/*
    * 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.info;
  
  import org.waarp.common.command.ReplyCode;
  import org.waarp.common.command.exception.CommandAbstractException;
  import org.waarp.common.command.exception.Reply501Exception;
  import org.waarp.common.command.exception.Reply502Exception;
  import org.waarp.common.command.exception.Reply503Exception;
  import org.waarp.ftp.core.command.AbstractCommand;
  import org.waarp.ftp.core.command.FtpCommandCode;
  import org.waarp.ftp.core.command.extension.XCRC;
  import org.waarp.ftp.core.command.extension.XDIGEST;
  import org.waarp.ftp.core.command.extension.XMD5;
  import org.waarp.ftp.core.command.extension.XSHA1;
  import org.waarp.ftp.core.command.internal.IncorrectCommand;
  
  /**
   * SITE command: implements some specific command like {@link XMD5} {@link XCRC}
   * {@link XSHA1} or {@link XDIGEST} as if they were
   * called directly
   */
  public class SITE extends AbstractCommand {
  
    @Override
    public final void exec() throws CommandAbstractException {
      if (!hasArg()) {
        invalidCurrentCommand();
        throw new Reply501Exception("Need a command at least as argument");
      }
      // First check if this command is a special extension
      AbstractCommand command = getSession().getBusinessHandler()
                                            .getSpecializedSiteCommand(
                                                getSession(), getArg());
      boolean special = true;
      if (command == null) {
        // Now check what is the command as if we were in the NetworkHandler
        command = FtpCommandCode.getFromLine(getSession(), getArg());
        special = false;
      }
      // Default message
      getSession().setReplyCode(ReplyCode.REPLY_200_COMMAND_OKAY, null);
      // First check if the command is an extension command
      if (special || FtpCommandCode.isExtensionCommand(command.getCode())) {
        // Now check if a transfer is on its way: illegal to have at same
        // time two commands
        if (getSession().getDataConn().getFtpTransferControl()
                        .isFtpTransferExecuting()) {
          throw new Reply503Exception(
              "Previous transfer command is not finished yet");
        }
      } else {
        throw new Reply502Exception("Command not implemented: " + getArg());
      }
      // Command is OK, set it as current by first undo current command then
      // set it as next after testing validity
      getSession().setPreviousAsCurrentCommand();
      if (getSession().getCurrentCommand().isNextCommandValid(command)) {
        getSession().setNextCommand(command);
        getSession().getBusinessHandler().beforeRunCommand();
        command.exec();
      } else {
        command = new IncorrectCommand();
        command.setArgs(getSession(), getArg(), null,
                        FtpCommandCode.IncorrectSequence);
        getSession().setNextCommand(command);
        getSession().getBusinessHandler().beforeRunCommand();
        command.exec();
      }
    }
  }