/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Creator.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
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** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
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****************************************************************************/

#include "readmessageblock.h"

#include "messageenvelop.h"

#include <QDataStream>
#include <QDebug>
#include <QIODevice>
#include <QVariant>

namespace ClangBackEnd {

ReadMessageBlock::ReadMessageBlock(QIODevice *ioDevice)
    : m_ioDevice(ioDevice),
      m_messageCounter(0),
      m_blockSize(0)
{
}

bool ReadMessageBlock::checkIfMessageIsLost(QDataStream &in)
{
    qint64 currentMessageCounter;

    in >> currentMessageCounter;

    bool messageIsLost = false;
#ifndef DONT_CHECK_MESSAGE_COUNTER
    messageIsLost = !((currentMessageCounter == 0 && m_messageCounter == 0) || (m_messageCounter + 1 == currentMessageCounter));
    if (messageIsLost)
        qWarning() << "message lost: " << m_messageCounter <<  currentMessageCounter;
#endif

    m_messageCounter = currentMessageCounter;

    return messageIsLost;
}

MessageEnvelop ReadMessageBlock::read()
{
    QDataStream in(m_ioDevice);

    MessageEnvelop message;

    if (isTheWholeMessageReadable(in)) {
        bool messageIsLost = checkIfMessageIsLost(in);

        in >> message;

        if (messageIsLost)
            qDebug() << message;
    }

    return message;
}

std::vector<MessageEnvelop> ReadMessageBlock::readAll()
{
    std::vector<MessageEnvelop> messages;

    while (true) {
        MessageEnvelop message = read();
        if (message.isValid())
            messages.push_back(std::move(message));
        else
            return messages;
    }

    Q_UNREACHABLE();
}

void ReadMessageBlock::resetState()
{
    m_messageCounter = 0;
}

void ReadMessageBlock::setIoDevice(QIODevice *ioDevice)
{
    m_ioDevice = ioDevice;
}

bool ReadMessageBlock::isTheWholeMessageReadable(QDataStream &in)
{
    if (m_ioDevice->bytesAvailable() < qint64(sizeof(m_blockSize)))
        return false;

    if (m_blockSize == 0)
        in >> m_blockSize;

    if (m_ioDevice->bytesAvailable() < m_blockSize)
        return false;

    m_blockSize = 0;

    return true;
}

} // namespace ClangBackEnd