/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.felix.bundleplugin.baseline;
  
  import java.io.File;
  import java.io.IOException;
  import java.text.SimpleDateFormat;
  import java.util.Arrays;
  import java.util.Date;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.maven.artifact.Artifact;
  import org.apache.maven.artifact.factory.ArtifactFactory;
  import org.apache.maven.artifact.metadata.ArtifactMetadataRetrievalException;
  import org.apache.maven.artifact.metadata.ArtifactMetadataSource;
  import org.apache.maven.artifact.resolver.ArtifactNotFoundException;
  import org.apache.maven.artifact.resolver.ArtifactResolutionException;
  import org.apache.maven.artifact.resolver.ArtifactResolver;
  import org.apache.maven.artifact.versioning.ArtifactVersion;
  import org.apache.maven.artifact.versioning.InvalidVersionSpecificationException;
  import org.apache.maven.artifact.versioning.OverConstrainedVersionException;
  import org.apache.maven.artifact.versioning.VersionRange;
  import org.apache.maven.execution.MavenSession;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.apache.maven.plugins.annotations.Component;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.project.MavenProject;
  import org.codehaus.plexus.util.StringUtils;
  import org.sonatype.plexus.build.incremental.BuildContext;
  
  import aQute.bnd.differ.Baseline;
  import aQute.bnd.differ.Baseline.Info;
  import aQute.bnd.differ.DiffPluginImpl;
  import aQute.bnd.osgi.Instructions;
  import aQute.bnd.osgi.Jar;
  import aQute.bnd.osgi.Processor;
  import aQute.bnd.service.diff.Delta;
  import aQute.bnd.service.diff.Diff;
  import aQute.bnd.version.Version;
  import aQute.service.reporter.Reporter;
  
  /**
   * Abstract BND Baseline check between two bundles.
   */
  abstract class AbstractBaselinePlugin
      extends AbstractMojo
  {
  
      /**
       * Flag to easily skip execution.
       */
      @Parameter( property = "baseline.skip", defaultValue = "false" )
      protected boolean skip;
  
      /**
       * Whether to fail on errors.
       */
      @Parameter( property = "baseline.failOnError", defaultValue = "true" )
      protected boolean failOnError;
  
      /**
       * Whether to fail on warnings.
       */
      @Parameter( property = "baseline.failOnWarning", defaultValue = "false" )
      protected boolean failOnWarning;
  
      @Parameter( defaultValue = "${project}", readonly = true, required = true )
      protected MavenProject project;
  
      @Parameter( defaultValue = "${session}", readonly = true, required = true )
      protected MavenSession session;
  
      @Parameter( defaultValue = "${project.build.directory}", readonly = true, required = true )
      private File buildDirectory;
  
      @Parameter( defaultValue = "${project.build.finalName}", readonly = true, required = true )
      private String finalName;
  
     @Component
     protected ArtifactResolver resolver;
 
     @Component
     protected ArtifactFactory factory;
 
     @Component
     private ArtifactMetadataSource metadataSource;
 
     /**
      * Group id to compare the current code against.
      */
     @Parameter( defaultValue = "${project.groupId}", property="comparisonGroupId" )
     protected String comparisonGroupId;
 
     /**
      * Artifact to compare the current code against.
      */
     @Parameter( defaultValue = "${project.artifactId}", property="comparisonArtifactId" )
     protected String comparisonArtifactId;
 
     /**
      * Version to compare the current code against.
      */
     @Parameter( defaultValue = "(,${project.version})", property="comparisonVersion" )
     protected String comparisonVersion;
 
     /**
      * Artifact to compare the current code against.
      */
     @Parameter( defaultValue = "${project.packaging}", property="comparisonPackaging" )
     protected String comparisonPackaging;
 
     /**
      * Classifier for the artifact to compare the current code against.
      */
     @Parameter( property="comparisonClassifier" )
     protected String comparisonClassifier;
 
     /**
      * A list of packages filter, if empty the whole bundle will be traversed. Values are specified in OSGi package
      * instructions notation, e.g. <code>!org.apache.felix.bundleplugin</code>.
      */
     @Parameter
     private String[] filters;
 
     /**
      * Project types which this plugin supports.
      */
     @Parameter
     protected List<String> supportedProjectTypes = Arrays.asList( new String[] { "jar", "bundle" } );
 
