/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.classic.control;
  
  import java.util.Random;
  
  import ch.qos.logback.classic.Level;
  import ch.qos.logback.classic.corpus.RandomUtil;
  
  public class ScenarioRandomUtil {
      private final static long SEED = 74130;
  
      private final static Random random = new Random(SEED);
      private final static int AVERAGE_ID_LEN = 32;
      private final static int AVERAGE_ID_DEV = 16;
  
      private final static int AVERAGE_CHILDREN_COUNT = 30;
      private final static int CHILDREN_COUNT_VAR = 10;
  
      public static boolean oneInFreq(int freq) {
          return (random.nextInt(freq) % freq) == 0;
      }
  
      public static Level randomLevel() {
          int rl = random.nextInt(6);
          switch (rl) {
          case 0:
              return null;
          case 1:
              return Level.TRACE;
          case 2:
              return Level.DEBUG;
          case 3:
              return Level.INFO;
          case 4:
              return Level.WARN;
          case 5:
              return Level.ERROR;
          default:
              throw new IllegalStateException("rl should have been a value between 0 to 5, but it is " + rl);
          }
      }
  
      public static String randomLoggerName(int average, int stdDeviation) {
          int depth = RandomUtil.gaussianAsPositiveInt(random, average, stdDeviation);
          StringBuilder buf = new StringBuilder();
          for (int i = 0; i < depth; i++) {
              if (i != 0) {
                  buf.append('.');
              }
              buf.append(randomId());
          }
          return buf.toString();
      }
  
      public static String randomId() {
  
          int len = RandomUtil.gaussianAsPositiveInt(random, AVERAGE_ID_LEN, AVERAGE_ID_DEV);
          StringBuilder buf = new StringBuilder();
          for (int i = 0; i < len; i++) {
              int offset = random.nextInt(26);
              char c = (char) ('a' + offset);
              buf.append(c);
          }
          return buf.toString();
      }
  
      /**
       * Returns 3 for root, 3 for children of root, 9 for offspring of generation 2
       * and 3, and for generations 4 and later, return 0 with probability 0.5 and a
       * gaussian (average=AVERAGE_CHILDREN_COUNT) with probability 0.5.
       * 
       * @param name
       * @return
       */
      public static int randomChildrenCount(String name) {
          int dots = dotCount(name);
          if (dots <= 1) {
              return 3;
          } else if (dots == 2 || dots == 3) {
              return 9;
          } else {
              if (shouldHaveChildrenWithProbabilitz(0.5)) {
                  return RandomUtil.gaussianAsPositiveInt(random, AVERAGE_CHILDREN_COUNT, CHILDREN_COUNT_VAR);
              } else {
                  return 0;
              }
          }
 
     }
 
     /**
      * Returns true with probability p.
      * 
      * @param p
      * @return
      */
     static boolean shouldHaveChildrenWithProbabilitz(double p) {
         if (p < 0 || p > 1.0) {
             throw new IllegalArgumentException("p must be a value between 0 and 1.0, it was " + p + " instead.");
         }
         double r = random.nextDouble();
         if (r < p) {
             return true;
         } else {
             return false;
         }
     }
 
     static int dotCount(String s) {
         int count = 0;
         int len = s.length();
         for (int i = 0; i < len; i++) {
             char c = s.charAt(i);
             if (c == '.') {
                 count++;
             }
         }
         return count;
     }
 }