package org.apache.maven.plugins.dependency.fromDependencies;
   
   /*
    * 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.
   */
  
  import java.io.BufferedReader;
  import java.io.BufferedWriter;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.OutputStreamWriter;
  import java.io.Writer;
  import java.util.ArrayList;
  import java.util.Comparator;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Objects;
  import java.util.Set;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.maven.artifact.Artifact;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugins.annotations.Component;
  import org.apache.maven.plugins.annotations.LifecyclePhase;
  import org.apache.maven.plugins.annotations.Mojo;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.plugins.annotations.ResolutionScope;
  import org.apache.maven.plugins.dependency.utils.DependencyUtil;
  import org.apache.maven.project.MavenProjectHelper;
  import org.apache.maven.project.ProjectBuildingRequest;
  import org.apache.maven.shared.artifact.filter.collection.ArtifactsFilter;
  import org.apache.maven.shared.transfer.repository.RepositoryManager;
  import org.codehaus.plexus.util.StringUtils;
  
  /**
   * This goal outputs a classpath string of dependencies from the local repository to a file or log.
   *
   * @author ankostis
   * @since 2.0-alpha-2
   */
  // CHECKSTYLE_OFF: LineLength
  @Mojo( name = "build-classpath", requiresDependencyResolution = ResolutionScope.TEST, defaultPhase = LifecyclePhase.GENERATE_SOURCES, threadSafe = true )
  // CHECKSTYLE_ON: LineLength
  public class BuildClasspathMojo
      extends AbstractDependencyFilterMojo
      implements Comparator<Artifact>
  {
  
      @Parameter( property = "outputEncoding", defaultValue = "${project.reporting.outputEncoding}" )
      private String outputEncoding;
      
      /**
       * Strip artifact version during copy (only works if prefix is set)
       */
      @Parameter( property = "mdep.stripVersion", defaultValue = "false" )
      private boolean stripVersion = false;
  
      /**
       * Strip artifact classifier during copy (only works if prefix is set)
       */
      @Parameter( property = "mdep.stripClassifier", defaultValue = "false" )
      private boolean stripClassifier = false;
  
      /**
       * The prefix to prepend on each dependent artifact. If undefined, the paths refer to the actual files store in the
       * local repository (the stripVersion parameter does nothing then).
       */
      @Parameter( property = "mdep.prefix" )
      private String prefix;
  
      /**
       * A property to set to the content of the classpath string.
       */
      @Parameter( property = "mdep.outputProperty" )
      private String outputProperty;
  
      /**
       * The file to write the classpath string. If undefined, it just prints the classpath as [INFO].
       */
      @Parameter( property = "mdep.outputFile" )
     private File outputFile;
 
     /**
      * If 'true', it skips the up-to-date-check, and always regenerates the classpath file.
      */
     @Parameter( property = "mdep.regenerateFile", defaultValue = "false" )
     private boolean regenerateFile;
 
     /**
      * Override the char used between the paths. This field is initialized to contain the first character of the value
      * of the system property file.separator. On UNIX systems the value of this field is '/'; on Microsoft Windows
      * systems it is '\'. The default is File.separator
      *
      * @since 2.0
      */
     @Parameter( property = "mdep.fileSeparator", defaultValue = "" )
     private String fileSeparator;
 
     /**
      * Override the char used between path folders. The system-dependent path-separator character. This field is
      * initialized to contain the first character of the value of the system property path.separator. This character is
      * used to separate filenames in a sequence of files given as a path list. On UNIX systems, this character is ':';
      * on Microsoft Windows systems it is ';'.
      *
      * @since 2.0
      */
     @Parameter( property = "mdep.pathSeparator", defaultValue = "" )
     private String pathSeparator;
 
     /**
      * Replace the absolute path to the local repo with this property. This field is ignored it prefix is declared. The
      * value will be forced to "${M2_REPO}" if no value is provided AND the attach flag is true.
      *
      * @since 2.0
      */
     @Parameter( property = "mdep.localRepoProperty", defaultValue = "" )
     private String localRepoProperty;
 
     /**
      * Attach the classpath file to the main artifact so it can be installed and deployed.
      *
      * @since 2.0
      */
     @Parameter( defaultValue = "false" )
     private boolean attach;
 
     /**
      * Write out the classpath in a format compatible with filtering (classpath=xxxxx)
      *
      * @since 2.0
      */
     @Parameter( property = "mdep.outputFilterFile", defaultValue = "false" )
     private boolean outputFilterFile;
 
     /**
      * Either append the artifact's baseVersion or uniqueVersion to the filename. Will only be used if
      * {@link #isStripVersion()} is {@code false}.
      * 
      * @since 2.6
      */
     @Parameter( property = "mdep.useBaseVersion", defaultValue = "true" )
     private boolean useBaseVersion = true;
 
