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#include "qversitreader_p.h"

#include "qversitdocument.h"

#include "versitutils_p.h"

#include "qmobilityglobal.h"

#include <QTextCodec>

#include <QMutexLocker>

#include <QVariant>

#include <QBuffer>

QTM_USE_NAMESPACE

// Some big enough value for nested versit documents to prevent infinite recursion

#define MAX_VERSIT_DOCUMENT_NESTING_DEPTH 20

/*!

  \class LineReader

  \brief The LineReader class is a wrapper around a QIODevice that allows line-by-line reading.

  This class keeps an internal buffer which it uses to temporarily store data which it has read from

  the device but not returned to the user.

 */

/*!

  Constructs a LineReader that reads from the given \a device using the given \a codec.

  \a chunkSize is the number of bytes to read at a time (it is useful for testing but shouldn't

  otherwise be set).

  */

LineReader::LineReader(QIODevice* device, QTextCodec *codec, int chunkSize)

    : mDevice(device),

    mCodec(codec),

    mChunkSize(chunkSize),

    mCrlfList(*VersitUtils::newlineList(mCodec)),

    mBuffer(VersitCursor(QByteArray())),

    mOdometer(0)

{

}

/*!

  Attempts to read a line and returns a VersitCursor describing the line.  The cursor returned

  includes the data, as well as the position and selection index bounds.  Data within those bounds

  represents the line.  Data outside those bounds should not be used.

 */

VersitCursor LineReader::readLine()

{

    mBuffer.position = mBuffer.selection;

    mSearchFrom = mBuffer.position;

    // First, look for a newline in the already-existing buffer.  If found, return the line.

    if (tryReadLine(mBuffer, false)) {

        mBuffer.dropOldData();

        mOdometer += mBuffer.selection - mBuffer.position;

        return mBuffer;

    }

    // Otherwise, keep reading more data until either a CRLF is found, or there's no more to read.

    while (!mDevice->atEnd()) {

        QByteArray temp = mDevice->read(mChunkSize);

        if (!temp.isEmpty()) {

            mBuffer.data.append(temp);

            if (tryReadLine(mBuffer, false)) {

                mBuffer.dropOldData();

                mOdometer += mBuffer.selection - mBuffer.position;

                return mBuffer;

            }

        } else {

            mDevice->waitForReadyRead(500);

        }

    }

    // We've reached the end of the stream.  Find a newline from the buffer (or return what's left).

    tryReadLine(mBuffer, true);

    mBuffer.dropOldData();

    mOdometer += mBuffer.selection - mBuffer.position;

    return mBuffer;

}

/*!

  How many bytes have been returned in the VersitCursor in the lifetime of the LineReader.

 */

int LineReader::odometer()

{

    return mOdometer;

}

/*!

  Returns true if there are no more lines left for readLine() to return.  It is possible for atEnd()

  to return false and for there to be no more data left (eg. if there are trailing newlines at the

  end of the input.  In this case, readLine() will return an empty line (ie. position == selection).

 */

bool LineReader::atEnd()

{

    return mDevice->atEnd() && mBuffer.selection == mBuffer.data.size();

}

/*!

  Returns the codec that the LineReader reads with.

 */

QTextCodec* LineReader::codec()

{

    return mCodec;

}

/*!

 * Get the next line of input from \a device to parse.  Also performs unfolding by removing

 * sequences of newline-space from the retrieved line.  Skips over any newlines at the start of the

 * input.

 *

 * Returns a VersitCursor containing and selecting the line.

 */

bool LineReader::tryReadLine(VersitCursor &cursor, bool atEnd)

{

    QByteArray space = VersitUtils::encode(' ', mCodec);

    QByteArray tab = VersitUtils::encode('\t', mCodec);

    int spaceLength = space.length();

    forever {

        foreach(const QByteArrayMatcher& crlf, mCrlfList) {

            int crlfLength = crlf.pattern().length();

            crlfPos = crlf.indexIn(cursor.data, mSearchFrom);

            if (crlfPos == cursor.position) {

                // Newline at start of line.  Set position to directly after it.

                cursor.position += crlfLength;

                mSearchFrom = cursor.position;

                break;

