michael@0: /**
michael@0:  * Copyright (c) 2012, Ben Fortuna
michael@0:  * All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  *
michael@0:  *  o Redistributions of source code must retain the above copyright
michael@0:  * notice, this list of conditions and the following disclaimer.
michael@0:  *
michael@0:  *  o Redistributions in binary form must reproduce the above copyright
michael@0:  * notice, this list of conditions and the following disclaimer in the
michael@0:  * documentation and/or other materials provided with the distribution.
michael@0:  *
michael@0:  *  o Neither the name of Ben Fortuna nor the names of any other contributors
michael@0:  * may be used to endorse or promote products derived from this software
michael@0:  * without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0:  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0:  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
michael@0:  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
michael@0:  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
michael@0:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
michael@0:  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
michael@0:  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
michael@0:  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
michael@0:  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: package net.fortuna.ical4j.model;
michael@0: 
michael@0: import java.io.Serializable;
michael@0: import java.text.ParseException;
michael@0: import java.util.Collection;
michael@0: import java.util.Collections;
michael@0: import java.util.Iterator;
michael@0: import java.util.Set;
michael@0: import java.util.StringTokenizer;
michael@0: import java.util.TreeSet;
michael@0: 
michael@0: import org.apache.commons.lang.builder.EqualsBuilder;
michael@0: import org.apache.commons.lang.builder.HashCodeBuilder;
michael@0: 
michael@0: /**
michael@0:  * $Id$ [23-Apr-2004]
michael@0:  *
michael@0:  * Defines a list of iCalendar periods. NOTE: By implementing the
michael@0:  * <code>java.util.SortedSet</code> interface period lists will always be
michael@0:  * sorted according to natural ordering.
michael@0:  * 
michael@0:  * @author Ben Fortuna
michael@0:  */
michael@0: public class PeriodList implements Set, Serializable {
michael@0: 
michael@0: 	private static final long serialVersionUID = -2317587285790834492L;
michael@0: 
michael@0: 	private final Set periods;
michael@0:     
michael@0:     private TimeZone timezone;
michael@0:     
michael@0:     private boolean utc;
michael@0: 
michael@0:     private final boolean unmodifiable;
michael@0: 
michael@0:     /**
michael@0:      * Default constructor.
michael@0:      */
michael@0:     public PeriodList() {
michael@0:         this(true);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @param utc indicates whether the period list is in UTC time
michael@0:      */
michael@0:     public PeriodList(boolean utc) {
michael@0:     	this(utc, false);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @param utc indicates whether the period list is in UTC time
michael@0:      */
michael@0:     public PeriodList(boolean utc, final boolean unmodifiable) {
michael@0:         this.utc = utc;
michael@0:         this.unmodifiable = unmodifiable;
michael@0:         if (unmodifiable) {
michael@0:         	periods = Collections.EMPTY_SET;
michael@0:         }
michael@0:         else {
michael@0:         	periods = new TreeSet();
michael@0:         }
michael@0:     }
michael@0:     
michael@0:     /**
michael@0:      * Parses the specified string representation to create a list of periods.
michael@0:      * 
michael@0:      * @param aValue
michael@0:      *            a string representation of a list of periods
michael@0:      * @throws ParseException
michael@0:      *             thrown when an invalid string representation of a period list
michael@0:      *             is specified
michael@0:      */
michael@0:     public PeriodList(final String aValue) throws ParseException {
michael@0:         this();
michael@0:         final StringTokenizer t = new StringTokenizer(aValue, ",");
michael@0:         while (t.hasMoreTokens()) {
michael@0:             add((Object) new Period(t.nextToken()));
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * {@inheritDoc}
michael@0:      */
michael@0:     public final String toString() {
michael@0:         final StringBuffer b = new StringBuffer();
michael@0:         for (final Iterator i = iterator(); i.hasNext();) {
michael@0:             b.append(i.next().toString());
michael@0:             if (i.hasNext()) {
michael@0:                 b.append(',');
michael@0:             }
michael@0:         }
michael@0:         return b.toString();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Add a period to the list.
michael@0:      * 
michael@0:      * @param period
michael@0:      *            the period to add
michael@0:      * @return true
michael@0:      * @see java.util.List#add(java.lang.Object)
michael@0:      */
michael@0:     public final boolean add(final Period period) {
michael@0:         if (isUtc()) {
michael@0:             period.setUtc(true);
michael@0:         }
michael@0:         else {
michael@0:             period.setTimeZone(timezone);
michael@0:         }
michael@0:         return add((Object) period);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Overrides superclass to throw an <code>IllegalArgumentException</code>
michael@0:      * where argument is not a <code>net.fortuna.ical4j.model.Period</code>.
