// 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.Generic;
using System.Collections.Immutable;
using Roslyn.Utilities;

namespace Microsoft.CodeAnalysis.Remote;

internal sealed class RemoteServiceCallbackDispatcherRegistry(IEnumerable<Lazy<IRemoteServiceCallbackDispatcher, RemoteServiceCallbackDispatcherRegistry.ExportMetadata>> dispatchers) : IRemoteServiceCallbackDispatcherProvider
{
    public sealed class ExportMetadata
    {
        public Type ServiceInterface { get; }

        public ExportMetadata(Type serviceInterface)
            => ServiceInterface = serviceInterface;

        public ExportMetadata(IDictionary<string, object> data)
        {
            var serviceInterface = data.GetValueOrDefault(nameof(ExportRemoteServiceCallbackDispatcherAttribute.ServiceInterface));
            Contract.ThrowIfNull(serviceInterface);
            ServiceInterface = (Type)serviceInterface;
        }
    }

    private readonly ImmutableDictionary<Type, Lazy<IRemoteServiceCallbackDispatcher, ExportMetadata>> _callbackDispatchers = dispatchers.ToImmutableDictionary(d => d.Metadata.ServiceInterface);

    public IRemoteServiceCallbackDispatcher GetDispatcher(Type serviceType)
        => _callbackDispatchers[serviceType].Value;
}