/* ===========================================================

 * JFreeChart : a free chart library for the Java(tm) platform

 * ===========================================================

 *

 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.

 *

 * Project Info:  http://www.jfree.org/jfreechart/index.html

 *

 * 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.

 *

 * 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.

 *

 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

 * in the United States and other countries.]

 *

 * ------------------

 * KeyToGroupMap.java

 * ------------------

 * (C) Copyright 2004, by Object Refinery Limited and Contributors.

 *

 * Original Author:  David Gilbert (for Object Refinery Limited);

 * Contributor(s):   -;

 *

 * $Id: KeyToGroupMap.java,v 1.1 2004/08/31 15:21:49 mungady Exp $

 *

 * Changes

 * -------

 * 29-Apr-2004 : Version 1 (DG);

 * 07-Jul-2004 : Added a group list to ensure group index is consistent, fixed cloning 

 *               problem (DG);

 * 

 */



package org.jfree.data;



import java.io.Serializable;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;



import org.jfree.util.ObjectUtils;

import org.jfree.util.PublicCloneable;



/**

 * A class that maps keys (instances of <code>Comparable</code>) to groups.

 */

public class KeyToGroupMap implements Cloneable, PublicCloneable, Serializable {

    

    /** The default group. */

    private Comparable defaultGroup;

    

    /** The groups. */

    private List groups;

    

    /** A mapping between keys and groups. */

    private Map keyToGroupMap;

    

    /**

     * Creates a new map with a default group named 'Default Group'.

     */

    public KeyToGroupMap() {

        this("Default Group");

    }

    

    /**

     * Creates a new map with the specified default group.

     * 

     * @param defaultGroup  the default group (<code>null</code> not permitted).

     */

    public KeyToGroupMap(Comparable defaultGroup) {

        if (defaultGroup == null) {

            throw new IllegalArgumentException("Null 'defaultGroup' argument.");   

        }

        this.defaultGroup = defaultGroup;

        this.groups = new ArrayList();

        this.keyToGroupMap = new HashMap();

    }

    

    /**

     * Returns the number of groups in the map.

     * 

     * @return The number of groups in the map.

     */

    public int getGroupCount() {

        return this.groups.size() + 1;

    }

    

    /**

     * Returns a list of the groups (always including the default group) in the map.  The

     * returned list is independent of the map, so altering the list will have no effect.

     * 

     * @return The groups (never <code>null</code>).

     */

    public List getGroups() {

        List result = new ArrayList();

        result.add(this.defaultGroup);

        Iterator iterator = this.groups.iterator();

        while (iterator.hasNext()) {

            Comparable group = (Comparable) iterator.next();

            if (!result.contains(group)) {

                result.add(group);   

            }

        } 

        return result;

    }

    

    /**

     * Returns the index for the group.

     * 

     * @param group  the group.

     * 

     * @return The group index (or -1 if the group is not represented within the map).

     */

    public int getGroupIndex(Comparable group) {

        int result = this.groups.indexOf(group);

        if (result < 0) {

            if (this.defaultGroup.equals(group)) {

                result = 0;

            }

        }

        else {

            result = result + 1;   

        }

        return result;   

    }

    

    /**

     * Returns the group that a key is mapped to.

     * 

     * @param key  the key (<code>null</code> not permitted).

     * 

     * @return The group (never <code>null</code>, returns the default group if there

     *         is no mapping for the specified key).

     */

    public Comparable getGroup(Comparable key) {

        if (key == null) {

            throw new IllegalArgumentException("Null 'key' argument.");   

        }

        Comparable result = this.defaultGroup;

        Comparable group = (Comparable) this.keyToGroupMap.get(key);

        if (group != null) {

            result = group;   

        }

        return result;

    }

    

    /**

     * Maps a key to a group.

     * 

     * @param key  the key (<code>null</code> not permitted).

     * @param group  the group (<code>null</code> permitted, clears any existing mapping).

