File indexing completed on 2024-04-28 03:53:33

 /*
     This file is part of the KContacts framework.
     SPDX-FileCopyrightText: 2003 Tobias Koenig <tokoe@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "kcontacts_debug.h"
 #include "vcardparser_p.h"
 #include <KCodecs>
 #include <QStringDecoder>
 #include <QStringEncoder>
 #include <functional>
 
 // This cache for QString::fromLatin1() isn't about improving speed, but about reducing memory usage by sharing common strings
 class StringCache
 {
 public:
     QString fromLatin1(const QByteArray &value)
     {
         if (value.isEmpty()) {
             return QString();
         }
 
         auto it = m_values.constFind(value);
         if (it != m_values.constEnd()) {
             return it.value();
         }
 
         QString string = QString::fromLatin1(value);
         m_values.insert(value, string);
         return string;
     }
 
 private:
     QHash<QByteArray, QString> m_values;
 };
 
 using namespace KContacts;
 
 static void addEscapes(QByteArray &str, bool excludeEscapedComma)
 {
     str.replace('\\', "\\\\");
     if (!excludeEscapedComma) {
         str.replace(',', "\\,");
     }
     str.replace('\r', "\\r");
     str.replace('\n', "\\n");
 }
 
 static void removeEscapes(QByteArray &str)
 {
     // It's more likely that no escape is present, so add fast path
     if (!str.contains('\\')) {
         return;
     }
     str.replace("\\n", "\n");
     str.replace("\\N", "\n");
     str.replace("\\r", "\r");
     str.replace("\\,", ",");
     str.replace("\\\\", "\\");
 }
 
 class VCardLineParser
 {
 public:
     VCardLineParser(StringCache &cache, std::function<QByteArray()> fetchAnotherLine)
         : m_cache(cache)
         , m_fetchAnotherLine(fetchAnotherLine)
     {
     }
 
     void parseLine(const QByteArray &currentLine, VCardLine *vCardLine);
 
 private:
     void addParameter(const QByteArray &paramKey, const QByteArray &paramValue);
 
 private:
     StringCache &m_cache;
     std::function<QByteArray()> m_fetchAnotherLine;
 
     VCardLine *m_vCardLine = nullptr;
     QByteArray m_encoding;
     QByteArray m_charset;
 };
 
 void VCardLineParser::addParameter(const QByteArray &paramKey, const QByteArray &paramValue)
 {
     if (paramKey == "encoding") {
         m_encoding = paramValue.toLower();
     } else if (paramKey == "charset") {
         m_charset = paramValue.toLower();
     }
     // qDebug() << "  add parameter" << paramKey << "    =    " << paramValue;
     m_vCardLine->addParameter(m_cache.fromLatin1(paramKey), m_cache.fromLatin1(paramValue));
 }
 
