/*
    * 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 java.util.List;
  import java.util.regex.Pattern;
  
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.Configuration;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.layout.PatternLayout;
  
  /**
   * Replacement pattern converter.
   */
  @Plugin(name = "replace", category = PatternConverter.CATEGORY)
  @ConverterKeys({ "replace" })
  public final class RegexReplacementConverter extends LogEventPatternConverter {
  
      private final Pattern pattern;
  
      private final String substitution;
  
      private final List<PatternFormatter> formatters;
  
      /**
       * Construct the converter.
       * @param formatters The PatternFormatters to generate the text to manipulate.
       * @param pattern The regular expression Pattern.
       * @param substitution The substitution string.
       */
      private RegexReplacementConverter(final List<PatternFormatter> formatters,
                                        final Pattern pattern, final String substitution) {
          super("replace", "replace");
          this.pattern = pattern;
          this.substitution = substitution;
          this.formatters = formatters;
      }
  
      /**
       * Gets an instance of the class.
       *
       * @param config The current Configuration.
       * @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 RegexReplacementConverter newInstance(final Configuration config, final String[] options) {
          if (options.length != 3) {
              LOGGER.error("Incorrect number of options on replace. Expected 3 received " + options.length);
              return null;
          }
          if (options[0] == null) {
              LOGGER.error("No pattern supplied on replace");
              return null;
          }
          if (options[1] == null) {
              LOGGER.error("No regular expression supplied on replace");
              return null;
          }
          if (options[2] == null) {
              LOGGER.error("No substitution supplied on replace");
              return null;
          }
          final Pattern p = Pattern.compile(options[1]);
          final PatternParser parser = PatternLayout.createPatternParser(config);
          final List<PatternFormatter> formatters = parser.parse(options[0]);
          return new RegexReplacementConverter(formatters, p, options[2]);
      }
  
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void format(final LogEvent event, final StringBuilder toAppendTo) {
          final StringBuilder buf = new StringBuilder();
          for (final PatternFormatter formatter : formatters) {
              formatter.format(event, buf);
          }
          toAppendTo.append(pattern.matcher(buf.toString()).replaceAll(substitution));
      }
  }