package org.codehaus.mojo.apt;
   
   /*
    * The MIT License
    *
    * Copyright 2006-2008 The Codehaus.
    *
    * Permission is hereby granted, free of charge, to any person obtaining a copy of
    * this software and associated documentation files (the "Software"), to deal in
   * the Software without restriction, including without limitation the rights to
   * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
   * of the Software, and to permit persons to whom the Software is furnished to do
   * so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.Reader;
  import java.util.Collection;
  
  import org.apache.maven.plugin.logging.Log;
  import org.codehaus.plexus.util.IOUtil;
  
  /**
   * Provides utilities for working with Mojo logs.
   * 
   * @author <a href="mailto:markhobson@gmail.com">Mark Hobson</a>
   * @version $Id: LogUtils.java 7031 2008-05-22 09:41:31Z mark $
   */
  public final class LogUtils
  {
      // constants --------------------------------------------------------------
  
      public static final int LEVEL_DEBUG = 0;
  
      public static final int LEVEL_INFO = 1;
  
      public static final int LEVEL_WARN = 2;
  
      public static final int LEVEL_ERROR = 3;
  
      // constructors -----------------------------------------------------------
  
      private LogUtils()
      {
          throw new AssertionError();
      }
  
      // public methods ---------------------------------------------------------
  
      public static void log( Log log, int level, File file )
      {
          log( log, level, file, null );
      }
  
      public static void log( Log log, int level, File file, CharSequence prefix )
      {
          if ( !isEnabled( log, level ) )
          {
              return;
          }
  
          FileReader reader = null;
  
          try
          {
              reader = new FileReader( file );
  
              log( log, level, reader, prefix );
          }
          catch ( FileNotFoundException exception )
          {
              log.warn( "Error logging file", exception );
          }
          finally
          {
              IOUtil.close( reader );
          }
      }
  
      public static void log( Log log, int level, Reader reader )
      {
          log( log, level, reader, null );
      }
  
     public static void log( Log log, int level, Reader reader, CharSequence prefix )
     {
         if ( !isEnabled( log, level ) )
         {
             return;
         }
 
         BufferedReader bufferedReader = new BufferedReader( reader );
 
         String line;
 
         try
         {
             while ( ( line = bufferedReader.readLine() ) != null )
             {
                 log( log, level, line, prefix );
             }
         }
         catch ( IOException exception )
         {
             log.warn( "Error logging reader", exception );
         }
     }
 
     public static void log( Log log, int level, Collection<?> messages )
     {
         log( log, level, messages, null );
     }
 
     public static void log( Log log, int level, Collection<?> messages, CharSequence prefix )
     {
         if ( !isEnabled( log, level ) )
         {
             return;
         }
 
         for ( Object message : messages )
         {
             log( log, level, message, prefix );
         }
     }
 
     public static void log( Log log, int level, Object message )
     {
         log( log, level, message, null );
     }
 
     public static void log( Log log, int level, Object message, CharSequence prefix )
     {
         CharSequence chars;
 
         if ( message instanceof CharSequence )
         {
             chars = (CharSequence) message;
         }
         else
         {
             chars = String.valueOf( message );
         }
 
         log( log, level, chars, prefix );
     }
 
     public static void log( Log log, int level, CharSequence message )
     {
         if ( level == LEVEL_DEBUG )
         {
             log.debug( message );
         }
         else if ( level == LEVEL_INFO )
         {
             log.info( message );
         }
         else if ( level == LEVEL_WARN )
         {
             log.warn( message );
         }
         else if ( level == LEVEL_ERROR )
         {
             log.error( message );
         }
         else
         {
             throw new IllegalArgumentException( "Unknown log level: " + level );
         }
     }
 
     public static void log( Log log, int level, CharSequence message, CharSequence prefix )
     {
         log( log, level, format( message, prefix ) );
     }
 
     public static boolean isEnabled( Log log, int level )
     {
         boolean enabled;
 
         if ( level == LEVEL_DEBUG )
         {
             enabled = log.isDebugEnabled();
         }
         else if ( level == LEVEL_INFO )
         {
             enabled = log.isInfoEnabled();
         }
         else if ( level == LEVEL_WARN )
         {
             enabled = log.isWarnEnabled();
         }
         else if ( level == LEVEL_ERROR )
         {
             enabled = log.isErrorEnabled();
         }
         else
         {
             throw new IllegalArgumentException( "Unknown log level: " + level );
         }
 
         return enabled;
     }
 
     // private methods --------------------------------------------------------
 
     private static CharSequence format( CharSequence message, CharSequence prefix )
     {
         if ( prefix == null || prefix.length() == 0 )
         {
             return message;
         }
 
         return new StringBuffer( prefix ).append( message ).toString();
     }
 }