            } else if (crlfPos > cursor.position) {

                // Found the CRLF.

                if (QVersitReaderPrivate::containsAt(cursor.data, space, crlfPos + crlfLength)

                    || QVersitReaderPrivate::containsAt(cursor.data, tab, crlfPos + crlfLength)) {

                    // If it's followed by whitespace, collapse it.

                    cursor.data.remove(crlfPos, crlfLength + spaceLength);

                    mSearchFrom = crlfPos;

                    break;

                } else if (!atEnd && crlfPos + crlfLength + spaceLength >= cursor.data.size()) {

                    // If our CRLF is at the end of the current buffer but there's more to read,

                    // it's possible that a space could be hiding on the next read from the device.

                    // Just pretend we didn't see the CRLF and pick it up the next time round.

                    mSearchFrom = crlfPos;

                    return false;

                } else {

                    // Found the CRLF.

                    cursor.selection = crlfPos;

                    return true;

                }

            }

        }

        if (crlfPos == -1) {

            // No CRLF found.

            cursor.selection = cursor.data.size();

            return false;

        }

    }

}

/*! Construct a reader. */

QVersitReaderPrivate::QVersitReaderPrivate()

    : mIoDevice(0),

    mDocumentNestingLevel(0),

    mDefaultCodec(QTextCodec::codecForName("UTF-8")),

    mState(QVersitReader::InactiveState),

    mError(QVersitReader::NoError),

    mIsCanceling(false)

{

}

/*! Destroy a reader. */

QVersitReaderPrivate::~QVersitReaderPrivate()

{

}

/*!

 * Inherited from QThread, called by QThread when the thread has been started.

 */

void QVersitReaderPrivate::run()

{

    read();

}

/*!

 * Does the actual reading and sets the error and state as appropriate.

 * If \a async, then stateChanged() signals are emitted as the reading happens.

 */

void QVersitReaderPrivate::read()

{

    mMutex.lock();

    mVersitDocuments.clear();

    mMutex.unlock();

    bool canceled = false;

    LineReader lineReader(mIoDevice, mDefaultCodec);

    while(!lineReader.atEnd()) {

        if (isCanceling()) {

            canceled = true;

            break;

        }

        QVersitDocument document;

        int oldPos = lineReader.odometer();

        bool ok = parseVersitDocument(lineReader, document);

        if (ok) {

            if (document.isEmpty())

                break;

            else {

                QMutexLocker locker(&mMutex);

                mVersitDocuments.append(document);

            }

        } else {

            setError(QVersitReader::ParseError);

            if (lineReader.odometer() == oldPos)

                break;

        }

    };

    if (canceled)

        setState(QVersitReader::CanceledState);

    else

        setState(QVersitReader::FinishedState);

}

void QVersitReaderPrivate::setState(QVersitReader::State state)

{

    mMutex.lock();

    mState = state;

    mMutex.unlock();

    emit stateChanged(state);

}

QVersitReader::State QVersitReaderPrivate::state() const

{

    QMutexLocker locker(&mMutex);

    return mState;

}

void QVersitReaderPrivate::setError(QVersitReader::Error error)

{

    QMutexLocker locker(&mMutex);

    mError = error;

}

QVersitReader::Error QVersitReaderPrivate::error() const

{

    QMutexLocker locker(&mMutex);

    return mError;

}

void QVersitReaderPrivate::setCanceling(bool canceling)

{

    QMutexLocker locker(&mMutex);

    mIsCanceling = canceling;

}

bool QVersitReaderPrivate::isCanceling()

{

    QMutexLocker locker(&mMutex);

    return mIsCanceling;

}

/*!

 * Parses a versit document. Returns true if the parsing was successful.

 */

bool QVersitReaderPrivate::parseVersitDocument(LineReader& lineReader, QVersitDocument& document,

                                               bool foundBegin)

{

    if (mDocumentNestingLevel >= MAX_VERSIT_DOCUMENT_NESTING_DEPTH)

        return false; // To prevent infinite recursion

    bool parsingOk = true;

    mDocumentNestingLevel++;

    // TODO: Various readers should be made subclasses and eliminate assumptions like this.

