/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */

/*
 *  Main authors:
 *     Guido Tack <guido.tack@monash.edu>
 *     Gleb Belov <gleb.belov@monash.edu>
 */

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* This (main) file coordinates flattening and solving.
 * The corresponding modules are flexibly plugged in
 * as derived classes, prospectively from DLLs.
 * A flattening module should provide MinZinc::GetFlattener()
 * A solving module should provide an object of a class derived from SolverFactory.
 * Need to get more flexible for multi-pass & multi-solving stuff  TODO
 */

#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#endif

#include <minizinc/param_config.hh>
#include <minizinc/solver.hh>

#include <chrono>
#include <cstdlib>
#include <ctime>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <ratio>

#ifdef HAS_GUROBI
#include <minizinc/solvers/MIP/MIP_gurobi_solverfactory.hh>
#endif
#ifdef HAS_CPLEX
#include <minizinc/solvers/MIP/MIP_cplex_solverfactory.hh>
#endif
#ifdef HAS_OSICBC
#include <minizinc/solvers/MIP/MIP_osicbc_solverfactory.hh>
#endif
#ifdef HAS_XPRESS
#include <minizinc/solvers/MIP/MIP_xpress_solverfactory.hh>
#endif
#ifdef HAS_GECODE
#include <minizinc/solvers/gecode_solverfactory.hh>
#endif
#ifdef HAS_GEAS
#include <minizinc/solvers/geas_solverfactory.hh>
#endif
#ifdef HAS_SCIP
#include <minizinc/solvers/MIP/MIP_scip_solverfactory.hh>
#endif
#include <minizinc/solvers/fzn_solverfactory.hh>
#include <minizinc/solvers/fzn_solverinstance.hh>
#include <minizinc/solvers/mzn_solverfactory.hh>
#include <minizinc/solvers/mzn_solverinstance.hh>
#include <minizinc/solvers/nl/nl_solverfactory.hh>
#include <minizinc/solvers/nl/nl_solverinstance.hh>

using namespace std;
using namespace MiniZinc;

SolverInitialiser::SolverInitialiser() {
#ifdef HAS_GUROBI
  GurobiSolverFactoryInitialiser _gurobi_init;
#endif
#ifdef HAS_CPLEX
  static CplexSolverFactoryInitialiser _cplex_init;
#endif
#ifdef HAS_OSICBC
  static OSICBCSolverFactoryInitialiser _osicbc_init;
#endif
#ifdef HAS_XPRESS
  static XpressSolverFactoryInitialiser _xpress_init;
#endif
#ifdef HAS_GECODE
  static GecodeSolverFactoryInitialiser _gecode_init;
#endif
#ifdef HAS_GEAS
  static GeasSolverFactoryInitialiser _geas_init;
#endif
#ifdef HAS_SCIP
  static SCIPSolverFactoryInitialiser _scip_init;
#endif
  static FZNSolverFactoryInitialiser _fzn_init;
  static MZNSolverFactoryInitialiser _mzn_init;
  static NLSolverFactoryInitialiser _nl_init;
}

MZNFZNSolverFlag MZNFZNSolverFlag::std(const std::string& n0) {
  const std::string argFlags("-I -n -p -r -n-o");
  if (argFlags.find(n0) != std::string::npos) {
    return MZNFZNSolverFlag(FT_ARG, n0);
  }
  return MZNFZNSolverFlag(FT_NOARG, n0);
}

MZNFZNSolverFlag MZNFZNSolverFlag::extra(const SolverConfig::ExtraFlag& ef) {
  return MZNFZNSolverFlag(
      ef.flagType == SolverConfig::ExtraFlag::FlagType::T_BOOL && ef.range.empty() ? FT_NOARG
                                                                                   : FT_ARG,
      ef.flag);
}

// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
SolverRegistry* MiniZinc::get_global_solver_registry() {
  static SolverRegistry sr;
  return &sr;
}

void SolverRegistry::addSolverFactory(SolverFactory* pSF) {
  assert(pSF);
  _sfstorage.push_back(pSF);
}

void SolverRegistry::removeSolverFactory(SolverFactory* pSF) {
  auto it = find(_sfstorage.begin(), _sfstorage.end(), pSF);
  assert(pSF);
  _sfstorage.erase(it);
}

void SolverRegistry::addFactoryFlag(const std::string& flag, SolverFactory* sf) {
  assert(sf);
  _factoryFlagStorage.push_back(std::make_pair(flag, sf));
}

void SolverRegistry::removeFactoryFlag(const std::string& flag, SolverFactory* sf) {
  assert(sf);
  auto it = find(_factoryFlagStorage.begin(), _factoryFlagStorage.end(), std::make_pair(flag, sf));
  _factoryFlagStorage.erase(it);
}

/// Function createSI also adds each SI to the local storage
SolverInstanceBase* SolverFactory::createSI(Env& env, std::ostream& log,
                                            SolverInstanceBase::Options* opt) {
  SolverInstanceBase* pSI = doCreateSI(env, log, opt);
  if (pSI == nullptr) {
    throw InternalError("SolverFactory: failed to initialize solver " + getDescription());
  }
  _sistorage.resize(_sistorage.size() + 1);
  _sistorage.back().reset(pSI);
  return pSI;
}

/// also providing a destroy function for a DLL or just special allocator etc.
void SolverFactory::destroySI(SolverInstanceBase* pSI) {
  auto it = _sistorage.begin();
  for (; it != _sistorage.end(); ++it) {
    if (it->get() == pSI) {
      break;
    }
  }
  if (_sistorage.end() == it) {
    cerr << "  SolverFactory: failed to remove solver at " << pSI << endl;
    throw InternalError("  SolverFactory: failed to remove solver");
  }
  _sistorage.erase(it);
}

MznSolver::MznSolver(std::ostream& os0, std::ostream& log0)
    : _solverConfigs(log0),
      _flt(os0, log0, _solverConfigs.mznlibDir()),
      _executableName("<executable>"),
      _os(os0),
      _log(log0),
      s2out(os0, log0, _solverConfigs.mznlibDir()) {}

MznSolver::~MznSolver() {
  //   if (si)                         // first the solver
  //     CleanupSolverInterface(si);
  // TODO cleanup the used solver interfaces
  _si = nullptr;
  _siOpt = nullptr;
  GC::trigger();
}

bool MznSolver::ifMzn2Fzn() const { return _isMzn2fzn; }

bool MznSolver::ifSolns2out() const { return s2out.opt.flagStandaloneSolns2Out; }

void MznSolver::addSolverInterface(SolverFactory* sf) {
  _si = sf->createSI(*_flt.getEnv(), _log, _siOpt);
  assert(_si);
  if (s2out.getEnv() == nullptr) {
    s2out.initFromEnv(_flt.getEnv());
  }
  _si->setSolns2Out(&s2out);
  if (flagCompilerVerbose) {
    _log
        //     << "  ---------------------------------------------------------------------------\n"
        << "      % SOLVING PHASE\n"
        << sf->getDescription(_siOpt) << endl;
  }
}

void MznSolver::addSolverInterface() {
  GCLock lock;
  if (_sf == nullptr) {
    if (get_global_solver_registry()->getSolverFactories().empty()) {
      _log << " MznSolver: NO SOLVER FACTORIES LINKED." << endl;
      assert(0);
    }
    _sf = get_global_solver_registry()->getSolverFactories().back();
  }
  addSolverInterface(_sf);
}

void MznSolver::printUsage() {
  _os << _executableName << ": ";
  if (ifMzn2Fzn()) {
    _os << "MiniZinc to FlatZinc converter.\n"
        << "Usage: " << _executableName
        << "  [<options>] [-I <include path>] <model>.mzn [<data>.dzn ...]" << std::endl;
  } else if (ifSolns2out()) {
    _os << "Solutions to output translator.\n"
        << "Usage: " << _executableName << "  [<options>] <model>.ozn" << std::endl;
  } else {
    _os << "MiniZinc driver.\n"
        << "Usage: " << _executableName
        << "  [<options>] [-I <include path>] <model>.mzn [<data>.dzn ...] or just <flat>.fzn"
        << std::endl;
  }
}

