/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  package org.apache.myfaces.custom.schedule.model;
  
  import java.io.Serializable;
  import java.util.Calendar;
  import java.util.Collection;
  import java.util.Date;
  import java.util.Iterator;
  import java.util.SortedSet;
  import java.util.TimeZone;
  import java.util.TreeSet;
  
  import org.apache.myfaces.custom.schedule.util.ScheduleUtil;
  
  /**
   * <p>
   * Extend this class to create your own implementation of a ScheduleModel
   * </p>
   * 
   * @author Jurgen Lust (latest modification by $Author: baranda $)
   * @version $Revision: 372589 $
   */
  public abstract class AbstractScheduleModel implements ScheduleModel,
          Serializable
  {
      // ~ Instance fields
      // --------------------------------------------------------
  
      private TreeSet days;
  
      private Date selectedDate = new Date();
  
      private ScheduleEntry selectedEntry;
  
      private int mode;
  
      protected final TimeZone timeZone;
  
      // ~ Constructors
      // -----------------------------------------------------------
  
      /**
       * Creates a new AbstractScheduleModel object.
       */
      public AbstractScheduleModel()
      {
          this(TimeZone.getDefault());
      }
  
      public AbstractScheduleModel(TimeZone timeZone)
      {
        this.timeZone = timeZone;
      }
  
      // ~ Methods
      // ----------------------------------------------------------------
  
      /**
       * Get the set of days. Initialise on first call.
       * 
       */
      protected SortedSet getDays()
      {
          if (days == null)
          {
              days = new TreeSet();
              
              switch (mode)
              {
              case DAY:
                  setDay(this.selectedDate);
  
                  break;
  
              case WORKWEEK:
                  setWorkWeek(this.selectedDate);
  
                  break;
  
              case WEEK:
                  setWeek(this.selectedDate);
 
                 break;
 
             case MONTH:
                 setMonth(this.selectedDate);
 
                 break;
 
             default:
                 setDay(this.selectedDate);
             }        
         }
         
         return days;
     }
     
     /**
      * Returns the timezone setting for this model
      */
     public TimeZone getTimeZone ()
     {
       return this.timeZone;
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#isEmpty()
      */
     public boolean isEmpty()
     {
         return getDays().isEmpty();
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#setMode(int)
      */
     public void setMode(int mode)
     {
         this.mode = mode;
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#getMode()
      */
     public int getMode()
     {
         return mode;
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#setSelectedDate(java.util.Date)
      */
     public void setSelectedDate(Date date)
     {
         if (date == null)
         {
             // do nothing when the date is null
             return;
         }
 
         this.selectedDate = date;
         this.days = null;
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#getSelectedDate()
      */
     public Date getSelectedDate()
     {
         return selectedDate;
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#setSelectedEntry(org.apache.myfaces.custom.schedule.model.ScheduleEntry)
      */
     public void setSelectedEntry(ScheduleEntry selectedEntry)
     {
         this.selectedEntry = selectedEntry;
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#getSelectedEntry()
      */
     public ScheduleEntry getSelectedEntry()
     {
         return selectedEntry;
     }
     
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#isEntrySelected()
      */
     public boolean isEntrySelected() {
         return getSelectedEntry() != null;
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#containsDate(java.util.Date)
      */
     public boolean containsDate(Date date)
     {
         for (Iterator iterator = iterator(); iterator.hasNext();)
         {
             ScheduleDay day = (ScheduleDay) iterator.next();
 
             if (day.equalsDate(date))
             {
                 return true;
             }
         }
 
         return false;
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#get(int)
      */
     public Object get(int index)
     {
         Object[] dayArray = getDays().toArray();
 
         Object returnObject = dayArray[index];
 
         return returnObject;
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#iterator()
      */
     public Iterator iterator()
     {
         return getDays().iterator();
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#size()
      */
     public int size()
     {
         return getDays().size();
     }
 
     /**
      * <p>
      * Set the day
      * </p>
      * 
      * @param date
      *            the new day
      */
     protected void setDay(Date date)
     {
         if (date == null)
         {
             return;
         }
 
         clear();
 
         ScheduleDay day = add(date);
         load(day.getDayStart(), day.getDayEnd());
     }
 
     /**
      * <p>
      * navigate to the specified month
      * </p>
      * 
      * @param date
      *            the date to navigate to
      */
     protected void setMonth(Date date)
     {
         if (date == null)
         {
             return;
         }
 
         clear();
 
         Calendar cal = getCalendarInstance(date);
 
         // go back to the first day of the month;
         cal.set(Calendar.DAY_OF_MONTH, cal.getMinimum(Calendar.DAY_OF_MONTH));
 
         Date temp = cal.getTime();
         cal.add(Calendar.MONTH, 1);
         int nextMonth = cal.get(Calendar.MONTH);
         cal.setTime(temp);
 
         ScheduleDay firstDay = null;
         ScheduleDay lastDay = null;
         
         // we want to show the whole first week, including the days from the previous month
         cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
 
         while (true)
         {
             ScheduleDay addedDay = add(cal.getTime());
 
             if (firstDay == null)
             {
                 firstDay = addedDay;
             }
 
             lastDay = addedDay;
             cal.add(Calendar.DATE, 1);
             
