core/import/importparser.cpp

/**
 * \file importparser.cpp
 * Import parser.
 *
 * \b Project: Kid3
 * \author Urs Fleisch
 * \date 17 Sep 2003
 *
 * Copyright (C) 2003-2018  Urs Fleisch
 *
 * This file is part of Kid3.
 *
 * Kid3 is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Kid3 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "importparser.h"
#include <QCoreApplication>
#include <QRegularExpression>
#include "trackdata.h"
#include "genres.h"

/**
 * Constructor.
 */
ImportParser::ImportParser() : m_trackIncrNr(0), m_trackIncrEnabled(false)
{
}

/**
 * Get help text for format codes supported by setFormat().
 *
 * @param onlyRows if true only the tr elements are returned,
 *                 not the surrounding table
 *
 * @return help text.
 */
QString ImportParser::getFormatToolTip(bool onlyRows)
{
  QString str;
  if (!onlyRows) str += QLatin1String("<table>\n");

  str += QLatin1String("<tr><td>%s</td><td>%{title}</td><td>");
  str += QCoreApplication::translate("@default", "Title");
  str += QLatin1String("</td></tr>\n");

  str += QLatin1String("<tr><td>%l</td><td>%{album}</td><td>");
  str += QCoreApplication::translate("@default", "Album");
  str += QLatin1String("</td></tr>\n");

  str += QLatin1String("<tr><td>%a</td><td>%{artist}</td><td>");
  str += QCoreApplication::translate("@default", "Artist");
  str += QLatin1String("</td></tr>\n");

  str += QLatin1String("<tr><td>%c</td><td>%{comment}</td><td>");
  str += QCoreApplication::translate("@default", "Comment");
  str += QLatin1String("</td></tr>\n");

  str += QLatin1String("<tr><td>%y</td><td>%{year}</td><td>");
  const char* const yearStr = QT_TRANSLATE_NOOP("@default", "Year");
  str += QCoreApplication::translate("@default", yearStr);
  str += QLatin1String("</td></tr>\n");

  str += QLatin1String("<tr><td>%t</td><td>%{track}</td><td>");
  str += QCoreApplication::translate("@default", "Track");
  str += QLatin1String("</td></tr>\n");

  str += QLatin1String("<tr><td>%g</td><td>%{genre}</td><td>");
  str += QCoreApplication::translate("@default", "Genre");
  str += QLatin1String("</td></tr>\n");

  str += QLatin1String("<tr><td>%d</td><td>%{duration}</td><td>");
  const char* const lengthStr = QT_TRANSLATE_NOOP("@default", "Length");
  str += QCoreApplication::translate("@default", lengthStr);
  str += QLatin1String("</td></tr>\n");

  if (!onlyRows) str += QLatin1String("</table>\n");
  return str;
}

/**
 * Set import format.
 *
 * @param fmt format regexp
 * @param enableTrackIncr enable automatic track increment if no %t is found
 */
void ImportParser::setFormat(const QString& fmt, bool enableTrackIncr)
{
  static const struct {
    const char* from;
    const char* to;
  } codeToName[] = {
    { "%s", "%{title}" },
    { "%l", "%{album}" },
    { "%a", "%{artist}" },
    { "%c", "%{comment}" },
    { "%y", "%{date}" },
    { "%t", "%{track number}" },
    { "%g", "%{genre}" },
    { "%d", "%{__duration}" },
    { "%f", "%{file}" },
    { "%{year}", "%{date}" },
    { "%{track}", "%{track number}" },
    { "%{tracknumber}", "%{track number}" },
    { "%{duration}", "%{__duration}" },
  };
  int percentIdx = 0, nr = 1, lastIdx = fmt.length() - 1;
  m_pattern = fmt;
  for (const auto& c2n : codeToName) {
    m_pattern.replace(QString::fromLatin1(c2n.from), QString::fromLatin1(c2n.to));
  }

  m_codePos.clear();
  while (((percentIdx = m_pattern.indexOf(QLatin1String("%{"), percentIdx)) >= 0) &&
         (percentIdx < lastIdx)) {
    int closingBracePos = m_pattern.indexOf(QLatin1String("}("), percentIdx + 2);
    if (closingBracePos > percentIdx + 2) {
      QString code =
        m_pattern.mid(percentIdx + 2, closingBracePos - percentIdx - 2);
      m_codePos[code] = nr;
      percentIdx = closingBracePos + 2;
      ++nr;
    } else {
      percentIdx += 2;
    }
  }

  if (enableTrackIncr && !m_codePos.contains(QLatin1String("track number"))) {
    m_trackIncrEnabled = true;
    m_trackIncrNr = 1;
  } else {
    m_trackIncrEnabled = false;
    m_trackIncrNr = 0;
  }

  m_pattern.remove(QRegularExpression(QLatin1String("%\\{[^}]+\\}")));
  m_re.setPattern(m_pattern);
}

/**
 * Get next tags in text buffer.
 *
 * @param text text buffer containing data from file or clipboard
 * @param frames frames for output
 * @param pos  current position in buffer, will be updated to point
 *             behind current match (to be used for next call)
 * @return true if tags found (pos is index behind match).
 */
bool ImportParser::getNextTags(const QString& text, TrackData& frames, int& pos)
{
  QRegularExpressionMatch match;
  int idx, oldpos = pos;
  if (m_pattern.isEmpty()) {
    m_trackDuration.clear();
    return false;
  }
  if (!m_codePos.contains(QLatin1String("__duration"))) {
    m_trackDuration.clear();
  } else if (pos == 0) {
    m_trackDuration.clear();
    int dsp = 0; // "duration search pos"
    int lastDsp = dsp;
    while ((idx = (match = m_re.match(text, dsp)).capturedStart()) != -1) {
      QString durationStr = match.captured(m_codePos.value(QLatin1String("__duration")));
      int duration;
      QRegularExpression durationRe(QLatin1String("(\\d+):(\\d+)"));
      auto durationMatch = durationRe.match(durationStr);
      if (durationMatch.hasMatch()) {
        duration = durationMatch.captured(1).toInt() * 60 +
            durationMatch.captured(2).toInt();
      } else {
        duration = durationStr.toInt();
      }
      m_trackDuration.append(duration);

      dsp = idx + durationMatch.capturedLength();
      if (dsp > lastDsp) { /* avoid endless loop */
        lastDsp = dsp;
      } else {
        break;
      }
    }
  }
  if ((idx = (match = m_re.match(text, pos)).capturedStart()) != -1) {
    for (auto it = m_codePos.constBegin(); it != m_codePos.constEnd(); ++it) {
      const QString& name = it.key();
      QString str = match.captured(*it);
      if (name == QLatin1String("__return")) {
        m_returnValues.append(str);
      } else if (!str.isEmpty() && !name.startsWith(QLatin1String("__"))) {
        if (name == QLatin1String("file")) {
          if (TaggedFile* taggedFile = frames.getTaggedFile()) {
            frames.transformToFilename(str);
            taggedFile->setFilenameFormattedIfEnabled(str);
          }
        } else {
          frames.setValue(Frame::ExtendedType(name), str);
        }
      }
    }
    if (m_trackIncrEnabled) {
      frames.setTrack(m_trackIncrNr++);
    }
    pos = idx + match.capturedLength();
    if (pos > oldpos) { /* avoid endless loop */
      return true;
    }
  }
  return false;
}