/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements. See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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.
   */
  package org.apache.logging.log4j.appserver.tomcat;
  
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.net.URL;
  
  import org.apache.juli.logging.Log;
  import org.apache.logging.log4j.Level;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.spi.ExtendedLogger;
  import org.apache.logging.log4j.spi.LoggerContext;
  
  /**
   * Implements the Log interface from Tomcat 8.5 and greater.
   *
   * In order to use this class to cause Tomcat to use Log4j for logging, the jar containing this class as well as the
   * log4j-api and log4j-core jars must be added to Tomcat's boot classpath. This is most easily accomplished by
   * placing these jars in a directory and then adding the contents of that directory to the CLASSPATH
   * environment variable in setenv.sh in Tomcat's bin directory.
   *
   * The Log4j configuration file must also be present on the classpath. This implementation will use the
   * first file it finds with one of the following file names: log4j2-tomcat.xml, log4j2-tomcat.json,
   * log4j2-tomcat.yaml, log4j2-tomcat.yml, log4j2-tomcat.properties. Again, this can be accomplished by adding
   * this file to a directory and then adding that directory to the CLASSPATH environment variable in setenv.sh.
   *
   * @since 2.10.0
   */
  public class TomcatLogger implements Log {
  
      private static final long serialVersionUID = 1L;
      private static final String FQCN = TomcatLogger.class.getName();
      private static final String[] FILE_NAMES = {
          "log4j2-tomcat.xml", "log4j2-tomcat.json", "log4j2-tomcat.yaml", "log4j2-tomcat.yml",
          "log4j2-tomcat.properties"
      };
  
      private final ExtendedLogger logger;
  
      /**
       * This constructor is used by ServiceLoader to load an instance of the class.
       */
      public TomcatLogger() {
          logger = null;
      }
  
      /**
       * This constructor is used by LogFactory to create a new Logger.
       * @param name The name of the Logger.
       */
      public TomcatLogger(final String name) {
          this.logger = PrivateManager.getLogger(name);
      }
  
      @Override
      public boolean isDebugEnabled() {
          return logger.isDebugEnabled();
      }
  
      @Override
      public boolean isErrorEnabled() {
          return logger.isErrorEnabled();
      }
  
      @Override
      public boolean isFatalEnabled() {
          return logger.isFatalEnabled();
      }
  
      @Override
      public boolean isInfoEnabled() {
          return logger.isInfoEnabled();
      }
  
      @Override
      public boolean isTraceEnabled() {
          return logger.isTraceEnabled();
      }
  
      @Override
      public boolean isWarnEnabled() {
          return logger.isWarnEnabled();
      }
  
     @Override
     public void trace(final Object o) {
         logger.logIfEnabled(FQCN, Level.TRACE, null, o, null);
     }
 
     @Override
     public void trace(final Object o, final Throwable throwable) {
         logger.logIfEnabled(FQCN, Level.TRACE, null, o, throwable);
     }
 
     @Override
     public void debug(final Object o) {
         logger.logIfEnabled(FQCN, Level.DEBUG, null, o, null);
     }
 
     @Override
     public void debug(final Object o, final Throwable throwable) {
         logger.logIfEnabled(FQCN, Level.DEBUG, null, o, throwable);
     }
 
     @Override
     public void info(final Object o) {
         logger.logIfEnabled(FQCN, Level.INFO, null, o, null);
     }
 
     @Override
     public void info(final Object o, final Throwable throwable) {
         logger.logIfEnabled(FQCN, Level.INFO, null, o, throwable);
     }
 
     @Override
     public void warn(final Object o) {
         logger.logIfEnabled(FQCN, Level.WARN, null, o, null);
     }
 
     @Override
     public void warn(final Object o, final Throwable throwable) {
         logger.logIfEnabled(FQCN, Level.WARN, null, o, throwable);
     }
 
     @Override
     public void error(final Object o) {
         logger.logIfEnabled(FQCN, Level.ERROR, null, o, null);
     }
 
     @Override
     public void error(final Object o, final Throwable throwable) {
         logger.logIfEnabled(FQCN, Level.ERROR, null, o, throwable);
     }
 
     @Override
     public void fatal(final Object o) {
         logger.logIfEnabled(FQCN, Level.FATAL, null, o, null);
     }
 
     @Override
     public void fatal(final Object o, final Throwable throwable) {
         logger.logIfEnabled(FQCN, Level.FATAL, null, o, throwable);
     }
 
     /**
      * Internal LogManager.
      */
     private static class PrivateManager extends LogManager {
 
         public static LoggerContext getContext() {
             final ClassLoader cl = TomcatLogger.class.getClassLoader();
             URI uri = null;
             for (final String fileName : FILE_NAMES) {
                 try {
                     final URL url = cl.getResource(fileName);
                     if (url != null) {
                         uri = url.toURI();
                         break;
                     }
                 } catch (final URISyntaxException ex) {
                     // Ignore the exception.
                 }
             }
             if (uri == null) {
                 return getContext(FQCN, cl, false);
             }
             return getContext(FQCN, cl, false, uri, "Tomcat");
         }
 
         public static ExtendedLogger getLogger(final String name) {
             return getContext().getLogger(name);
         }
     }
 }