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.SimpleDateFormat;
import java.text.DateFormat;
import java.text.ParseException;
import java.util.Date;
import java.util.regex.Pattern;

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 <a href="http://jboss.org/">JBoss</a>'s server logs. By default, the classification rules generated by
 * the GUI for this type of logs will sort events based on the following attributes: <code>level</code> then
 * <code>logger</code>.
 *
 * @since 0.9
 */
public class JBossLogEvent
    extends LogEvent
    implements Comparable<JBossLogEvent>
{
    public final static String ID = "jboss";

    public final String timestamp;

    public final Date date;

    public final String level;

    public final String logger;

    public final String message;

    public final String throwable;

    public final String throwable_firstLine;

    public final String throwable_class;

    public final static LogType LOGTYPE = new LogType.Basic( ID );

    private final static DateFormat DATE_FORMAT = new SimpleDateFormat( "yyyy-MM-dd HH:mm:ss,SSS" );

    private final static String[] ATTRIBUTE_NAMES =
        { "logSource", "timestamp", "timestamp.date", "timestamp.time", "level", "logger", "message", "throwable",
            "throwable.firstline", "throwable.class" };

    public final static LogType.Description DESCRIPTION = new Description( (LogType.Basic) LOGTYPE, ATTRIBUTE_NAMES );

    public JBossLogEvent( LogEvent.Factory factory, String firstLine, String secondLine, String throwable )
        throws ParseException
    {
        super( factory, ( secondLine == null ) ? firstLine : ( firstLine + Factory.NEWLINE + throwable ) );
        timestamp = firstLine.substring( 0, 23 );
        date = DATE_FORMAT.parse( timestamp );
        level = firstLine.substring( 24, 29 ).trim();
        StringCutter cutter = new StringCutter( firstLine.substring( 31 ) );
        logger = cutter.parseTo( "] " );
        message = cutter.getRemaining();
        this.throwable = throwable;
        throwable_firstLine = ( secondLine == null ) ? "" : secondLine;
        int index = throwable_firstLine.indexOf( ':' );
        throwable_class = ( index > 0 ) ? throwable.substring( 0, index ) : "";
        setAttributes( new String[] { factory.getLogSource(), timestamp, timestamp.substring( 0, 10 ),
            timestamp.substring( 11, 23 ), level, logger, message, throwable, throwable_firstLine, throwable_class } );
    }

    public int compareTo( JBossLogEvent o )
    {
        return date.compareTo( o.date );
    }

    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 getDefaultSpecificGroups()
        {
            return "  <group id=\"warn\">\n"
                + "    <description>WARN events</description>\n"
                + "    <condition>\n"
                + "      <match attribute=\"level\" type=\"equals\">WARN</match>\n"
                + "    </condition>\n"
                + "    <report publisher=\"file\"/>\n"
                + "    <plugin type=\"sampling\">\n"
                + "      <param name=\"attributes\">logger</param>\n"
                + "    </plugin>\n"
                + "  </group>\n"
                + "\n"
                + "  <group id=\"error\">\n"
                + "    <description>ERROR events</description>\n"
                + "    <condition>\n"
                + "      <match attribute=\"level\" type=\"equals\">ERROR</match>\n"
                + "    </condition>\n"
                + "    <report publisher=\"file\"/>\n"
                + "    <plugin type=\"sampling\">\n"
                + "      <param name=\"attributes\">logger</param>\n"
                + "    </plugin>\n"
                + "  </group>";
        }

        public String getDefaultSamplingAttributes()
        {
            return "level,logger";
        }
    }

    private static class Factory
        extends LogEvent.Factory
    {
        private final LineNumberReader reader;

        private String curLine;

        public Factory( Description description, Reader reader, String logSource )
            throws FileNotFoundException
        {
            super( description, logSource );
            this.reader = new LineNumberReader( reader );
        }

        private final static Pattern DATE_PATTERN =
            Pattern.compile( "\\A\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2},\\d{3} " );

        /**
         * Detect the start of a new log event
         */
        protected boolean detectLogEventStart( String line )
        {
            // heuristics: detects the beginning of the date...
            return DATE_PATTERN.matcher( line ).find();
        }

        protected LogEvent readNextEvent()
            throws IOException, ParseException
        {
            if ( curLine == null )
            {
                curLine = reader.readLine();
                if ( curLine == null )
                {
                    // EOF
                    return null;
                }
            }
            String firstLine = curLine;
            int lineNumber = reader.getLineNumber();

            String secondLine = null;
            StringBuffer buffer = new StringBuffer();
            while ( ( ( curLine = reader.readLine() ) != null ) && ( !detectLogEventStart( curLine ) ) )
            {
                if ( secondLine == null )
                {
                    secondLine = curLine;
                }
                else
                {
                    buffer.append( NEWLINE );
                }
                buffer.append( curLine );
            }
            return BUILDER.buildLogEvent( this, lineNumber, firstLine, secondLine, buffer.toString() );
        }

        private final static LogEventBuilder BUILDER = new LogEventBuilder()
        {
            protected LogEvent newEvent( LogEvent.Factory factory, String curLine, Object... objects )
                throws ParseException
            {
                return new JBossLogEvent( factory, curLine, (String) objects[0], (String) objects[1] );
            }
        };
    }
}