/*************************************************************************
 * ModernUO                                                              *
 * Copyright (C) 2019-2020 - ModernUO Development Team                   *
 * Email: hi@modernuo.com                                                *
 * File: MessagePumpService.cs                                           *
 * Created: 2020/04/12 - Updated: 2020/04/12                             *
 *                                                                       *
 * This program is free software: you can redistribute it and/or modify  *
 * it under the terms of the GNU 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 General Public License for more details.                          *
 *                                                                       *
 * You should have received a copy of the GNU General Public License     *
 * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
 *************************************************************************/

using System.Buffers;
using System.Collections.Concurrent;

namespace Server.Network
{
  public interface IMessagePumpService
  {
    void QueueWork(NetState ns, IMemoryOwner<byte> memOwner, OnPacketReceive onReceive);
    void DoWork();
  }

  public class MessagePumpService : IMessagePumpService
  {
    private readonly ConcurrentQueue<Work> m_WorkQueue = new ConcurrentQueue<Work>();

    public void QueueWork(NetState ns, IMemoryOwner<byte> memOwner, OnPacketReceive onReceive)
    {
      m_WorkQueue.Enqueue(new Work(ns, memOwner, onReceive));
      Core.Set();
    }

    public void DoWork()
    {
      var count = 0;
      while (!m_WorkQueue.IsEmpty && count++ < 250)
      {
        if (!m_WorkQueue.TryDequeue(out var work))
          break;

        work.OnReceive(work.State, new PacketReader(new ReadOnlySequence<byte>(work.MemoryOwner.Memory)));
        work.MemoryOwner.Dispose();
      }
    }

    private class Work
    {
      public readonly NetState State;

      // TODO: Force dispose?
      public readonly IMemoryOwner<byte> MemoryOwner;
      public readonly OnPacketReceive OnReceive;

      public Work(NetState ns, IMemoryOwner<byte> memOwner, OnPacketReceive onReceive)
      {
        State = ns;
        MemoryOwner = memOwner;
        OnReceive = onReceive;
      }
    }
  }
}