/*
    * 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.pattern;
  
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.impl.ThrowableProxy;
  
  /**
   * Outputs the Throwable portion of the LoggingEvent as a full stacktrace
   * unless this converter's option is 'short', where it just outputs the first line of the trace, or if
   * the number of lines to print is explicitly specified.
   * <p>
   * The extended stack trace will also include the location of where the class was loaded from and the
   * version of the jar if available.
   */
  @Plugin(name = "ExtendedThrowablePatternConverter", type = "Converter")
  @ConverterKeys({"xEx", "xThrowable", "xException" })
  public final class ExtendedThrowablePatternConverter extends ThrowablePatternConverter {
      /**
       * Private constructor.
       *
       * @param options options, may be null.
       */
      private ExtendedThrowablePatternConverter(final String[] options) {
          super("ExtendedThrowable", "throwable", options);
      }
  
      /**
       * Gets an instance of the class.
       *
       * @param options pattern options, may be null.  If first element is "short",
       *                only the first line of the throwable will be formatted.
       * @return instance of class.
       */
      public static ExtendedThrowablePatternConverter newInstance(
          final String[] options) {
          return new ExtendedThrowablePatternConverter(options);
      }
  
      /**
       * {@inheritDoc}
       */
      public void format(final LogEvent event, final StringBuilder toAppendTo) {
          Throwable throwable = event.getThrown();
          if (throwable != null) {
              if (!(throwable instanceof ThrowableProxy)) {
                  super.format(event, toAppendTo);
                  return;
              }
              ThrowableProxy t = (ThrowableProxy) throwable;
              String trace = t.getExtendedStackTrace();
              int len = toAppendTo.length();
              if (len > 0 && !Character.isWhitespace(toAppendTo.charAt(len - 1))) {
                  toAppendTo.append(" ");
              }
              if (lines > 0) {
                  StringBuilder sb = new StringBuilder();
                  String[] array = trace.split("\n");
                  for (int i = 0; i < lines; ++i) {
                      sb.append(array[i]).append("\n");
                  }
                  toAppendTo.append(sb.toString());
  
              } else {
                  toAppendTo.append(trace);
              }
          }
      }
  }