                var types = await DependentTypeFinder.FindTypesInCurrentProcessAsync(namedType, solution, projects, transitive, kind, cancellationToken).ConfigureAwait(false);
 
                return types.SelectAsArray(
                    t => SerializableSymbolAndProjectId.Dehydrate(solution, t, cancellationToken));
            }, cancellationToken);
        }
    }
}