     @Component
     protected BuildContext buildContext;
     
     public final void execute()
         throws MojoExecutionException, MojoFailureException
     {
         this.execute(null);
     }
 
     protected void execute( Object context)
             throws MojoExecutionException, MojoFailureException
     {
         if ( skip )
         {
             getLog().info( "Skipping Baseline execution" );
             return;
         }
 
         if ( !supportedProjectTypes.contains( project.getArtifact().getType() ) )
         {
             getLog().info("Skipping Baseline (project type " + project.getArtifact().getType() + " not supported)");
             return;
         }
 
         // get the bundles that have to be compared
 
         final Jar currentBundle = getCurrentBundle();
         if ( currentBundle == null )
         {
             getLog().info( "Not generating Baseline report as there is no bundle generated by the project" );
             return;
         }
 
         final Artifact previousArtifact = getPreviousArtifact();
 
         final Jar previousBundle;
         if (previousArtifact != null)
         {
             previousBundle = openJar(previousArtifact.getFile());
         }
         else
         {
             previousBundle = null;
         }
 
         if ( previousBundle == null )
         {
             getLog().info( "Not generating Baseline report as there is no previous version of the library to compare against" );
             return;
         }
 
         // preparing the filters
 
         final Instructions packageFilters;
         if ( filters == null || filters.length == 0 )
         {
             packageFilters = new Instructions();
         }
         else
         {
             packageFilters = new Instructions( Arrays.asList( filters ) );
         }
 
 
         String generationDate = new SimpleDateFormat( "yyyy-MM-dd'T'HH:mm'Z'" ).format( new Date() );
         final Reporter reporter = new Processor();
 
         final Info[] infos;
         try
         {
             final Set<Info> infoSet = new Baseline( reporter, new DiffPluginImpl() )
                                 .baseline( currentBundle, previousBundle, packageFilters );
             infos = infoSet.toArray( new Info[infoSet.size()] );
             Arrays.sort( infos, new InfoComparator() );
         }
         catch ( final Exception e )
         {
             throw new MojoExecutionException( "Impossible to calculate the baseline", e );
         }
         finally
         {
             closeJars( currentBundle, previousBundle );
         }
 
         try
         {
             // go!
             context = this.init(context);
             startBaseline( context, generationDate, project.getArtifactId(), project.getVersion(), previousArtifact.getVersion() );
 
             for ( final Info info : infos )
             {
                 DiffMessage diffMessage = null;
 
                 if ( info.suggestedVersion != null )
                 {
                     if ( info.newerVersion.compareTo( info.suggestedVersion ) > 0 )
                     {
                         diffMessage = new DiffMessage( "Excessive version increase", DiffMessage.Type.warning );
                         reporter.warning( "%s: %s; detected %s, suggested %s",
                                           info.packageName, diffMessage, info.newerVersion, info.suggestedVersion );
                     }
                     else if ( info.newerVersion.compareTo( info.suggestedVersion ) < 0 )
                     {
                         diffMessage = new DiffMessage( "Version increase required", DiffMessage.Type.error );
                         reporter.error( "%s: %s; detected %s, suggested %s",
                                         info.packageName, diffMessage, info.newerVersion, info.suggestedVersion );
                     }
                 }
 
                 switch ( info.packageDiff.getDelta() )
                 {
                     case UNCHANGED:
                         if ( info.newerVersion.compareTo( info.suggestedVersion ) != 0 )
                         {
                             diffMessage = new DiffMessage( "Version has been increased but analysis detected no changes", DiffMessage.Type.warning );
                             reporter.warning( "%s: %s; detected %s, suggested %s",
                                               info.packageName, diffMessage, info.newerVersion, info.suggestedVersion );
                         }
                         break;
 
                     case REMOVED:
                         diffMessage = new DiffMessage( "Package removed", DiffMessage.Type.info );
                         reporter.trace( "%s: %s ", info.packageName, diffMessage );
                         break;
 
                     case CHANGED:
                     case MICRO:
                     case MINOR:
                     case MAJOR:
                     case ADDED:
                     default:
                         // ok
                         break;
                 }
 
                 startPackage( context,
                               info.mismatch,
                               info.packageName,
                               getShortDelta( info.packageDiff.getDelta() ),
                               StringUtils.lowerCase( String.valueOf( info.packageDiff.getDelta() ) ),
                               info.newerVersion,
                               info.olderVersion,
                               info.suggestedVersion,
                               diffMessage,
                               info.attributes );
 
                 if ( Delta.REMOVED != info.packageDiff.getDelta() )
                 {
                     doPackageDiff( context, info.packageDiff );
                 }
 
                 endPackage(context);
             }
 
             endBaseline(context);
         }
         finally
         {
             this.close(context);
         }
 
