/*

  * 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.apache.commons.classscan.builtin;

 import java.io.IOException;

 import java.net.URL;

 import java.net.URLClassLoader;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.Collections;

 import java.util.HashMap;

 import java.util.List;

 import java.util.Map;

 import org.apache.commons.classscan.ClassPathElement;

 import org.apache.commons.classscan.ResourceFile;

 import org.apache.commons.classscan.spi.model.SpiClassPath;

 import org.apache.commons.classscan.spi.model.SpiClassPathElement;

 import org.apache.commons.classscan.spi.model.SpiMetaClassLoader;

 import org.apache.commons.classscan.spi.model.SpiMetaRegistry;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 public class UrlClassPath implements SpiClassPath {

     private static final Logger logger = LoggerFactory.getLogger(UrlClassPath.class);

     private final SpiMetaRegistry registry;

         private final List<SpiClassPathElement> classPathElements;

         public UrlClassPath(SpiMetaRegistry registry, URLClassLoader urlClassLoader) {

                 this.registry = registry;

                 classPathElements = Collections.unmodifiableList(getClassPathElements(registry, urlClassLoader.getURLs()));

         }

         static List<SpiClassPathElement> getClassPathElements(SpiMetaRegistry registry, URL[] urls) {

                 List<SpiClassPathElement> elements = new ArrayList<SpiClassPathElement>();

                 Map<String, URL> locations = new HashMap<String, URL>();

                 for(URL url : urls) {

                         String baseLocation= url.toExternalForm();

                         if( locations.containsKey(baseLocation) ) {

                                 continue;

                         }

                         locations.put(baseLocation, url);

                         try {

                                 SpiClassPathElement element= registry.createClassPathElement(url);

                                 elements.add(element);

                         } catch (IOException e) {

                             logger.info("Problem with URL "+url, e);

                         }

                 }

                 return elements;

         }

         @Override

         public List<? extends ClassPathElement> getClassPathElements() {

                 return classPathElements;

         }

         @Override

         public SpiMetaClassLoader createMetaClassLoader(SpiMetaRegistry registry, ClassLoader classLoader) {

                 return new UrlMetaClassLoader(registry, classLoader);

         }

         @Override

         public Map<ClassPathElement, ResourceFile> getResources(String fileName) {

                 Map<ClassPathElement, ResourceFile> resources = new HashMap<ClassPathElement, ResourceFile>();

                 Map<String,ClassPathElement> visited = new HashMap<String,ClassPathElement>();

                 searchElements(visited, resources, classPathElements, fileName);

                 return resources;

         }

         public void searchElements(Map<String,ClassPathElement> visited, Map<ClassPathElement, ResourceFile> resources, Collection<SpiClassPathElement> elements, String fileName) {

                 for(SpiClassPathElement element : elements) {

                         String location = element.getLocation();

                         if(visited.put(location, element)!=null) {

                                 continue;

                         }

                         ResourceFile resource= element.getResource(fileName);

                         if(resource!=null) {

                                 resources.put(element, resource);

                         }

                         Collection<SpiClassPathElement> additionalLocations = element.getAdditionalLocations(registry);

                         if(additionalLocations!=null) {

                                 searchElements(visited, resources, additionalLocations, fileName);

                         }

                 }

         }

 }