File indexing completed on 2024-04-28 03:53:49

 /*
     SPDX-FileCopyrightText: 2002 Dave Corrie <kde@davecorrie.com>
     SPDX-FileCopyrightText: 2014 Daniel Vrátil <dvratil@redhat.com>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "ktexttohtml.h"
 #include "kemoticonsparser_p.h"
 #include "ktexttohtml_p.h"
 
 #include <QCoreApplication>
 #include <QFile>
 #include <QRegularExpression>
 #include <QStringList>
 
 #include <limits.h>
 
 KTextToHTMLHelper::KTextToHTMLHelper(const QString &plainText, int pos, int maxUrlLen, int maxAddressLen)
     : mText(plainText)
     , mMaxUrlLen(maxUrlLen)
     , mMaxAddressLen(maxAddressLen)
     , mPos(pos)
 {
 }
 
 QString KTextToHTMLHelper::getEmailAddress()
 {
     QString address;
 
     if (mPos < mText.length() && mText.at(mPos) == QLatin1Char('@')) {
         // the following characters are allowed in a dot-atom (RFC 2822):
         // a-z A-Z 0-9 . ! # $ % & ' * + - / = ? ^ _ ` { | } ~
         const QString allowedSpecialChars = QStringLiteral(".!#$%&'*+-/=?^_`{|}~");
 
         // determine the local part of the email address
         int start = mPos - 1;
         while (start >= 0 && mText.at(start).unicode() < 128
                && (mText.at(start).isLetterOrNumber() //
                    || mText.at(start) == QLatin1Char('@') // allow @ to find invalid email addresses
                    || allowedSpecialChars.indexOf(mText.at(start)) != -1)) {
             if (mText.at(start) == QLatin1Char('@')) {
                 return QString(); // local part contains '@' -> no email address
             }
             --start;
         }
         ++start;
         // we assume that an email address starts with a letter or a digit
         while ((start < mPos) && !mText.at(start).isLetterOrNumber()) {
             ++start;
         }
         if (start == mPos) {
             return QString(); // local part is empty -> no email address
         }
 
         // determine the domain part of the email address
         int dotPos = INT_MAX;
         int end = mPos + 1;
         while (end < mText.length()
                && (mText.at(end).isLetterOrNumber() //
                    || mText.at(end) == QLatin1Char('@') // allow @ to find invalid email addresses
                    || mText.at(end) == QLatin1Char('.') //
                    || mText.at(end) == QLatin1Char('-'))) {
             if (mText.at(end) == QLatin1Char('@')) {
                 return QString(); // domain part contains '@' -> no email address
             }
             if (mText.at(end) == QLatin1Char('.')) {
                 dotPos = qMin(dotPos, end); // remember index of first dot in domain
             }
             ++end;
         }
         // we assume that an email address ends with a letter or a digit
         while ((end > mPos) && !mText.at(end - 1).isLetterOrNumber()) {
             --end;
         }
         if (end == mPos) {
             return QString(); // domain part is empty -> no email address
         }
         if (dotPos >= end) {
             return QString(); // domain part doesn't contain a dot
         }
 
         if (end - start > mMaxAddressLen) {
             return QString(); // too long -> most likely no email address
         }
         address = mText.mid(start, end - start);
 
         mPos = end - 1;
     }
     return address;
 }
 
 QString KTextToHTMLHelper::getPhoneNumber()
 {
     if (!mText.at(mPos).isDigit() && mText.at(mPos) != QLatin1Char('+')) {
         return {};
     }
 
     const QString allowedBeginSeparators = QStringLiteral(" \r\t\n:");
     if (mPos > 0 && !allowedBeginSeparators.contains(mText.at(mPos - 1))) {
         return {};
     }
 
     // this isn't 100% accurate, we filter stuff below that is too hard to capture with a regexp
     static const QRegularExpression telPattern(QStringLiteral(R"([+0](( |( ?[/-] ?)?)\(?\d+\)?+){6,30})"));
     const auto match = telPattern.match(mText, mPos, QRegularExpression::NormalMatch, QRegularExpression::AnchorAtOffsetMatchOption);
     if (match.hasMatch()) {
         QStringView matchedText = match.capturedView();
         // check for maximum number of digits (15), see https://en.wikipedia.org/wiki/Telephone_numbering_plan
         const int digitsCount = std::count_if(matchedText.cbegin(), matchedText.cend(), [](const QChar c) {
             return c.isDigit();
         });
 
         if (digitsCount > 15) {
             return {};
         }
 
         // only one / is allowed, otherwise we trigger on dates
         if (matchedText.count(QLatin1Char('/')) > 1) {
             return {};
         }
 
