/*
    * 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.appender.rolling;
  
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.config.plugins.PluginAttr;
  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
  import org.apache.logging.log4j.status.StatusLogger;
  
  import java.text.NumberFormat;
  import java.text.ParseException;
  import java.util.Locale;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  /**
   *
   */
  @Plugin(name = "SizeBasedTriggeringPolicy", type = "Core", printObject = true)
  public class SizeBasedTriggeringPolicy implements TriggeringPolicy {
      /**
       * Allow subclasses access to the status logger without creating another instance.
       */
      protected static final Logger LOGGER = StatusLogger.getLogger();
  
      private static final long KB = 1024;
      private static final long MB = KB * KB;
      private static final long GB = KB * MB;
  
      /**
       * Rollover threshold size in bytes.
       */
      private static final long MAX_FILE_SIZE = 10 * 1024 * 1024; // let 10 MB the default max size
  
  
      /**
       * Pattern for string parsing.
       */
      private static final Pattern VALUE_PATTERN =
          Pattern.compile("([0-9]+([\\.,][0-9]+)?)\\s*(|K|M|G)B?", Pattern.CASE_INSENSITIVE);
  
      private final long maxFileSize;
  
      private RollingFileManager manager;
  
      /**
       * Constructs a new instance.
       */
      protected SizeBasedTriggeringPolicy() {
          this.maxFileSize = MAX_FILE_SIZE;
      }
  
      /**
       * Constructs a new instance.
       *
       * @param maxFileSize rollover threshold size in bytes.
       */
      protected SizeBasedTriggeringPolicy(final long maxFileSize) {
          this.maxFileSize = maxFileSize;
      }
  
      /**
       * Initialize the TriggeringPolicy.
       * @param manager The RollingFileManager.
       */
      public void initialize(RollingFileManager manager) {
          this.manager = manager;
      }
  
  
      /**
       * Returns true if a rollover should occur.
       * @param event   A reference to the currently event.
       * @return true if a rollover should take place, false otherwise.
       */
      public boolean isTriggeringEvent(LogEvent event) {
          return manager.getFileSize() > maxFileSize;
      }
  
      @Override
      public String toString() {
          return "SizeBasedTriggeringPolicy(size=" + maxFileSize + ")";
      }
 
     /**
      * Create a SizeBasedTriggeringPolicy.
      * @param size The size of the file before rollover is required.
      * @return A SizeBasedTriggeringPolicy.
      */
     @PluginFactory
     public static SizeBasedTriggeringPolicy createPolicy(@PluginAttr("size") String size) {
 
         long maxSize = size == null ? MAX_FILE_SIZE : valueOf(size);
         return new SizeBasedTriggeringPolicy(maxSize);
     }
 
     /**
      * Converts a string to a number of bytes. Strings consist of a floating point value followed by
      * K, M, or G for kilobytes, megabytes, gigabytes, respectively. The
      * abbreviations KB, MB, and GB are also accepted. Matching is case insensitive.
      *
      * @param string The string to convert
      * @return The Bytes value for the string
      */
     private static long valueOf(final String string) {
         final Matcher matcher = VALUE_PATTERN.matcher(string);
 
         // Valid input?
         if (matcher.matches()) {
             try {
                 // Get double precision value
                 final long value = NumberFormat.getNumberInstance(Locale.getDefault()).parse(
                     matcher.group(1)).longValue();
 
                 // Get units specified
                 final String units = matcher.group(3);
 
                 if (units.equalsIgnoreCase("")) {
                     return value;
                 } else if (units.equalsIgnoreCase("K")) {
                     return value * KB;
                 } else if (units.equalsIgnoreCase("M")) {
                     return value * MB;
                 } else if (units.equalsIgnoreCase("G")) {
                     return value * GB;
                 } else {
                     LOGGER.error("Units not recognized: " + string);
                     return MAX_FILE_SIZE;
                 }
             } catch (ParseException e) {
                 LOGGER.error("Unable to parse numeric part: " + string, e);
                 return MAX_FILE_SIZE;
             }
         } else {
             LOGGER.error("Unable to parse bytes: " + string);
             return MAX_FILE_SIZE;
         }
     }
 }