/**

  * Copyright (c) 2012-2013, JCabi.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 jcabi.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.jcabi.beanstalk.maven.plugin;

 import com.amazonaws.services.elasticbeanstalk.AWSElasticBeanstalk;

 import com.amazonaws.services.elasticbeanstalk.model.ConfigurationOptionSetting;

 import com.amazonaws.services.elasticbeanstalk.model.ConfigurationSettingsDescription;

 import com.amazonaws.services.elasticbeanstalk.model.DescribeConfigurationSettingsRequest;

 import com.amazonaws.services.elasticbeanstalk.model.DescribeConfigurationSettingsResult;

 import com.amazonaws.services.elasticbeanstalk.model.DescribeEnvironmentsRequest;

 import com.amazonaws.services.elasticbeanstalk.model.DescribeEnvironmentsResult;

 import com.amazonaws.services.elasticbeanstalk.model.DescribeEventsRequest;

 import com.amazonaws.services.elasticbeanstalk.model.DescribeEventsResult;

 import com.amazonaws.services.elasticbeanstalk.model.EnvironmentDescription;

 import com.amazonaws.services.elasticbeanstalk.model.EnvironmentInfoDescription;

 import com.amazonaws.services.elasticbeanstalk.model.EnvironmentInfoType;

 import com.amazonaws.services.elasticbeanstalk.model.EventDescription;

 import com.amazonaws.services.elasticbeanstalk.model.RequestEnvironmentInfoRequest;

 import com.amazonaws.services.elasticbeanstalk.model.RetrieveEnvironmentInfoRequest;

 import com.amazonaws.services.elasticbeanstalk.model.TerminateEnvironmentRequest;

 import com.amazonaws.services.elasticbeanstalk.model.TerminateEnvironmentResult;

 import com.amazonaws.services.elasticbeanstalk.model.UpdateEnvironmentRequest;

 import com.amazonaws.services.elasticbeanstalk.model.UpdateEnvironmentResult;

 import com.jcabi.aspects.Loggable;

 import com.jcabi.aspects.Tv;

 import com.jcabi.log.Logger;

 import java.io.IOException;

 import java.net.URL;

 import java.util.Collection;

 import java.util.LinkedList;

 import java.util.List;

 import java.util.concurrent.TimeUnit;

 import javax.validation.constraints.NotNull;

 import lombok.EqualsAndHashCode;

 import org.apache.commons.io.IOUtils;

 /**

  * EBT environment.

  *

  * @author Yegor Bugayenko (yegor@tpc2.com)

  * @version $Id$

  * @since 0.3

  * @checkstyle ClassDataAbstractionCoupling (500 lines)

  */

 @EqualsAndHashCode(of = { "client", "eid" })

 @SuppressWarnings({ "PMD.TooManyMethods", "PMD.ExcessiveImports" })

 @Loggable(Loggable.DEBUG)

 final class Environment {

     /**

      * For how long we can wait until env reaches certain status.

      */

     private static final long DELAY_MS = TimeUnit.MINUTES.toMillis(Tv.THIRTY);

     /**

      * AWS beanstalk client.

      */

     private final transient AWSElasticBeanstalk client;

     /**

      * Environment ID.

      */

     private final transient String eid;

     /**

      * Public ctor.

      * @param clnt The client

      * @param idnt Environment ID

      */

     protected Environment(@NotNull final AWSElasticBeanstalk clnt,

         @NotNull final String idnt) {

         this.client = clnt;

         this.eid = idnt;

         final EnvironmentDescription desc = this.description();

         final String template = desc.getTemplateName();

         if (template != null) {

             final DescribeConfigurationSettingsResult res =

                 this.client.describeConfigurationSettings(

                     new DescribeConfigurationSettingsRequest()

                         .withApplicationName(desc.getApplicationName())

                         .withTemplateName(template)

                 );

             for (ConfigurationSettingsDescription config

                 : res.getConfigurationSettings()) {

                 Logger.debug(

                     Environment.class,

                     "Environment '%s/%s/%s' settings:",

                     config.getApplicationName(), config.getEnvironmentName()

                 );

                 for (ConfigurationOptionSetting opt

                     : config.getOptionSettings()) {

                     Logger.debug(

                         Environment.class,

                         "  %s/%s: %s",

                         opt.getNamespace(), opt.getOptionName(), opt.getValue()

                     );

                 }

             }

         }

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public String toString() {

         final EnvironmentDescription desc = this.description();

         return String.format(

             "%s/%s/%s",

             desc.getEnvironmentName(), desc.getEnvironmentId(), desc.getCNAME()

         );

     }

     /**

      * Is it primary environment in the application?

