text: //------------------------------------------------------------------------------
  /*
      
      Copyright (c) 2012, 2013 Ripple Labs Inc.
  
      Permission to use, copy, modify, and/or distribute this software for any
      purpose  with  or without fee is hereby granted, provided that the above
      copyright notice and this permission notice appear in all copies.
  
      THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
      MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
      ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
      WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
      ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
      OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
  //==============================================================================
  
  
  #include <ripple/app/misc/AmendmentTable.h>
  #include <ripple/basics/BasicConfig.h>
  #include <ripple/basics/chrono.h>
  #include <ripple/basics/Log.h>
  #include <ripple/beast/unit_test.h>
  #include <ripple/core/ConfigSections.h>
  #include <ripple/protocol/Feature.h>
  #include <ripple/protocol/PublicKey.h>
  #include <ripple/protocol/SecretKey.h>
  #include <ripple/protocol/digest.h>
  #include <ripple/protocol/TxFlags.h>
  #include <test/unit_test/SuiteJournal.h>
  
  namespace ripple
  {
  
  class AmendmentTable_test final : public beast::unit_test::suite
  {
  private:
      // 204/256 about 80% (we round down because the implementation rounds up)
      static int const majorityFraction{204};
  
      static
      uint256
      amendmentId (std::string in)
      {
          sha256_hasher h;
          using beast::hash_append;
          hash_append(h, in);
          auto const d = static_cast<sha256_hasher::result_type>(h);
          uint256 result;
          std::memcpy(result.data(), d.data(), d.size());
          return result;
      }
  
      static
      std::vector<std::string>
      createSet (int group, int count)
      {
          std::vector<std::string> amendments;
          for (int i = 0; i < count; i++)
              amendments.push_back (
                  "Amendment" + std::to_string ((1000000 * group) + i));
          return amendments;
      }
  
      static
      Section
      makeSection (std::vector<std::string> const& amendments)
      {
          Section section ("Test");
          for (auto const& a : amendments)
              section.append (to_string(amendmentId (a)) + " " + a);
          return section;
      }
  
      static
      Section
      makeSection (uint256 const& amendment)
      {
          Section section ("Test");
          section.append (to_string (amendment) + " " + to_string(amendment));
          return section;
      }
  
      std::vector<std::string> const m_set1;
      std::vector<std::string> const m_set2;
      std::vector<std::string> const m_set3;
      std::vector<std::string> const m_set4;
  
      Section const emptySection;
  
      test::SuiteJournal journal;
  
  public:
      AmendmentTable_test ()
          : m_set1 (createSet (1, 12))
          , m_set2 (createSet (2, 12))
          , m_set3 (createSet (3, 12))
          , m_set4 (createSet (4, 12))
          , journal ("AmendmentTable_test", *this)
      {
      }
  
      std::unique_ptr<AmendmentTable>
      makeTable(
          int w,
          Section const supported,
          Section const enabled,
          Section const vetoed)
      {
          return make_AmendmentTable (
              weeks (w),
              majorityFraction,
              supported,
              enabled,
              vetoed,
              journal);
      }
  
      std::unique_ptr<AmendmentTable>
      makeTable (int w)
      {
          return makeTable (
              w,
              makeSection (m_set1),
              makeSection (m_set2),
              makeSection (m_set3));
      }
  
      void testConstruct ()
      {
          testcase ("Construction");
  
          auto table = makeTable(1);
  
          for (auto const& a : m_set1)
          {
              BEAST_EXPECT(table->isSupported (amendmentId (a)));
              BEAST_EXPECT(!table->isEnabled (amendmentId (a)));
          }
  
          for (auto const& a : m_set2)
          {
              BEAST_EXPECT(table->isSupported (amendmentId (a)));
              BEAST_EXPECT(table->isEnabled (amendmentId (a)));
          }
  
          for (auto const& a : m_set3)
          {
              BEAST_EXPECT(!table->isSupported (amendmentId (a)));
              BEAST_EXPECT(!table->isEnabled (amendmentId (a)));
          }
      }
  
      void testGet ()
      {
          testcase ("Name to ID mapping");
  
          auto table = makeTable (1);
  
          for (auto const& a : m_set1)
              BEAST_EXPECT(table->find (a) == amendmentId (a));
          for (auto const& a : m_set2)
              BEAST_EXPECT(table->find (a) == amendmentId (a));
  
          for (auto const& a : m_set3)
              BEAST_EXPECT(!table->find (a));
          for (auto const& a : m_set4)
              BEAST_EXPECT(!table->find (a));
      }
  
      void testBadConfig ()
      {
          auto const section = makeSection (m_set1);
          auto const id = to_string (amendmentId (m_set2[0]));
  
          testcase ("Bad Config");
  
