/*
    * 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.layout;
  
  import java.io.IOException;
  import java.io.Writer;
  import java.nio.charset.Charset;
  
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.Configuration;
  import org.apache.logging.log4j.core.impl.Log4jLogEvent;
  import org.apache.logging.log4j.core.impl.MutableLogEvent;
  import org.apache.logging.log4j.core.util.StringBuilderWriter;
  import org.apache.logging.log4j.util.Strings;
  
  import com.fasterxml.jackson.core.JsonGenerationException;
  import com.fasterxml.jackson.databind.JsonMappingException;
  import com.fasterxml.jackson.databind.ObjectWriter;
  
  abstract class AbstractJacksonLayout extends AbstractStringLayout {
  
      protected static final String DEFAULT_EOL = "\r\n";
      protected static final String COMPACT_EOL = Strings.EMPTY;
  
      protected final String eol;
      protected final ObjectWriter objectWriter;
      protected final boolean compact;
      protected final boolean complete;
  
      protected AbstractJacksonLayout(final Configuration config, final ObjectWriter objectWriter, final Charset charset,
              final boolean compact, final boolean complete, final boolean eventEol, final Serializer headerSerializer,
              final Serializer footerSerializer) {
          super(config, charset, headerSerializer, footerSerializer);
          this.objectWriter = objectWriter;
          this.compact = compact;
          this.complete = complete;
          this.eol = compact && !eventEol ? COMPACT_EOL : DEFAULT_EOL;
      }
  
      /**
       * Formats a {@link org.apache.logging.log4j.core.LogEvent}.
       *
       * @param event The LogEvent.
       * @return The XML representation of the LogEvent.
       */
      @Override
      public String toSerializable(final LogEvent event) {
          final StringBuilderWriter writer = new StringBuilderWriter();
          try {
              toSerializable(event, writer);
              return writer.toString();
          } catch (final IOException e) {
              // Should this be an ISE or IAE?
              LOGGER.error(e);
              return Strings.EMPTY;
          }
      }
  
      private static LogEvent convertMutableToLog4jEvent(final LogEvent event) {
          // TODO Jackson-based layouts have certain filters set up for Log4jLogEvent.
          // TODO Need to set up the same filters for MutableLogEvent but don't know how...
          // This is a workaround.
          return event instanceof MutableLogEvent
                  ? ((MutableLogEvent) event).createMemento()
                  : event;
      }
  
      public void toSerializable(final LogEvent event, final Writer writer)
              throws JsonGenerationException, JsonMappingException, IOException {
          objectWriter.writeValue(writer, convertMutableToLog4jEvent(event));
          writer.write(eol);
          markEvent();
      }
  
  }