/**
 * Stone of Orthanc
 * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
 * Department, University Hospital of Liege, Belgium
 * Copyright (C) 2017-2019 Osimis S.A., Belgium
 *
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License
 * as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 **/

#pragma once

#include <Core/Enumerations.h>
#include <Core/OrthancException.h>

#include "IMessageEmitter.h"
#include "IObservable.h"

#include <Core/Enumerations.h>  // For ORTHANC_OVERRIDE

#include <boost/thread/shared_mutex.hpp>

namespace OrthancStone
{
  namespace Deprecated
  {
    /**
     * This class is used when using the ThreadedOracle : since messages
     * can be sent from multiple Oracle threads, this IMessageEmitter
     * implementation serializes the callbacks.
     * 
     * The internal mutex used in Oracle messaging can also be used to 
     * protect the application data. Thus, this class can be used as a single
     * application-wide mutex.
     */
    class LockingEmitter : public IMessageEmitter
    {
    private:
      boost::shared_mutex  mutex_;
      IObservable          oracleObservable_;

    public:
      virtual void EmitMessage(boost::weak_ptr<IObserver> observer,
                               const IMessage& message) ORTHANC_OVERRIDE;


      class ReaderLock : public boost::noncopyable
      {
      private:
        LockingEmitter& that_;
        boost::shared_lock<boost::shared_mutex>  lock_;

      public:
        ReaderLock(LockingEmitter& that) :
        that_(that),
        lock_(that.mutex_)
        {
        }
      };


      class WriterLock : public boost::noncopyable
      {
      private:
        LockingEmitter& that_;
        boost::unique_lock<boost::shared_mutex>  lock_;

      public:
        WriterLock(LockingEmitter& that) :
        that_(that),
        lock_(that.mutex_)
        {
        }

        IObservable& GetOracleObservable()
        {
          return that_.oracleObservable_;
        }
      };
    };
  }
}