         // check if it has to fail if some error has been detected
 
         boolean fail = false;
 
         if ( !reporter.isOk() )
         {
             for ( String errorMessage : reporter.getErrors() )
             {
                 getLog().error( errorMessage );
             }
 
             if ( failOnError )
             {
                 fail = true;
             }
         }
 
         // check if it has to fail if some warning has been detected
 
         if ( !reporter.getWarnings().isEmpty() )
         {
             for ( String warningMessage : reporter.getWarnings() )
             {
                 getLog().warn( warningMessage );
             }
 
             if ( failOnWarning )
             {
                 fail = true;
             }
         }
 
         getLog().info( String.format( "Baseline analysis complete, %s error(s), %s warning(s)",
                                       reporter.getErrors().size(),
                                       reporter.getWarnings().size() ) );
 
         if ( fail )
         {
             throw new MojoFailureException( "Baseline failed, see generated report" );
         }
     }
 
     private void doPackageDiff( Object context, Diff diff )
     {
         int depth = 1;
 
         for ( Diff curDiff : diff.getChildren() )
         {
             if ( Delta.UNCHANGED != curDiff.getDelta() )
             {
                 doDiff( context, curDiff, depth );
             }
         }
     }
 
     private void doDiff( Object context, Diff diff, int depth )
     {
         String type = StringUtils.lowerCase( String.valueOf( diff.getType() ) );
         String shortDelta = getShortDelta( diff.getDelta() );
         String delta = StringUtils.lowerCase( String.valueOf( diff.getDelta() ) );
         String name = diff.getName();
 
         startDiff( context, depth, type, name, delta, shortDelta );
 
         for ( Diff curDiff : diff.getChildren() )
         {
             if ( Delta.UNCHANGED != curDiff.getDelta() )
             {
                 doDiff( context, curDiff, depth + 1 );
             }
         }
 
         endDiff( context, depth );
     }
 
     // extensions APIs
 
     protected abstract Object init(final Object initialContext);
 
     protected abstract void close(final Object context);
 
     protected abstract void startBaseline( final Object context, String generationDate, String bundleName, String currentVersion, String previousVersion );
 
     protected abstract void startPackage( final Object context,
             boolean mismatch,
                                           String name,
                                           String shortDelta,
                                           String delta,
                                           Version newerVersion,
                                           Version olderVersion,
                                           Version suggestedVersion,
                                           DiffMessage diffMessage,
                                           Map<String,String> attributes );
 
     protected abstract void startDiff( final Object context,
                                        int depth,
                                        String type,
                                        String name,
                                        String delta,
                                        String shortDelta );
 
     protected abstract void endDiff( final Object context, int depth );
 
     protected abstract void endPackage(final Object context);
 
     protected abstract void endBaseline(final Object context);
 
     // internals
 
     private Jar getCurrentBundle()
         throws MojoExecutionException
     {
         /*
          * Resolving the aQute.bnd.osgi.Jar via the produced artifact rather than what is produced in the target/classes
          * directory would make the Mojo working also in projects where the bundle-plugin is used just to generate the
          * manifest file and the final jar is assembled via the jar-plugin
          */
         File currentBundle = new File( buildDirectory, getBundleName() );
         if ( !currentBundle.exists() )
         {
             getLog().debug( "Produced bundle not found: " + currentBundle );
             return null;
         }
 
         return openJar( currentBundle );
     }
 
     private Artifact getPreviousArtifact()
         throws MojoFailureException, MojoExecutionException
     {
         // Find the previous version JAR and resolve it, and it's dependencies
         final VersionRange range;
         try
         {
             range = VersionRange.createFromVersionSpec( comparisonVersion );
         }
         catch ( InvalidVersionSpecificationException e )
         {
             throw new MojoFailureException( "Invalid comparison version: " + e.getMessage() );
         }
 