      * @return TRUE if this environment is attached to the main CNAME

      */

     public boolean primary() {

         final EnvironmentDescription desc = this.description();

         final String prefix = String.format("%s.", desc.getApplicationName());

         final boolean primary = this.stable()

             && desc.getCNAME().startsWith(prefix);

         if (primary) {

             Logger.info(

                 this,

                 "Environment '%s' considered primary", this

             );

         } else {

             Logger.info(

                 this,

                 // @checkstyle LineLength (1 line)

                 "Environment '%s' considered secondary since its CNAME doesn't start with '%s'",

                 this, prefix

             );

         }

         return primary;

     }

     /**

      * Get environment name.

      * @return Name of it

      */

     public String name() {

         return this.description().getEnvironmentName();

     }

     /**

      * Environment is in Green health?

      * @return TRUE if environment is in Green health

      */

     public boolean green() {

         return this.stable() && "Green".equals(this.description().getHealth());

     }

     /**

      * Wait for stable state, and return TRUE if achieved or FALSE if not.

      * @return TRUE if environment is stable

      */

     public boolean stable() {

         return this.until(

             new Environment.Barrier() {

                 @Override

                 public String message() {

                     return "stable state";

                 }

                 @Override

                 public boolean allow(final EnvironmentDescription desc) {

                     return !desc.getStatus().matches(".*ing$");

                 }

             }

         );

     }

     /**

      * Is it terminated?

      * @return Yes or no

      */

     public boolean terminated() {

         return this.stable()

             && "Terminated".equals(this.description().getStatus());

     }

     /**

      * Terminate environment.

      */

     public void terminate() {

         if (!this.stable()) {

             throw new DeploymentException(

                 String.format(

                     "env '%s' is not stable, can't terminate",

                     this.eid

                 )

             );

         }

         if (!this.terminated()) {

             final TerminateEnvironmentResult res =

                 this.client.terminateEnvironment(

                     new TerminateEnvironmentRequest()

                         .withEnvironmentId(this.eid)

                         .withTerminateResources(true)

                 );

             Logger.info(

                 this,

                 "Environment '%s/%s/%s' is terminated (label:'%s', status:%s)",

                 res.getApplicationName(), res.getEnvironmentName(),

                 res.getEnvironmentId(), res.getCNAME(),

                 res.getVersionLabel(), res.getStatus()

             );

         }

     }

     /**

      * Get latest events.

      * @return Collection of events

      */

     public String[] events() {

         if (!this.stable()) {

             throw new DeploymentException(

                 String.format(

                     "env '%s' is not stable, can't get list of events",

                     this.eid

                 )

             );

         }

         final DescribeEventsResult res = this.client.describeEvents(

             new DescribeEventsRequest().withEnvironmentId(this.eid)

         );

         final Collection<String> events = new LinkedList<String>();

         for (EventDescription desc : res.getEvents()) {

             events.add(

                 String.format("[%s]: %s", desc.getSeverity(), desc.getMessage())

             );

         }

         return events.toArray(new String[events.size()]);

     }

     /**

      * Tail log.

      * @return Full text of tail log from the environment

      */

     public String tail() {

         if (!this.stable()) {

             throw new DeploymentException(

                 String.format(

                     "env '%s' is not stable, can't get TAIL report",

                     this.eid

                 )

             );

         }

         if (this.terminated()) {

             throw new DeploymentException(

                 String.format(

                     "env '%s' is terminated, can't get TAIL report",

                     this.eid

                 )

             );

         }

         this.client.requestEnvironmentInfo(

             new RequestEnvironmentInfoRequest()

                 .withEnvironmentId(this.eid)

                 .withInfoType(EnvironmentInfoType.Tail)

         );

         final RetrieveEnvironmentInfoRequest req =

             new RetrieveEnvironmentInfoRequest()

                 .withEnvironmentId(this.eid)

