/**************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** Commercial Usage
**
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
**
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://qt.nokia.com/contact.
**
**************************************************************************/

#include "trkdevicex.h"
#include "trkutils.h"

#include <QtCore/QString>
#include <QtCore/QDebug>
#include <QtCore/QQueue>
#include <QtCore/QHash>
#include <QtCore/QMap>
#include <QtCore/QSharedPointer>

#ifdef Q_OS_WIN
#  include <windows.h>
#else
#  include <QtCore/QFile>

#  include <stdio.h>
#  include <sys/ioctl.h>
#  include <termios.h>
#  include <errno.h>
#  include <string.h>
#endif

enum { TimerInterval = 100 };

#ifdef Q_OS_WIN

// Format windows error from GetLastError() value: TODO: Use the one provided by the utisl lib.
QString winErrorMessage(unsigned long error)
{
    QString rc = QString::fromLatin1("#%1: ").arg(error);
    ushort *lpMsgBuf;

    const int len = FormatMessage(
            FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
            NULL, error, 0, (LPTSTR)&lpMsgBuf, 0, NULL);
    if (len) {
        rc = QString::fromUtf16(lpMsgBuf, len);
        LocalFree(lpMsgBuf);
    } else {
        rc += QString::fromLatin1("<unknown error>");
    }
    return rc;
}

// Non-blocking replacement for win-api ReadFile function
BOOL WINAPI TryReadFile(HANDLE          hFile,
                        LPVOID          lpBuffer,
                        DWORD           nNumberOfBytesToRead,
                        LPDWORD         lpNumberOfBytesRead,
                        LPOVERLAPPED    lpOverlapped)
{
    COMSTAT comStat;
    if (!ClearCommError(hFile, NULL, &comStat)){
        logMessage("ClearCommError() failed");
        return FALSE;
    }
    if (comStat.cbInQue == 0) {
        *lpNumberOfBytesRead = 0;
        return FALSE;
    }
    return ReadFile(hFile,
                    lpBuffer,
                    qMin(comStat.cbInQue, nNumberOfBytesToRead),
                    lpNumberOfBytesRead,
                    lpOverlapped);
}
#endif

namespace trk {

///////////////////////////////////////////////////////////////////////
//
// TrkMessage
//
///////////////////////////////////////////////////////////////////////

/* A message to be send to TRK, triggering a callback on receipt
 * of the answer. */
struct TrkMessage
{
    typedef TrkFunctor1<const TrkResult &> Callback;

    explicit TrkMessage(byte code = 0u, byte token = 0u,
                        Callback callback = Callback());

    byte code;
    byte token;
    QByteArray data;
    QVariant cookie;
    Callback callback;
};

TrkMessage::TrkMessage(byte c, byte t, Callback cb) :
    code(c),
    token(t),
    callback(cb)
{
}

///////////////////////////////////////////////////////////////////////
//
// TrkWriteQueue
//
///////////////////////////////////////////////////////////////////////

/* Mixin class that manages a write queue of Trk messages. */
class TrkWriteQueue
{
public:
    typedef TrkDevice::Callback Callback;   

    TrkWriteQueue();

    // Enqueue messages.
    void queueTrkMessage(byte code, Callback callback,
                        const QByteArray &data, const QVariant &cookie);
    void queueTrkInitialPing();

    // Call this from the device read notification with the results.
    void slotHandleResult(const TrkResult &result);

    // This can be called periodically in a timer to retrieve
    // the pending messages to be sent.
    bool pendingMessage(TrkMessage *message);
    // Notify the queue about the success of the write operation
    // after taking the pendingMessage off.
    void notifyWriteResult(bool ok);

private:
    typedef QMap<byte, TrkMessage> TokenMessageMap;

    byte nextTrkWriteToken();

    byte trkWriteToken;
    QQueue<TrkMessage> trkWriteQueue;
    TokenMessageMap writtenTrkMessages;
    bool trkWriteBusy;
};

