content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library 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
   * Lesser General Public License for more details.
   *
   * For further information about Alkacon Software, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.opencms.widgets.serialdate;
  
  import org.opencms.acacia.shared.I_CmsSerialDateValue;
  import org.opencms.acacia.shared.I_CmsSerialDateValue.EndType;
  import org.opencms.acacia.shared.I_CmsSerialDateValue.WeekDay;
  import org.opencms.acacia.shared.I_CmsSerialDateValue.WeekOfMonth;
  
  import java.util.Calendar;
  import java.util.Date;
  import java.util.Iterator;
  import java.util.SortedSet;
  
  /**
   * Implementation of @{link org.opencms.widgets.serialdate.I_CmsSerialDateBean}
   * that handles series' specified on a monthly base.
   */
  public class CmsSerialDateBeanMonthlyWeeks extends A_CmsSerialDateBean {
  
      /** The number of months till the next event. */
      private int m_interval;
      /** The number of the day or week day of the month the event should occur. */
      private SortedSet<WeekOfMonth> m_weeksOfMonth;
      /** The weekday the event should occur. Can be <code>null</code> if the weekday does not matter. */
      private WeekDay m_weekDay;
      /** The index of the current week from the weeks of the month */
      private Iterator<WeekOfMonth> m_weekOfMonthIterator;
  
      /**
       * Constructs the bean with all the information provided by the {@link org.opencms.widgets.CmsSerialDateWidget}.
       *
       * @param startDate the start date of the series as provided by the serial date widget.
       * @param endDate the end date of the series as provided by the serial date widget.
       * @param isWholeDay flag, indicating if the event lasts the whole day
       * @param endType the end type of the series as provided by the serial date widget.
       * @param serialEndDate the end date of the series as provided by the serial date widget.
       * @param occurrences the maximal number of occurrences of the event as provided by the serial date widget.
       * @param exceptions dates where the event does not take place, even if it is in the series.
       * @param interval the number of month to the next events.
       * @param weeksOfMonth the weeks in the month the event should take place, e.g., the first and the third week.
       * @param weekDay the weekday on which the event should occur
       */
      public CmsSerialDateBeanMonthlyWeeks(
          Date startDate,
          Date endDate,
          boolean isWholeDay,
          EndType endType,
          Date serialEndDate,
          int occurrences,
          SortedSet<Date> exceptions,
          int interval,
          SortedSet<WeekOfMonth> weeksOfMonth,
          WeekDay weekDay) {
          super(startDate, endDate, isWholeDay, endType, serialEndDate, occurrences, exceptions);
          m_interval = interval;
          m_weeksOfMonth = weeksOfMonth;
          m_weekDay = weekDay;
      }
  
      /**
       * @see org.opencms.widgets.serialdate.A_CmsSerialDateBean#getFirstDate()
       */
      @Override
      protected Calendar getFirstDate() {
  
          m_weekOfMonthIterator = m_weeksOfMonth.iterator();
          Calendar date = (Calendar)getStartDate().clone();
          toCorrectDateWithDay(date, m_weekOfMonthIterator.next());
          while (date.getTimeInMillis() < getStartDate().getTimeInMillis()) {
              toNextDate(date, 1);
          }
          return date;
  
      }
  
      /**
       * @see org.opencms.widgets.serialdate.A_CmsSerialDateBean#isAnyDatePossible()
       */
      @Override
      protected boolean isAnyDatePossible() {
  
          return m_weeksOfMonth.size() > 0;
      }
  
      /**
       * @see org.opencms.widgets.serialdate.A_CmsSerialDateBean#toNextDate(java.util.Calendar)
       */
      @Override
      protected void toNextDate(Calendar date) {
  
          toNextDate(date, m_interval);
      }
  
      /**
       * Sets the day of the month that matches the condition, i.e., the day of month of the 2nd Saturday.
       * If the day does not exist in the current month, the last possible date is set, i.e.,
       * instead of the fifth Saturday, the fourth is chosen.
       *
       * @param date date that has the correct year and month already set.
       * @param week the number of the week to choose.
       */
      private void toCorrectDateWithDay(Calendar date, WeekOfMonth week) {
  
          date.set(Calendar.DAY_OF_MONTH, 1);
          int daysToFirstWeekDayMatch = ((m_weekDay.toInt() + I_CmsSerialDateValue.NUM_OF_WEEKDAYS)
              - (date.get(Calendar.DAY_OF_WEEK))) % I_CmsSerialDateValue.NUM_OF_WEEKDAYS;
          date.add(Calendar.DAY_OF_MONTH, daysToFirstWeekDayMatch);
          int wouldBeDayOfMonth = date.get(Calendar.DAY_OF_MONTH)
              + ((week.ordinal()) * I_CmsSerialDateValue.NUM_OF_WEEKDAYS);
          if (wouldBeDayOfMonth > date.getActualMaximum(Calendar.DAY_OF_MONTH)) {
              date.set(Calendar.DAY_OF_MONTH, wouldBeDayOfMonth - I_CmsSerialDateValue.NUM_OF_WEEKDAYS);
          } else {
              date.set(Calendar.DAY_OF_MONTH, wouldBeDayOfMonth);
          }
  
      }
  
      /**
       * Calculates the next date, starting from the provided date.
       *
       * @param date the current date.
       * @param interval the number of month to add when moving to the next month.
       */
      private void toNextDate(Calendar date, int interval) {
  
          long previousDate = date.getTimeInMillis();
          if (!m_weekOfMonthIterator.hasNext()) {
              date.add(Calendar.MONTH, interval);
              m_weekOfMonthIterator = m_weeksOfMonth.iterator();
          }
          toCorrectDateWithDay(date, m_weekOfMonthIterator.next());
          if (previousDate == date.getTimeInMillis()) { // this can happen if the fourth and the last week are checked.
              toNextDate(date);
          }
  
      }
  
  }
  