// Copyright 2007-2017 Chris Patterson, Dru Sellers, Travis Smith, et. al.
//  
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
// this file except in compliance with the License. You may obtain a copy of the 
// License at 
// 
//     http://www.apache.org/licenses/LICENSE-2.0 
// 
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR 
// CONDITIONS OF ANY KIND, either express or implied. See the License for the 
// specific language governing permissions and limitations under the License.
namespace MassTransit.Context.SetCorrelationIds
{
    using System;


    public class NullableDelegateSetCorrelationId<T> :
        ISetCorrelationId<T>
        where T : class
    {
        readonly Func<T, Guid?> _getCorrelationId;

        public NullableDelegateSetCorrelationId(Func<T, Guid?> getCorrelationId)
        {
            _getCorrelationId = getCorrelationId;
        }

        public void SetCorrelationId(SendContext<T> context)
        {
            Guid? correlationId = _getCorrelationId(context.Message);
            if (correlationId.HasValue && correlationId.Value != Guid.Empty)
                context.CorrelationId = correlationId;
        }
    }
}