// serverLog.java 
// -------------------------------------
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
// last major change: 04.08.2004
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.

package de.anomic.server;

import java.text.*;
import java.util.*;

public final class serverLog {
    
    // statics
    private static TimeZone GMTTimeZone = TimeZone.getTimeZone("PST");
    private static SimpleDateFormat longFormatter  = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
    private static SimpleDateFormat shortFormatter = new SimpleDateFormat("yyyyMMddHHmmss");
    
    // log-level categories
    public static final int LOGLEVEL_ZERO    = 0; // no output at all
    public static final int LOGLEVEL_FAILURE = 1; // system-level error, internal cause, critical and not fixeable (i.e. inconsistency)
    public static final int LOGLEVEL_ERROR   = 2; // exceptional error, catcheable and non-critical (i.e. file error)
    public static final int LOGLEVEL_WARNING = 3; // uncritical service failure, may require user activity (i.e. input required, wrong authorization)
    public static final int LOGLEVEL_SYSTEM  = 4; // regular system status information (i.e. start-up messages)
    public static final int LOGLEVEL_INFO    = 5; // regular action information (i.e. any httpd request URL)
    public static final int LOGLEVEL_DEBUG   = 6; // in-function status debug output
    
    // these categories are also present as character tokens
    public static final char LOGTOKEN_ZERO    = 'Z';
    public static final char LOGTOKEN_FAILURE = 'F';
    public static final char LOGTOKEN_ERROR   = 'E';
    public static final char LOGTOKEN_WARNING = 'W';
    public static final char LOGTOKEN_SYSTEM  = 'S';
    public static final char LOGTOKEN_INFO    = 'I';
    public static final char LOGTOKEN_DEBUG   = 'D';

    // an array-wrapped function
    private static final char[] l2t = new char[] {
        LOGTOKEN_ZERO, LOGTOKEN_FAILURE, LOGTOKEN_ERROR, LOGTOKEN_WARNING,
        LOGTOKEN_SYSTEM, LOGTOKEN_INFO, LOGTOKEN_DEBUG
    };
    
    // statics
    private static serverLog genericLog = new serverLog("GENERIC", LOGLEVEL_DEBUG); // generic log
    private static LinkedList lastLog = new LinkedList(); // for Web-Interface
    private static int lastlogMaxSize = 400; // for Web-Interface
    
    // class variables
    private String appName;
    private int logLevel;
    
    public serverLog(String appName) {
        this(appName, LOGLEVEL_DEBUG);
    }
    
    public serverLog(String appName, int logLevel) {
        this.logLevel = logLevel;
        this.appName = appName;
    }
    
    public serverLog(String appName, char logToken) {
        this(appName, t2l(logToken));
    }
    
    public void setLoglevel(int newLevel) {
        this.logLevel = newLevel;
    }
    
    private static int t2l(char token) {
        switch (token) {
            case LOGTOKEN_ZERO:    return LOGLEVEL_ZERO;
            case LOGTOKEN_FAILURE: return LOGLEVEL_FAILURE;
            case LOGTOKEN_ERROR:   return LOGLEVEL_ERROR;
            case LOGTOKEN_WARNING: return LOGLEVEL_WARNING;
            case LOGTOKEN_SYSTEM:  return LOGLEVEL_SYSTEM;
            case LOGTOKEN_INFO:    return LOGLEVEL_INFO;
            case LOGTOKEN_DEBUG:   return LOGLEVEL_DEBUG;
        }
        return LOGLEVEL_DEBUG;
    }
    
    private static String dateLongString() {
	return longFormatter.format(new GregorianCalendar(GMTTimeZone).getTime());
    }

    private static String dateShortString() {
	return shortFormatter.format(new GregorianCalendar(GMTTimeZone).getTime());
    }

    private void log(int messageLevel, String message) {
        if (messageLevel <= logLevel) {
	    System.out.println(l2t[messageLevel] + " " + dateLongString() + " " + appName + " " + message);
	    lastLog.add(l2t[messageLevel] + " " + dateLongString() + " " + appName + " " + message);
	    while (lastLog.size() > lastlogMaxSize) lastLog.removeFirst();
	}
    }

    public static LinkedList getLastLog(){
	return lastLog;
    }

    // class log messages
    public void logFailure(String message) {log(LOGLEVEL_FAILURE, message);}
    public void logError(String message)   {log(LOGLEVEL_ERROR, message);}
    public void logWarning(String message) {log(LOGLEVEL_WARNING, message);}
    public void logSystem(String message)  {log(LOGLEVEL_SYSTEM, message);}
    public void logInfo(String message)    {log(LOGLEVEL_INFO, message);}
    public void logDebug(String message)   {log(LOGLEVEL_DEBUG, message);}

    
    // static log messages: log everything
    private static void log(String appName, int messageLevel, String message) {
        genericLog.appName = appName;
        genericLog.log(messageLevel, message);
    }
    
    public static void logFailure(String appName, String message) {log(appName, LOGLEVEL_FAILURE, message);}
    public static void logError(String appName, String message)   {log(appName, LOGLEVEL_ERROR, message);}
    public static void logWarning(String appName, String message) {log(appName, LOGLEVEL_WARNING, message);}
    public static void logSystem(String appName, String message)  {log(appName, LOGLEVEL_SYSTEM, message);}
    public static void logInfo(String appName, String message)    {log(appName, LOGLEVEL_INFO, message);}
    public static void logDebug(String appName, String message)   {log(appName, LOGLEVEL_DEBUG, message);}
    
}