         // parenthesis need to be balanced, and must not be nested
         int openIdx = -1;
         for (int i = 0, size = matchedText.size(); i < size; ++i) {
             const QChar ch = matchedText.at(i);
             if ((ch == QLatin1Char('(') && openIdx >= 0) || (ch == QLatin1Char(')') && openIdx < 0)) {
                 return {};
             }
 
             if (ch == QLatin1Char('(')) {
                 openIdx = i;
             } else if (ch == QLatin1Char(')')) {
                 openIdx = -1;
             }
         }
 
         if (openIdx > 0) {
             matchedText.truncate(openIdx - 1);
             matchedText = matchedText.trimmed();
         }
 
         // check if there's a plausible separator at the end
         const int matchedTextLength = matchedText.size();
         const int endIdx = mPos + matchedTextLength;
         if (endIdx < mText.size() && !QStringView(u" \r\t\n,.").contains(mText.at(endIdx))) {
             return {};
         }
 
         mPos += matchedTextLength - 1;
         return matchedText.toString();
     }
     return {};
 }
 
 static QString normalizePhoneNumber(const QString &str)
 {
     QString res;
     res.reserve(str.size());
     for (const auto c : str) {
         if (c.isDigit() || c == QLatin1Char('+')) {
             res.push_back(c);
         }
     }
     return res;
 }
 
 // The following characters are allowed in a dot-atom (RFC 2822):
 // a-z A-Z 0-9 . ! # $ % & ' * + - / = ? ^ _ ` { | } ~
 static const char s_allowedSpecialChars[] = ".!#$%&'*+-/=?^_`{|}~";
 
 bool KTextToHTMLHelper::atUrl() const
 {
     // The character directly before the URL must not be a letter, a number or
     // any other character allowed in a dot-atom (RFC 2822).
     if (mPos > 0) {
         const auto chBefore = mText.at(mPos - 1);
         if (chBefore.isLetterOrNumber() || QLatin1String(s_allowedSpecialChars).contains(chBefore)) {
             return false;
         }
     }
 
     const auto segment = QStringView(mText).mid(mPos);
     /* clang-format off */
     return segment.startsWith(QLatin1String("http://"))
         || segment.startsWith(QLatin1String("https://"))
         || segment.startsWith(QLatin1String("vnc://"))
         || segment.startsWith(QLatin1String("fish://"))
         || segment.startsWith(QLatin1String("ftp://"))
         || segment.startsWith(QLatin1String("ftps://"))
         || segment.startsWith(QLatin1String("sftp://"))
         || segment.startsWith(QLatin1String("smb://"))
         || segment.startsWith(QLatin1String("irc://"))
         || segment.startsWith(QLatin1String("ircs://"))
         || segment.startsWith(QLatin1String("mailto:"))
         || segment.startsWith(QLatin1String("www."))
         || segment.startsWith(QLatin1String("ftp."))
         || segment.startsWith(QLatin1String("file://"))
         || segment.startsWith(QLatin1String("news:"))
         || segment.startsWith(QLatin1String("tel:"))
         || segment.startsWith(QLatin1String("xmpp:"));
     /* clang-format on */
 }
 
 bool KTextToHTMLHelper::isEmptyUrl(const QString &url) const
 {
     /* clang-format off */
     return url.isEmpty()
         || url == QLatin1String("http://")
         || url == QLatin1String("https://")
         || url == QLatin1String("fish://")
         || url == QLatin1String("ftp://")
         || url == QLatin1String("ftps://")
         || url == QLatin1String("sftp://")
         || url == QLatin1String("smb://")
         || url == QLatin1String("vnc://")
         || url == QLatin1String("irc://")
         || url == QLatin1String("ircs://")
         || url == QLatin1String("mailto")
         || url == QLatin1String("mailto:")
         || url == QLatin1String("www")
         || url == QLatin1String("ftp")
         || url == QLatin1String("news:")
         || url == QLatin1String("news://")
         || url == QLatin1String("tel")
         || url == QLatin1String("tel:")
         || url == QLatin1String("xmpp:");
     /* clang-format on */
 }
 
 QString KTextToHTMLHelper::getUrl(bool *badurl)
 {
     QString url;
     if (atUrl()) {
         // NOTE: see http://tools.ietf.org/html/rfc3986#appendix-A and especially appendix-C
         // Appendix-C mainly says, that when extracting URLs from plain text, line breaks shall
         // be allowed and should be ignored when the URI is extracted.
 
