package org.molwind.util;
   
   /*
    * This file is part of Molwind.
    *
    * Molwind 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 3 of the License, or
    * (at your option) any later version.
   *
   * Molwind 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 Molwind. If not, see <http://www.gnu.org/licenses/>.
   */
  
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import javax.servlet.ServletContext;
  
  /**
   * MolwindLogger facade delegates log requests to the underlying logger(s).
   *
   * @author <a href="mailto:oliver.karch@molwind.org">Oliver Karch</a>
   * @version 1.0
   */
  public final class MolwindLogger {
  
      private Logger logger;
      private ServletContext servletContext;
  
      private static MolwindLogger molwindLogger;
  
      private MolwindLogger(final ServletContext context) {
          logger = Logger.getLogger("org.molwind");
          servletContext = context;
      }
  
      private MolwindLogger() {
          this(null);
      }
  
  
      /**
       * Returns an instance of the logger facade (optionally) initialized with a
       * servlet context.
       *
       * @param context
       *      the servlet context or null (if not available)
       * @return
       *      an initialized logging facility
       */
      public static MolwindLogger getInstance(final ServletContext context) {
          if (molwindLogger == null) {
              molwindLogger = new MolwindLogger(context);
          }
          return molwindLogger;
      }
  
      /**
       * Returns an instance of the logger facade.
       *
       * @return
       *      an initialized logging facility
       */
      public static MolwindLogger getInstance() {
          return getInstance(null);
      }
  
  
      private void setWarning(final String message, final Throwable cause) {
          String fullMessage = "WARN " + message;
  
          if (cause != null) {
              logger.log(Level.WARNING, fullMessage, cause);
          } else {
              logger.log(Level.WARNING, fullMessage);
          }
  
          if (servletContext != null) {
              servletContext.log(fullMessage, cause);
          }
      }
  
      private void setError(final String message, final Throwable cause) {
          String fullMessage = "ERROR " + message;
  
          if (cause != null) {
              logger.log(Level.WARNING, fullMessage, cause);
          } else {
              logger.log(Level.WARNING, fullMessage);
          }
  
          if (servletContext != null) {
              servletContext.log(fullMessage, cause);
         }
     }
 
     private void setDebugMessage(final String message, final Throwable cause) {
         String fullMessage = "DEBUG " + message;
 
         if (cause != null) {
             logger.log(Level.INFO, fullMessage, cause);
         } else {
             logger.log(Level.INFO, fullMessage);
         }
 
         if (servletContext != null) {
             servletContext.log(fullMessage, cause);
         }
     }
 
     private void setInfo(final String message, final Throwable cause) {
         String fullMessage = "INFO " + message;
 
         if (cause != null) {
             logger.log(Level.INFO, fullMessage, cause);
         } else {
             logger.log(Level.INFO, fullMessage);
         }
 
         if (servletContext != null) {
             servletContext.log(fullMessage, cause);
         }
     }
 
     private void setFatalError(final String message, final Throwable cause) {
         String fullMessage = "FATAL " + message;
 
         if (cause != null) {
             logger.log(Level.SEVERE, fullMessage, cause);
         } else {
             logger.log(Level.SEVERE, fullMessage);
         }
 
         if (servletContext != null) {
             servletContext.log(fullMessage, cause);
         }
     }
 
 
     public static void warn(final String message, final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setWarning(message, cause);
     }
     public static void error(final String message, final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setError(message, cause);
     }
     public static void fatal(final String message, final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setFatalError(message, cause);
     }
     public static void info(final String message, final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setInfo(message, cause);
     }
     public static void debug(final String message, final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setDebugMessage(message, cause);
     }
 
 
     public static void warn(final String message) {
         MolwindLogger logger = getInstance();
         logger.setWarning(message, null);
     }
     public static void error(final String message) {
         MolwindLogger logger = getInstance();
         logger.setError(message, null);
     }
     public static void fatal(final String message) {
         MolwindLogger logger = getInstance();
         logger.setFatalError(message, null);
     }
     public static void info(final String message) {
         MolwindLogger logger = getInstance();
         logger.setInfo(message, null);
     }
     public static void debug(final String message) {
         MolwindLogger logger = getInstance();
         logger.setDebugMessage(message, null);
     }
 
 
     public static void warn(final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setWarning("", cause);
     }
     public static void error(final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setError("", cause);
     }
     public static void fatal(final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setFatalError("", cause);
     }
     public static void info(final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setInfo("", cause);
     }
     public static void debug(final Throwable cause) {
         MolwindLogger logger = getInstance();
         logger.setDebugMessage("", cause);
     }
 
 }