/*
    * This file is part of Waarp Project (named also Waarp or GG).
    *
    *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
    *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
    * individual contributors.
    *
    *  All Waarp Project is free software: you can redistribute it and/or
    * modify it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or (at your
   * option) any later version.
   *
   * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY
   * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License along with
   * Waarp . If not, see <http://www.gnu.org/licenses/>.
   */
  package org.waarp.ftp.core.command.parameter;
  
  import org.waarp.common.command.ReplyCode;
  import org.waarp.common.command.exception.Reply425Exception;
  import org.waarp.common.command.exception.Reply501Exception;
  import org.waarp.common.logging.WaarpLogger;
  import org.waarp.common.logging.WaarpLoggerFactory;
  import org.waarp.ftp.core.command.AbstractCommand;
  import org.waarp.ftp.core.config.FtpConfiguration;
  import org.waarp.ftp.core.config.FtpInternalConfiguration;
  import org.waarp.ftp.core.data.FtpDataAsyncConn;
  import org.waarp.ftp.core.utils.FtpChannelUtils;
  
  import java.net.InetAddress;
  import java.net.InetSocketAddress;
  
  /**
   * PASV command
   */
  public class PASV extends AbstractCommand {
    /**
     * Internal Logger
     */
    private static final WaarpLogger logger =
        WaarpLoggerFactory.getLogger(PASV.class);
  
    @Override
    public final void exec() throws Reply425Exception, Reply501Exception {
      // Check if Passive mode is OK
      if (((FtpConfiguration) (FtpConfiguration.ftpConfiguration)).getActivePassiveMode() >
          0) {
        // Active only
        throw new Reply501Exception("Passive mode not allowed");
      }
      // First Check if any argument
      if (hasArg()) {
        throw new Reply501Exception("No argument allowed");
      }
      // Take a new port: 3 attempts
      boolean isInit = false;
      if (getSession().getDataConn().isPassiveMode()) {
        // Previous mode was Passive so remove the current configuration
        final InetSocketAddress local =
            getSession().getDataConn().getLocalAddress();
        final InetAddress remote =
            getSession().getDataConn().getRemoteAddress().getAddress();
        getConfiguration().delFtpSession(remote, local);
      }
      for (int i = 1; i <= FtpInternalConfiguration.RETRYNB; i++) {
        final int newport =
            FtpDataAsyncConn.getNewPassivePort(getConfiguration());
        if (newport == -1) {
          throw new Reply425Exception("No port available");
        }
        logger.info("PASV: set Passive Port {}", newport);
        getSession().getDataConn().setLocalPort(newport);
        getSession().getDataConn().setPassive();
        // Init the connection
        try {
          if (getSession().getDataConn().initPassiveConnection()) {
            isInit = true;
            break;
          }
        } catch (final Reply425Exception e) {
          logger.warn(
              "Pasv refused at try: " + i + " with port:  since {}" + newport,
              e.getMessage());
        }
      }
      if (!isInit) {
        throw new Reply425Exception("Passive mode not started");
      }
      // Return the address in Ftp format
      final InetSocketAddress local =
          getSession().getDataConn().getLocalAddress();
      final int servPort = local.getPort();
      String address = getSession().getConfiguration().getServerAddress();
      if (address == null) {
        address = local.getAddress().getHostAddress();
      }
     final String slocal = "Entering Passive Mode (" +
                           FtpChannelUtils.getAddress(address, servPort) + ')';
     final InetAddress remote =
         getSession().getDataConn().getRemoteAddress().getAddress();
     // Add the current FtpSession into the reference of session since the
     // client will open the connection
     getConfiguration().setNewFtpSession(remote, local, getSession());
     // prepare the validation of the next connection
     getSession().getDataConn().getFtpTransferControl()
                 .resetWaitForOpenedDataChannel();
     getSession().setReplyCode(ReplyCode.REPLY_227_ENTERING_PASSIVE_MODE,
                               slocal);
     logger.info("PASV: answer ready on {}", slocal);
   }
 
 }