/*
    * 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.net.server;
  
  import java.io.InputStream;
  import java.nio.charset.Charset;
  
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.jackson.Log4jJsonObjectMapper;
  import org.apache.logging.log4j.util.Chars;
  
  /**
   * Reads and logs JSON {@link LogEvent}s from an {@link InputStream}..
   */
  public class JsonInputStreamLogEventBridge extends InputStreamLogEventBridge {
  
      private static final int[] END_PAIR = new int[] { END, END };
      private static final char EVENT_END_MARKER = '}';
      private static final char EVENT_START_MARKER = '{';
      private static final char JSON_ESC = '\\';
      private static final char JSON_STR_DELIM = Chars.DQUOTE;
  
      public JsonInputStreamLogEventBridge() {
          this(1024, Charset.defaultCharset());
      }
  
      public JsonInputStreamLogEventBridge(final int bufferSize, final Charset charset) {
          super(new Log4jJsonObjectMapper(), bufferSize, charset, String.valueOf(EVENT_END_MARKER));
      }
  
      @Override
      protected int[] getEventIndices(final String text, final int beginIndex) {
          // Scan the text for the end of the next JSON object.
          final int start = text.indexOf(EVENT_START_MARKER, beginIndex);
          if (start == END) {
              return END_PAIR;
          }
          final char[] charArray = text.toCharArray();
          int stack = 0;
          boolean inStr = false;
          boolean inEsc = false;
          for (int i = start; i < charArray.length; i++) {
              final char c = charArray[i];
              if (!inEsc) {
                  inEsc = false;
                  switch (c) {
                  case EVENT_START_MARKER:
                      if (!inStr) {
                          stack++;
                      }
                      break;
                  case EVENT_END_MARKER:
                      if (!inStr) {
                          stack--;
                      }
                      break;
                  case JSON_STR_DELIM:
                      inStr = !inStr;
                      break;
                  case JSON_ESC:
                      inEsc = true;
                      break;
                  }
                  if (stack == 0) {
                      return new int[] { start, i };
                  }
              }
          }
          return END_PAIR;
      }
  
  }