TrkWriteQueue::TrkWriteQueue() :
    trkWriteToken(0),
    trkWriteBusy(false)
{
}

byte TrkWriteQueue::nextTrkWriteToken()
{
    ++trkWriteToken;
    if (trkWriteToken == 0)
        ++trkWriteToken;
    return trkWriteToken;
}

void TrkWriteQueue::queueTrkMessage(byte code, Callback callback,
    const QByteArray &data, const QVariant &cookie)
{
    const byte token = code == TRK_WRITE_QUEUE_NOOP_CODE ?
                                byte(0) : nextTrkWriteToken();
    TrkMessage msg(code, token, callback);
    msg.data = data;
    msg.cookie = cookie;
    trkWriteQueue.append(msg);
}

bool TrkWriteQueue::pendingMessage(TrkMessage *message)
{
    // Invoked from timer, try to flush out message queue
    if (trkWriteBusy || trkWriteQueue.isEmpty())
        return false;
    // Handle the noop message, just invoke CB
    if (trkWriteQueue.front().code == TRK_WRITE_QUEUE_NOOP_CODE) {
        TrkMessage noopMessage = trkWriteQueue.dequeue();
        if (noopMessage.callback) {
            TrkResult result;
            result.code = noopMessage.code;
            result.token = noopMessage.token;
            result.data = noopMessage.data;
            result.cookie = noopMessage.cookie;
            noopMessage.callback(result);
        }
    }
    // Check again for real messages
    if (trkWriteQueue.isEmpty())
        return false;
    if (message)
        *message = trkWriteQueue.front();
    return true;
}

void TrkWriteQueue::notifyWriteResult(bool ok)
{
    // On success, dequeue message and await result
    if (ok) {        
        TrkMessage firstMsg = trkWriteQueue.dequeue();
        writtenTrkMessages.insert(firstMsg.token, firstMsg);
        trkWriteBusy = true;
    }
}

void TrkWriteQueue::slotHandleResult(const TrkResult &result)
{
    trkWriteBusy = false;
    //if (result.code != TrkNotifyAck && result.code != TrkNotifyNak)
    //    return;
    // Find which request the message belongs to and invoke callback
    // if ACK or on NAK if desired.
    const TokenMessageMap::iterator it = writtenTrkMessages.find(result.token);
    if (it == writtenTrkMessages.end())
        return;
    const bool invokeCB = it.value().callback;
    if (invokeCB) {
        TrkResult result1 = result;
        result1.cookie = it.value().cookie;
        it.value().callback(result1);
    }
    writtenTrkMessages.erase(it);
}

void TrkWriteQueue::queueTrkInitialPing()
{
    // Ping, reset sequence count
    trkWriteQueue.append(TrkMessage(0, 0));
}


///////////////////////////////////////////////////////////////////////
//
// TrkDevicePrivate
//
///////////////////////////////////////////////////////////////////////

struct TrkDevicePrivate
{
    TrkDevicePrivate();

    TrkWriteQueue queue;
#ifdef Q_OS_WIN
    HANDLE hdevice;
#else
    QFile file;
#endif

    QByteArray trkReadBuffer;
    bool trkWriteBusy;
    int timerId;
    bool serialFrame;
    bool verbose;
    QString errorString;
};

///////////////////////////////////////////////////////////////////////
//
// TrkDevice
//
///////////////////////////////////////////////////////////////////////

TrkDevicePrivate::TrkDevicePrivate() :
#ifdef Q_OS_WIN
    hdevice(INVALID_HANDLE_VALUE),
#endif
    trkWriteBusy(false),
    timerId(-1),
    serialFrame(true),
    verbose(false)
{
}

///////////////////////////////////////////////////////////////////////
//
// TrkDevice
//
///////////////////////////////////////////////////////////////////////

TrkDevice::TrkDevice(QObject *parent) :
    QObject(parent),
    d(new TrkDevicePrivate)
{}

