/*
    * 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.core.config.plugins.convert;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.status.StatusLogger;
  import org.apache.logging.log4j.util.LoaderUtil;
  
  /**
   * @Since 2.9
   */
  public class Base64Converter {
  
      private static final Logger LOGGER = StatusLogger.getLogger();
      private static Method method = null;
      private static Object decoder = null;
  
      static {
          try {
              // Base64 is available in Java 8 and up.
              Class<?> clazz = LoaderUtil.loadClass("java.util.Base64");
              final Method getDecoder = clazz.getMethod("getDecoder", (Class[]) null);
              decoder = getDecoder.invoke(null, (Object[]) null);
              clazz = decoder.getClass();
              method = clazz.getMethod("decode", String.class);
          } catch (final ClassNotFoundException ex) {
  
          } catch (final NoSuchMethodException ex) {
  
          } catch (final IllegalAccessException ex) {
  
          } catch (final InvocationTargetException ex) {
  
          }
          if (method == null) {
              try {
                  // DatatypeConverter is not in the default module in Java 9.
                  final Class<?> clazz = LoaderUtil.loadClass("javax.xml.bind.DatatypeConverter");
                  method = clazz.getMethod("parseBase64Binary", String.class);
              } catch (final ClassNotFoundException ex) {
                  LOGGER.error("No Base64 Converter is available");
              } catch (final NoSuchMethodException ex) {
  
              }
          }
      }
  
      public static byte[] parseBase64Binary(final String encoded) {
          if (method == null) {
              LOGGER.error("No base64 converter");
          } else {
              try {
                  return (byte[]) method.invoke(decoder, encoded);
              } catch (final IllegalAccessException ex) {
                  LOGGER.error("Error decoding string - " + ex.getMessage());
              } catch (final InvocationTargetException ex) {
                  LOGGER.error("Error decoding string - " + ex.getMessage());
              }
          }
          return new byte[0];
      }
  }