         // This implementation follows this recommendation and
         // allows the URL to be enclosed within different kind of brackets/quotes
         // If an URL is enclosed, whitespace characters are allowed and removed, otherwise
         // the URL ends with the first whitespace
         // Also, if the URL is enclosed in brackets, the URL itself is not allowed
         // to contain the closing bracket, as this would be detected as the end of the URL
 
         QChar beforeUrl;
         QChar afterUrl;
 
         // detect if the url has been surrounded by brackets or quotes
         if (mPos > 0) {
             beforeUrl = mText.at(mPos - 1);
 
             /*if ( beforeUrl == '(' ) {
               afterUrl = ')';
             } else */
             if (beforeUrl == QLatin1Char('[')) {
                 afterUrl = QLatin1Char(']');
             } else if (beforeUrl == QLatin1Char('<')) {
                 afterUrl = QLatin1Char('>');
             } else if (beforeUrl == QLatin1Char('>')) { // for e.g. <link>http://.....</link>
                 afterUrl = QLatin1Char('<');
             } else if (beforeUrl == QLatin1Char('"')) {
                 afterUrl = QLatin1Char('"');
             }
         }
         url.reserve(mMaxUrlLen); // avoid allocs
         int start = mPos;
         bool previousCharIsSpace = false;
         bool previousCharIsADoubleQuote = false;
         bool previousIsAnAnchor = false;
         /* clang-format off */
         while (mPos < mText.length() //
                && (mText.at(mPos).isPrint() || mText.at(mPos).isSpace())
                && ((afterUrl.isNull() && !mText.at(mPos).isSpace())
                    || (!afterUrl.isNull() && mText.at(mPos) != afterUrl))) {
             if (!previousCharIsSpace
                 && mText.at(mPos) == QLatin1Char('<')
                 && (mPos + 1) < mText.length()) { /* clang-format on */
                 // Fix Bug #346132: allow "http://www.foo.bar<http://foo.bar/>"
                 // < inside a URL is not allowed, however there is a test which
                 // checks that "http://some<Host>/path" should be allowed
                 // Therefore: check if what follows is another URL and if so, stop here
                 mPos++;
                 if (atUrl()) {
                     mPos--;
                     break;
                 }
                 mPos--;
             }
             if (!previousCharIsSpace && (mText.at(mPos) == QLatin1Char(' ')) && ((mPos + 1) < mText.length())) {
                 // Fix kmail bug: allow "http://www.foo.bar http://foo.bar/"
                 // Therefore: check if what follows is another URL and if so, stop here
                 mPos++;
                 if (atUrl()) {
                     mPos--;
                     break;
                 }
                 mPos--;
             }
             if (mText.at(mPos).isSpace()) {
                 previousCharIsSpace = true;
             } else if (!previousIsAnAnchor && mText.at(mPos) == QLatin1Char('[')) {
                 break;
             } else if (!previousIsAnAnchor && mText.at(mPos) == QLatin1Char(']')) {
                 break;
             } else { // skip whitespace
                 if (previousCharIsSpace && mText.at(mPos) == QLatin1Char('<')) {
                     url.append(QLatin1Char(' '));
                     break;
                 }
                 previousCharIsSpace = false;
                 if (mText.at(mPos) == QLatin1Char('>') && previousCharIsADoubleQuote) {
                     // it's an invalid url
                     if (badurl) {
                         *badurl = true;
                     }
                     return QString();
                 }
                 if (mText.at(mPos) == QLatin1Char('"')) {
                     previousCharIsADoubleQuote = true;
                 } else {
                     previousCharIsADoubleQuote = false;
                 }
                 if (mText.at(mPos) == QLatin1Char('#')) {
                     previousIsAnAnchor = true;
                 }
                 url.append(mText.at(mPos));
                 if (url.length() > mMaxUrlLen) {
                     break;
                 }
             }
 
