EDIT

// $Id$

/**

 * Copyright (C) 2009 EDIT

 * European Distributed Institute of Taxonomy 

 * http://www.e-taxonomy.eu

 * 

 * The contents of this file are subject to the Mozilla Public License Version 1.1

 * See LICENSE.TXT at the top of this package for the full license terms.

 */

package eu.etaxonomy.cdm.model.common;

import java.util.Comparator;

import java.util.HashMap;

import java.util.Map;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import org.springframework.stereotype.Component;

import eu.etaxonomy.cdm.model.taxon.TaxonNode;

/**

 * Abstract Comparator for Strings which allows define substitution rules which

 * are applied to the String to be compared before the actual comparison takes

 * place. By this it is e.g. possible to influence the position of objects in sorted lists etc.

 * <p>

 * <b>Intended usage</b>: To allow maximum flexibility the property

 * {@link #setSubstitutionRules(Map)} should be set in the spring application

 * context.

 * 

 * @author a.kohlbecker

 * @date 24.06.2009

 */

@Component

public abstract class AbstractStringComparator implements Comparator<TaxonNode> {

	protected Map<Pattern, String> substitutionRules = null;

	/**

	 * Set the private field substitutionRules. The substitutionRules consist of

	 * a regular expression as key and a string to be prepended as value.

	 * 

	 * @param rules

	 */

	public void setSubstitutionRules(Map<String, String> substitutionRules) {

		this.substitutionRules = new HashMap<Pattern, String>(substitutionRules.size());

		for (String regex : substitutionRules.keySet()) {

			this.substitutionRules.put(Pattern.compile(regex), substitutionRules.get(regex));

		}

	}

	/**

	 * Applies the first matching <code>substitutionRules</code> set by

	 * {@link #setSubstitutionRules()} to the given String. A rules is applied

	 * in the following way: If the regular expression matches the given string

	 * <code>s</code> the String mapped by the regular expression is prepended

	 * to <code>s</code>.

	 * 

	 * @param s

	 * @return

	 */

	protected String applySubstitutionRules(String s) {

		if (substitutionRules == null) {

			return s;

		}

		StringBuffer sb = new StringBuffer();

		for (Pattern pattern : substitutionRules.keySet()) {

			if (pattern.matcher(s).matches()) {

				sb.append(substitutionRules.get(pattern)).append(s);

				return sb.toString();

			}

		}

		return s;

	}

}