void MznSolver::printHelp(const std::string& selectedSolver) {
  printUsage();
  _os << "General options:" << std::endl
      << "  --help, -h\n    Print this help message." << std::endl
      << "  --version\n    Print version information." << std::endl
      << "  --solvers\n    Print list of available solvers." << std::endl
      << "  --time-limit <ms>\n    Stop after <ms> milliseconds (includes compilation and solving)."
      << std::endl
      << "  --solver <solver id>, --solver <solver config file>.msc\n    Select solver to use."
      << std::endl
      << "  --help <solver id>\n    Print help for a particular solver." << std::endl
      << "  -v, -l, --verbose\n    Print progress/log statements. Note that some solvers may log "
         "to "
         "stdout."
      << std::endl
      << "  --verbose-compilation\n    Print progress/log statements for compilation." << std::endl
      << "  -s, --statistics\n    Print statistics." << std::endl
      << "  --compiler-statistics\n    Print statistics for compilation." << std::endl
      << "  -c, --compile\n    Compile only (do not run solver)." << std::endl
      << "  --config-dirs\n    Output configuration directories." << std::endl
      << "  --param-file <file>\n    Load parameters from the given JSON file." << std::endl;

  if (selectedSolver.empty()) {
    _flt.printHelp(_os);
    _os << endl;
    if (!ifMzn2Fzn()) {
      Solns2Out::printHelp(_os);
      _os << endl;
    }
    _os << "Available solvers (get help using --help <solver id>):" << endl;
    std::vector<std::string> solvers = _solverConfigs.solvers();
    if (solvers.empty()) {
      cout << "  none.\n";
    }
    for (auto& solver : solvers) {
      cout << "  " << solver << endl;
    }
  } else {
    const SolverConfig& sc = _solverConfigs.config(selectedSolver);
    string solverId = sc.executable().empty() ? sc.id()
                                              : (sc.supportsMzn() ? string("org.minizinc.mzn-mzn")
                                                                  : string("org.minizinc.mzn-fzn"));
    bool found = false;
    for (auto it = get_global_solver_registry()->getSolverFactories().rbegin();
         it != get_global_solver_registry()->getSolverFactories().rend(); ++it) {
      if ((*it)->getId() == solverId) {
        _os << endl;
        (*it)->printHelp(_os);
        if (!sc.executable().empty() && !sc.extraFlags().empty()) {
          _os << "Extra solver flags (use with ";
          _os << (sc.supportsMzn() ? "--mzn-flags" : "--fzn-flags") << ")" << endl;
          for (const SolverConfig::ExtraFlag& ef : sc.extraFlags()) {
            _os << "  " << ef.flag << endl << "    " << ef.description << endl;
          }
        }
        found = true;
      }
    }
    if (!found) {
      _os << "No help found for solver " << selectedSolver << endl;
    }
  }
}

void add_flags(const std::string& sep, const std::vector<std::string>& in_args,
               std::vector<std::string>& out_args) {
  for (const std::string& arg : in_args) {
    out_args.push_back(sep);
    out_args.push_back(arg);
  }
}

MznSolver::OptionStatus MznSolver::processOptions(std::vector<std::string>& argv) {
  _executableName = argv[0];
  _executableName = _executableName.substr(_executableName.find_last_of("/\\") + 1);
  size_t lastdot = _executableName.find_last_of('.');
  if (lastdot != std::string::npos) {
    _executableName = _executableName.substr(0, lastdot);
  }
  string solver;
  bool load_params = false;
  bool mzn2fzn_exe = (_executableName == "mzn2fzn");
  if (mzn2fzn_exe) {
    _isMzn2fzn = true;
  } else if (_executableName == "solns2out") {
    s2out.opt.flagStandaloneSolns2Out = true;
    flagIsSolns2out = true;
  }
  bool compileSolutionChecker = false;
  int i = 1;
  int j = 1;
  int argc = static_cast<int>(argv.size());
  std::vector<std::string> workingDirs = {""};
  if (argc < 2) {
    return OPTION_ERROR;
  }

