package org.eclipse.aether.internal.impl.slf4j;
   
   /*
    * 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.
   */
  
  import javax.inject.Inject;
  import javax.inject.Named;
  
  import org.eclipse.aether.spi.locator.Service;
  import org.eclipse.aether.spi.locator.ServiceLocator;
  import org.eclipse.aether.spi.log.Logger;
  import org.eclipse.aether.spi.log.LoggerFactory;
  import org.eclipse.sisu.Nullable;
  import org.slf4j.ILoggerFactory;
  import org.slf4j.spi.LocationAwareLogger;
  
  /**
   * A logger factory that delegates to <a href="http://www.slf4j.org/" target="_blank">SLF4J</a> logging.
   */
  @Named( "slf4j" )
  public class Slf4jLoggerFactory
      implements LoggerFactory, Service
  {
  
      private static final boolean AVAILABLE;
  
      static
      {
          boolean available;
          try
          {
              Slf4jLoggerFactory.class.getClassLoader().loadClass( "org.slf4j.ILoggerFactory" );
              available = true;
          }
          catch ( Exception | LinkageError e )
          {
              available = false;
          }
          AVAILABLE = available;
      }
  
      public static boolean isSlf4jAvailable()
      {
          return AVAILABLE;
      }
  
      private ILoggerFactory factory;
  
      /**
       * Creates an instance of this logger factory.
       */
      public Slf4jLoggerFactory()
      {
          // enables no-arg constructor
      }
  
      @Inject
      Slf4jLoggerFactory( @Nullable ILoggerFactory factory )
      {
          setLoggerFactory( factory );
      }
  
      public void initService( ServiceLocator locator )
      {
          setLoggerFactory( locator.getService( ILoggerFactory.class ) );
      }
  
      public Slf4jLoggerFactory setLoggerFactory( ILoggerFactory factory )
      {
          this.factory = factory;
          return this;
      }
  
      public Logger getLogger( String name )
      {
          org.slf4j.Logger logger = getFactory().getLogger( name );
          if ( logger instanceof LocationAwareLogger )
          {
              return new Slf4jLoggerEx( (LocationAwareLogger) logger );
          }
          return new Slf4jLogger( logger );
      }
  
     private ILoggerFactory getFactory()
     {
         if ( factory == null )
         {
             factory = org.slf4j.LoggerFactory.getILoggerFactory();
         }
         return factory;
     }
 
     private static final class Slf4jLogger
         implements Logger
     {
 
         private final org.slf4j.Logger logger;
 
         Slf4jLogger( org.slf4j.Logger logger )
         {
             this.logger = logger;
         }
 
         public boolean isDebugEnabled()
         {
             return logger.isDebugEnabled();
         }
 
         public void debug( String msg )
         {
             logger.debug( msg );
         }
 
         public void debug( String msg, Throwable error )
         {
             logger.debug( msg, error );
         }
 
         public boolean isWarnEnabled()
         {
             return logger.isWarnEnabled();
         }
 
         public void warn( String msg )
         {
             logger.warn( msg );
         }
 
         public void warn( String msg, Throwable error )
         {
             logger.warn( msg, error );
         }
 
     }
 
     private static final class Slf4jLoggerEx
         implements Logger
     {
 
         private static final String FQCN = Slf4jLoggerEx.class.getName();
 
         private final LocationAwareLogger logger;
 
         Slf4jLoggerEx( LocationAwareLogger logger )
         {
             this.logger = logger;
         }
 
         public boolean isDebugEnabled()
         {
             return logger.isDebugEnabled();
         }
 
         public void debug( String msg )
         {
             logger.log( null, FQCN, LocationAwareLogger.DEBUG_INT, msg, null, null );
         }
 
         public void debug( String msg, Throwable error )
         {
             logger.log( null, FQCN, LocationAwareLogger.DEBUG_INT, msg, null, error );
         }
 
         public boolean isWarnEnabled()
         {
             return logger.isWarnEnabled();
         }
 
         public void warn( String msg )
         {
             logger.log( null, FQCN, LocationAwareLogger.WARN_INT, msg, null, null );
         }
 
         public void warn( String msg, Throwable error )
         {
             logger.log( null, FQCN, LocationAwareLogger.WARN_INT, msg, null, error );
         }
 
     }
 
 }