TrkDevice::~TrkDevice()
{
    close();
    delete d;
}

bool TrkDevice::open(const QString &port, QString *errorMessage)
{
    close();
#ifdef Q_OS_WIN
    d->hdevice = CreateFile(port.toStdWString().c_str(),
                           GENERIC_READ | GENERIC_WRITE,
                           0,
                           NULL,
                           OPEN_EXISTING,
                           FILE_ATTRIBUTE_NORMAL,
                           NULL);

    if (INVALID_HANDLE_VALUE == d->hdevice) {
        *errorMessage = QString::fromLatin1("Could not open device '%1': %2").arg(port, winErrorMessage(GetLastError()));
        return false;
    }
    d->timerId = startTimer(TimerInterval);
    return true;
#else
    d->file.setFileName(port);
    if (!d->file.open(QIODevice::ReadWrite|QIODevice::Unbuffered)) {
        *errorMessage = QString::fromLatin1("Cannot open %1: %2").arg(port, d->file.errorString());
        return false;
    }

    struct termios termInfo;
    if (tcgetattr(d->file.handle(), &termInfo) < 0) {
        *errorMessage = QString::fromLatin1("Unable to retrieve terminal settings: %1 %2").arg(errno).arg(QString::fromAscii(strerror(errno)));
        return false;
    }
    // Turn off terminal echo as not get messages back, among other things
    termInfo.c_cflag |= CREAD|CLOCAL;
    termInfo.c_lflag &= (~(ICANON|ECHO|ECHOE|ECHOK|ECHONL|ISIG));
    termInfo.c_iflag &= (~(INPCK|IGNPAR|PARMRK|ISTRIP|ICRNL|IXANY));
    termInfo.c_oflag &= (~OPOST);
    termInfo.c_cc[VMIN]  = 0;
    termInfo.c_cc[VINTR] = _POSIX_VDISABLE;
    termInfo.c_cc[VQUIT] = _POSIX_VDISABLE;
    termInfo.c_cc[VSTART] = _POSIX_VDISABLE;
    termInfo.c_cc[VSTOP] = _POSIX_VDISABLE;
    termInfo.c_cc[VSUSP] = _POSIX_VDISABLE;
    if (tcsetattr(d->file.handle(), TCSAFLUSH, &termInfo) < 0) {
        *errorMessage = QString::fromLatin1("Unable to apply terminal settings: %1 %2").arg(errno).arg(QString::fromAscii(strerror(errno)));
        return false;
    }
    d->timerId = startTimer(TimerInterval);
    return true;
#endif
}

void TrkDevice::close()
{
    if (!isOpen())
        return;
    if (d->timerId != -1) {
        killTimer(d->timerId);
        d->timerId = -1;
    }
#ifdef Q_OS_WIN
    CloseHandle(d->hdevice);
    d->hdevice = INVALID_HANDLE_VALUE;
#else
    d->file.close();
#endif
    if (verbose())
        logMessage("Close");
}

bool TrkDevice::isOpen() const
{
#ifdef Q_OS_WIN
    return d->hdevice != INVALID_HANDLE_VALUE;
#else
    return d->file.isOpen();
#endif
}

QString TrkDevice::errorString() const
{
    return d->errorString;
}

bool TrkDevice::serialFrame() const
{
    return d->serialFrame;
}

void TrkDevice::setSerialFrame(bool f)
{
    d->serialFrame = f;
}

bool TrkDevice::verbose() const
{
    return true || d->verbose;
}

void TrkDevice::setVerbose(bool b)
{
    d->verbose = b;
}

bool TrkDevice::write(const QByteArray &data, QString *errorMessage)
{
#ifdef Q_OS_WIN
    DWORD charsWritten;
    if (!WriteFile(d->hdevice, data.data(), data.size(), &charsWritten, NULL)) {
        *errorMessage = QString::fromLatin1("Error writing data: %1").arg(winErrorMessage(GetLastError()));
        return false;
    }
    FlushFileBuffers(d->hdevice);
    return true;
#else
    if (d->file.write(data) == -1 || !d->file.flush()) {
        *errorMessage = QString::fromLatin1("Cannot write: %1").arg(d->file.errorString());
        return false;
    }
    return  true;
#endif
}