  // Add params from a file if necessary
  std::vector<std::string> paramFiles;
  for (i = 1; i < argc; ++i) {
    string paramFile;
    bool usedFlag = false;
    bool pushWorkingDir = true;

    if (argv[i] == "--param-file") {
      usedFlag = true;
      ++i;
      if (i == argc) {
        _log << "Argument required for --param-file" << endl;
        return OPTION_ERROR;
      }
      paramFile = argv[i];
    } else if (argv[i] == "--param-file-no-push") {
      usedFlag = true;
      pushWorkingDir = false;
      ++i;
      if (i == argc) {
        _log << "Argument required for --param-file-no-push" << endl;
        return OPTION_ERROR;
      }
      paramFile = argv[i];
    } else if (argv[i] == "--push-working-directory") {
      ++i;
      workingDirs.push_back(argv[i]);
    } else if (argv[i] == "--pop-working-directory") {
      workingDirs.pop_back();
    } else {
      size_t last_dot = argv[i].find_last_of('.');
      if (last_dot != string::npos && argv[i].substr(last_dot, string::npos) == ".mpc") {
        paramFile = argv[i];
      }
    }

    if (!paramFile.empty()) {
      try {
        auto paramFilePath = FileUtils::file_path(paramFile, workingDirs.back());
        if (std::find(paramFiles.begin(), paramFiles.end(), paramFilePath) != paramFiles.end()) {
          throw ParamException("Cyclic parameter configuration file");
        }
        // add parameter file arguments
        ParamConfig pc;
        pc.blacklist(
            {"--solvers", "--solvers-json", "--solver-json", "--help", "-h", "--config-dirs"});
        pc.negatedFlag("-i", "-n-i");
        pc.negatedFlag("--intermediate", "--no-intermediate");
        pc.negatedFlag("--intermediate-solutions", "--no-intermediate-solutions");
        pc.negatedFlag("--all-satisfaction", "--disable-all-satisfaction");
        pc.load(paramFilePath);

        // Insert the new options
        auto toInsert = pc.argv();
        auto remove = argv.begin() + (usedFlag ? i - 1 : i);
        auto position = argv.erase(remove, argv.begin() + i + 1);
        if (pushWorkingDir) {
          position =
              argv.insert(position, {"--push-working-directory",
                                     FileUtils::file_path(FileUtils::dir_name(paramFilePath))}) +
              2;
        }
        position = argv.insert(position, toInsert.begin(), toInsert.end()) + toInsert.size();
        if (pushWorkingDir) {
          position = argv.insert(position, "--pop-working-directory") + 1;
        }
        paramFiles.push_back(paramFilePath);
        argc = argv.size();

        // Have to process the newly added options
        if (usedFlag) {
          i -= 2;
        } else {
          i--;
        }
      } catch (ParamException& e) {
        _log << "Solver parameter exception: " << e.msg() << endl;
        return OPTION_ERROR;
      }
    }
  }

  // Process any registered factory flags
  const auto& factoryFlags = get_global_solver_registry()->getFactoryFlags();
  std::unordered_map<std::string, std::vector<std::string>> reducedSolverDefaults;
  if (!factoryFlags.empty()) {
    // Process solver default factory flags
    for (const auto& factoryFlag : factoryFlags) {
      auto factoryId = factoryFlag.second->getId();
      if (reducedSolverDefaults.count(factoryId) == 0) {
        reducedSolverDefaults.insert({factoryId, _solverConfigs.defaultOptions(factoryId)});
      }
      auto& defaultArgs = reducedSolverDefaults.find(factoryId)->second;
      std::vector<std::string> keep;
      for (i = 0; i < defaultArgs.size(); i++) {
        if (defaultArgs[i] != factoryFlag.first ||
            !factoryFlag.second->processFactoryOption(i, defaultArgs)) {
          keep.push_back(defaultArgs[i]);
        }
      }
      defaultArgs = keep;
    }
    // Process command line factory flags
    std::vector<std::string> remaining = {argv[0]};
    for (i = 1; i < argc; i++) {
      bool ok = false;
      if (argv[i] == "--push-working-directory") {
        remaining.push_back(argv[i]);
        i++;
        workingDirs.push_back(argv[i]);
      } else if (argv[i] == "--pop-working-directory") {
        workingDirs.pop_back();
      } else {
        for (const auto& factoryFlag : factoryFlags) {
          if (argv[i] == factoryFlag.first &&
              factoryFlag.second->processFactoryOption(i, argv, workingDirs.back())) {
            ok = true;
            break;
          }
        }
      }
      if (!ok) {
        remaining.push_back(argv[i]);
      }
    }
    argv = remaining;
    argc = remaining.size();
  }
  for (auto* sf : get_global_solver_registry()->getSolverFactories()) {
    // Notify solver factories that factory flags are done
    sf->factoryOptionsFinished();
  }