                 .withInfoType(EnvironmentInfoType.Tail);

         List<EnvironmentInfoDescription> infos;

         final long start = System.currentTimeMillis();

         do {

             if (System.currentTimeMillis() - start > Environment.DELAY_MS) {

                 throw new DeploymentException(

                     String.format(

                         "env '%s' doesn't report its TAIL, time out",

                         this.eid

                     )

                 );

             }

             Logger.info(

                 this,

                 "Waiting for TAIL report of %s",

                 this.eid

             );

             infos = this.client

                 .retrieveEnvironmentInfo(req)

                 .getEnvironmentInfo();

         } while (infos.isEmpty());

         final EnvironmentInfoDescription desc = infos.get(0);

         try {

             return IOUtils.toString(new URL(desc.getMessage()).openStream());

         } catch (IOException ex) {

             throw new IllegalStateException(ex);

         }

     }

     /**

      * Update this environment with a new version.

      * @param version The version to update to

      */

     public void update(final Version version) {

         final UpdateEnvironmentResult res = this.client.updateEnvironment(

             new UpdateEnvironmentRequest()

                 .withEnvironmentId(this.eid)

                 .withVersionLabel(version.label())

         );

         Logger.info(

             this,

             "Environment '%s' updated to '%s'",

             res.getEnvironmentId(), res.getVersionLabel()

         );

     }

     /**

      * Get environment description of this.

      * @return The description

      */

     private EnvironmentDescription description() {

         final DescribeEnvironmentsResult res = this.client.describeEnvironments(

             new DescribeEnvironmentsRequest()

                 .withEnvironmentIds(this.eid)

         );

         if (res.getEnvironments().isEmpty()) {

             throw new DeploymentException(

                 String.format("environment '%s' not found", this.eid)

             );

         }

         final EnvironmentDescription desc = res.getEnvironments().get(0);

         Logger.debug(

             this,

             // @checkstyle LineLength (1 line)

             "ID=%s, env=%s, app=%s, CNAME=%s, label=%s, template=%s, status=%s, health=%s",

             desc.getEnvironmentId(), desc.getEnvironmentName(),

             desc.getApplicationName(), desc.getCNAME(),

             desc.getVersionLabel(), desc.getTemplateName(), desc.getStatus(),

             desc.getHealth()

         );

         return desc;

     }

     /**

      * Wait for the barrier to pass.

      * @param barrier The barrier

      * @return TRUE if passed, FALSE if timeout

      */

     private boolean until(final Environment.Barrier barrier) {

         boolean passed = false;

         final long start = System.currentTimeMillis();

         while (true) {

             final EnvironmentDescription desc = this.description();

             if (barrier.allow(desc)) {

                 passed = true;

                 Logger.info(

                     this,

                     "Environment '%s/%s/%s': health=%s, status=%s",

                     desc.getApplicationName(), desc.getEnvironmentName(),

                     desc.getEnvironmentId(), desc.getHealth(),

                     desc.getStatus()

                 );

                 break;

             }

             Logger.info(

                 this,

                 // @checkstyle LineLength (1 line)

                 "Environment '%s/%s/%s': health=%s, status=%s (waiting for %s, %[ms]s)",

                 desc.getApplicationName(), desc.getEnvironmentName(),

                 desc.getEnvironmentId(), desc.getHealth(),

                 desc.getStatus(), barrier.message(),

                 System.currentTimeMillis() - start

             );

             if (System.currentTimeMillis() - start > Environment.DELAY_MS) {

                 Logger.warn(

                     this,

                     "Environment failed to reach '%s' after %[ms]s",

                     barrier.message(), System.currentTimeMillis() - start

                 );

                 break;

             }

             try {

                 TimeUnit.MINUTES.sleep(1);

             } catch (InterruptedException ex) {

                 Thread.currentThread().interrupt();

                 throw new DeploymentException(ex);

             }

         }

         return passed;

     }

     /**

      * Barrier before the next operation.

      */

     private interface Barrier {

         /**

          * Can we continue?

          * @param desc Description of environment

          * @return TRUE if we can continue, FALSE if extra cycle of waiting

          *  is required

          */

         boolean allow(EnvironmentDescription desc);

         /**

          * What are we waiting for?

          * @return Message to show in log

          */

         String message();

     }

 }