michael@0:      * @param period a period to add to the list
michael@0:      * @return true if the period was added, otherwise false
michael@3:      * @see java.util.List#add(Object)
michael@0:      */
michael@0:     public final boolean add(final Object period) {
michael@0:         if (!(period instanceof Period)) {
michael@0:             throw new IllegalArgumentException("Argument not a "
michael@0:                     + Period.class.getName());
michael@0:         }
michael@0:         return periods.add(period);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Remove a period from the list.
michael@0:      * 
michael@0:      * @param period
michael@0:      *            the period to remove
michael@0:      * @return true if the list contained the specified period
michael@0:      * @see java.util.List#remove(java.lang.Object)
michael@0:      */
michael@0:     public final boolean remove(final Period period) {
michael@0:         return remove((Object) period);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns a normalised version of this period list. Normalisation includes
michael@0:      * combining overlapping periods, removing periods contained by other
michael@0:      * periods, combining adjacent periods, and removing periods that consume
michael@0:      * no time. NOTE: If the period list is
michael@0:      * already normalised then this period list is returned.
michael@0:      * 
michael@0:      * @return a period list
michael@0:      */
michael@0:     public final PeriodList normalise() {
michael@0:         Period prevPeriod = null;
michael@0:         Period period = null;
michael@0:         final PeriodList newList = new PeriodList(isUtc());
michael@0:         if (timezone != null) {
michael@0:             newList.setTimeZone(timezone);
michael@0:         }
michael@0:         boolean normalised = false;
michael@0:         for (final Iterator i = iterator(); i.hasNext();) {
michael@0:             period = (Period) i.next();
michael@0:             if (period.isEmpty()) {
michael@0:                 period = prevPeriod;
michael@0:                 normalised = true;
michael@0:             }
michael@0:             else if (prevPeriod != null) {
michael@0:                 // ignore periods contained by other periods..
michael@0:                 if (prevPeriod.contains(period)) {
michael@0:                     period = prevPeriod;
michael@0:                     normalised = true;
michael@0:                 }
michael@0:                 // combine intersecting periods..
michael@0:                 else if (prevPeriod.intersects(period)) {
michael@0:                     period = prevPeriod.add(period);
michael@0:                     normalised = true;
michael@0:                 }
michael@0:                 // combine adjacent periods..
michael@0:                 else if (prevPeriod.adjacent(period)) {
michael@0:                     period = prevPeriod.add(period);
michael@0:                     normalised = true;
michael@0:                 }
michael@0:                 else {
michael@0:                     // if current period is recognised as distinct
michael@0:                     // from previous period, add the previous period
michael@0:                     // to the list..
michael@0:                     newList.add(prevPeriod);
michael@0:                 }
michael@0:             }
michael@0:             prevPeriod = period;
michael@0:         }
michael@0:         // remember to add the last period to the list..
michael@0:         if (prevPeriod != null) {
michael@0:             newList.add(prevPeriod);
michael@0:         }
michael@0:         // only return new list if normalisation
michael@0:         // has ocurred..
michael@0:         if (normalised) {
michael@0:             return newList;
michael@0:         }
michael@0:         else {
michael@0:             return this;
michael@0: 	}
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * A convenience method that combines all the periods in the specified list to
michael@0:      * this list. The result returned is a new PeriodList instance, except where
michael@0:      * no periods are specified in the arguments. In such cases this instance is returned.
michael@0:      * 
michael@0:      * Normalisation is also performed automatically after all periods have been added.
michael@0:      * 
michael@0:      * @param periods a list of periods to add
michael@0:      * @return a period list instance
michael@0:      */
michael@0:     public final PeriodList add(final PeriodList periods) {
michael@0:         if (periods != null) {
michael@0:             final PeriodList newList = new PeriodList();
michael@0:             newList.addAll(this);
michael@0:             for (final Iterator i = periods.iterator(); i.hasNext();) {
michael@0:                 newList.add((Period) i.next());
michael@0:             }
michael@0:             return newList.normalise();
michael@0:         }
michael@0:         return this;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Subtracts the intersection of this list with the specified list of
michael@0:      * periods from this list and returns the results as a new period list. If
michael@0:      * no intersection is identified this list is returned.