  // After this point all solver configurations must be available
  _solverConfigs.populate(_log);

  for (i = 1; i < argc; ++i) {
    if (argv[i] == "-h" || argv[i] == "--help") {
      if (argc > i + 1) {
        printHelp(argv[i + 1]);
      } else {
        printHelp();
      }
      return OPTION_FINISH;
    }
    if (argv[i] == "--version") {
      Flattener::printVersion(cout);
      return OPTION_FINISH;
    }
    if (argv[i] == "--solvers") {
      cout << "MiniZinc driver.\nAvailable solver configurations:\n";
      std::vector<std::string> solvers = _solverConfigs.solvers();
      if (solvers.empty()) {
        cout << "  none.\n";
      }
      for (auto& solver : solvers) {
        cout << "  " << solver << endl;
      }
      cout << "Search path for solver configurations:\n";
      for (const string& p : _solverConfigs.solverConfigsPath()) {
        cout << "  " << p << endl;
      }
      return OPTION_FINISH;
    }
    if (argv[i] == "--solvers-json") {
      cout << _solverConfigs.solverConfigsJSON();
      return OPTION_FINISH;
    }
    if (argv[i] == "--solver-json") {
      ++i;
      if (i == argc) {
        _log << "Argument required for --solver-json" << endl;
        return OPTION_ERROR;
      }
      if (!solver.empty() && solver != argv[i]) {
        _log << "Only one --solver-json option allowed" << endl;
        return OPTION_ERROR;
      }
      solver = argv[i];
      const SolverConfig& sc = _solverConfigs.config(solver);
      cout << sc.toJSON(_solverConfigs);
      return OPTION_FINISH;
    }
    if (argv[i] == "--config-dirs") {
      GCLock lock;
      cout << "{\n";
      cout << "  \"globalConfigFile\" : \""
           << Printer::escapeStringLit(FileUtils::global_config_file()) << "\",\n";
      cout << "  \"userConfigFile\" : \"" << Printer::escapeStringLit(FileUtils::user_config_file())
           << "\",\n";
      cout << "  \"userSolverConfigDir\" : \""
           << Printer::escapeStringLit(FileUtils::user_config_dir()) << "/solvers\",\n";
      cout << "  \"mznStdlibDir\" : \"" << Printer::escapeStringLit(_solverConfigs.mznlibDir())
           << "\"\n";
      cout << "}\n";
      return OPTION_FINISH;
    }
    if (argv[i] == "--time-limit") {
      ++i;
      if (i == argc) {
        _log << "Argument required for --time-limit" << endl;
        return OPTION_ERROR;
      }
      flagOverallTimeLimit = atoi(argv[i].c_str());
    } else if (argv[i] == "--solver") {
      ++i;
      if (i == argc) {
        _log << "Argument required for --solver" << endl;
        return OPTION_ERROR;
      }
      if (!solver.empty() && solver != argv[i]) {
        _log << "Only one --solver option allowed" << endl;
        return OPTION_ERROR;
      }
      solver = argv[i];
    } else if (argv[i] == "-c" || argv[i] == "--compile") {
      _isMzn2fzn = true;
    } else if (argv[i] == "-v" || argv[i] == "--verbose" || argv[i] == "-l") {
      flagVerbose = true;
      flagCompilerVerbose = true;
    } else if (argv[i] == "--verbose-compilation") {
      flagCompilerVerbose = true;
    } else if (argv[i] == "-s" || argv[i] == "--statistics") {
      flagStatistics = true;
      flagCompilerStatistics = true;
    } else if (argv[i] == "--compiler-statistics") {
      flagCompilerStatistics = true;
    } else {
      if ((argv[i] == "--fzn-cmd" || argv[i] == "--flatzinc-cmd") && solver.empty()) {
        solver = "org.minizinc.mzn-fzn";
      }
      if (argv[i] == "--compile-solution-checker") {
        compileSolutionChecker = true;
      }
      if (argv[i] == "--ozn-file") {
        flagIsSolns2out = true;
      }
      argv[j++] = argv[i];
    }
  }
  argv.resize(j);
  argc = j;