             ++mPos;
         }
 
         if (isEmptyUrl(url) || (url.length() > mMaxUrlLen)) {
             mPos = start;
             url.clear();
             return url;
         } else {
             --mPos;
         }
     }
 
     // HACK: This is actually against the RFC. However, most people don't properly escape the URL in
     //       their text with "" or <>. That leads to people writing an url, followed immediately by
     //       a dot to finish the sentence. That would lead the parser to include the dot in the url,
     //       even though that is not wanted. So work around that here.
     //       Most real-life URLs hopefully don't end with dots or commas.
     QString wordBoundaries = QStringLiteral(".,:!?>");
     bool hasOpenParenthese = url.contains(QLatin1Char('('));
     if (!hasOpenParenthese) {
         wordBoundaries += QLatin1Char(')');
     }
 
     if (url.length() > 1) {
         do {
             const QChar charact{url.at(url.length() - 1)};
             if (wordBoundaries.contains(charact)) {
                 url.chop(1);
                 --mPos;
             } else if (hasOpenParenthese && (charact == QLatin1Char(')'))) {
                 if (url.length() > 2) {
                     if (url.at(url.length() - 2) == QLatin1Char(')')) {
                         url.chop(1);
                         --mPos;
                         hasOpenParenthese = false;
                     } else {
                         break;
                     }
                 } else {
                     break;
                 }
             } else {
                 break;
             }
         } while (url.length() > 1);
     }
     return url;
 }
 
 QString KTextToHTMLHelper::highlightedText()
 {
     // formating symbols must be prepended with a whitespace
     if ((mPos > 0) && !mText.at(mPos - 1).isSpace()) {
         return QString();
     }
 
     const QChar ch = mText.at(mPos);
     if (ch != QLatin1Char('/') && ch != QLatin1Char('*') && ch != QLatin1Char('_') && ch != QLatin1Char('-')) {
         return QString();
     }
 
     const QRegularExpression re(QStringLiteral("\\%1([^\\s|^\\%1].*[^\\s|^\\%1])\\%1").arg(ch), QRegularExpression::InvertedGreedinessOption);
     const auto match =
         re.match(mText, mPos, QRegularExpression::NormalMatch, QRegularExpression::AnchorAtOffsetMatchOption); // clazy:exclude=use-static-qregularexpression
 
     if (match.hasMatch()) {
         if (match.capturedStart() == mPos) {
             int length = match.capturedLength();
             // there must be a whitespace after the closing formating symbol
             if (mPos + length < mText.length() && !mText.at(mPos + length).isSpace()) {
                 return QString();
             }
             mPos += length - 1;
             switch (ch.toLatin1()) {
             case '*':
                 return QLatin1String("<b>*") + match.capturedView(1) + QLatin1String("*</b>");
             case '_':
                 return QLatin1String("<u>_") + match.capturedView(1) + QLatin1String("_</u>");
             case '/':
                 return QLatin1String("<i>/") + match.capturedView(1) + QLatin1String("/</i>");
             case '-':
                 return QLatin1String("<s>-") + match.capturedView(1) + QLatin1String("-</s>");
             }
         }
     }
     return QString();
 }
 
 QString KTextToHTML::convertToHtml(const QString &plainText, const KTextToHTML::Options &flags, int maxUrlLen, int maxAddressLen)
 {
     KTextToHTMLHelper helper(plainText, 0, maxUrlLen, maxAddressLen);
 
     QString str;
     QString result(static_cast<QChar *>(nullptr), helper.mText.length() * 2);
     QChar ch;
     int x;
     bool startOfLine = true;
 
     for (helper.mPos = 0, x = 0; helper.mPos < helper.mText.length(); ++helper.mPos, ++x) {
         ch = helper.mText.at(helper.mPos);
         if (flags & PreserveSpaces) {
             if (ch == QLatin1Char(' ')) {
                 if (helper.mPos + 1 < helper.mText.length()) {
                     if (helper.mText.at(helper.mPos + 1) != QLatin1Char(' ')) {
                         // A single space, make it breaking if not at the start or end of the line
                         const bool endOfLine = helper.mText.at(helper.mPos + 1) == QLatin1Char('\n');
                         if (!startOfLine && !endOfLine) {
                             result += QLatin1Char(' ');
                         } else {
                             result += QLatin1String("&nbsp;");
                         }
                     } else {
                         // Whitespace of more than one space, make it all non-breaking
                         while (helper.mPos < helper.mText.length() && helper.mText.at(helper.mPos) == QLatin1Char(' ')) {
                             result += QLatin1String("&nbsp;");
                             ++helper.mPos;
                             ++x;
                         }
 