michael@0:      * 
michael@0:      * @param subtractions
michael@0:      *            a list of periods to subtract from this list
michael@0:      * @return a period list
michael@0:      */
michael@0:     public final PeriodList subtract(final PeriodList subtractions) {
michael@0:         if (subtractions == null || subtractions.isEmpty()) {
michael@0:             return this;
michael@0:         }
michael@0:         
michael@0:         PeriodList result = this;
michael@0:         PeriodList tmpResult = new PeriodList();
michael@0: 
michael@0:         for (final Iterator i = subtractions.iterator(); i.hasNext();) {
michael@0:             final Period subtraction = (Period) i.next();
michael@0:             for (final Iterator j = result.iterator(); j.hasNext();) {
michael@0:                 final Period period = (Period) j.next();
michael@0:                 tmpResult.addAll(period.subtract(subtraction));
michael@0:             }
michael@0:             result = tmpResult;
michael@0:             tmpResult = new PeriodList();
michael@0:         }
michael@0: 
michael@0:         return result;
michael@0:     }
michael@0: 
michael@0:     public final boolean isUnmodifiable() {
michael@0:         return unmodifiable;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Indicates whether this list is in local or UTC format.
michael@0:      * @return Returns true if in UTC format, otherwise false.
michael@0:      */
michael@0:     public final boolean isUtc() {
michael@0:         return utc;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Sets whether this list is in UTC or local time format.
michael@0:      * @param utc The utc to set.
michael@0:      */
michael@0:     public final void setUtc(final boolean utc) {
michael@0:         for (final Iterator i = iterator(); i.hasNext();) {
michael@0:             final Period period = (Period) i.next();
michael@0:             period.setUtc(utc);
michael@0:         }
michael@0:         this.timezone = null;
michael@0:         this.utc = utc;
michael@0:     }
michael@0:     
michael@0:     /**
michael@0:      * Applies the specified timezone to all dates in the list.
michael@0:      * All dates added to this list will also have this timezone
michael@0:      * applied.
michael@0:      * @param timeZone the timezone for the period list
michael@0:      */
michael@0:     public final void setTimeZone(final TimeZone timeZone) {
michael@0:         for (final Iterator i = iterator(); i.hasNext();) {
michael@0:             final Period period = (Period) i.next();
michael@0:             period.setTimeZone(timeZone);
michael@0:         }
michael@0:         this.timezone = timeZone;
michael@0:         this.utc = false;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * @return Returns the timeZone.
michael@0:      */
michael@0:     public final TimeZone getTimeZone() {
michael@0:         return timezone;
michael@0:     }
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final boolean addAll(Collection arg0) {
michael@0: 		for (Iterator i = arg0.iterator(); i.hasNext();) {
michael@0: 			add(i.next());
michael@0: 		}
michael@0: 		return true;
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final void clear() {
michael@0: 		periods.clear();
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final boolean contains(Object o) {
michael@0: 		return periods.contains(o);
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final boolean containsAll(Collection arg0) {
michael@0: 		return periods.containsAll(arg0);
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final boolean isEmpty() {
michael@0: 		return periods.isEmpty();
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final Iterator iterator() {
michael@0: 		return periods.iterator();
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final boolean remove(Object o) {
michael@0: 		return periods.remove(o);
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final boolean removeAll(Collection arg0) {
michael@0: 		return periods.removeAll(arg0);
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final boolean retainAll(Collection arg0) {
michael@0: 		return periods.retainAll(arg0);
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final int size() {
michael@0: 		return periods.size();
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final Object[] toArray() {
michael@0: 		return periods.toArray();
michael@0: 	}
michael@0: 
michael@0: 	/**
michael@0: 	 * {@inheritDoc}
michael@0: 	 */
michael@0: 	public final Object[] toArray(Object[] arg0) {
michael@0: 		return periods.toArray(arg0);
michael@0: 	}
michael@0: 	
michael@0: 	public final boolean equals(Object obj) {
michael@0: 		if (!getClass().isAssignableFrom(obj.getClass())) {
michael@0: 			return false;
michael@0: 		}
michael@0: 		final PeriodList rhs = (PeriodList) obj;
michael@0: 		return new EqualsBuilder().append(periods, rhs.periods)
michael@0: 			.append(timezone, rhs.timezone)
michael@0: 			.append(utc, utc)
michael@0: 			.isEquals();
michael@0: 	}
michael@0: 	
michael@0: 	public final int hashCode() {
michael@0: 		return new HashCodeBuilder().append(periods)
michael@0: 			.append(timezone)
michael@0: 			.append(utc)
michael@0: 			.toHashCode();
michael@0: 	}
michael@0: }