          { // Two arguments are required - we pass one
              Section test = section;
              test.append (id);
  
              try
              {
                  if (makeTable (2, test, emptySection, emptySection))
                      fail ("Accepted only amendment ID");
              }
              catch (...)
              {
                  pass();
              }
          }
  
          { // Two arguments are required - we pass three
              Section test = section;
              test.append (id + " Test Name");
  
              try
              {
                  if (makeTable (2, test, emptySection, emptySection))
                      fail ("Accepted extra arguments");
              }
              catch (...)
              {
                  pass();
              }
          }
  
          {
              auto sid = id;
              sid.resize (sid.length() - 1);
  
              Section test = section;
              test.append (sid + " Name");
  
              try
              {
                  if (makeTable (2, test, emptySection, emptySection))
                      fail ("Accepted short amendment ID");
              }
              catch (...)
              {
                  pass();
              }
          }
  
          {
              auto sid = id;
              sid.resize (sid.length() + 1, '0');
  
              Section test = section;
              test.append (sid + " Name");
  
              try
              {
                  if (makeTable (2, test, emptySection, emptySection))
                      fail ("Accepted long amendment ID");
              }
              catch (...)
              {
                  pass();
              }
          }
  
          {
              auto sid = id;
              sid.resize (sid.length() - 1);
              sid.push_back ('Q');
  
              Section test = section;
              test.append (sid + " Name");
  
              try
              {
                  if (makeTable (2, test, emptySection, emptySection))
                      fail ("Accepted non-hex amendment ID");
              }
              catch (...)
              {
                  pass();
              }
          }
      }
  
      std::map<uint256, bool>
      getState (
          AmendmentTable *table,
          std::set<uint256> const& exclude)
      {
          std::map<uint256, bool> state;
  
          auto track = [&state,table](std::vector<std::string> const& v)
          {
              for (auto const& a : v)
              {
                  auto const id = amendmentId(a);
                  state[id] = table->isEnabled (id);
              }
          };
  
          track (m_set1);
          track (m_set2);
          track (m_set3);
          track (m_set4);
  
          for (auto const& a : exclude)
              state.erase(a);
  
          return state;
      }
  
      void testEnableDisable ()
      {
          testcase ("enable & disable");
  
          auto const testAmendment = amendmentId("TestAmendment");
          auto table = makeTable (2);
  
          // Subset of amendments to enable
          std::set<uint256> enabled;
          enabled.insert (testAmendment);
          enabled.insert (amendmentId(m_set1[0]));
          enabled.insert (amendmentId(m_set2[0]));
          enabled.insert (amendmentId(m_set3[0]));
          enabled.insert (amendmentId(m_set4[0]));
  
          // Get the state before, excluding the items we'll change:
          auto const pre_state = getState (table.get(), enabled);
  
          // Enable the subset and verify
          for (auto const& a : enabled)
              table->enable (a);
  
          for (auto const& a : enabled)
              BEAST_EXPECT(table->isEnabled (a));
  
          // Disable the subset and verify
          for (auto const& a : enabled)
              table->disable (a);
  
          for (auto const& a : enabled)
              BEAST_EXPECT(!table->isEnabled (a));
  
          // Get the state after, excluding the items we changed:
          auto const post_state = getState (table.get(), enabled);
  
          // Ensure the states are identical
          auto ret = std::mismatch(
              pre_state.begin(), pre_state.end(),
              post_state.begin(), post_state.end());
  