                         // We incremented once to often, undo that
                         --helper.mPos;
                         --x;
                     }
                 } else {
                     // Last space in the text, it is non-breaking
                     result += QLatin1String("&nbsp;");
                 }
 
                 if (startOfLine) {
                     startOfLine = false;
                 }
                 continue;
             } else if (ch == QLatin1Char('\t')) {
                 do {
                     result += QLatin1String("&nbsp;");
                     ++x;
                 } while ((x & 7) != 0);
                 --x;
                 startOfLine = false;
                 continue;
             }
         }
         if (ch == QLatin1Char('\n')) {
             result += QLatin1String("<br />\n"); // Keep the \n, so apps can figure out the quoting levels correctly.
             startOfLine = true;
             x = -1;
             continue;
         }
 
         startOfLine = false;
         if (ch == QLatin1Char('&')) {
             result += QLatin1String("&amp;");
         } else if (ch == QLatin1Char('"')) {
             result += QLatin1String("&quot;");
         } else if (ch == QLatin1Char('<')) {
             result += QLatin1String("&lt;");
         } else if (ch == QLatin1Char('>')) {
             result += QLatin1String("&gt;");
         } else {
             const int start = helper.mPos;
             if (!(flags & IgnoreUrls)) {
                 bool badUrl = false;
                 str = helper.getUrl(&badUrl);
                 if (badUrl) {
                     QString resultBadUrl;
                     for (const QChar chBadUrl : std::as_const(helper.mText)) {
                         if (chBadUrl == QLatin1Char('&')) {
                             resultBadUrl += QLatin1String("&amp;");
                         } else if (chBadUrl == QLatin1Char('"')) {
                             resultBadUrl += QLatin1String("&quot;");
                         } else if (chBadUrl == QLatin1Char('<')) {
                             resultBadUrl += QLatin1String("&lt;");
                         } else if (chBadUrl == QLatin1Char('>')) {
                             resultBadUrl += QLatin1String("&gt;");
                         } else {
                             resultBadUrl += chBadUrl;
                         }
                     }
                     return resultBadUrl;
                 }
                 if (!str.isEmpty()) {
                     QString hyperlink;
                     if (str.startsWith(QLatin1String("www."))) {
                         hyperlink = QLatin1String("http://") + str;
                     } else if (str.startsWith(QLatin1String("ftp."))) {
                         hyperlink = QLatin1String("ftp://") + str;
                     } else {
                         hyperlink = str;
                     }
                     result += QLatin1String("<a href=\"") + hyperlink + QLatin1String("\">") + str.toHtmlEscaped() + QLatin1String("</a>");
                     x += helper.mPos - start;
                     continue;
                 }
                 str = helper.getEmailAddress();
                 if (!str.isEmpty()) {
                     // len is the length of the local part
                     int len = str.indexOf(QLatin1Char('@'));
                     QString localPart = str.left(len);
 
                     // remove the local part from the result (as '&'s have been expanded to
                     // &amp; we have to take care of the 4 additional characters per '&')
                     result.truncate(result.length() - len - (localPart.count(QLatin1Char('&')) * 4));
                     x -= len;
 
                     result += QLatin1String("<a href=\"mailto:") + str + QLatin1String("\">") + str + QLatin1String("</a>");
                     x += str.length() - 1;
                     continue;
                 }
                 if (flags & ConvertPhoneNumbers) {
                     str = helper.getPhoneNumber();
                     if (!str.isEmpty()) {
                         result += QLatin1String("<a href=\"tel:") + normalizePhoneNumber(str) + QLatin1String("\">") + str + QLatin1String("</a>");
                         x += str.length() - 1;
                         continue;
                     }
                 }
             }
             if (flags & HighlightText) {
                 str = helper.highlightedText();
                 if (!str.isEmpty()) {
                     result += str;
                     x += helper.mPos - start;
                     continue;
                 }
             }
             result += ch;
         }
     }
 
     if (flags & ReplaceSmileys) {
         result = KEmoticonsParser::parseEmoticons(result);
     }
 
     return result;
 }