/*
    * 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.eclipse.aether.transport.classpath;
  
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.net.URL;
  import java.net.URLConnection;
  
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.repository.RemoteRepository;
  import org.eclipse.aether.spi.connector.transport.AbstractTransporter;
  import org.eclipse.aether.spi.connector.transport.GetTask;
  import org.eclipse.aether.spi.connector.transport.PeekTask;
  import org.eclipse.aether.spi.connector.transport.PutTask;
  import org.eclipse.aether.spi.connector.transport.TransportTask;
  import org.eclipse.aether.transfer.NoTransporterException;
  import org.eclipse.aether.util.ConfigUtils;
  
  /**
   * A transporter reading from the classpath.
   */
  final class ClasspathTransporter extends AbstractTransporter {
  
      private final String resourceBase;
  
      private final ClassLoader classLoader;
  
      ClasspathTransporter(RepositorySystemSession session, RemoteRepository repository) throws NoTransporterException {
          String base;
          try {
              URI uri = new URI(repository.getUrl());
              String ssp = uri.getSchemeSpecificPart();
              if (ssp.startsWith("/")) {
                  base = uri.getPath();
                  if (base == null) {
                      base = "";
                  } else if (base.startsWith("/")) {
                      base = base.substring(1);
                  }
              } else {
                  base = ssp;
              }
              if (!base.isEmpty() && !base.endsWith("/")) {
                  base += '/';
              }
          } catch (URISyntaxException e) {
              throw new NoTransporterException(repository, e);
          }
          resourceBase = base;
  
          Object cl = ConfigUtils.getObject(session, null, ClasspathTransporterFactory.CONFIG_PROP_CLASS_LOADER);
          if (cl instanceof ClassLoader) {
              classLoader = (ClassLoader) cl;
          } else {
              classLoader = Thread.currentThread().getContextClassLoader();
          }
      }
  
      private URL getResource(TransportTask task) throws Exception {
          String resource = resourceBase + task.getLocation().getPath();
          URL url = classLoader.getResource(resource);
          if (url == null) {
              throw new ResourceNotFoundException("Could not locate " + resource);
          }
          return url;
      }
  
      @Override
      public int classify(Throwable error) {
          if (error instanceof ResourceNotFoundException) {
              return ERROR_NOT_FOUND;
          }
          return ERROR_OTHER;
      }
  
      @Override
      protected void implPeek(PeekTask task) throws Exception {
          getResource(task);
      }
  
      @Override
      protected void implGet(GetTask task) throws Exception {
         URL url = getResource(task);
         URLConnection conn = url.openConnection();
         utilGet(task, conn.getInputStream(), true, conn.getContentLength(), false);
     }
 
     @Override
     protected void implPut(PutTask task) throws Exception {
         throw new UnsupportedOperationException("Uploading to a classpath: repository is not supported");
     }
 
     @Override
     protected void implClose() {}
 }