/*
    * 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.internal.impl;
  
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.regex.Pattern;
  
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.impl.OfflineController;
  import org.eclipse.aether.repository.RemoteRepository;
  import org.eclipse.aether.transfer.RepositoryOfflineException;
  import org.eclipse.aether.util.ConfigUtils;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   *
   */
  @Singleton
  @Named
  public class DefaultOfflineController implements OfflineController {
  
      static final String CONFIG_PROP_OFFLINE_PROTOCOLS = "aether.offline.protocols";
  
      static final String CONFIG_PROP_OFFLINE_HOSTS = "aether.offline.hosts";
  
      private static final Pattern SEP = Pattern.compile("\\s*,\\s*");
  
      public DefaultOfflineController() {
          // enables default constructor
      }
  
      public void checkOffline(RepositorySystemSession session, RemoteRepository repository)
              throws RepositoryOfflineException {
          requireNonNull(session, "session cannot be null");
          requireNonNull(repository, "repository cannot be null");
          if (isOfflineProtocol(session, repository) || isOfflineHost(session, repository)) {
              return;
          }
  
          throw new RepositoryOfflineException(repository);
      }
  
      private boolean isOfflineProtocol(RepositorySystemSession session, RemoteRepository repository) {
          String[] protocols = getConfig(session, CONFIG_PROP_OFFLINE_PROTOCOLS);
          if (protocols != null) {
              String protocol = repository.getProtocol();
              if (protocol.length() > 0) {
                  for (String p : protocols) {
                      if (p.equalsIgnoreCase(protocol)) {
                          return true;
                      }
                  }
              }
          }
          return false;
      }
  
      private boolean isOfflineHost(RepositorySystemSession session, RemoteRepository repository) {
          String[] hosts = getConfig(session, CONFIG_PROP_OFFLINE_HOSTS);
          if (hosts != null) {
              String host = repository.getHost();
              if (host.length() > 0) {
                  for (String h : hosts) {
                      if (h.equalsIgnoreCase(host)) {
                          return true;
                      }
                  }
              }
          }
          return false;
      }
  
      private String[] getConfig(RepositorySystemSession session, String key) {
          String value = ConfigUtils.getString(session, "", key).trim();
          if (value.isEmpty()) {
              return null;
          }
          return SEP.split(value);
      }
  }