     /**
      * Maven ProjectHelper
      */
     @Component
     private MavenProjectHelper projectHelper;
 
     @Component
     private RepositoryManager repositoryManager;
 
     /**
      * Main entry into mojo. Gets the list of dependencies and iterates to create a classpath.
      *
      * @throws MojoExecutionException with a message if an error occurs.
      * @see #getResolvedDependencies(boolean)
      */
     @Override
     protected void doExecute()
         throws MojoExecutionException
     {
         // initialize the separators.
         boolean isFileSepSet = StringUtils.isNotEmpty( fileSeparator );
         boolean isPathSepSet = StringUtils.isNotEmpty( pathSeparator );
 
         // don't allow them to have absolute paths when they attach.
         if ( attach && StringUtils.isEmpty( localRepoProperty ) )
         {
             localRepoProperty = "${M2_REPO}";
         }
 
         Set<Artifact> artifacts = getResolvedDependencies( true );
 
         if ( artifacts == null || artifacts.isEmpty() )
         {
             getLog().info( "No dependencies found." );
         }
 
         List<Artifact> artList = new ArrayList<>( artifacts );
 
         StringBuilder sb = new StringBuilder();
         Iterator<Artifact> i = artList.iterator();
 
         if ( i.hasNext() )
         {
             appendArtifactPath( i.next(), sb );
 
             while ( i.hasNext() )
             {
                 sb.append( isPathSepSet ? this.pathSeparator : File.pathSeparator );
                 appendArtifactPath( i.next(), sb );
             }
         }
 
         String cpString = sb.toString();
 
         // if file separator is set, I need to replace the default one from all
         // the file paths that were pulled from the artifacts
         if ( isFileSepSet )
         {
             // Escape file separators to be used as literal strings
             final String pattern = Pattern.quote( File.separator );
             final String replacement = Matcher.quoteReplacement( fileSeparator );
             cpString = cpString.replaceAll( pattern, replacement );
         }
 
         // make the string valid for filtering
         if ( outputFilterFile )
         {
             cpString = "classpath=" + cpString;
         }
 
         if ( outputProperty != null )
         {
             getProject().getProperties().setProperty( outputProperty, cpString );
             if ( getLog().isDebugEnabled() )
             {
                 getLog().debug( outputProperty + " = " + cpString );
             }
         }
 
         if ( outputFile == null )
         {
             getLog().info( "Dependencies classpath:" + System.lineSeparator() + cpString );
         }
         else
         {
             if ( regenerateFile || !isUpToDate( cpString ) )
             {
                 storeClasspathFile( cpString, outputFile );
             }
             else
             {
                 this.getLog().info( "Skipped writing classpath file '" + outputFile + "'.  No changes found." );
             }
         }
         if ( attach )
         {
             attachFile( cpString );
         }
     }
 
     /**
      * @param cpString The classpath.
      * @throws MojoExecutionException in case of an error.
      */
     protected void attachFile( String cpString )
         throws MojoExecutionException
     {
         File attachedFile = new File( getProject().getBuild().getDirectory(), "classpath" );
         storeClasspathFile( cpString, attachedFile );
 
         projectHelper.attachArtifact( getProject(), attachedFile, "classpath" );
     }
 
     /**
      * Appends the artifact path into the specified StringBuilder.
      *
      * @param art {@link Artifact}
      * @param sb {@link StringBuilder}
      */
     protected void appendArtifactPath( Artifact art, StringBuilder sb )
     {
         if ( prefix == null )
         {
             String file = art.getFile().getPath();
             // substitute the property for the local repo path to make the classpath file portable.
             if ( StringUtils.isNotEmpty( localRepoProperty ) )
             {
                 ProjectBuildingRequest projectBuildingRequest = session.getProjectBuildingRequest();
                 File localBasedir = repositoryManager.getLocalRepositoryBasedir( projectBuildingRequest );
 
                 file = StringUtils.replace( file, localBasedir.getAbsolutePath(), localRepoProperty );
             }
             sb.append( file );
         }
         else
         {
             // TODO: add param for prepending groupId and version.
             sb.append( prefix );
             sb.append( File.separator );
             sb.append( DependencyUtil.getFormattedFileName( art, this.stripVersion, this.prependGroupId,
                                                             this.useBaseVersion, this.stripClassifier ) );
         }
     }
 
