text: // Parts are Copyright (c) 2019, The Dinastycoin team
  // 
  // All rights reserved.
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  // Redistribution and use in source and binary forms, with or without modification, are
  // permitted provided that the following conditions are met:
  // 
  // 1. Redistributions of source code must retain the above copyright notice, this list of
  //    conditions and the following disclaimer.
  // 
  // 2. Redistributions in binary form must reproduce the above copyright notice, this list
  //    of conditions and the following disclaimer in the documentation and/or other
  //    materials provided with the distribution.
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  // 3. Neither the name of the copyright holder nor the names of its contributors may be
  //    used to endorse or promote products derived from this software without specific
  //    prior written permission.
  // 
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
  // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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  // THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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  // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  // 
  // Parts of this file are originally copyright (c) 2015-2019 The Monero Project
  
  #include "gtest/gtest.h"
  
  #include "cryptonote_core/blockchain.h"
  
  using namespace cryptonote;
  
  namespace
  {
    static uint64_t clamp_fee(uint64_t fee)
    {
      static uint64_t mask = 0;
      if (mask == 0)
      {
        mask = 1;
        for (size_t n = PER_KB_FEE_QUANTIZATION_DECIMALS; n < CRYPTONOTE_DISPLAY_DECIMAL_POINT; ++n)
          mask *= 10;
      }
      return (fee + mask - 1) / mask * mask;
    }
  
    //--------------------------------------------------------------------------------------------------------------------
    class fee : public ::testing::Test
    {
    };
  
    // try with blocks ~ 1GB. Passing 2 GB will break on 32 bit systems
  
    TEST_F(fee, 10dcy)
    {
      // CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 and lower are clamped
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(10000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2, 3), clamp_fee(2000000000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(10000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 / 2, 3), clamp_fee(2000000000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(10000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 / 100, 3), clamp_fee(2000000000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(10000000000000, 1, 3), 2000000000);
  
      // higher is inverse proportional
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(10000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 2, 3), clamp_fee(2000000000 / 2));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(10000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 10, 3), clamp_fee(2000000000 / 10));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(10000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 1000, 3), clamp_fee(2000000000 / 1000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(10000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 20000ull, 3), clamp_fee(2000000000 / 20000));
    }
  
    TEST_F(fee, 1dcy)
    {
      // CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 and lower are clamped
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(1000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2, 3), clamp_fee(200000000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(1000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 / 2, 3), clamp_fee(200000000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(1000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 / 100, 3), clamp_fee(200000000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(1000000000000, 1, 3), 200000000);
  
      // higher is inverse proportional
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(1000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 2, 3), clamp_fee(200000000 / 2));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(1000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 10, 3), clamp_fee(200000000 / 10));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(1000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 1000, 3), clamp_fee(200000000 / 1000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(1000000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 20000ull, 3), clamp_fee(200000000 / 20000));
    }
  
    TEST_F(fee, dot3dcy)
    {
      // CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 and lower are clamped
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(300000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2, 3), clamp_fee(60000000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(300000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 / 2, 3), clamp_fee(60000000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(300000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 / 100, 3), clamp_fee(60000000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(300000000000, 1, 3), 60000000);
  
      // higher is inverse proportional
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(300000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 2, 3), clamp_fee(60000000 / 2));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(300000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 10, 3), clamp_fee(60000000 / 10));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(300000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 1000, 3), clamp_fee(60000000 / 1000));
      ASSERT_EQ(Blockchain::get_dynamic_base_fee(300000000000, CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 20000ull, 3), clamp_fee(60000000 / 20000));
    }
  
    static bool is_more_or_less(double x, double y)
    {
      return fabs(y - x) < 0.001;
    }
  
    static const double MAX_MULTIPLIER = 166.f;
  
    TEST_F(fee, double_at_full)
    {
      static const uint64_t block_rewards[] = {
        20000000000000ull, // 20 dinastycoin
        13000000000000ull,
        1000000000000ull,
        600000000000ull, // .6 dinastycoin, minimum reward per block at 2min
        300000000000ull, // .3 dinastycoin, minimum reward per block at 1min
      };
      static const uint64_t median_block_weights[] = {
        CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2,
        CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 2,
        CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 10,
        CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 1000,
        // with clamping, the formula does not hold for such large blocks and small fees
        // CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 20000ull
      };
  
      for (uint64_t block_reward: block_rewards)
      {
        for (uint64_t median_block_weight: median_block_weights)
        {
          ASSERT_TRUE(is_more_or_less(Blockchain::get_dynamic_base_fee(block_reward, median_block_weight, 3) * (median_block_weight / 1024.) * MAX_MULTIPLIER / (double)block_reward, 1.992 * 1000 / 1024));
        }
      }
    }
  }
  