textfactory.cpp

/*
  Copyright (c) 2012, BuildmLearn Contributors listed at http://buildmlearn.org/people/
  All rights reserved.

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  modification, are permitted provided that the following conditions are met:

  * Redistributions of source code must retain the above copyright notice, this
    list of conditions and the following disclaimer.

  * Redistributions in binary form must reproduce the above copyright notice,
    this list of conditions and the following disclaimer in the documentation
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  * Neither the name of the BuildmLearn nor the names of its
    contributors may be used to endorse or promote products derived from
    this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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*/

#include "miscellaneous/textfactory.h"

#include "definitions/definitions.h"

#include <QString>
#include <QStringList>
#include <QLocale>


TextFactory::TextFactory() {
}

QDateTime TextFactory::parseDateTime(const QString &date_time) {
  QString date = date_time.simplified();
  QStringList date_patterns;
  QStringList timezone_offset_patterns;
  QDateTime dt;
  QTime time_zone_offset;
  QLocale locale(QLocale::C);
  bool positive_time_zone_offset = false;

  date_patterns << "yyyy-MM-ddTHH:mm:ss" << "MMM dd yyyy hh:mm:ss" <<
                   "MMM d yyyy hh:mm:ss" << "ddd, dd MMM yyyy HH:mm:ss" <<
                   "dd MMM yyyy" << "yyyy-MM-dd HH:mm:ss.z" << "yyyy-MM-dd" <<
                   "yyyy" << "yyyy-MM" << "yyyy-MM-dd" << "yyyy-MM-ddThh:mm" <<
                   "yyyy-MM-ddThh:mm:ss";

  timezone_offset_patterns << "+hh:mm" << "-hh:mm" << "+hhmm" << "-hhmm" << "+hh" << "-hh";

  if (date.size() >= 5) {
    foreach (const QString &pattern, timezone_offset_patterns) {
      time_zone_offset = QTime::fromString(date.right(pattern.size()), pattern);

      if (time_zone_offset.isValid()) {
        positive_time_zone_offset = pattern.at(0) == '+';
        break;
      }
    }
  }

  // Iterate over patterns and check if input date/time matches the pattern.
  foreach (const QString &pattern, date_patterns) {
    dt = locale.toDateTime(date.left(pattern.size()), pattern);

    if (dt.isValid()) {
      // Make sure that this date/time is considered UTC.
      dt.setTimeSpec(Qt::UTC);

      if (time_zone_offset.isValid()) {
        // Time zone offset was detected.
        if (positive_time_zone_offset) {
          // Offset is positive, so we have to subtract it to get
          // the original UTC.
          return dt.addSecs(- QTime(0, 0, 0, 0).secsTo(time_zone_offset));
        }
        else {
          // Vice versa.
          return dt.addSecs(QTime(0, 0, 0, 0).secsTo(time_zone_offset));
        }
      }
      else {
        return dt;
      }
    }
  }

  // Parsing failed, return invalid datetime.
  return QDateTime();
}

QDateTime TextFactory::parseDateTime(qint64 milis_from_epoch) {
  return QDateTime::fromMSecsSinceEpoch(milis_from_epoch);
}

QString TextFactory::shorten(const QString &input, int text_length_limit) {
  if (input.size() > text_length_limit) {
    return input.left(text_length_limit - ELLIPSIS_LENGTH) + QString(ELLIPSIS_LENGTH, '.');
  }
  else {
    return input;
  }
}