/*
GanttProject is an opensource project management tool.
Copyright (C) 2011 GanttProject Team

This program 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 3
of the License, or (at your option) any later version.

This program 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, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package net.sourceforge.ganttproject.parser;


import java.awt.Color;
import java.util.Date;
import java.util.List;
import java.util.Set;
import java.util.logging.Level;

import net.sourceforge.ganttproject.GPLogger;
import net.sourceforge.ganttproject.io.GanttXMLOpen;
import net.sourceforge.ganttproject.util.ColorConvertion;

import org.xml.sax.Attributes;

import com.google.common.base.Strings;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;

import biz.ganttproject.core.calendar.CalendarEvent;
import biz.ganttproject.core.calendar.GPCalendar;
import biz.ganttproject.core.time.CalendarFactory;

/**
 * @author nbohn
 */
public class HolidayTagHandler extends AbstractTagHandler {
  private static final Set<String> TAGS = ImmutableSet.of("date", "calendars");
  private final GPCalendar myCalendar;
  private final List<CalendarEvent> myEvents = Lists.newArrayList();
  private Attributes myAttrs;
  // We may have event titles written as comments after <date> tag.
  // To process them properly we remember the last event created from <date> tag
  // and "patch" it if we find any non-empty cdata afterwards.
  private CalendarEvent myLastEvent = null;

  public HolidayTagHandler(GPCalendar calendar) {
    super("date", true);
    myCalendar = calendar;
    myAttrs = null;
  }

  /**
   * @see net.sourceforge.ganttproject.parser.TagHandler#endElement(String,
   *      String, String)
   */
  @Override
  public void endElement(String namespaceURI, String sName, String qName) {
    if (!TAGS.contains(qName)) {
      return;
    }
    if ("date".equals(qName)) {
      loadHoliday(myAttrs);
    }
    if ("calendars".equals(qName)) {
      onCalendarLoaded();
      setTagStarted(false);
    }
  }

  /**
   * @see net.sourceforge.ganttproject.parser.TagHandler#startElement(String,
   *      String, String, Attributes)
   */
  @Override
  public void startElement(String namespaceURI, String sName, String qName, Attributes attrs) {
    if (!TAGS.contains(qName)) {
      return;
    }
    setTagStarted(true);
    if (qName.equals("date")) {
      processLastEvent();
      myAttrs = attrs;
    }
  }

  private void processLastEvent() {
    if (myLastEvent != null) {
      String cdata = getCdata().replaceAll("^\\p{Space}+", "").replaceAll("\\p{Space}+$", "");
      if (Strings.isNullOrEmpty(cdata)) {
        myEvents.add(myLastEvent);
      } else {
        myEvents.add(CalendarEvent.newEvent(myLastEvent.myDate, myLastEvent.isRecurring, myLastEvent.getType(), cdata, null));
        clearCdata();
      }
      myLastEvent = null;
    }
  }

  private void loadHoliday(Attributes atts) {
    try {
      String yearAsString = atts.getValue("year");
      String monthAsString = atts.getValue("month");
      String dayAsString = atts.getValue("date");
      String typeAsString = atts.getValue("type");
      String colorAsString = atts.getValue("color");
      int month = Integer.parseInt(monthAsString);
      int day = Integer.parseInt(dayAsString);
      CalendarEvent.Type type = Strings.isNullOrEmpty(typeAsString) ? CalendarEvent.Type.HOLIDAY : CalendarEvent.Type.valueOf(typeAsString);
      Color color = colorAsString == null ? null : ColorConvertion.determineColor(colorAsString);
      String description = getCdata().replaceAll("^\\p{Space}+", "").replaceAll("\\p{Space}+$", "");
      if (Strings.isNullOrEmpty(yearAsString)) {
        Date date = CalendarFactory.createGanttCalendar(1, month - 1, day).getTime();
        myLastEvent = CalendarEvent.newEvent(date, true, type, description, color);
      } else {
        int year = Integer.parseInt(yearAsString);
        Date date = CalendarFactory.createGanttCalendar(year, month - 1, day).getTime();
        myLastEvent = CalendarEvent.newEvent(date, false, type, description, color);
      }
      clearCdata();
    } catch (NumberFormatException e) {
      GPLogger.getLogger(GanttXMLOpen.class).log(Level.WARNING, String.format("Error when parsing calendar data. Raw data: %s", atts.toString()), e);
      return;
    }
  }

  public void onCalendarLoaded() {
    processLastEvent();
    myCalendar.setPublicHolidays(myEvents);
  }
}