/*

  * 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.shiro.guice.web;

 import java.util.Arrays;

 import java.util.Iterator;

 import java.util.Map;

 import javax.servlet.Filter;

 import javax.servlet.FilterChain;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 import com.google.inject.Injector;

 import com.google.inject.Key;

 import org.apache.shiro.util.PatternMatcher;

 import org.apache.shiro.web.filter.mgt.FilterChainResolver;

 import org.apache.shiro.web.util.WebUtils;

 class SimpleFilterChainResolver implements FilterChainResolver {

     private final Map<String, Key<? extends Filter>[]> chains;

     private final Injector injector;

     private final PatternMatcher patternMatcher;

     SimpleFilterChainResolver(Map<String, Key<? extends Filter>[]> chains, Injector injector, PatternMatcher patternMatcher) {

         this.chains = chains;

         this.injector = injector;

         this.patternMatcher = patternMatcher;

     }

     public FilterChain getChain(ServletRequest request, ServletResponse response, final FilterChain originalChain) {

         String path = WebUtils.getPathWithinApplication(WebUtils.toHttp(request));

         for (final String pathPattern : chains.keySet()) {

             if (patternMatcher.matches(pathPattern, path)) {

                 final Iterator<Key<? extends Filter>> chain = Arrays.asList(chains.get(pathPattern)).iterator();

                 return new SimpleFilterChain(originalChain, new Iterator<Filter>() {

                     public boolean hasNext() {

                         return chain.hasNext();

                     }

                     public Filter next() {

                         return injector.getInstance(chain.next());

                     }

                     public void remove() {

                         throw new UnsupportedOperationException();

                     }

                 });

             }

         }

         return null;

     }

 }