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

 * 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.]

 *

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

 * DefaultKeyedValues.java

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

 * (C) Copyright 2002-2004, by Object Refinery Limited.

 *

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

 * Contributor(s):   -;

 *

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

 *

 * Changes:

 * --------

 * 31-Oct-2002 : Version 1 (DG);

 * 11-Feb-2003 : Fixed bug in getValue(key) method for unrecognised key (DG);

 * 05-Mar-2003 : Added methods to sort stored data 'by key' or 'by value' (DG);

 * 13-Mar-2003 : Implemented Serializable (DG);

 * 08-Apr-2003 : Modified removeValue(Comparable) method to fix bug 717049 (DG);

 * 18-Aug-2003 : Implemented Cloneable (DG);

 * 27-Aug-2003 : Moved SortOrder from org.jfree.data --> org.jfree.util (DG);

 * 09-Feb-2004 : Modified getIndex() method - see bug report 893256 (DG);

 *

 */



package org.jfree.data;



import java.io.Serializable;

import java.util.Collections;

import java.util.Comparator;

import java.util.Iterator;

import java.util.List;



import org.jfree.util.SortOrder;



/**

 * A collection of (key, value) pairs.  This class provides a default implementation of the 

 * {@link KeyedValues} interface.

 */

public class DefaultKeyedValues implements KeyedValues, Cloneable, Serializable {



    /** Storage for the data. */

    private List data;



    /**

     * Creates a new collection (initially empty).

     */

    public DefaultKeyedValues() {

        this.data = new java.util.ArrayList();

    }



    /**

     * Returns the number of items (values) in the collection.

     *

     * @return the item count.

     */

    public int getItemCount() {

        return this.data.size();

    }



    /**

     * Returns a value.

     *

     * @param item  the item of interest (zero-based index).

     *

     * @return the value.

     */

    public Number getValue(final int item) {



        Number result = null;

        final KeyedValue kval = (KeyedValue) this.data.get(item);

        if (kval != null) {

            result = kval.getValue();

        }

        return result;



    }



    /**

     * Returns a key.

     *

     * @param index  the item index (zero-based).

     *

     * @return the row key.

     */

    public Comparable getKey(final int index) {



        Comparable result = null;

        final KeyedValue item = (KeyedValue) this.data.get(index);

        if (item != null) {

            result = item.getKey();

        }

        return result;



    }



    /**

     * Returns the index for a given key or -1 if the key is not found.

     *

     * @param key  the key.

     *

     * @return the index.

     */

    public int getIndex(final Comparable key) {



        int i = 0;

        final Iterator iterator = this.data.iterator();

        while (iterator.hasNext()) {

            final KeyedValue kv = (KeyedValue) iterator.next();

            if (kv.getKey().equals(key)) {

                return i;

            }

            i++;

        }

        return -1;  // key not found



    }



    /**

     * Returns the keys for the values in the collection.

     *

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

     */

    public List getKeys() {



        final List result = new java.util.ArrayList();

        final Iterator iterator = this.data.iterator();

        while (iterator.hasNext()) {

            final KeyedValue kv = (KeyedValue) iterator.next();

            result.add(kv.getKey());

        }

        return result;



    }



    /**

     * Returns the value (possibly <code>null</code>) for a given key.  If the key is not 

     * recognised, the method returns <code>null</code>.

     *

     * @param key  the key.

     *

     * @return the value.

     */

    public Number getValue(final Comparable key) {



        Number result = null;

        final int index = getIndex(key);

        if (index >= 0) {

            result = getValue(index);

        }

        return result;



    }



    /**

     * Adds a new value to the collection, or updates an existing value.

     * <P>

     * This is the same as the setValue(...) method.

     *

     * @param key  the key.

     * @param value  the value.

     */

    public void addValue(final Comparable key, final Number value) {

        setValue(key, value);

    }



    /**

     * Updates an existing value, or adds a new value to the collection.

     * <P>

     * This is the same as the addValue(...) method.

     *

     * @param key  the key.

     * @param value  the value.

     */

    public void setValue(final Comparable key, final Number value) {

        final int keyIndex = getIndex(key);

        if (keyIndex >= 0) {

            final DefaultKeyedValue kv = (DefaultKeyedValue) this.data.get(keyIndex);

            kv.setValue(value);

        }

        else {

            final KeyedValue kv = new DefaultKeyedValue(key, value);

            this.data.add(kv);

        }

    }



    /**

     * Removes a value from the collection.

     *

     * @param index  the index of the item to remove.

     */

    public void removeValue(final int index) {

        this.data.remove(index);

    }



    /**

     * Removes a value from the collection.  If there is no value with the specified key,

     * then this method does nothing.

     *

     * @param key  the key of the item to remove.

     */

    public void removeValue(final Comparable key) {

        final int index = getIndex(key);

        if (index >= 0) {

            removeValue(index);

        }

    }



    /**

     * Sorts the items in the list by key.

     *

     * @param order  the sort order (ascending or descending).

     */

    public void sortByKeys(final SortOrder order) {



        final Comparator comparator = new KeyedValueComparator(

            KeyedValueComparatorType.BY_KEY, order

        );

        Collections.sort(this.data, comparator);

    }



    /**

     * Sorts the items in the list by value.  If the list contains <code>null</code> values, they

     * will sort to the end of the list, irrespective of the sort order.

     *

     * @param order  the sort order (ascending or descending).

     */

    public void sortByValues(final SortOrder order) {

        final Comparator comparator = new KeyedValueComparator(

            KeyedValueComparatorType.BY_VALUE, order

        );

        Collections.sort(this.data, comparator);

    }



    /**

     * Tests if this object is equal to another.

     *

     * @param o  the other object.

     *

     * @return A boolean.

     */

    public boolean equals(final Object o) {



        if (o == null) {

            return false;

        }

        if (o == this) {

            return true;

        }



        if (!(o instanceof KeyedValues)) {

            return false;

        }



        final KeyedValues kvs = (KeyedValues) o;

        final int count = getItemCount();

        if (count != kvs.getItemCount()) {

            return false;

        }



        for (int i = 0; i < count; i++) {

            final Comparable k1 = getKey(i);

            final Comparable k2 = kvs.getKey(i);

            if (!k1.equals(k2)) {

                return false;

            }

            final Number v1 = getValue(i);

            final Number v2 = kvs.getValue(i);

            if (v1 == null) {

                if (v2 != null) {

                    return false;

                }

            }

            else {

                if (!v1.equals(v2)) {

                    return false;

                }

            }

        }

        return true;

    }



    /**

     * Returns a hash code.

     * 

     * @return a hash code.

     */

    public int hashCode() {

        return (this.data != null ? this.data.hashCode() : 0);

    }



    /**

     * Returns a clone.

     * 

     * @return A clone.

     * 

     * @throws CloneNotSupportedException  this class will not throw this exception, but subclasses 

     *         might.

     */

    public Object clone() throws CloneNotSupportedException {

        final DefaultKeyedValues clone = (DefaultKeyedValues) super.clone();

        clone.data = new java.util.ArrayList();

        final Iterator iterator = this.data.iterator();

        while (iterator.hasNext()) {

            final DefaultKeyedValue kv = (DefaultKeyedValue) iterator.next();

            clone.data.add(kv.clone());

        }

        return clone;    

    }

    

}

