/*
    * 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.util.HashSet;
  import java.util.Set;
  
  import javax.xml.stream.XMLStreamException;
  
  import org.apache.logging.log4j.core.impl.Log4jLogEvent;
  import org.apache.logging.log4j.core.jackson.JsonConstants;
  import org.apache.logging.log4j.core.jackson.Log4jJsonObjectMapper;
  import org.apache.logging.log4j.core.jackson.Log4jXmlObjectMapper;
  import org.apache.logging.log4j.core.jackson.Log4jYamlObjectMapper;
  import org.apache.logging.log4j.core.jackson.XmlConstants;
  import org.codehaus.stax2.XMLStreamWriter2;
  
  import com.fasterxml.jackson.core.PrettyPrinter;
  import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
  import com.fasterxml.jackson.core.util.MinimalPrettyPrinter;
  import com.fasterxml.jackson.databind.ObjectMapper;
  import com.fasterxml.jackson.databind.ObjectWriter;
  import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
  import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
  import com.fasterxml.jackson.dataformat.xml.util.DefaultXmlPrettyPrinter;
  
  abstract class JacksonFactory {
  
      static class JSON extends JacksonFactory {
  
          private final boolean encodeThreadContextAsList;
  
          public JSON(final boolean encodeThreadContextAsList) {
              this.encodeThreadContextAsList = encodeThreadContextAsList;
          }
  
          @Override
          protected String getPropertNameForContextMap() {
              return JsonConstants.ELT_CONTEXT_MAP;
          }
  
          @Override
          protected String getPropertNameForSource() {
              return JsonConstants.ELT_SOURCE;
          }
  
          @Override
          protected String getPropertNameForNanoTime() {
              return JsonConstants.ELT_NANO_TIME;
          }
  
          @Override
          protected PrettyPrinter newCompactPrinter() {
              return new MinimalPrettyPrinter();
          }
  
          @Override
          protected ObjectMapper newObjectMapper() {
              return new Log4jJsonObjectMapper(encodeThreadContextAsList);
          }
  
          @Override
          protected PrettyPrinter newPrettyPrinter() {
              return new DefaultPrettyPrinter();
          }
      }
  
      static class XML extends JacksonFactory {
  
          static final int DEFAULT_INDENT = 1;
  
          @Override
          protected String getPropertNameForContextMap() {
              return XmlConstants.ELT_CONTEXT_MAP;
          }
  
          @Override
          protected String getPropertNameForSource() {
              return XmlConstants.ELT_SOURCE;
          }
  
          @Override
          protected String getPropertNameForNanoTime() {
              return JsonConstants.ELT_NANO_TIME;
          }
 
         @Override
         protected PrettyPrinter newCompactPrinter() {
             // Yes, null is the proper answer.
             return null;
         }
 
         @Override
         protected ObjectMapper newObjectMapper() {
             return new Log4jXmlObjectMapper();
         }
 
         @Override
         protected PrettyPrinter newPrettyPrinter() {
             return new Log4jXmlPrettyPrinter(DEFAULT_INDENT);
         }
     }
 
     static class YAML extends JacksonFactory {
 
         @Override
         protected String getPropertNameForContextMap() {
             return JsonConstants.ELT_CONTEXT_MAP;
         }
 
         @Override
         protected String getPropertNameForSource() {
             return JsonConstants.ELT_SOURCE;
         }
 
         @Override
         protected String getPropertNameForNanoTime() {
             return JsonConstants.ELT_NANO_TIME;
         }
 
         @Override
         protected PrettyPrinter newCompactPrinter() {
             return new MinimalPrettyPrinter();
         }
 
         @Override
         protected ObjectMapper newObjectMapper() {
             return new Log4jYamlObjectMapper(false);
         }
 
         @Override
         protected PrettyPrinter newPrettyPrinter() {
             return new DefaultPrettyPrinter();
         }
     }
 
     /**
      * When <Event>s are written into a XML file; the "Event" object is not the root element, but an element named
      * <Events> created using {@link XmlLayout#getHeader()} and {@link XmlLayout#getFooter()} methods.
      * <p>
      * {@link com.fasterxml.jackson.dataformat.xml.util.DefaultXmlPrettyPrinter} is used to print the Event object into
      * XML; hence it assumes &lt;Event&gt; tag as the root element, so it prints the &lt;Event&gt; tag without any
      * indentation. To add an indentation to the &lt;Event&gt; tag; hence an additional indentation for any
      * sub-elements, this class is written. As an additional task, to avoid the blank line printed after the ending
      * &lt;/Event&gt; tag, {@link #writePrologLinefeed(XMLStreamWriter2)} method is also overridden.
      * </p>
      */
     static class Log4jXmlPrettyPrinter extends DefaultXmlPrettyPrinter {
 
         private static final long serialVersionUID = 1L;
 
         Log4jXmlPrettyPrinter(final int nesting) {
             _nesting = nesting;
         }
 
         @Override
         public void writePrologLinefeed(final XMLStreamWriter2 sw) throws XMLStreamException {
             // nothing
         }
 
         /**
          * Sets the nesting level to 1 rather than 0, so the "Event" tag will get indentation of next level below root.
          */
         @Override
         public DefaultXmlPrettyPrinter createInstance() {
             return new Log4jXmlPrettyPrinter(XML.DEFAULT_INDENT);
         }
 
     }
 
     abstract protected String getPropertNameForContextMap();
 
     abstract protected String getPropertNameForSource();
 
     abstract protected String getPropertNameForNanoTime();
 
     abstract protected PrettyPrinter newCompactPrinter();
 
     abstract protected ObjectMapper newObjectMapper();
 
     abstract protected PrettyPrinter newPrettyPrinter();
 
     ObjectWriter newWriter(final boolean locationInfo, final boolean properties, final boolean compact) {
         final SimpleFilterProvider filters = new SimpleFilterProvider();
         final Set<String> except = new HashSet<>(2);
         if (!locationInfo) {
             except.add(this.getPropertNameForSource());
         }
         if (!properties) {
             except.add(this.getPropertNameForContextMap());
         }
         except.add(this.getPropertNameForNanoTime());
         filters.addFilter(Log4jLogEvent.class.getName(), SimpleBeanPropertyFilter.serializeAllExcept(except));
         final ObjectWriter writer = this.newObjectMapper().writer(compact ? this.newCompactPrinter() : this.newPrettyPrinter());
         return writer.with(filters);
     }
 
 }