 void VCardLineParser::parseLine(const QByteArray &currentLine, KContacts::VCardLine *vCardLine)
 {
     // qDebug() << currentLine;
     m_vCardLine = vCardLine;
     // The syntax is key:value, but the key can contain semicolon-separated parameters, which can contain a ':', so indexOf(':') is wrong.
     // EXAMPLE: ADR;GEO="geo:22.500000,45.099998";LABEL="My Label";TYPE=home:P.O. Box 101;;;Any Town;CA;91921-1234;
     // Therefore we need a small state machine, just the way I like it.
     enum State {
         StateInitial,
         StateParamKey,
         StateParamValue,
         StateQuotedValue,
         StateAfterParamValue,
         StateValue,
     };
     State state = StateInitial;
     const int lineLength = currentLine.length();
     const char *lineData = currentLine.constData(); // to skip length checks from at() in debug mode
     QByteArray paramKey;
     QByteArray paramValue;
     int start = 0;
     int pos = 0;
     for (; pos < lineLength; ++pos) {
         const char ch = lineData[pos];
         const bool colonOrSemicolon = (ch == ';' || ch == ':');
         switch (state) {
         case StateInitial:
             if (colonOrSemicolon) {
                 const QByteArray identifier = currentLine.mid(start, pos - start);
                 // qDebug() << " identifier" << identifier;
                 vCardLine->setIdentifier(m_cache.fromLatin1(identifier));
                 start = pos + 1;
             }
             if (ch == ';') {
                 state = StateParamKey;
             } else if (ch == ':') {
                 state = StateValue;
             } else if (ch == '.') {
                 vCardLine->setGroup(m_cache.fromLatin1(currentLine.mid(start, pos - start)));
                 start = pos + 1;
             }
             break;
         case StateParamKey:
             if (colonOrSemicolon || ch == '=') {
                 paramKey = currentLine.mid(start, pos - start);
                 start = pos + 1;
             }
             if (colonOrSemicolon) {
                 // correct the so-called 2.1 'standard'
                 paramValue = paramKey;
                 const QByteArray lowerKey = paramKey.toLower();
                 if (lowerKey == "quoted-printable" || lowerKey == "base64") {
                     paramKey = "encoding";
                 } else {
                     paramKey = "type";
                 }
                 addParameter(paramKey, paramValue);
             }
             if (ch == ';') {
                 state = StateParamKey;
             } else if (ch == ':') {
                 state = StateValue;
             } else if (ch == '=') {
                 state = StateParamValue;
             }
             break;
         case StateQuotedValue:
             if (ch == '"' || (ch == ',' && paramKey.toLower() == "type")) {
                 // TODO the hack above is for TEL;TYPE=\"voice,home\":... without breaking GEO.... TODO: check spec
                 paramValue = currentLine.mid(start, pos - start);
                 addParameter(paramKey.toLower(), paramValue);
                 start = pos + 1;
                 if (ch == '"') {
                     state = StateAfterParamValue; // to avoid duplicating code with StateParamValue, we use this intermediate state for one char
                 }
             }
             break;
         case StateParamValue:
             if (colonOrSemicolon || ch == ',') {
                 paramValue = currentLine.mid(start, pos - start);
                 addParameter(paramKey.toLower(), paramValue);
                 start = pos + 1;
             }
             // fall-through intended
             Q_FALLTHROUGH();
         case StateAfterParamValue:
             if (ch == ';') {
                 state = StateParamKey;
                 start = pos + 1;
             } else if (ch == ':') {
                 state = StateValue;
             } else if (pos == start && ch == '"') { // don't treat foo"bar" as quoted - TODO check the vCard 3.0 spec.
                 state = StateQuotedValue;
                 start = pos + 1;
             }
             break;
         case StateValue:
             Q_UNREACHABLE();
             break;
         }
 
         if (state == StateValue) {
             break;
         }
     }
 
     if (state != StateValue) { // invalid line, no ':'
         return;
     }
 
     QByteArray value = currentLine.mid(pos + 1);
     removeEscapes(value);
 
     QByteArray output;
     bool wasBase64Encoded = false;
 
     if (!m_encoding.isEmpty()) {
         // have to decode the data
         if (m_encoding == "b" || m_encoding == "base64") {
             output = QByteArray::fromBase64(value);
             wasBase64Encoded = true;
         } else if (m_encoding == "quoted-printable") {
             // join any qp-folded lines
             while (value.endsWith('=')) {
                 value.chop(1); // remove the '='
                 value.append(m_fetchAnotherLine());
             }
             KCodecs::quotedPrintableDecode(value, output);
         } else if (m_encoding == "8bit") {
             output = value;
         } else {
             qDebug("Unknown vcard encoding type!");
         }
     } else {
         output = value;
     }
 
     if (!m_charset.isEmpty()) {
         // have to convert the data
         auto codec = QStringDecoder(m_charset.constData());
         if (codec.isValid()) {
             vCardLine->setValue(QVariant::fromValue<QString>(codec.decode(output)));
         } else {
             vCardLine->setValue(QString::fromUtf8(output));
         }
     } else if (wasBase64Encoded) {
         vCardLine->setValue(output);
     } else {
         vCardLine->setValue(QString::fromUtf8(output));
     }
 }
 
