/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited

  *

  * Licensed 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.acegisecurity.intercept.web;

 import org.acegisecurity.ConfigAttributeDefinition;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.oro.text.regex.MalformedPatternException;

 import org.apache.oro.text.regex.Pattern;

 import org.apache.oro.text.regex.PatternMatcher;

 import org.apache.oro.text.regex.Perl5Compiler;

 import org.apache.oro.text.regex.Perl5Matcher;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Set;

 import java.util.Vector;

 /**

  * Maintains a <code>List</code> of <code>ConfigAttributeDefinition</code>s associated with different HTTP request

  * URL regular expression patterns.<p>Regular expressions are used to match a HTTP request URL against a

  * <code>ConfigAttributeDefinition</code>.</p>

  *  <p>The order of registering the regular expressions using the {@link #addSecureUrl(String,

  * ConfigAttributeDefinition)} is very important. The system will identify the <b>first</b>  matching regular

  * expression for a given HTTP URL. It will not proceed to evaluate later regular expressions if a match has already

  * been found. Accordingly, the most specific regular expressions should be registered first, with the most general

  * regular expressions registered last.</p>

  *  <p>If no registered regular expressions match the HTTP URL, <code>null</code> is returned.</p>

  */

 public class RegExpBasedFilterInvocationDefinitionMap extends AbstractFilterInvocationDefinitionSource

     implements FilterInvocationDefinition {

     //~ Static fields/initializers =====================================================================================

     private static final Log logger = LogFactory.getLog(RegExpBasedFilterInvocationDefinitionMap.class);

     //~ Instance fields ================================================================================================

     private List requestMap = new Vector();

     private boolean convertUrlToLowercaseBeforeComparison = false;

     //~ Methods ========================================================================================================

     public void addSecureUrl(String perl5RegExp, ConfigAttributeDefinition attr) {

         Pattern compiledPattern;

         Perl5Compiler compiler = new Perl5Compiler();

         try {

             compiledPattern = compiler.compile(perl5RegExp, Perl5Compiler.READ_ONLY_MASK);

         } catch (MalformedPatternException mpe) {

             throw new IllegalArgumentException("Malformed regular expression: " + perl5RegExp);

         }

         requestMap.add(new EntryHolder(compiledPattern, attr));

         if (logger.isDebugEnabled()) {

             logger.debug("Added regular expression: " + compiledPattern.getPattern().toString() + "; attributes: "

                 + attr);

         }

     }

     public Iterator getConfigAttributeDefinitions() {

         Set set = new HashSet();

         Iterator iter = requestMap.iterator();

         while (iter.hasNext()) {

             EntryHolder entryHolder = (EntryHolder) iter.next();

             set.add(entryHolder.getConfigAttributeDefinition());

         }

         return set.iterator();

     }

     public int getMapSize() {

         return this.requestMap.size();

     }

     public boolean isConvertUrlToLowercaseBeforeComparison() {

         return convertUrlToLowercaseBeforeComparison;

     }

     public ConfigAttributeDefinition lookupAttributes(String url) {

         PatternMatcher matcher = new Perl5Matcher();

         Iterator iter = requestMap.iterator();

         if (isConvertUrlToLowercaseBeforeComparison()) {

             url = url.toLowerCase();

             if (logger.isDebugEnabled()) {

                 logger.debug("Converted URL to lowercase, from: '" + url + "'; to: '" + url + "'");

             }

         }

         while (iter.hasNext()) {

             EntryHolder entryHolder = (EntryHolder) iter.next();

             boolean matched = matcher.matches(url, entryHolder.getCompiledPattern());

             if (logger.isDebugEnabled()) {

                 logger.debug("Candidate is: '" + url + "'; pattern is " + entryHolder.getCompiledPattern().getPattern()

                     + "; matched=" + matched);

             }

             if (matched) {

                 return entryHolder.getConfigAttributeDefinition();

             }

         }

         return null;

     }

     public void setConvertUrlToLowercaseBeforeComparison(boolean convertUrlToLowercaseBeforeComparison) {

         this.convertUrlToLowercaseBeforeComparison = convertUrlToLowercaseBeforeComparison;

     }

     //~ Inner Classes ==================================================================================================

     protected class EntryHolder {

         private ConfigAttributeDefinition configAttributeDefinition;

         private Pattern compiledPattern;

         public EntryHolder(Pattern compiledPattern, ConfigAttributeDefinition attr) {

             this.compiledPattern = compiledPattern;

             this.configAttributeDefinition = attr;

         }

         protected EntryHolder() {

             throw new IllegalArgumentException("Cannot use default constructor");

         }

         public Pattern getCompiledPattern() {

             return compiledPattern;

         }

         public ConfigAttributeDefinition getConfigAttributeDefinition() {

             return configAttributeDefinition;

         }

     }

 }