/*
    * 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 org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.util.PerformanceSensitive;
  
  /**
   * Equals pattern converter.
   */
  @PerformanceSensitive("allocation")
  public abstract class EqualsBaseReplacementConverter extends LogEventPatternConverter {
      private final List<PatternFormatter> formatters;
      private final List<PatternFormatter> substitutionFormatters;
      private final String substitution;
      private final String testString;
  
      /**
       * Construct the converter.
       *
       * @param name          converter name
       * @param style         converter style
       * @param formatters   The PatternFormatters to generate the text to manipulate.
       * @param testString   The test string.
       * @param substitution The substitution string.
       * @param parser        The PatternParser.
       */
      protected EqualsBaseReplacementConverter(final String name, final String style,
                                              final List<PatternFormatter> formatters, final String testString,
                                              final String substitution, final PatternParser parser) {
          super(name, style);
          this.testString = testString;
          this.substitution = substitution;
          this.formatters = formatters;
  
          // check if substitution needs to be parsed
          substitutionFormatters = substitution.contains("%") ? parser.parse(substitution) : null;
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void format(final LogEvent event, final StringBuilder toAppendTo) {
          final int initialSize = toAppendTo.length();
          for (int i = 0; i < formatters.size(); i++) {
              final PatternFormatter formatter = formatters.get(i);
              formatter.format(event, toAppendTo);
          }
          if (equals(testString, toAppendTo, initialSize, toAppendTo.length() - initialSize)) {
              toAppendTo.setLength(initialSize);
              parseSubstitution(event, toAppendTo);
          }
      }
  
      /**
       * Returns true if the specified String equals the specified section of the specified StringBuilder.
       *
       * @param str the String to compare
       * @param buff the StringBuilder to compare a section of
       * @param from start index in the StringBuilder
       * @param len length of the section in the StringBuilder
       * @return true if equal, false otherwise
       */
      protected abstract boolean equals(String str, StringBuilder buff, int from, int len);
  
      /**
       * Adds the parsed substitution text to the specified buffer.
       *
       * @param event the current log event
       * @param substitutionBuffer the StringBuilder to append the parsed substitution text to
       */
      void parseSubstitution(final LogEvent event, final StringBuilder substitutionBuffer) {
          if (substitutionFormatters != null) {
              for (int i = 0; i < substitutionFormatters.size(); i++) {
                  final PatternFormatter formatter = substitutionFormatters.get(i);
                  formatter.format(event, substitutionBuffer);
              }
          } else {
              substitutionBuffer.append(substitution);
          }
      }
  }