 ////
 
 VCardParser::VCardParser()
 {
 }
 
 VCardParser::~VCardParser()
 {
 }
 
 VCard::List VCardParser::parseVCards(const QByteArray &text)
 {
     VCard currentVCard;
     VCard::List vCardList;
     QByteArray currentLine;
 
     int lineStart = 0;
     int lineEnd = text.indexOf('\n');
 
     bool inVCard = false;
 
     StringCache cache;
     for (; lineStart != text.size() + 1;
          lineStart = lineEnd + 1, lineEnd = (text.indexOf('\n', lineStart) == -1) ? text.size() : text.indexOf('\n', lineStart)) {
         QByteArray cur = text.mid(lineStart, lineEnd - lineStart);
         // remove the trailing \r, left from \r\n
         if (cur.endsWith('\r')) {
             cur.chop(1);
         }
 
         if (cur.startsWith(' ') //
             || cur.startsWith('\t')) { // folded line => append to previous
             currentLine.append(cur.mid(1));
             continue;
         } else {
             if (cur.trimmed().isEmpty()) { // empty line
                 continue;
             }
             if (inVCard && !currentLine.isEmpty()) { // now parse the line
                 VCardLine vCardLine;
 
                 // Provide a way for the parseVCardLine function to read more lines (for quoted-printable support)
                 auto fetchAnotherLine = [&text, &lineStart, &lineEnd, &cur]() -> QByteArray {
                     const QByteArray ret = cur;
                     lineStart = lineEnd + 1;
                     lineEnd = text.indexOf('\n', lineStart);
                     if (lineEnd != -1) {
                         cur = text.mid(lineStart, lineEnd - lineStart);
                         // remove the trailing \r, left from \r\n
                         if (cur.endsWith('\r')) {
                             cur.chop(1);
                         }
                     }
                     return ret;
                 };
 
                 VCardLineParser lineParser(cache, fetchAnotherLine);
 
                 lineParser.parseLine(currentLine, &vCardLine);
 
                 currentVCard.addLine(vCardLine);
             }
 
             // we do not save the start and end tag as vcardline
             if (qstrnicmp(cur.constData(), "begin:vcard", 11) == 0) {
                 inVCard = true;
                 currentLine.clear();
                 currentVCard.clear(); // flush vcard
                 continue;
             }
 
             if (qstrnicmp(cur.constData(), "end:vcard", 9) == 0) {
                 inVCard = false;
                 vCardList.append(currentVCard);
                 currentLine.clear();
                 currentVCard.clear(); // flush vcard
                 continue;
             }
 
             currentLine = cur;
         }
     }
 
     return vCardList;
 }
 
 static const int FOLD_WIDTH = 75;
 
 QByteArray VCardParser::createVCards(const VCard::List &list)
 {
     QByteArray text;
     QByteArray textLine;
     QString encodingType;
     QStringList params;
     QStringList values;
 
     VCardLine::List lines;
 
     bool hasEncoding;
 
     text.reserve(list.size() * 300); // reserve memory to be more efficient
 
     // iterate over the cards
     for (const VCard &card : list) {
         text.append("BEGIN:VCARD\r\n");
 
         QStringList idents = card.identifiers();
         // VERSION must be first
         if (idents.contains(QLatin1String("VERSION"))) {
             const QString str = idents.takeAt(idents.indexOf(QLatin1String("VERSION")));
             idents.prepend(str);
         }
 
         for (const auto &id : std::as_const(idents)) {
             lines = card.lines(id);
 
             // iterate over the lines
             for (const VCardLine &vline : std::as_const(lines)) {
                 QVariant val = vline.value();
                 if (val.isValid()) {
                     if (vline.hasGroup()) {
                         textLine = vline.group().toLatin1() + '.' + vline.identifier().toLatin1();
                     } else {
                         textLine = vline.identifier().toLatin1();
                     }
 
                     params = vline.parameterList();
                     hasEncoding = false;
                     if (!params.isEmpty()) { // we have parameters
                         for (const QString &param : std::as_const(params)) {
                             if (param == QLatin1String("encoding")) {
                                 hasEncoding = true;
                                 encodingType = vline.parameter(QStringLiteral("encoding")).toLower();
                             }
 
