/**
 * Looking Glass
 * Copyright © 2017-2026 The Looking Glass Authors
 * https://looking-glass.io
 *
 * 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 2 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, write to the Free Software Foundation, Inc., 59
 * Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#pragma once

#include <Windows.h>
#include <stdint.h>

extern "C" {
  #include <lgmp/lgmp.h>
}

#include "common/KVMFR.h"

class CFrameScheduler
{
public:
  struct Schedule
  {
    uint32_t clientID;
    uint32_t generation;
    uint64_t period;
    uint64_t targetSlack;
  };

private:
  struct Client
  {
    uint32_t clientID;
    uint32_t generation;
    uint64_t period;
    uint64_t targetSlack;
    uint64_t expiry;
    bool     subscribed;
    bool     active;
  };

  mutable SRWLOCK m_lock = SRWLOCK_INIT;
  Client          m_clients[LGMP_MAX_CLIENTS] = {};
  Schedule        m_schedule                  = {};
  bool            m_scheduling                = false;

  Client * FindClient(uint32_t clientID);
  void ElectOwner(uint64_t now);

public:
  static uint64_t Nanotime();

  void Reset();
  void UpdateSubscribers(const uint32_t * clientIDs, unsigned count,
    uint64_t now);
  bool UpdateSchedule(const KVMFRFrameSchedule& schedule, uint64_t now);
  bool GetSchedule(Schedule& schedule) const;
};