text: // Copyright (c) 2011-2020 The XBit Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  //
  
  #include <netaddress.h>
  #include <noui.h>
  #include <test/util/logging.h>
  #include <test/util/setup_common.h>
  #include <timedata.h>
  #include <util/string.h>
  #include <util/translation.h>
  #include <warnings.h>
  
  #include <string>
  
  #include <boost/test/unit_test.hpp>
  
  BOOST_FIXTURE_TEST_SUITE(timedata_tests, BasicTestingSetup)
  
  BOOST_AUTO_TEST_CASE(util_MedianFilter)
  {
      CMedianFilter<int> filter(5, 15);
  
      BOOST_CHECK_EQUAL(filter.median(), 15);
  
      filter.input(20); // [15 20]
      BOOST_CHECK_EQUAL(filter.median(), 17);
  
      filter.input(30); // [15 20 30]
      BOOST_CHECK_EQUAL(filter.median(), 20);
  
      filter.input(3); // [3 15 20 30]
      BOOST_CHECK_EQUAL(filter.median(), 17);
  
      filter.input(7); // [3 7 15 20 30]
      BOOST_CHECK_EQUAL(filter.median(), 15);
  
      filter.input(18); // [3 7 18 20 30]
      BOOST_CHECK_EQUAL(filter.median(), 18);
  
      filter.input(0); // [0 3 7 18 30]
      BOOST_CHECK_EQUAL(filter.median(), 7);
  }
  
  static void MultiAddTimeData(int n, int64_t offset)
  {
      static int cnt = 0;
      for (int i = 0; i < n; ++i) {
          CNetAddr addr;
          addr.SetInternal(ToString(++cnt));
          AddTimeData(addr, offset);
      }
  }
  
  
  BOOST_AUTO_TEST_CASE(addtimedata)
  {
      BOOST_CHECK_EQUAL(GetTimeOffset(), 0);
  
      //Part 1: Add large offsets to test a warning message that our clock may be wrong.
      MultiAddTimeData(3, DEFAULT_MAX_TIME_ADJUSTMENT + 1);
      // Filter size is 1 + 3 = 4: It is always initialized with a single element (offset 0)
  
      {
          ASSERT_DEBUG_LOG("Please check that your computer's date and time are correct!");
          MultiAddTimeData(1, DEFAULT_MAX_TIME_ADJUSTMENT + 1); //filter size 5
      }
  
      BOOST_CHECK(GetWarnings(true).original.find("clock is wrong") != std::string::npos);
  
      // nTimeOffset is not changed if the median of offsets exceeds DEFAULT_MAX_TIME_ADJUSTMENT
      BOOST_CHECK_EQUAL(GetTimeOffset(), 0);
  
      // Part 2: Test positive and negative medians by adding more offsets
      MultiAddTimeData(4, 100); // filter size 9
      BOOST_CHECK_EQUAL(GetTimeOffset(), 100);
      MultiAddTimeData(10, -100); //filter size 19
      BOOST_CHECK_EQUAL(GetTimeOffset(), -100);
  
      // Part 3: Test behaviour when filter has reached maximum number of offsets
      const int MAX_SAMPLES = 200;
      int nfill = (MAX_SAMPLES - 3 - 19) / 2; //89
      MultiAddTimeData(nfill, 100);
      MultiAddTimeData(nfill, -100); //filter size MAX_SAMPLES - 3
      BOOST_CHECK_EQUAL(GetTimeOffset(), -100);
  
      MultiAddTimeData(2, 100);
      //filter size MAX_SAMPLES -1, median is the initial 0 offset
      //since we added same number of positive/negative offsets
  
      BOOST_CHECK_EQUAL(GetTimeOffset(), 0);
  
      // After the number of offsets has reached MAX_SAMPLES -1 (=199), nTimeOffset will never change
      // because it is only updated when the number of elements in the filter becomes odd. It was decided
      // not to fix this because it prevents possible attacks. See the comment in AddTimeData() or issue #4521
      // for a more detailed explanation.
      MultiAddTimeData(2, 100); // filter median is 100 now, but nTimeOffset will not change
      BOOST_CHECK_EQUAL(GetTimeOffset(), 0);
  
      // We want this test to end with nTimeOffset==0, otherwise subsequent tests of the suite will fail.
  }
  
  BOOST_AUTO_TEST_SUITE_END()
  