/*
    * 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.DeleteApplicationVersionRequest;
  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 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.Date;
  import java.util.List;
  import java.util.ListIterator;
  import java.util.regex.Pattern;
  
  import br.com.ingenieux.mojo.beanstalk.AbstractBeanstalkMojo;
  
  /**
   * Deletes application versions, either by count and/or by date old
   *
   * @since 0.2.2
   */
  @Mojo(name = "clean-previous-versions")
  public class CleanPreviousVersionsMojo extends AbstractBeanstalkMojo {
  
    /**
     * Beanstalk Application Name
     */
    @Parameter(property = "beanstalk.applicationName", defaultValue = "${project.artifactId}", required = true)
    String applicationName;
  
    /**
     * Delete the source bundle?
     */
    @Parameter(property = "beanstalk.deleteSourceBundle", defaultValue = "false")
    boolean deleteSourceBundle;
  
    /**
     * How many versions to keep?
     */
    @Parameter(property = "beanstalk.versionsToKeep")
    Integer versionsToKeep;
  
    /**
     * How many versions to keep?
     */
    @Parameter(property = "beanstalk.daysToKeep")
    Integer daysToKeep;
  
    /**
     * Filter application version list to examine for cleaning based on java.util.regex.Pattern
     * string.
     */
    @Parameter(property = "beanstalk.cleanFilter")
    String cleanFilter;
  
    /**
     * Simulate deletion changing algorithm?
     */
    @Parameter(property = "beanstalk.dryRun", defaultValue = "true")
    boolean dryRun;
  
    private int deletedVersionsCount;
  
    @Override
    protected Object executeInternal() throws MojoExecutionException, MojoFailureException {
      boolean bVersionsToKeepDefined = (null != versionsToKeep);
      boolean bDaysToKeepDefined = (null != daysToKeep);
  
      if (!(bVersionsToKeepDefined ^ bDaysToKeepDefined)) {
        throw new MojoFailureException("Declare either versionsToKeep or daysToKeep, but not both nor none!");
      }
  
      DescribeApplicationVersionsRequest describeApplicationVersionsRequest = new DescribeApplicationVersionsRequest().withApplicationName(applicationName);
 
     DescribeApplicationVersionsResult appVersions = getService().describeApplicationVersions(describeApplicationVersionsRequest);
 
     DescribeEnvironmentsResult environments = getService().describeEnvironments(new DescribeEnvironmentsRequest().withApplicationName(applicationName));
 
     List<ApplicationVersionDescription> appVersionList = new ArrayList<ApplicationVersionDescription>(appVersions.getApplicationVersions());
 
     deletedVersionsCount = 0;
 
     for (EnvironmentDescription d : environments.getEnvironments()) {
       boolean bActiveEnvironment = (d.getStatus().equals("Running") || d.getStatus().equals("Launching") || d.getStatus().equals("Ready"));
 
       for (ListIterator<ApplicationVersionDescription> appVersionIterator = appVersionList.listIterator(); appVersionIterator.hasNext(); ) {
         ApplicationVersionDescription appVersion = appVersionIterator.next();
 
         boolean bMatchesVersion = appVersion.getVersionLabel().equals(d.getVersionLabel());
 
         if (bActiveEnvironment && bMatchesVersion) {
           getLog().info("VersionLabel " + appVersion.getVersionLabel() + " is bound to environment " + d.getEnvironmentName() + " - Skipping it");
 
           appVersionIterator.remove();
         }
       }
     }
 
     filterAppVersionListByVersionLabelPattern(appVersionList, cleanFilter);
 
     Collections.sort(
         appVersionList,
         new Comparator<ApplicationVersionDescription>() {
           @Override
           public int compare(ApplicationVersionDescription o1, ApplicationVersionDescription o2) {
             return new CompareToBuilder().append(o1.getDateUpdated(), o2.getDateUpdated()).toComparison();
           }
         });
 
     if (bDaysToKeepDefined) {
       Date now = new Date();
 
       for (ApplicationVersionDescription d : appVersionList) {
         long delta = now.getTime() - d.getDateUpdated().getTime();
 
         delta /= 1000;
         delta /= 86400;
 
         boolean shouldDeleteP = (delta > daysToKeep);
 
         if (getLog().isDebugEnabled()) {
           getLog().debug("Version " + d.getVersionLabel() + " was from " + delta + " days ago. Should we delete? " + shouldDeleteP);
         }
 
         if (shouldDeleteP) {
           deleteVersion(d);
         }
       }
     } else {
       while (appVersionList.size() > versionsToKeep) {
         deleteVersion(appVersionList.remove(0));
       }
     }
 
     getLog().info("Deleted " + deletedVersionsCount + " versions.");
 
     return null;
   }
 
   void deleteVersion(ApplicationVersionDescription versionToRemove) {
     getLog().info("Must delete version: " + versionToRemove.getVersionLabel());
 
     DeleteApplicationVersionRequest req =
         new DeleteApplicationVersionRequest()
             .withApplicationName(versionToRemove.getApplicationName()) //
             .withDeleteSourceBundle(deleteSourceBundle) //
             .withVersionLabel(versionToRemove.getVersionLabel());
 
     if (!dryRun) {
       getService().deleteApplicationVersion(req);
       deletedVersionsCount++;
     }
   }
 
   void filterAppVersionListByVersionLabelPattern(List<ApplicationVersionDescription> appVersionList, String patternString) {
     if (patternString == null) {
       return;
     }
 
     getLog().info("Filtering versions with pattern : " + patternString);
 
     Pattern p = Pattern.compile(patternString);
     for (ListIterator<ApplicationVersionDescription> appVersionIterator = appVersionList.listIterator(); appVersionIterator.hasNext(); ) {
 
       if (!p.matcher(appVersionIterator.next().getVersionLabel()).matches()) {
         appVersionIterator.remove();
       }
     }
   }
 }