/*
 * barrier -- mouse and keyboard sharing utility
 * Copyright (C) 2012-2016 Symless Ltd.
 * Copyright (C) 2004 Chris Schoeneman
 *
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file LICENSE that should have accompanied this file.
 *
 * This package 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/>.
 */

#include "base/SimpleEventQueueBuffer.h"
#include "base/Stopwatch.h"
#include "arch/Arch.h"

class EventQueueTimer { };

//
// SimpleEventQueueBuffer
//

SimpleEventQueueBuffer::SimpleEventQueueBuffer()
{
    m_queueMutex     = ARCH->newMutex();
    m_queueReadyCond = ARCH->newCondVar();
    m_queueReady     = false;
}

SimpleEventQueueBuffer::~SimpleEventQueueBuffer()
{
    ARCH->closeCondVar(m_queueReadyCond);
    ARCH->closeMutex(m_queueMutex);
}

void
SimpleEventQueueBuffer::waitForEvent(double timeout)
{
    ArchMutexLock lock(m_queueMutex);
    Stopwatch timer(true);
    while (!m_queueReady) {
        double timeLeft = timeout;
        if (timeLeft >= 0.0) {
            timeLeft -= timer.getTime();
            if (timeLeft < 0.0) {
                return;
            }
        }
        ARCH->waitCondVar(m_queueReadyCond, m_queueMutex, timeLeft);
    }
}

IEventQueueBuffer::Type
SimpleEventQueueBuffer::getEvent(Event&, UInt32& dataID)
{
    ArchMutexLock lock(m_queueMutex);
    if (!m_queueReady) {
        return kNone;
    }
    dataID = m_queue.back();
    m_queue.pop_back();
    m_queueReady = !m_queue.empty();
    return kUser;
}

bool
SimpleEventQueueBuffer::addEvent(UInt32 dataID)
{
    ArchMutexLock lock(m_queueMutex);
    m_queue.push_front(dataID);
    if (!m_queueReady) {
        m_queueReady = true;
        ARCH->broadcastCondVar(m_queueReadyCond);
    }
    return true;
}

bool
SimpleEventQueueBuffer::isEmpty() const
{
    ArchMutexLock lock(m_queueMutex);
    return !m_queueReady;
}

EventQueueTimer*
SimpleEventQueueBuffer::newTimer(double, bool) const
{
    return new EventQueueTimer;
}

void
SimpleEventQueueBuffer::deleteTimer(EventQueueTimer* timer) const
{
    delete timer;
}