         final Artifact previousArtifact;
         try
         {
             previousArtifact =
                 factory.createDependencyArtifact( comparisonGroupId,
                                                   comparisonArtifactId,
                                                   range,
                                                   comparisonPackaging,
                                                   comparisonClassifier,
                                                   Artifact.SCOPE_COMPILE );
 
             if ( !previousArtifact.getVersionRange().isSelectedVersionKnown( previousArtifact ) )
             {
                 getLog().debug( "Searching for versions in range: " + previousArtifact.getVersionRange() );
                 @SuppressWarnings( "unchecked" )
                 // type is konwn
                 List<ArtifactVersion> availableVersions =
                     metadataSource.retrieveAvailableVersions( previousArtifact, session.getLocalRepository(),
                                                               project.getRemoteArtifactRepositories() );
                 filterSnapshots( availableVersions );
                 ArtifactVersion version = range.matchVersion( availableVersions );
                 if ( version != null )
                 {
                     previousArtifact.selectVersion( version.toString() );
                 }
             }
         }
         catch ( OverConstrainedVersionException ocve )
         {
             throw new MojoFailureException( "Invalid comparison version: " + ocve.getMessage() );
         }
         catch ( ArtifactMetadataRetrievalException amre )
         {
             throw new MojoExecutionException( "Error determining previous version: " + amre.getMessage(), amre );
         }
 
         if ( previousArtifact.getVersion() == null )
         {
             getLog().info( "Unable to find a previous version of the project in the repository" );
             return null;
         }
 
         try
         {
             resolver.resolve( previousArtifact, project.getRemoteArtifactRepositories(), session.getLocalRepository() );
         }
         catch ( ArtifactResolutionException are )
         {
             throw new MojoExecutionException( "Artifact " + previousArtifact + " cannot be resolved : " + are.getMessage(), are );
         }
         catch ( ArtifactNotFoundException anfe )
         {
             throw new MojoExecutionException( "Artifact " + previousArtifact
                 + " does not exist on local/remote repositories", anfe );
         }
 
         return previousArtifact;
     }
 
     private void filterSnapshots( List<ArtifactVersion> versions )
     {
         for ( Iterator<ArtifactVersion> versionIterator = versions.iterator(); versionIterator.hasNext(); )
         {
             ArtifactVersion version = versionIterator.next();
             if ( version.getQualifier() != null && version.getQualifier().endsWith( "SNAPSHOT" ) )
             {
                 versionIterator.remove();
             }
         }
     }
 
     private static Jar openJar( final File file )
         throws MojoExecutionException
     {
         try
         {
             return new Jar( file );
         }
         catch ( final IOException e )
         {
             throw new MojoExecutionException( "An error occurred while opening JAR directory: " + file, e );
         }
     }
 
     private static void closeJars( final Jar...jars )
     {
         for ( Jar jar : jars )
         {
             jar.close();
         }
     }
 
     private String getBundleName()
     {
         String extension;
         try
         {
             extension = project.getArtifact().getArtifactHandler().getExtension();
         }
         catch ( Throwable e )
         {
             extension = project.getArtifact().getType();
         }
 
         if ( StringUtils.isEmpty( extension ) || "bundle".equals( extension ) || "pom".equals( extension ) )
         {
             extension = "jar"; // just in case maven gets confused
         }
 
         String classifier = this.comparisonClassifier != null ? this.comparisonClassifier : project.getArtifact().getClassifier();
         if ( null != classifier && classifier.trim().length() > 0 )
         {
             return finalName + '-' + classifier + '.' + extension;
         }
 
         return finalName + '.' + extension;
     }
 
     private static String getShortDelta( Delta delta )
     {
         switch ( delta )
         {
             case ADDED:
                 return "+";
 
             case CHANGED:
                 return "~";
 
             case MAJOR:
                 return ">";
 
             case MICRO:
                 return "0xB5";
 
             case MINOR:
                 return "<";
 
             case REMOVED:
                 return "-";
 
             case UNCHANGED:
                 return " ";
 
             default:
                 String deltaString = delta.toString();
                 return String.valueOf( deltaString.charAt( 0 ) );
         }
     }
 }