    // We don't know what type it is: just assume it's a vCard 3.0

    document.setType(QVersitDocument::VCard30Type);

    QVersitProperty property;

    if (!foundBegin) {

        property = parseNextVersitProperty(document.type(), lineReader);

        if (property.name() == QLatin1String("BEGIN")

            && property.value().trimmed().toUpper() == QLatin1String("VCARD")) {

            foundBegin = true;

        } else if (property.isEmpty()) {

            // A blank document (or end of file) was found.

            document = QVersitDocument();

        } else {

            // Some property other than BEGIN was found.

            parsingOk = false;

        }

    }

    if (foundBegin) {

        do {

            /* Grab it */

            property = parseNextVersitProperty(document.type(), lineReader);

            /* Discard embedded vcard documents - not supported yet.  Discard the entire vCard */

            if (property.name() == QLatin1String("BEGIN") &&

                QString::compare(property.value().trimmed(),

                                 QLatin1String("VCARD"), Qt::CaseInsensitive) == 0) {

                parsingOk = false;

                QVersitDocument nestedDocument;

                if (!parseVersitDocument(lineReader, nestedDocument, true))

                    break;

            }

            // See if this is a version property and continue parsing under that version

            if (!setVersionFromProperty(document, property)) {

                parsingOk = false;

                break;

            }

            /* Nope, something else.. just add it */

            if (property.name() != QLatin1String("VERSION") &&

                property.name() != QLatin1String("END"))

                document.addProperty(property);

        } while (property.name().length() > 0 && property.name() != QLatin1String("END"));

        if (property.name() != QLatin1String("END"))

            parsingOk = false;

    }

    mDocumentNestingLevel--;

    if (!parsingOk)

        document = QVersitDocument();

    return parsingOk;

}

/*!

 * Parses a versit document and returns whether parsing succeeded.

 */

QVersitProperty QVersitReaderPrivate::parseNextVersitProperty(

        QVersitDocument::VersitType versitType,

        LineReader& lineReader)

{

    VersitCursor cursor = lineReader.readLine();

    if (cursor.position >= cursor.selection)

        return QVersitProperty();

    // Otherwise, do stuff.

    QPair<QStringList,QString> groupsAndName =

            extractPropertyGroupsAndName(cursor, lineReader.codec());

    QVersitProperty property;

    property.setGroups(groupsAndName.first);

    property.setName(groupsAndName.second);

    if (versitType == QVersitDocument::VCard21Type)

        parseVCard21Property(cursor, property, lineReader);

    else if (versitType == QVersitDocument::VCard30Type)

        parseVCard30Property(cursor, property, lineReader);

    return property;

}

/*!

 * Parses the property according to vCard 2.1 syntax.

 */

void QVersitReaderPrivate::parseVCard21Property(VersitCursor& cursor, QVersitProperty& property,

                                                LineReader& lineReader)

{

    property.setParameters(extractVCard21PropertyParams(cursor, lineReader.codec()));

    QByteArray value = extractPropertyValue(cursor);

        // Hack to handle cases where start of document is on the same or next line as "AGENT:"

        bool foundBegin = false;

        if (value == "BEGIN:VCARD") {

            foundBegin = true;

        } else if (value.isEmpty()) {

        } else {

            property = QVersitProperty();

            return;

        }

            property = QVersitProperty();

        } else {

        }

    } else {

        QTextCodec* codec;

        QVariant valueVariant(decodeCharset(value, property, lineReader.codec(), &codec));

        property.setValue(valueVariant);

    }

}

/*!

 * Parses the property according to vCard 3.0 syntax.

 */

void QVersitReaderPrivate::parseVCard30Property(VersitCursor& cursor, QVersitProperty& property,

                                                LineReader& lineReader)

{

    property.setParameters(extractVCard30PropertyParams(cursor, lineReader.codec()));

    QByteArray value = extractPropertyValue(cursor);

    QTextCodec* codec;

    QString valueString(decodeCharset(value, property, lineReader.codec(), &codec));

        // Make a line reader from the value of the property.

            property = QVersitProperty();

        } else {

        }

    } else {

        QVariant valueVariant(valueString);

        }

    }

}