     */

    public void mapKeyToGroup(Comparable key, Comparable group) {

        if (key == null) {

            throw new IllegalArgumentException("Null 'key' argument.");   

        }

        Comparable currentGroup = getGroup(key);

        if (!currentGroup.equals(this.defaultGroup)) {

            if (!currentGroup.equals(group)) {

                int count = getKeyCount(currentGroup);

                if (count == 1) {

                    this.groups.remove(currentGroup);   

                }

            }

        }

        if (group == null) {

            this.keyToGroupMap.remove(key); 

        }

        else {

            if (!this.groups.contains(group)) {

                if (!this.defaultGroup.equals(group)) {

                    this.groups.add(group);

                }

            }

            this.keyToGroupMap.put(key, group);

        }

    }

    

    /**

     * Returns the number of keys mapped to the specified group.  This method won't

     * always return an accurate result for the default group, since explicit mappings 

     * are not required for this group.

     * 

     * @param group  the group (<code>null</code> not permitted).

     * 

     * @return The key count.

     */

    public int getKeyCount(Comparable group) {

        if (group == null) {

            throw new IllegalArgumentException("Null 'group' argument.");   

        }

        int result = 0;

        Iterator iterator = this.keyToGroupMap.values().iterator();

        while (iterator.hasNext()) {

            Comparable g = (Comparable) iterator.next();

            if (group.equals(g)) {

                result++;

            }

        }

        return result;

    }

    

    /**

     * Tests the map for equality against an arbitrary object.

     * 

     * @param obj  the object to test against (<code>null</code> permitted).

     * 

     * @return A boolean.

     */

    public boolean equals(Object obj) {

        if (obj == this) {

            return true;      

        }

        if (obj instanceof KeyToGroupMap) {

            KeyToGroupMap m = (KeyToGroupMap) obj;

            boolean b0 = ObjectUtils.equal(this.defaultGroup, m.defaultGroup);

            boolean b1 = this.keyToGroupMap.equals(m.keyToGroupMap);

            return b0 && b1;

        }

        return false;

    }

    

    /**

     * Returns a clone of the map.

     * 

     * @return A clone.

     * 

     * @throws CloneNotSupportedException  if there is a problem cloning the map.

     */

    public Object clone() throws CloneNotSupportedException {

        KeyToGroupMap result = (KeyToGroupMap) super.clone();

        result.defaultGroup = (Comparable) KeyToGroupMap.clone(this.defaultGroup);

        result.groups = (List) KeyToGroupMap.clone(this.groups);

        result.keyToGroupMap = (Map) KeyToGroupMap.clone(this.keyToGroupMap);

        return result;

    }

    

    /**

     * Attempts to clone the specified object using reflection.

     * 

     * @param object  the object (<code>null</code> permitted).

     * 

     * @return The cloned object, or the original object if cloning failed.

     */

    private static Object clone(Object object) {

        if (object == null) {

            return null;   

        }

        Class c = object.getClass();

        Object result = null;

        try {

            Method m = c.getMethod("clone", null);

            if (Modifier.isPublic(m.getModifiers())) {

                try {

                    result = m.invoke(object, null);

                }

                catch (Exception e) {

                    System.out.println(e);   

                }

            }

        }

        catch (NoSuchMethodException e) {

            result = object;

        }

        return result;

    }

    

    /**

     * Returns a clone of the list.

     * 

     * @param list  the list.

     * 

     * @return A clone of the list.

     * 

     * @throws CloneNotSupportedException if the list could not be cloned.

     */

    private static Collection clone(Collection list) throws CloneNotSupportedException {

        Collection result = null;

        if (list != null) {

            try {

                final List clone = (List) list.getClass().newInstance();

                final Iterator iterator = list.iterator();

                while (iterator.hasNext()) {

                    clone.add(KeyToGroupMap.clone(iterator.next()));

                }

                result = clone;

            }

            catch (Exception e) {

                throw new CloneNotSupportedException("Exception.");

            }

        }

        return result;

    }



}