                             values = vline.parameters(param);
                             for (const QString &str : std::as_const(values)) {
                                 textLine.append(';' + param.toLatin1().toUpper());
                                 if (!str.isEmpty()) {
                                     textLine.append('=' + str.toLatin1());
                                 }
                             }
                         }
                     }
 
                     QByteArray input;
                     QByteArray output;
                     bool checkMultibyte = false; // avoid splitting a multibyte character
 
                     // handle charset
                     const QString charset = vline.parameter(QStringLiteral("charset"));
                     if (!charset.isEmpty()) {
                         // have to convert the data
                         const QString value = vline.value().toString();
                         auto codec = QStringEncoder(charset.toLatin1().constData());
                         if (codec.isValid()) {
                             input = codec.encode(value);
                         } else {
                             checkMultibyte = true;
                             input = value.toUtf8();
                         }
                     } else if (vline.value().userType() == QMetaType::QByteArray) {
                         input = vline.value().toByteArray();
                     } else {
                         checkMultibyte = true;
                         input = vline.value().toString().toUtf8();
                     }
 
                     // handle encoding
                     if (hasEncoding) { // have to encode the data
                         if (encodingType == QLatin1Char('b')) {
                             checkMultibyte = false;
                             output = input.toBase64();
                         } else if (encodingType == QLatin1String("quoted-printable")) {
                             checkMultibyte = false;
                             KCodecs::quotedPrintableEncode(input, output, false);
                         }
                     } else {
                         output = input;
                     }
                     addEscapes(output, (vline.identifier() == QLatin1String("CATEGORIES") || vline.identifier() == QLatin1String("GEO")));
 
                     if (!output.isEmpty()) {
                         textLine.append(':' + output);
 
                         if (textLine.length() > FOLD_WIDTH) { // we have to fold the line
                             if (checkMultibyte) {
                                 // RFC 6350: Multi-octet characters MUST remain contiguous.
                                 // we know that textLine contains UTF-8 encoded characters
                                 int lineLength = 0;
                                 for (int i = 0; i < textLine.length(); ++i) {
                                     if ((textLine[i] & 0xC0) == 0xC0) { // a multibyte sequence follows
                                         int sequenceLength = 2;
                                         if ((textLine[i] & 0xE0) == 0xE0) {
                                             sequenceLength = 3;
                                         } else if ((textLine[i] & 0xF0) == 0xF0) {
                                             sequenceLength = 4;
                                         }
                                         if ((lineLength + sequenceLength) > FOLD_WIDTH) {
                                             // the current line would be too long. fold it
                                             text += "\r\n " + textLine.mid(i, sequenceLength);
                                             lineLength = 1 + sequenceLength; // incl. leading space
                                         } else {
                                             text += textLine.mid(i, sequenceLength);
                                             lineLength += sequenceLength;
                                         }
                                         i += sequenceLength - 1;
                                     } else {
                                         text += textLine[i];
                                         ++lineLength;
                                     }
                                     if ((lineLength == FOLD_WIDTH) && (i < (textLine.length() - 1))) {
                                         text += "\r\n ";
                                         lineLength = 1; // leading space
                                     }
                                 }
                                 text += "\r\n";
                             } else {
                                 for (int i = 0; i <= (textLine.length() / FOLD_WIDTH); ++i) {
                                     text.append((i == 0 ? "" : " ") + textLine.mid(i * FOLD_WIDTH, FOLD_WIDTH) + "\r\n");
                                 }
                             }
                         } else {
                             text.append(textLine);
                             text.append("\r\n");
                         }
                     }
                 }
             }
         }
 
         text.append("END:VCARD\r\n");
         text.append("\r\n");
     }
 
     return text;
 }