package org.apache.commons.codec;

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 * The Apache Software License, Version 1.1
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 * reserved.
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 * modification, are permitted provided that the following conditions
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 *    notice, this list of conditions and the following disclaimer.
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 *       "This product includes software developed by the
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 * This software consists of voluntary contributions made by many
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 * <http://www.apache.org/>.
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/**
 * Encodes a string into a refined soundex value.  
 * A refined soundex code is optimized for spell checking word. 
 * "Soundex" method originally developed by Margaret Odell and 
 *          Robert Russell
 * 
 * http://www.bluepoof.com/Soundex/info2.html
 * 
 * @todo Needs internationalisation in a future release.
 *
 * @author bayard@generationjava.com
 * @author tobrien@transolutions.net
 * @version $Id: Soundex.java,v 1.1 2002/02/22 05:20:00 bayard Exp $
 */
public class Soundex implements Encoder {

    static public final char[] US_ENGLISH_MAPPING =
        "01230120022455012623010202".toCharArray();

    static public final Soundex US_ENGLISH = new Soundex();
    
    private char[] soundexMapping;
    private int maxLength = 4;

    public Soundex() {
        this(US_ENGLISH_MAPPING);
    }

    public Soundex(char[] mapping) {
        this.soundexMapping = mapping;
    }

    /**
     * Get the SoundEx value of a string.
     * This implementation is taken from the code-snippers on 
     * http://www.sourceforge.net/
     */
    public String soundex(String str) {
        char out[] = { '0', '0', '0', '0' };
        char last, mapped;
        int incount = 1, count = 1;
        out[0] = Character.toUpperCase( str.charAt(0) );
        last = getMappingCode( str.charAt(0) );
        while( (incount < str.length() ) && 
               (mapped = getMappingCode(str.charAt(incount++))) != 0 &&
               (count < maxLength) )
        {
            if( (mapped != '0') && (mapped != last) ) {
                out[count++] = mapped;
            }
            last = mapped;
        }
        return new String(out);
    }

    public String encode(String pString) {
        return( soundex( pString ) );   
    }

    /**
     * Used internally by the SoundEx algorithm.
     */
    private char getMappingCode(char c) {
        if( !Character.isLetter(c) ) {
            return 0;
        } else {
            return soundexMapping[Character.toUpperCase(c) - 'A'];
        }
    }

	/**
	 * Returns the maxLength.  Standard Soundex
	 * @return int
	 */
	public int getMaxLength() {
		return maxLength;
	}

	/**
	 * Sets the maxLength.
	 * @param maxLength The maxLength to set
	 */
	public void setMaxLength(int maxLength) {
		this.maxLength = maxLength;
	}

}