          BEAST_EXPECT(ret.first == pre_state.end());
          BEAST_EXPECT(ret.second == post_state.end());
      }
  
      std::vector<std::pair<PublicKey,SecretKey>> makeValidators (int num)
      {
          std::vector <std::pair<PublicKey, SecretKey>> ret;
          ret.reserve (num);
          for (int i = 0; i < num; ++i)
          {
              ret.emplace_back(randomKeyPair(KeyType::secp256k1));
          }
          return ret;
      }
  
      static NetClock::time_point weekTime (weeks w)
      {
          return NetClock::time_point{w};
      }
  
      // Execute a pretend consensus round for a flag ledger
      void doRound(
          AmendmentTable& table,
          weeks week,
          std::vector <std::pair<PublicKey, SecretKey>> const& validators,
          std::vector <std::pair <uint256, int>> const& votes,
          std::vector <uint256>& ourVotes,
          std::set <uint256>& enabled,
          majorityAmendments_t& majority)
      {
          // Do a round at the specified time
          // Returns the amendments we voted for
  
          // Parameters:
          // table:      Our table of known and vetoed amendments
          // validators: The addreses of validators we trust
          // votes:      Amendments and the number of validators who vote for them
          // ourVotes:   The amendments we vote for in our validation
          // enabled:    In/out enabled amendments
          // majority:   In/our majority amendments (and when they got a majority)
  
          auto const roundTime = weekTime (week);
  
          // Build validations
          std::vector<STValidation::pointer> validations;
          validations.reserve (validators.size ());
  
          int i = 0;
          for (auto const& val : validators)
          {
              ++i;
              std::vector<uint256> field;
  
              for (auto const& amendment : votes)
              {
                  if ((256 * i) < (validators.size() * amendment.second))
                  {
                      // We vote yes on this amendment
                      field.push_back (amendment.first);
                  }
              }
  
              auto v = std::make_shared<STValidation>(
                  uint256(),
                  i,
                  uint256(),
                  roundTime,
                  val.first,
                  val.second,
                  calcNodeID(val.first),
                  true,
                  STValidation::FeeSettings{},
                  field);
  
              validations.emplace_back(v);
          }
  
          ourVotes = table.doValidation (enabled);
  
          auto actions = table.doVoting (
              roundTime, enabled, majority, validations);
          for (auto const& action : actions)
          {
              // This code assumes other validators do as we do
  
              auto const& hash = action.first;
              switch (action.second)
              {
                  case 0:
                  // amendment goes from majority to enabled
                      if (enabled.find (hash) != enabled.end ())
                          Throw<std::runtime_error> ("enabling already enabled");
                      if (majority.find (hash) == majority.end ())
                          Throw<std::runtime_error> ("enabling without majority");
                      enabled.insert (hash);
                      majority.erase (hash);
                      break;
  
                  case tfGotMajority:
                      if (majority.find (hash) != majority.end ())
                          Throw<std::runtime_error> ("got majority while having majority");
                      majority[hash] = roundTime;
                      break;
  
                  case tfLostMajority:
                      if (majority.find (hash) == majority.end ())
                          Throw<std::runtime_error> ("lost majority without majority");
                      majority.erase (hash);
                      break;
  
                  default:
                      Throw<std::runtime_error> ("unknown action");
              }
          }
      }
  
      // No vote on unknown amendment
      void testNoOnUnknown ()
      {
          testcase ("Vote NO on unknown");
  
          auto const testAmendment = amendmentId("TestAmendment");
          auto const validators = makeValidators (10);
  
          auto table = makeTable (2,
              emptySection,
              emptySection,
              emptySection);
  
          std::vector <std::pair <uint256, int>> votes;
          std::vector <uint256> ourVotes;
          std::set <uint256> enabled;
          majorityAmendments_t majority;
  
          doRound (*table, weeks{1},
              validators,
              votes,
              ourVotes,
              enabled,
              majority);
          BEAST_EXPECT(ourVotes.empty());
          BEAST_EXPECT(enabled.empty());
          BEAST_EXPECT(majority.empty());
  
          votes.emplace_back (testAmendment, 256);
  
          doRound (*table, weeks{2},
                  validators,
                  votes,
                  ourVotes,
                  enabled,
                  majority);
          BEAST_EXPECT(ourVotes.empty());
          BEAST_EXPECT(enabled.empty());
  
          majority[testAmendment] = weekTime(weeks{1});
  
