/**

  * Copyright (c) 2014-2015, Thindeck.com

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met: 1) Redistributions of source code must retain the above

  * copyright notice, this list of conditions and the following

  * disclaimer. 2) Redistributions in binary form must reproduce the above

  * copyright notice, this list of conditions and the following

  * disclaimer in the documentation and/or other materials provided

  * with the distribution. 3) Neither the name of the thindeck.com nor

  * the names of its contributors may be used to endorse or promote

  * products derived from this software without specific prior written

  * permission.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT

  * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

  * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL

  * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,

  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

  * OF THE POSSIBILITY OF SUCH DAMAGE.

  */

 package com.thindeck.agents;

 import com.google.common.base.Joiner;

 import com.jcabi.aspects.Immutable;

 import com.jcabi.log.Logger;

 import com.jcabi.xml.XML;

 import com.thindeck.api.Agent;

 import org.xembly.Directive;

 import org.xembly.Directives;

 /**

  * Swap BLUE and GREEN containers.

  *

  * @author Yegor Bugayenko (yegor@teamed.io)

  * @version $Id$

  * @since 0.1

  * @checkstyle MultipleStringLiteralsCheck (500 lines)

  */

 @Immutable

 public final class Swap implements Agent {

     @Override

     public Iterable<Directive> exec(final XML deck) {

         final boolean ready = !deck.nodes(

             Joiner.on(" and ").join(

                 "/deck/containers[not(container/@waste)",

                 "not(container[@state='dead' and @type='blue'])",

                 "not(container[@state='unknown' and @type='blue'])",

                 "container/@type='blue']"

             )

         ).isEmpty();

         final Directives dirs = new Directives();

         if (ready) {

             final String today = new Today().iso();

             for (final XML ctr : deck.nodes("/deck/containers/container")) {

                 final String name = ctr.xpath("name/text()").get(0);

                 dirs.xpath(

                     String.format(

                         "/deck/containers/container[name='%s']",

                         name

                     )

                 );

                 final String img = ctr.xpath("image/text()").get(0);

                 if ("blue".equals(ctr.xpath("@type").get(0))) {

                     dirs.attr("type", "green");

                     Logger.info(this, "Blue container %s set to green", name);

                     dirs.xpath("/deck/images/image").attr("waste", today);

                     dirs.xpath(

                         String.format(

                             "/deck/images/image[name='%s']",

                             img

                         )

                     ).attr("type", "green").xpath("@waste").remove();

                     Logger.info(

                         this, "Image %s set to green, others to waste", img

                     );

                 } else {

                     dirs.attr("waste", today);

                     Logger.info(this, "Green container %s set to waste", name);

                     dirs.xpath(

                         String.format(

                             "/deck/images/image[name='%s']",

                             img

                         )

                     ).attr("waste", today);

                     Logger.info(this, "Image %s set to waste", img);

                 }

             }

         }

         return dirs;

     }

 }