     /**
      * Checks that new classpath differs from that found inside the old classpathFile.
      *
      * @return true if the specified classpath equals the one found inside the file, false otherwise (including when
      *         file does not exist but new classpath does).
      */
     private boolean isUpToDate( String cpString )
     {
         try
         {
             String oldCp = readClasspathFile();
             return ( cpString == null ? oldCp == null : cpString.equals( oldCp ) );
         }
         catch ( IOException ex )
         {
             this.getLog().warn( "Error while reading old classpath file '" + outputFile + "' for up-to-date check: "
                 + ex );
 
             return false;
         }
     }
 
     /**
      * Stores the specified string into that file.
      *
      * @param cpString the string to write into the file
      */
     private void storeClasspathFile( String cpString, File out )
         throws MojoExecutionException
     {
         // make sure the parent path exists.
         out.getParentFile().mkdirs();
         
         String encoding = Objects.toString( outputEncoding, "UTF-8" );
 
         try ( Writer w =
             new BufferedWriter( new OutputStreamWriter( new FileOutputStream( out ), encoding ) ) )
         {
             w.write( cpString );
             getLog().info( "Wrote classpath file '" + out + "'." );
         }
         catch ( IOException ex )
         {
             throw new MojoExecutionException( "Error while writing to classpath file '" + out + "': " + ex.toString(),
                                               ex );
         }
     }
 
     /**
      * Reads the file specified by the mojo param 'outputFile' into a string. Assumes the field
      * 'outputFile' is not null.
      * 
      * @return the string contained in the classpathFile, if it exists, or null otherwise
      * @throws IOException in case of an error
      */
     protected String readClasspathFile()
         throws IOException
     {
         if ( outputFile == null )
         {
             throw new IllegalArgumentException( "The outputFile parameter "
                 + "cannot be null if the file is intended to be read." );
         }
 
         if ( !outputFile.isFile() )
         {
             return null;
         }
         StringBuilder sb = new StringBuilder();
         String encoding = Objects.toString( outputEncoding, "UTF-8" );
 
         try ( BufferedReader r =
             new BufferedReader( new InputStreamReader( new FileInputStream( outputFile ), encoding ) ) )
         {
             for ( String line = r.readLine(); line != null; line = r.readLine() )
             {
                 sb.append( line );
             }
 
             return sb.toString();
         }
     }
 
     /**
      * Compares artifacts lexicographically, using pattern [group_id][artifact_id][version].
      *
      * @param art1 first object
      * @param art2 second object
      * @return the value <code>0</code> if the argument string is equal to this string; a value less than <code>0</code>
      *         if this string is lexicographically less than the string argument; and a value greater than
      *         <code>0</code> if this string is lexicographically greater than the string argument.
      */
     @Override
     public int compare( Artifact art1, Artifact art2 )
     {
         if ( art1 == art2 )
         {
             return 0;
         }
         else if ( art1 == null )
         {
             return -1;
         }
         else if ( art2 == null )
         {
             return +1;
         }
 
         String s1 = art1.getGroupId() + art1.getArtifactId() + art1.getVersion();
         String s2 = art2.getGroupId() + art2.getArtifactId() + art2.getVersion();
 
         return s1.compareTo( s2 );
     }
 
     @Override
     protected ArtifactsFilter getMarkedArtifactFilter()
     {
         return null;
     }
 
     /**
      * @param outputFile the outputFile to set
      */
     public void setOutputFile( File outputFile )
     {
         this.outputFile = outputFile;
     }
 
     /**
      * @param theOutputProperty the outputProperty to set
      */
     public void setOutputProperty( String theOutputProperty )
     {
         this.outputProperty = theOutputProperty;
     }
 
     /**
      * @param theFileSeparator the fileSeparator to set
      */
     public void setFileSeparator( String theFileSeparator )
     {
         this.fileSeparator = theFileSeparator;
     }
 
     /**
      * @param thePathSeparator the pathSeparator to set
      */
     public void setPathSeparator( String thePathSeparator )
     {
         this.pathSeparator = thePathSeparator;
     }
 
     /**
      * @param thePrefix the prefix to set
      */
     public void setPrefix( String thePrefix )
     {
         this.prefix = thePrefix;
     }
 
     /**
      * @param theRegenerateFile the regenerateFile to set
      */
     public void setRegenerateFile( boolean theRegenerateFile )
     {
         this.regenerateFile = theRegenerateFile;
     }
 
     /**
      * @return the stripVersion
      */
     public boolean isStripVersion()
     {
         return this.stripVersion;
     }
 
     /**
      * @param theStripVersion the stripVersion to set
      */
     public void setStripVersion( boolean theStripVersion )
     {
         this.stripVersion = theStripVersion;
     }
 
     /**
      * @param localRepoProperty {@link #localRepoProperty}
      */
     public void setLocalRepoProperty( String localRepoProperty )
     {
         this.localRepoProperty = localRepoProperty;
     }
 }