          // Note that the simulation code assumes others behave as we do,
          // so the amendment won't get enabled
          doRound (*table, weeks{5},
                  validators,
                  votes,
                  ourVotes,
                  enabled,
                  majority);
          BEAST_EXPECT(ourVotes.empty());
          BEAST_EXPECT(enabled.empty());
      }
  
      // No vote on vetoed amendment
      void testNoOnVetoed ()
      {
          testcase ("Vote NO on vetoed");
  
          auto const testAmendment = amendmentId ("vetoedAmendment");
  
          auto table = makeTable (2,
              emptySection,
              emptySection,
              makeSection (testAmendment));
  
          auto const validators = makeValidators (10);
  
          std::vector <std::pair <uint256, int>> votes;
          std::vector <uint256> ourVotes;
          std::set <uint256> enabled;
          majorityAmendments_t majority;
  
          doRound (*table, weeks{1},
              validators,
              votes,
              ourVotes,
              enabled,
              majority);
          BEAST_EXPECT(ourVotes.empty());
          BEAST_EXPECT(enabled.empty());
          BEAST_EXPECT(majority.empty());
  
          votes.emplace_back (testAmendment, 256);
  
          doRound (*table, weeks{2},
                  validators,
                  votes,
                  ourVotes,
                  enabled,
                  majority);
          BEAST_EXPECT(ourVotes.empty());
          BEAST_EXPECT(enabled.empty());
  
          majority[testAmendment] = weekTime(weeks{1});
  
          doRound (*table, weeks{5},
                  validators,
                  votes,
                  ourVotes,
                  enabled,
                  majority);
          BEAST_EXPECT(ourVotes.empty());
          BEAST_EXPECT(enabled.empty());
      }
  
      // Vote on and enable known, not-enabled amendment
      void testVoteEnable ()
      {
          testcase ("voteEnable");
  
          auto table = makeTable (
              2,
              makeSection (m_set1),
              emptySection,
              emptySection);
  
          auto const validators = makeValidators (10);
          std::vector <std::pair <uint256, int>> votes;
          std::vector <uint256> ourVotes;
          std::set <uint256> enabled;
          majorityAmendments_t majority;
  
          // Week 1: We should vote for all known amendments not enabled
          doRound (*table, weeks{1},
              validators,
              votes,
              ourVotes,
              enabled,
              majority);
          BEAST_EXPECT(ourVotes.size() == m_set1.size());
          BEAST_EXPECT(enabled.empty());
          for (auto const& i : m_set1)
              BEAST_EXPECT(majority.find(amendmentId (i)) == majority.end());
  
          // Now, everyone votes for this feature
          for (auto const& i : m_set1)
              votes.emplace_back (amendmentId(i), 256);
  
          // Week 2: We should recognize a majority
          doRound (*table, weeks{2},
                  validators,
                  votes,
                  ourVotes,
                  enabled,
                  majority);
          BEAST_EXPECT(ourVotes.size() == m_set1.size());
          BEAST_EXPECT(enabled.empty());
  
          for (auto const& i : m_set1)
              BEAST_EXPECT(majority[amendmentId (i)] == weekTime(weeks{2}));
  
          // Week 5: We should enable the amendment
          doRound (*table, weeks{5},
                  validators,
                  votes,
                  ourVotes,
                  enabled,
                  majority);
          BEAST_EXPECT(enabled.size() == m_set1.size());
  
          // Week 6: We should remove it from our votes and from having a majority
          doRound (*table, weeks{6},
                  validators,
                  votes,
                  ourVotes,
                  enabled,
                  majority);
          BEAST_EXPECT(enabled.size() == m_set1.size());
          BEAST_EXPECT(ourVotes.empty());
          for (auto const& i : m_set1)
              BEAST_EXPECT(majority.find(amendmentId (i)) == majority.end());
      }
  