             //stop when we are at the last day of the last week
             if (cal.get(Calendar.MONTH) == nextMonth && cal.get(Calendar.DAY_OF_WEEK) == Calendar.MONDAY)
             {
                    break;
             }
         }
 
         load(firstDay.getDayStart(), lastDay.getDayEnd());
     }
 
     /**
      * <p>
      * navigate to the specified week
      * </p>
      * 
      * @param date
      *            the date to navigate to
      */
     protected void setWeek(Date date)
     {
         if (date == null)
         {
             return;
         }
 
         clear();
 
         Calendar cal = getCalendarInstance(date);
 
         // go back to the monday of this week
         cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
 
         ScheduleDay firstDay = null;
         ScheduleDay lastDay = null;
 
         for (int i = 0; i < 7; i++)
         {
             ScheduleDay addedDay = add(cal.getTime());
 
             if (firstDay == null)
             {
                 firstDay = addedDay;
             }
 
             lastDay = addedDay;
             cal.add(Calendar.DATE, 1);
         }
 
         load(firstDay.getDayStart(), lastDay.getDayEnd());
     }
 
     /**
      * <p>
      * navigate to the specified workweek
      * </p>
      * 
      * @param date
      *            the date to navigate to
      */
     protected void setWorkWeek(Date date)
     {
         if (date == null)
         {
             return;
         }
 
         clear();
 
         Calendar cal = getCalendarInstance(date);
 
         // go back to the monday of this week
         cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
 
         ScheduleDay firstDay = null;
         ScheduleDay lastDay = null;
 
         for (int i = 0; i < 5; i++)
         {
             ScheduleDay addedDay = add(cal.getTime());
 
             if (firstDay == null)
             {
                 firstDay = addedDay;
             }
 
             lastDay = addedDay;
             cal.add(Calendar.DATE, 1);
         }
 
         load(firstDay.getDayStart(), lastDay.getDayEnd());
     }
 
     /**
      * <p>
      * Add a day to the schedule
      * </p>
      * 
      * @param date
      *            the day to add
      * 
      * @return the day that was added
      */
     protected ScheduleDay add(Date date)
     {
         if (date == null)
         {
             return null;
         }
 
         ScheduleDay day = new ScheduleDay(date, getTimeZone());
         loadDayAttributes(day);
         getDays().add(day);
 
         return day;
     }
 
     /**
      * <p>
      * Remove all days
      * </p>
      */
     protected void clear()
     {
         if (days != null)
         {
             for (Iterator dayIterator = days.iterator(); dayIterator.hasNext();)
             {
                 ScheduleDay day = (ScheduleDay) dayIterator.next();
                 day.clear();
             }
 
             days.clear();
         }
     }
 
     /**
      * @see org.apache.myfaces.custom.schedule.model.ScheduleModel#refresh()
      */
     public void refresh()
     {
         setSelectedDate(selectedDate);
     }
 
     /**
      * <p>
      * Load the schedule entries that fall between the startDate and the
      * endDate.
      * </p>
      * 
      * @param startDate
      *            0 AM on the start date
      * @param endDate
      *            12 PM on the end date
      */
     protected abstract Collection loadEntries(Date startDate, Date endDate);
 
     /**
      * <p>
      * Load any attributes for this day: is it a working day or a holiday, and
      * what is the name of the day (e.g. "Christmas").
      * </p>
      * 
      * @param day
      *            the day that should be loaded
      */
     protected abstract void loadDayAttributes(Day day);
 
     /**
      * @return true, if each day contains the same set of intervals
      */
     public boolean containsRepeatedIntervals() {
         boolean firstDay = true;
         TreeSet firstDayIntervals = null;
         
         if (mode == DAY)
         {
             return true;
         }
         
         for (Iterator dayIterator = iterator(); dayIterator.hasNext(); )
         {
             Day day = (Day) dayIterator.next();
             
             if (firstDay)
             {
                 firstDayIntervals = day.getIntervals();
                 firstDay = false;
             }
             else
             {
                 if (firstDayIntervals == null || firstDayIntervals.size() == 0) {
                     if (day.getIntervals() != null && day.getIntervals().size() > 0)
                     {
                         return false;
                     }
                 }
                 else if (!ScheduleUtil.areEquivalentIntervals(firstDayIntervals, day.getIntervals()))
                 {
                     
                     return false;
                 }
             }
         }
         
         return true;
     }
     
     private void load(Date startDate, Date endDate)
     {
         Collection entries = loadEntries(startDate, endDate);
 
         for (Iterator entryIterator = entries.iterator(); entryIterator
                 .hasNext();)
         {
             ScheduleEntry entry = (ScheduleEntry) entryIterator.next();
 
             for (Iterator dayIterator = getDays().iterator(); dayIterator.hasNext();)
             {
                 ScheduleDay day = (ScheduleDay) dayIterator.next();
 
                 day.addEntry(entry);
             }
         }
     }
     
     protected Calendar getCalendarInstance(Date date) {
 
         return ScheduleUtil.getCalendarInstance(date, getTimeZone());
     }
 }
 // The End