package org.apache.maven.plugins.pmd.exec;
   
   /*
    * 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.File;
  import java.io.FileInputStream;
  import java.io.FilterReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import org.apache.maven.plugins.pmd.model.PmdErrorDetail;
  import org.apache.maven.plugins.pmd.model.PmdFile;
  import org.apache.maven.plugins.pmd.model.ProcessingError;
  import org.apache.maven.plugins.pmd.model.Violation;
  import org.apache.maven.plugins.pmd.model.io.xpp3.PmdXpp3Reader;
  import org.apache.maven.reporting.MavenReportException;
  
  /**
   * Provides access to the result of the pmd analysis.
   */
  public class PmdResult
  {
      private final List<ProcessingError> processingErrors = new ArrayList<>();
      private final List<Violation> violations = new ArrayList<>();
  
      public static final PmdResult EMPTY = new PmdResult();
  
      private PmdResult()
      {
      }
  
      public PmdResult( File pmdFile, String encoding ) throws MavenReportException
      {
          loadResult( pmdFile, encoding );
      }
  
      public boolean hasViolations()
      {
          return !violations.isEmpty();
      }
  
      private void loadResult( File pmdFile, String encoding ) throws MavenReportException
      {
          try ( Reader reader1 = new BomFilter( encoding, new InputStreamReader(
                  new FileInputStream( pmdFile ), encoding ) ) )
          {
              PmdXpp3Reader reader = new PmdXpp3Reader();
              PmdErrorDetail details = reader.read( reader1, false );
              processingErrors.addAll( details.getErrors() );
  
              for ( PmdFile file : details.getFiles() )
              {
                  String filename = file.getName();
                  for ( Violation violation : file.getViolations() )
                  {
                      violation.setFileName( filename );
                      violations.add( violation );
                  }
              }
          }
          catch ( Exception e )
          {
              throw new MavenReportException( e.getMessage(), e );
          }
      }
  
      // Note: This seems to be a bug in PMD's XMLRenderer. The BOM is rendered multiple times.
      // once at the beginning of the file, which is Ok, but also in the middle of the file.
      // This filter just skips all BOMs if the encoding is not UTF-8
      private static class BomFilter extends FilterReader
      {
          private static final char BOM = '\uFEFF';
          private final boolean filter;
  
          BomFilter( String encoding, Reader in )
          {
              super( in );
              filter = !"UTF-8".equalsIgnoreCase( encoding );
         }
 
         @Override
         public int read() throws IOException
         {
             int c = super.read();
 
             if ( !filter )
             {
                 return c;
             }
 
             while ( c != -1 && c == BOM )
             {
                 c = super.read();
             }
             return c;
         }
 
         @Override
         public int read( char[] cbuf, int off, int len ) throws IOException
         {
             int count = super.read( cbuf, off, len );
 
             if ( !filter )
             {
                 return count;
             }
 
             if ( count != -1 )
             {
                 for ( int i = off; i < off + count; i++ )
                 {
                     if ( cbuf[i] == BOM )
                     {
                         // shift the content one char to the left
                         System.arraycopy( cbuf, i + 1, cbuf, i, off + count - 1 - i );
                         count--;
                     }
                 }
             }
             return count;
         }
     }
 
     public Collection<Violation> getViolations()
     {
         return violations;
     }
 
     public Collection<ProcessingError> getErrors()
     {
         return processingErrors;
     }
 }