      // Detect majority at 80%, enable later
      void testDetectMajority ()
      {
          testcase ("detectMajority");
  
          auto const testAmendment = amendmentId ("detectMajority");
          auto table = makeTable (
              2,
              makeSection (testAmendment),
              emptySection,
              emptySection);
  
          auto const validators = makeValidators (16);
  
          std::set <uint256> enabled;
          majorityAmendments_t majority;
  
          for (int i = 0; i <= 17; ++i)
          {
              std::vector <std::pair <uint256, int>> votes;
              std::vector <uint256> ourVotes;
  
              if ((i > 0) && (i < 17))
                  votes.emplace_back (testAmendment, i * 16);
  
              doRound (*table, weeks{i},
                  validators, votes, ourVotes, enabled, majority);
  
              if (i < 13)
              {
                  // We are voting yes, not enabled, no majority
                  BEAST_EXPECT(!ourVotes.empty());
                  BEAST_EXPECT(enabled.empty());
                  BEAST_EXPECT(majority.empty());
              }
              else if (i < 15)
              {
                  // We have a majority, not enabled, keep voting
                  BEAST_EXPECT(!ourVotes.empty());
                  BEAST_EXPECT(!majority.empty());
                  BEAST_EXPECT(enabled.empty());
              }
              else if (i == 15)
              {
                  // enable, keep voting, remove from majority
                  BEAST_EXPECT(!ourVotes.empty());
                  BEAST_EXPECT(majority.empty());
                  BEAST_EXPECT(!enabled.empty());
              }
              else
              {
                  // Done, we should be enabled and not voting
                  BEAST_EXPECT(ourVotes.empty());
                  BEAST_EXPECT(majority.empty());
                  BEAST_EXPECT(!enabled.empty());
              }
          }
      }
  
      // Detect loss of majority
      void testLostMajority ()
      {
          testcase ("lostMajority");
  
          auto const testAmendment = amendmentId ("lostMajority");
          auto const validators = makeValidators (16);
  
          auto table = makeTable (
              8,
              makeSection (testAmendment),
              emptySection,
              emptySection);
  
          std::set <uint256> enabled;
          majorityAmendments_t majority;
  
          {
              // establish majority
              std::vector <std::pair <uint256, int>> votes;
              std::vector <uint256> ourVotes;
  
              votes.emplace_back (testAmendment, 250);
  
              doRound (*table, weeks{1},
                  validators, votes, ourVotes, enabled, majority);
  
              BEAST_EXPECT(enabled.empty());
              BEAST_EXPECT(!majority.empty());
          }
  
          for (int i = 1; i < 16; ++i)
          {
              std::vector <std::pair <uint256, int>> votes;
              std::vector <uint256> ourVotes;
  
              // Gradually reduce support
              votes.emplace_back (testAmendment, 256 - i * 8);
  
              doRound (*table, weeks{i + 1},
                  validators, votes, ourVotes, enabled, majority);
  
              if (i < 8)
              {
                  // We are voting yes, not enabled, majority
                  BEAST_EXPECT(!ourVotes.empty());
                  BEAST_EXPECT(enabled.empty());
                  BEAST_EXPECT(!majority.empty());
              }
              else
              {
                  // No majority, not enabled, keep voting
                  BEAST_EXPECT(!ourVotes.empty());
                  BEAST_EXPECT(majority.empty());
                  BEAST_EXPECT(enabled.empty());
              }
          }
      }
  
      void testHasUnsupported ()
      {
          testcase ("hasUnsupportedEnabled");
  
          auto table = makeTable(1);
          BEAST_EXPECT(! table->hasUnsupportedEnabled());
  
          std::set <uint256> enabled;
          std::for_each(m_set4.begin(), m_set4.end(),
              [&enabled](auto const &s){ enabled.insert(amendmentId(s)); });
          table->doValidatedLedger(1, enabled);
          BEAST_EXPECT(table->hasUnsupportedEnabled());
      }
  
      void run () override
      {
          testConstruct();
          testGet ();
          testBadConfig ();
          testEnableDisable ();
          testNoOnUnknown ();
          testNoOnVetoed ();
          testVoteEnable ();
          testDetectMajority ();
          testLostMajority ();
          testHasUnsupported ();
      }
  };
  
  BEAST_DEFINE_TESTSUITE (AmendmentTable, app, ripple);
  
  }  // ripple
  