/*
    * 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.log4j.layout;
  
  import java.io.PrintWriter;
  import java.io.StringWriter;
  import java.nio.charset.StandardCharsets;
  import java.util.List;
  import java.util.Objects;
  
  import org.apache.logging.log4j.core.Layout;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.Node;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
  import org.apache.logging.log4j.core.layout.AbstractStringLayout;
  import org.apache.logging.log4j.core.layout.ByteBufferDestination;
  import org.apache.logging.log4j.core.util.Transform;
  import org.apache.logging.log4j.util.ReadOnlyStringMap;
  import org.apache.logging.log4j.util.Strings;
  
  /**
   * Port of XMLLayout in Log4j 1.x. Provided for compatibility with existing Log4j 1 configurations.
   *
   * Originally developed by Ceki Gülcü, Mathias Bogaert.
   */
  @Plugin(name = "Log4j1XmlLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
  public final class Log4j1XmlLayout extends AbstractStringLayout {
  
      private final boolean locationInfo;
      private final boolean properties;
  
      @PluginFactory
      public static Log4j1XmlLayout createLayout(
              // @formatter:off
              @PluginAttribute(value = "locationInfo") final boolean locationInfo,
              @PluginAttribute(value = "properties") final boolean properties
              // @formatter:on
      ) {
          return new Log4j1XmlLayout(locationInfo, properties);
      }
  
      private Log4j1XmlLayout(final boolean locationInfo, final boolean properties) {
          super(StandardCharsets.UTF_8);
          this.locationInfo = locationInfo;
          this.properties = properties;
      }
  
      public boolean isLocationInfo() {
          return locationInfo;
      }
  
      public boolean isProperties() {
          return properties;
      }
  
      @Override
      public void encode(final LogEvent event, final ByteBufferDestination destination) {
          final StringBuilder text = getStringBuilder();
          formatTo(event, text);
          getStringBuilderEncoder().encode(text, destination);
      }
  
      @Override
      public String toSerializable(final LogEvent event) {
          final StringBuilder text = getStringBuilder();
          formatTo(event, text);
          return text.toString();
      }
  
      private void formatTo(final LogEvent event, final StringBuilder buf) {
          // We yield to the \r\n heresy.
  
          buf.append("<log4j:event logger=\"");
          buf.append(Transform.escapeHtmlTags(event.getLoggerName()));
          buf.append("\" timestamp=\"");
          buf.append(event.getTimeMillis());
          buf.append("\" level=\"");
          buf.append(Transform.escapeHtmlTags(String.valueOf(event.getLevel())));
          buf.append("\" thread=\"");
          buf.append(Transform.escapeHtmlTags(event.getThreadName()));
          buf.append("\">\r\n");
  
          buf.append("<log4j:message><![CDATA[");
         // Append the rendered message. Also make sure to escape any existing CDATA sections.
         Transform.appendEscapingCData(buf, event.getMessage().getFormattedMessage());
         buf.append("]]></log4j:message>\r\n");
 
         final List<String> ndc = event.getContextStack().asList();
         if (!ndc.isEmpty()) {
             buf.append("<log4j:NDC><![CDATA[");
             Transform.appendEscapingCData(buf, Strings.join(ndc, ' '));
             buf.append("]]></log4j:NDC>\r\n");
         }
 
         @SuppressWarnings("ThrowableResultOfMethodCallIgnored")
 		final Throwable thrown = event.getThrown();
         if (thrown != null) {
             buf.append("<log4j:throwable><![CDATA[");
             final StringWriter w = new StringWriter();
             thrown.printStackTrace(new PrintWriter(w));
             Transform.appendEscapingCData(buf, w.toString());
             buf.append("]]></log4j:throwable>\r\n");
         }
 
         if (locationInfo) {
             final StackTraceElement source = event.getSource();
             if (source != null) {
                 buf.append("<log4j:locationInfo class=\"");
                 buf.append(Transform.escapeHtmlTags(source.getClassName()));
                 buf.append("\" method=\"");
                 buf.append(Transform.escapeHtmlTags(source.getMethodName()));
                 buf.append("\" file=\"");
                 buf.append(Transform.escapeHtmlTags(source.getFileName()));
                 buf.append("\" line=\"");
                 buf.append(source.getLineNumber());
                 buf.append("\"/>\r\n");
             }
         }
 
         if (properties) {
             final ReadOnlyStringMap contextMap = event.getContextData();
             if (!contextMap.isEmpty()) {
                 buf.append("<log4j:properties>\r\n");
                 contextMap.forEach((key, val) -> {
                     if (val != null) {
                         buf.append("<log4j:data name=\"");
                         buf.append(Transform.escapeHtmlTags(key));
                         buf.append("\" value=\"");
                         buf.append(Transform.escapeHtmlTags(Objects.toString(val, null)));
                         buf.append("\"/>\r\n");
                     }
                 });
                 buf.append("</log4j:properties>\r\n");
             }
         }
 
         buf.append("</log4j:event>\r\n\r\n");
     }
 
 }