/*
    * 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.regex.Pattern;
  
  import org.apache.logging.log4j.Logger;
  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.status.StatusLogger;
  
  /**
   * Replace tokens in the LogEvent message.
   */
  @Plugin(name = "replace", category = "Core", printObject = true)
  public final class RegexReplacement {
  
      private static final Logger LOGGER = StatusLogger.getLogger();
  
      private final Pattern pattern;
  
      private final String substitution;
  
      /**
       * Private constructor.
       *
       * @param pattern The Pattern.
       * @param substitution The substitution String.
       */
      private RegexReplacement(final Pattern pattern, final String substitution) {
          this.pattern = pattern;
          this.substitution = substitution;
      }
  
      /**
       * Perform the replacement.
       * @param msg The String to match against.
       * @return the replacement String.
       */
      public String format(final String msg) {
          return pattern.matcher(msg).replaceAll(substitution);
      }
  
      @Override
      public String toString() {
          return "replace(regex=" + pattern.pattern() + ", replacement=" + substitution + ')';
      }
  
      /**
       * Create a RegexReplacement.
       * @param regex The regular expression to locate.
       * @param replacement The replacement value.
       * @return A RegexReplacement.
       */
      @PluginFactory
      public static RegexReplacement createRegexReplacement(
              @PluginAttribute("regex") final Pattern regex,
              @PluginAttribute("replacement") final String replacement) {
          if (regex == null) {
              LOGGER.error("A regular expression is required for replacement");
              return null;
          }
          if (replacement == null) {
              LOGGER.error("A replacement string is required to perform replacement");
          }
          // FIXME: should we use Matcher.quoteReplacement() here?
          return new RegexReplacement(regex, replacement);
      }
  
  }