/*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project 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:
    *
    *   https://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 io.netty.util.internal.logging;
  
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.slf4j.helpers.NOPLoggerFactory;
  import org.slf4j.spi.LocationAwareLogger;
  
  /**
   * Logger factory which creates a <a href="https://www.slf4j.org/">SLF4J</a>
   * logger.
   */
  public class Slf4JLoggerFactory extends InternalLoggerFactory {
  
      @SuppressWarnings("deprecation")
      public static final InternalLoggerFactory INSTANCE = new Slf4JLoggerFactory();
  
      /**
       * @deprecated Use {@link #INSTANCE} instead.
       */
      @Deprecated
      public Slf4JLoggerFactory() {
      }
  
      Slf4JLoggerFactory(boolean failIfNOP) {
          assert failIfNOP; // Should be always called with true.
          if (LoggerFactory.getILoggerFactory() instanceof NOPLoggerFactory) {
              throw new NoClassDefFoundError("NOPLoggerFactory not supported");
          }
      }
  
      @Override
      public InternalLogger newInstance(String name) {
          return wrapLogger(LoggerFactory.getLogger(name));
      }
  
      // package-private for testing.
      static InternalLogger wrapLogger(Logger logger) {
          return logger instanceof LocationAwareLogger ?
                  new LocationAwareSlf4JLogger((LocationAwareLogger) logger) : new Slf4JLogger(logger);
      }
  
      static InternalLoggerFactory getInstanceWithNopCheck() {
          return NopInstanceHolder.INSTANCE_WITH_NOP_CHECK;
      }
  
      private static final class NopInstanceHolder {
          private static final InternalLoggerFactory INSTANCE_WITH_NOP_CHECK = new Slf4JLoggerFactory(true);
      }
  }