/*
    * Jour - java profiler and monitoring library
    *
    * Copyright (C) 2007 Jour team
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Library General Public
    * License as published by the Free Software Foundation; either
    * version 2 of the License, or (at your option) any later version.
   *
   * This library 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
   * Library General Public License for more details.
   *
   * You should have received a copy of the GNU Library General Public
   * License along with this library; if not, write to the
   * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   * Boston, MA  02111-1307, USA.
   */
  package net.sf.jour.log;
  
  import java.util.WeakHashMap;
  
  /**
   * Log4j wrapper
   * 
   * @author vlads
   *
   */
  public class Logger {
  	
  	/** The fully qualified name of the Log class. */
      private static final String FQCN = Logger.class.getName();
      
      private static int log4jAvalable = 0;
      
      private static WeakHashMap instances = new WeakHashMap();
      
      protected Logger() {
      }
      
      private static int detectLog4j() {
      	try {
  			Class.forName("org.apache.log4j.Logger");
  			return 1;
  		} catch (ClassNotFoundException e) {
  			return -1;
  		}
      }
      
      /**
       * We are in java 1.4 lets save some typing.
       */
      public static Logger getLogger() {
          String useName = null;
          StackTraceElement[] ste = new Throwable().getStackTrace();
          for (int i = 0; i < ste.length; i++ ) {
              if (ste[i].getClassName().equals(FQCN)) {
                  i ++;
                  useName = ste[i].getClassName();
                  break;
              }
          }
          if (useName == null) {
              throw new Error("Can't find call origin");
          }
          return getLogger(useName);    
      }
      
      /**
       * Return the native Logger instance we are using.
       */
      public static Logger getLogger(String name) {
          return createLogger(name);
      }
      
      private static Logger createLogger(String name) {
      	if (log4jAvalable == 0) {
      		log4jAvalable = detectLog4j();
      	} 
      	if (log4jAvalable > 0) {
      		return createLoggerWrapper(name);
      	} else {
      		return new Logger();
      	}
      }
      
      private static Logger createLoggerWrapper(String name) {
      	org.apache.log4j.Logger logger = org.apache.log4j.Logger.getLogger(name);
          if (instances.containsKey(logger)) {
              return (Logger)instances.get(logger);
          } else {
              Logger log = new LoggerLog4j(logger);
              instances.put(logger, log);
              return log;
          }
      }
      
     public static Logger getLogger(Class clazz) {
         return getLogger(clazz.getName());
     }
     
     public static Logger getLog(Class clazz) {
         return getLogger(clazz.getName());
     }
     
     private static class LoggerLog4j extends Logger {
 
 		private org.apache.log4j.Logger logger;
 
 		protected LoggerLog4j(org.apache.log4j.Logger log4jLogger) {
 			this.logger = log4jLogger;
 		}
 
 		public void error(Object message) {
 			this.logger.log(FQCN, org.apache.log4j.Level.ERROR, message, null);
 		}
 
 		public void error(Object message, Throwable t) {
 			this.logger.log(FQCN, org.apache.log4j.Level.ERROR, message, t);
 		}
 
 		public void warn(Object message) {
 			this.logger.log(FQCN, org.apache.log4j.Level.WARN, message, null);
 		}
 
 		public void info(Object message) {
 			this.logger.log(FQCN, org.apache.log4j.Level.INFO, message, null);
 		}
 
 		public boolean isDebugEnabled() {
 			return this.logger.isDebugEnabled();
 		}
 
 		public void debug(Object message) {
 			this.logger.log(FQCN, org.apache.log4j.Level.DEBUG, message, null);
 		}
 	}
 
 	public void error(Object message) {
 		System.err.println(message);
 	}
 
 	public void error(Object message, Throwable t) {
 		System.err.println(message);
 		if (t != null) {
 			t.printStackTrace(System.err);
 		}
 	}
     
     public void warn(Object message) {
     }
     
     public void info(Object message) {
     }
     
     public boolean isDebugEnabled() {
    		return false;
     }
 
     public void debug(Object message) {
     }
 }