  if ((mzn2fzn_exe || compileSolutionChecker) && solver.empty()) {
    solver = "org.minizinc.mzn-fzn";
  }

  if (flagVerbose) {
    argv.emplace_back("--verbose-solving");
    argc++;
  }
  if (flagStatistics) {
    argv.emplace_back("--solver-statistics");
    argc++;
  }

  _flt.setFlagOutputByDefault(ifMzn2Fzn());

  bool isMznMzn = false;

  if (!flagIsSolns2out) {
    try {
      const SolverConfig& sc = _solverConfigs.config(solver);
      string solverId;
      if (sc.executable().empty()) {
        solverId = sc.id();
      } else if (sc.supportsMzn()) {
        solverId = "org.minizinc.mzn-mzn";
      } else if (sc.supportsFzn()) {
        solverId = "org.minizinc.mzn-fzn";
      } else if (sc.supportsNL()) {
        solverId = "org.minizinc.mzn-nl";
      } else {
        _log << "Selected solver does not support MiniZinc, FlatZinc or NL input." << endl;
        return OPTION_ERROR;
      }

      // Check support of -a and -i
      for (const auto& flag : sc.stdFlags()) {
        if (flag == "-a") {
          _supportsA = true;
        } else if (flag == "-i") {
          _supportsI = true;
        }
      }

      for (auto* it : get_global_solver_registry()->getSolverFactories()) {
        if (it->getId() ==
            solverId) {  /// TODO: also check version (currently assumes all ids are unique)
          _sf = it;
          delete _siOpt;
          _siOpt = _sf->createOptions();
          if (!sc.executable().empty() || solverId == "org.minizinc.mzn-fzn" ||
              solverId == "org.minizinc.mzn-nl") {
            std::vector<MZNFZNSolverFlag> acceptedFlags;
            for (const auto& sf : sc.stdFlags()) {
              acceptedFlags.push_back(MZNFZNSolverFlag::std(sf));
            }
            for (const auto& ef : sc.extraFlags()) {
              acceptedFlags.push_back(MZNFZNSolverFlag::extra(ef));
            }

            // Collect arguments required for underlying exe
            vector<string> fzn_mzn_flags;
            if (sc.needsStdlibDir()) {
              fzn_mzn_flags.emplace_back("--stdlib-dir");
              fzn_mzn_flags.push_back(FileUtils::share_directory());
            }
            if (sc.needsMznExecutable()) {
              fzn_mzn_flags.emplace_back("--minizinc-exe");
              fzn_mzn_flags.push_back(FileUtils::progpath() + "/" + _executableName);
            }

            if (sc.supportsMzn()) {
              isMznMzn = true;
              MZNSolverFactory::setAcceptedFlags(_siOpt, acceptedFlags);
              std::vector<std::string> additionalArgs_s;
              additionalArgs_s.emplace_back("-m");
              if (!sc.executableResolved().empty()) {
                additionalArgs_s.push_back(sc.executableResolved());
              } else {
                additionalArgs_s.push_back(sc.executable());
              }

              if (!fzn_mzn_flags.empty()) {
                add_flags("--mzn-flag", fzn_mzn_flags, additionalArgs_s);
              }

              // This should maybe be moved to fill in fzn_mzn_flags when
              // --find-muses is implemented (these arguments will be passed
              // through to the subsolver of findMUS)
              if (!sc.mznlib().empty()) {
                if (sc.mznlib().substr(0, 2) == "-G") {
                  additionalArgs_s.emplace_back("--mzn-flag");
                  additionalArgs_s.push_back(sc.mznlib());
                } else {
                  additionalArgs_s.emplace_back("--mzn-flag");
                  additionalArgs_s.emplace_back("-I");
                  additionalArgs_s.emplace_back("--mzn-flag");
                  std::string _mznlib;
                  if (!sc.mznlibResolved().empty()) {
                    _mznlib = sc.mznlibResolved();
                  } else {
                    _mznlib = sc.mznlib();
                  }
                  additionalArgs_s.push_back(_mznlib);
                }
              }

