/**

  *

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to You under the Apache License, Version 2.0

  * (the "License"); you may not use this file except in compliance with

  * the License.  You may obtain a copy of the License at

  *

  * http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.apache.maven.doxia.linkcheck.validation;

 import java.util.regex.Matcher;

 import java.util.regex.Pattern;

 /**

  * A helper class to test if some content matches the given HTML anchor

  */

 public class Anchors

 {

     /**

      * Returns true if the given anchor can be found in the content markup.

      *

      * @param content the content string.

      * @param anchor the anchor to match.

      *

      * @return true if the given anchor can be found in the content markup.

      */

     public static boolean matchesAnchor( String content, String anchor )

     {

         if ( content != null && anchor.length() > 0 ) {

             // can use name or id attributes and also can use single or double quotes with whitespace around the =

             String regex = "(?i)(name|id)(?-i)\\s*=\\s*('|\")" + escapeBrackets( anchor ) + "('|\")";

             Pattern pattern = Pattern.compile( regex );

             Matcher matcher = pattern.matcher( content );

             return matcher.find();

         }

         return false;

     }

     // for javadoc links, see DOXIA-410

     private static String escapeBrackets( String content )

     {

         final String escaped = content.replace( "(", "\\(" ).replace( ")", "\\)" );

         return escaped.replace( "[", "\\[" ).replace( "]", "\\]" );

     }

     private Anchors()

     {

         // utility class

     }

 }