package net.sf.logdistiller.logtypes;
   
   /*
    * 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.
   */
  
  import java.io.*;
  import java.text.ParseException;
  
  import net.sf.logdistiller.LogEvent;
  import net.sf.logdistiller.LogType;
  import net.sf.logdistiller.util.LogEventBuilder;
  import net.sf.logdistiller.util.StringCutter;
  
  /**
   * Log event for Unix syslog facility. By default, the classification rules generated by the GUI for this type of logs
   * will sort events based on the following attributes: <code>host</code>, then <code>program</code>.
   */
  public class SyslogLogEvent
      extends LogEvent
  {
      public final static String ID = "syslog";
  
      // see http://logreport.org/doc/gen/os/
      public final String timestamp;
  
      public final String host;
  
      public final String program;
  
      public final String pid;
  
      public final String message;
  
      public final static LogType LOGTYPE = new LogType.Basic( ID );
  
      private final static String[] ATTRIBUTE_NAMES = { "logSource", "timestamp", "host", "program", "pid", "message" };
  
      public final static LogType.Description DESCRIPTION = new Description( (LogType.Basic) LOGTYPE, ATTRIBUTE_NAMES );
  
      public SyslogLogEvent( LogEvent.Factory factory, String rawLog )
          throws ParseException
      {
          super( factory, rawLog );
          timestamp = rawLog.substring( 0, 15 );
          StringCutter sc = new StringCutter( rawLog, 16 );
          host = sc.parseTo( " " );
          String remaining = sc.getRemaining();
          if ( remaining.indexOf( ": " ) < 0 )
          {
              program = "";
              pid = "";
              message = remaining;
          }
          else
          {
              // <program>[<pid>]: <message>
              String programPid = sc.parseTo( ": " );
              message = sc.getRemaining();
  
              int index = programPid.indexOf( '[' );
              if ( ( index >= 0 ) && programPid.endsWith( "]" ) )
              {
                  program = programPid.substring( 0, index );
                  pid = programPid.substring( index + 1, programPid.length() - 1 );
              }
              else
              {
                  program = programPid;
                  pid = "";
              }
          }
          setAttributes( new String[] { factory.getLogSource(), timestamp, host, program, pid, message } );
      }
  
      private static class Description
          extends LogType.Description
      {
          public Description( LogType.Basic logtype, String[] attributeNames )
          {
              super( logtype, attributeNames );
              logtype.setDescription( this );
          }
  
          public LogEvent.Factory newFactory( Reader reader, String logSource )
              throws IOException
          {
              return new Factory( this, reader, logSource );
          }
 
         public String getDefaultSamplingAttributes()
         {
             return "host,program";
         }
     }
 
     private static class Factory
         extends LogEvent.Factory
     {
         private final LineNumberReader reader;
 
         public Factory( Description description, Reader reader, String logSource )
             throws FileNotFoundException
         {
             super( description, logSource );
             this.reader = new LineNumberReader( reader );
         }
 
         protected LogEvent readNextEvent()
             throws IOException, ParseException
         {
             String curLine = reader.readLine();
             if ( curLine == null )
             {
                 // EOF
                 return null;
             }
 
             return BUILDER.buildLogEvent( this, reader.getLineNumber(), curLine );
         }
 
         private final static LogEventBuilder BUILDER = new LogEventBuilder()
         {
             protected LogEvent newEvent( LogEvent.Factory factory, String curLine, Object... objects )
                 throws ParseException
             {
                 return new SyslogLogEvent( factory, curLine );
             }
         };
     }
 }