/**

  * 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.jcabi.aspects.Immutable;

 import com.jcabi.aspects.Tv;

 import com.jcabi.log.Logger;

 import com.jcabi.xml.XML;

 import com.thindeck.api.Agent;

 import java.io.IOException;

 import java.text.ParseException;

 import java.util.Collection;

 import java.util.Date;

 import java.util.concurrent.TimeUnit;

 import org.apache.commons.lang3.time.DateFormatUtils;

 import org.xembly.Directive;

 import org.xembly.Directives;

 /**

  * Remove repo if it's too old and still has no images.

  *

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

  * @version $Id$

  * @since 0.1

  */

 @Immutable

 public final class WipeRepo implements Agent {

     @Override

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

         final Collection<XML> images = deck.nodes(

             "/deck/images/image[repo=/deck/repo/name]"

         );

         final Directives dirs = new Directives();

         if (images.isEmpty() && !deck.nodes("/deck/repo/name").isEmpty()) {

             final Date today = new Date();

             final int age;

             try {

                 age = (int) ((today.getTime()

                     - DateFormatUtils.ISO_DATETIME_FORMAT.parse(

                         deck.xpath("/deck/repo/@added").get(0)

                     ).getTime()) / TimeUnit.MINUTES.toMillis(1L));

             } catch (final ParseException ex) {

                 throw new IOException(ex);

             }

             if (age > Tv.TEN) {

                 Logger.info(

                     this, "Repo %s still has no images for over %d mins",

                     deck.xpath("/deck/repo/uri/text()"), age

                 );

                 dirs.xpath("/deck/repo").remove();

             }

         }

         return dirs;

     }

 }