/*
    * 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.commons.vfs2.provider.ftps;
  
  import java.io.IOException;
  
  import javax.net.ssl.KeyManager;
  import javax.net.ssl.SSLException;
  import javax.net.ssl.TrustManager;
  
  import org.apache.commons.net.ftp.FTPSClient;
  import org.apache.commons.vfs2.FileSystemException;
  import org.apache.commons.vfs2.FileSystemOptions;
  import org.apache.commons.vfs2.provider.ftp.FtpClientFactory;
  
  /**
   * Create FTPSClient instances.
   *
   * @since 2.0
   */
  public final class FtpsClientFactory {
  
      /** Connection Factory for FTPS case. */
      private static final class FtpsConnectionFactory
              extends FtpClientFactory.ConnectionFactory<FTPSClient, FtpsFileSystemConfigBuilder> {
  
          private FtpsConnectionFactory(final FtpsFileSystemConfigBuilder builder) {
              super(builder);
          }
  
          @Override
          protected FTPSClient createClient(final FileSystemOptions fileSystemOptions) throws FileSystemException {
              final FTPSClient client = new FTPSClient(builder.getFtpsMode(fileSystemOptions) == FtpsMode.IMPLICIT);
  
              final TrustManager trustManager = builder.getTrustManager(fileSystemOptions);
              if (trustManager != null) {
                  client.setTrustManager(trustManager);
              }
  
              final KeyManager keyManager = builder.getKeyManager(fileSystemOptions);
              if (keyManager != null) {
                  client.setKeyManager(keyManager);
              }
              return client;
          }
  
          @Override
          protected void setupOpenConnection(final FTPSClient client, final FileSystemOptions fileSystemOptions)
                  throws IOException {
              final FtpsDataChannelProtectionLevel level = builder.getDataChannelProtectionLevel(fileSystemOptions);
              if (level != null) {
                  // '0' means streaming, that's what we do!
                  try {
                      client.execPBSZ(0);
                      client.execPROT(level.name());
                  } catch (final SSLException e) {
                      throw new FileSystemException("vfs.provider.ftps/data-channel.level", e, level.toString());
                  }
              }
          }
      }
  
      /**
       * Creates a new connection to the server.
       *
       * @param hostname The host name.
       * @param port The port.
       * @param username The user name for authentication.
       * @param password The user's password.
       * @param workingDirectory The directory to use.
       * @param fileSystemOptions The FileSystemOptions.
       * @return The FTPSClient.
       * @throws FileSystemException if an error occurs while establishing a connection.
       */
      public static FTPSClient createConnection(final String hostname, final int port, final char[] username,
              final char[] password, final String workingDirectory, final FileSystemOptions fileSystemOptions)
              throws FileSystemException {
          final FtpsConnectionFactory factory = new FtpsConnectionFactory(FtpsFileSystemConfigBuilder.getInstance());
          return factory.createConnection(hostname, port, username, password, workingDirectory, fileSystemOptions);
      }
  
      private FtpsClientFactory() {
          // empty
      }
  }