#ifndef Q_OS_WIN
static inline int bytesAvailable(int fileNo)
{
    int numBytes;
    const int rc = ioctl(fileNo, FIONREAD, &numBytes);
    if (rc < 0)
        numBytes=0;
    return numBytes;
}
#endif

void TrkDevice::tryTrkRead()
{
#ifdef Q_OS_WIN
    const DWORD BUFFERSIZE = 1024;
    char buffer[BUFFERSIZE];
    DWORD charsRead;
    DWORD totalCharsRead = 0;

    while (TryReadFile(d->hdevice, buffer, BUFFERSIZE, &charsRead, NULL)) {
        totalCharsRead += charsRead;
        d->trkReadBuffer.append(buffer, charsRead);
        if (isValidTrkResult(d->trkReadBuffer, d->serialFrame))
            break;
    }
    if (verbose() && totalCharsRead)
        logMessage("Read" + d->trkReadBuffer.toHex());
    if (!totalCharsRead)
        return;
    const ushort len = isValidTrkResult(d->trkReadBuffer, d->serialFrame);
    if (!len) {
        const QString msg = QString::fromLatin1("Partial message: %1").arg(stringFromArray(d->trkReadBuffer));
        emitError(msg);
        return;
    }
#else
    const int size = bytesAvailable(d->file.handle());
    if (!size)
        return;
    const QByteArray data = d->file.read(size);
    if (verbose())
        logMessage("trk: <- " + stringFromArray(data));
    d->trkReadBuffer.append(data);
    const ushort len = isValidTrkResult(d->trkReadBuffer, d->serialFrame);
    if (!len) {
        if (d->trkReadBuffer.size() > 10) {
            const QString msg = QString::fromLatin1("Unable to extract message from '%1' '%2'").
                             arg(QLatin1String(d->trkReadBuffer.toHex())).arg(QString::fromAscii(d->trkReadBuffer));
            emitError(msg);
        }
        return;
    }
#endif // Q_OS_WIN
    TrkResult r;
    QByteArray rawData;
    while (extractResult(&d->trkReadBuffer, d->serialFrame, &r, &rawData)) {
        //if (verbose())
        //    logMessage("Read TrkResult " + r.data.toHex());
        d->queue.slotHandleResult(r);
        emit messageReceived(r);
        if (!rawData.isEmpty())
            emit rawDataReceived(rawData);
    }
}

void TrkDevice::timerEvent(QTimerEvent *)
{
    tryTrkWrite();
    tryTrkRead();
}

void TrkDevice::emitError(const QString &s)
{
    d->errorString = s;
    qWarning("%s\n", qPrintable(s));
    emit error(s);
}

void TrkDevice::sendTrkMessage(byte code, Callback callback,
     const QByteArray &data, const QVariant &cookie)
{
    d->queue.queueTrkMessage(code, callback, data, cookie);
}

void TrkDevice::sendTrkInitialPing()
{
    d->queue.queueTrkInitialPing();
}

bool TrkDevice::sendTrkAck(byte token)
{
    // The acknowledgement must not be queued!
    TrkMessage msg(0x80, token);
    msg.token = token;
    msg.data.append('\0');
    return trkWriteRawMessage(msg);
    // 01 90 00 07 7e 80 01 00 7d 5e 7e
}

void TrkDevice::tryTrkWrite()
{
    TrkMessage message;
    if (!d->queue.pendingMessage(&message))
        return;
    const bool success = trkWriteRawMessage(message);
    d->queue.notifyWriteResult(success);
}

bool TrkDevice::trkWriteRawMessage(const TrkMessage &msg)
{
    const QByteArray ba = frameMessage(msg.code, msg.token, msg.data, serialFrame());
    if (verbose())
         logMessage("trk: -> " + stringFromArray(ba));
    QString errorMessage;
    const bool rc = write(ba, &errorMessage);
    if (!rc)
        emitError(errorMessage);
    return rc;
}

} // namespace trk