/*
    * Copyright (c) 2016 ingenieux Labs
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package br.com.ingenieux.mojo.beanstalk.version;
  
  import com.amazonaws.services.elasticbeanstalk.model.ApplicationVersionDescription;
  import com.amazonaws.services.elasticbeanstalk.model.DescribeApplicationVersionsRequest;
  import com.amazonaws.services.elasticbeanstalk.model.DescribeApplicationVersionsResult;
  import com.amazonaws.services.elasticbeanstalk.model.DescribeEnvironmentsRequest;
  import com.amazonaws.services.elasticbeanstalk.model.DescribeEnvironmentsResult;
  import com.amazonaws.services.elasticbeanstalk.model.EnvironmentDescription;
  import com.amazonaws.services.elasticbeanstalk.model.UpdateEnvironmentRequest;
  
  import org.apache.commons.lang.builder.CompareToBuilder;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.apache.maven.plugins.annotations.Mojo;
  import org.apache.maven.plugins.annotations.Parameter;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.List;
  import java.util.ListIterator;
  
  import br.com.ingenieux.mojo.beanstalk.AbstractNeedsEnvironmentMojo;
  
  /**
   * Deletes application versions, either by count and/or by date old
   *
   * @author Aldrin Leal
   * @since 0.2.3
   */
  @Mojo(name = "rollback-version")
  public class RollbackVersionMojo extends AbstractNeedsEnvironmentMojo {
  
    /**
     * Simulate deletion changing algorithm?
     */
    @Parameter(property = "beanstalk.dryRun", defaultValue = "true")
    boolean dryRun;
  
    /**
     * Updates to the latest version instead?
     */
    @Parameter(property = "beanstalk.latestVersionInstead")
    boolean latestVersionInstead;
  
    @Override
    protected Object executeInternal() throws MojoExecutionException, MojoFailureException {
      // TODO: Deal with withVersionLabels
      DescribeApplicationVersionsRequest describeApplicationVersionsRequest = new DescribeApplicationVersionsRequest().withApplicationName(applicationName);
  
      DescribeApplicationVersionsResult appVersions = getService().describeApplicationVersions(describeApplicationVersionsRequest);
  
      DescribeEnvironmentsRequest describeEnvironmentsRequest =
          new DescribeEnvironmentsRequest()
              .withApplicationName(applicationName)
              .withEnvironmentIds(curEnv.getEnvironmentId())
              .withEnvironmentNames(curEnv.getEnvironmentName())
              .withIncludeDeleted(false);
  
      DescribeEnvironmentsResult environments = getService().describeEnvironments(describeEnvironmentsRequest);
  
      List<ApplicationVersionDescription> appVersionList = new ArrayList<ApplicationVersionDescription>(appVersions.getApplicationVersions());
  
      List<EnvironmentDescription> environmentList = environments.getEnvironments();
  
      if (environmentList.isEmpty()) {
        throw new MojoFailureException("No environments were found");
      }
  
      EnvironmentDescription d = environmentList.get(0);
  
      Collections.sort(
          appVersionList,
          new Comparator<ApplicationVersionDescription>() {
            @Override
            public int compare(ApplicationVersionDescription o1, ApplicationVersionDescription o2) {
              return new CompareToBuilder().append(o1.getDateUpdated(), o2.getDateUpdated()).toComparison();
            }
          });
  
      Collections.reverse(appVersionList);
  
      if (latestVersionInstead) {
       ApplicationVersionDescription latestVersionDescription = appVersionList.get(0);
 
       return changeToVersion(d, latestVersionDescription);
     }
 
     ListIterator<ApplicationVersionDescription> versionIterator = appVersionList.listIterator();
 
     String curVersionLabel = d.getVersionLabel();
 
     while (versionIterator.hasNext()) {
       ApplicationVersionDescription versionDescription = versionIterator.next();
 
       String versionLabel = versionDescription.getVersionLabel();
 
       if (curVersionLabel.equals(versionLabel) && versionIterator.hasNext()) {
         return changeToVersion(d, versionIterator.next());
       }
     }
 
     throw new MojoFailureException("No previous version was found (current version: " + curVersionLabel);
   }
 
   Object changeToVersion(EnvironmentDescription d, ApplicationVersionDescription latestVersionDescription) {
     String curVersionLabel = d.getVersionLabel();
     String versionLabel = latestVersionDescription.getVersionLabel();
 
     UpdateEnvironmentRequest request = new UpdateEnvironmentRequest().withEnvironmentId(d.getEnvironmentId()).withVersionLabel(versionLabel);
 
     getLog()
         .info(
             "Changing versionLabel for Environment[name="
                 + curEnv.getEnvironmentName()
                 + "; environmentId="
                 + curEnv.getEnvironmentId()
                 + "] from version "
                 + curVersionLabel
                 + " to version "
                 + latestVersionDescription.getVersionLabel());
 
     if (dryRun) {
       return null;
     }
 
     return getService().updateEnvironment(request);
   }
 }