              for (i = 0; i < additionalArgs_s.size(); ++i) {
                bool success = _sf->processOption(_siOpt, i, additionalArgs_s);
                if (!success) {
                  _log << "Solver backend " << solverId << " does not recognise option "
                       << additionalArgs_s[i] << "." << endl;
                  return OPTION_ERROR;
                }
              }
            } else {
              // supports fzn or nl
              std::vector<std::string> additionalArgs;
              if (sc.supportsFzn()) {
                FZNSolverFactory::setAcceptedFlags(_siOpt, acceptedFlags);
                additionalArgs.emplace_back("--fzn-cmd");
              } else {
                // supports nl
                additionalArgs.emplace_back("--nl-cmd");
              }
              if (!sc.executableResolved().empty()) {
                additionalArgs.push_back(sc.executableResolved());
              } else {
                additionalArgs.push_back(sc.executable());
              }
              if (!fzn_mzn_flags.empty()) {
                if (sc.supportsFzn()) {
                  add_flags("--fzn-flag", fzn_mzn_flags, additionalArgs);
                } else {
                  add_flags("--nl-flag", fzn_mzn_flags, additionalArgs);
                }
              }
              if (sc.needsPathsFile()) {
                // Instruct flattener to hold onto paths
                int i = 0;
                vector<string> args{"--keep-paths"};
                _flt.processOption(i, args);

                // Instruct FznSolverInstance to write a path file
                // and pass it to the executable with --paths arg
                additionalArgs.emplace_back("--fzn-needs-paths");
              }
              if (!sc.needsSolns2Out()) {
                additionalArgs.emplace_back("--fzn-output-passthrough");
              }
              int i = 0;
              for (i = 0; i < additionalArgs.size(); ++i) {
                bool success = _sf->processOption(_siOpt, i, additionalArgs);
                if (!success) {
                  _log << "Solver backend " << solverId << " does not recognise option "
                       << additionalArgs[i] << "." << endl;
                  return OPTION_ERROR;
                }
              }
            }
          }
          if (!sc.mznlib().empty()) {
            if (sc.mznlib().substr(0, 2) == "-G") {
              std::vector<std::string> additionalArgs({sc.mznlib()});
              int i = 0;
              if (!_flt.processOption(i, additionalArgs)) {
                _log << "Flattener does not recognise option " << sc.mznlib() << endl;
                return OPTION_ERROR;
              }
            } else {
              std::vector<std::string> additionalArgs(2);
              additionalArgs[0] = "-I";
              if (!sc.mznlibResolved().empty()) {
                additionalArgs[1] = sc.mznlibResolved();
              } else {
                additionalArgs[1] = sc.mznlib();
              }
              int i = 0;
              if (!_flt.processOption(i, additionalArgs)) {
                _log << "Flattener does not recognise option -I." << endl;
                return OPTION_ERROR;
              }
            }
          }
          auto reducedDefaultFlags = reducedSolverDefaults.find(sc.id());
          const auto& defaultFlags = reducedDefaultFlags == reducedSolverDefaults.end()
                                         ? sc.defaultFlags()
                                         : reducedDefaultFlags->second;
          if (!defaultFlags.empty()) {
            std::vector<std::string> addedArgs;
            addedArgs.push_back(argv[0]);  // excutable name
            for (const auto& df : defaultFlags) {
              addedArgs.push_back(df);
            }
            for (int i = 1; i < argv.size(); i++) {
              addedArgs.push_back(argv[i]);
            }
            argv = addedArgs;
            argc = addedArgs.size();
          }
          break;
        }
      }

    } catch (ConfigException& e) {
      _log << "Config exception: " << e.msg() << endl;
      return OPTION_ERROR;
    }

    if (_sf == nullptr) {
      _log << "Solver " << solver << " not found." << endl;
      return OPTION_ERROR;
    }

    CLOParser cop(i, argv);  // For special handling of -a, -i and -n-i
    for (i = 1; i < argc; ++i) {
      if (argv[i] == "--push-working-directory") {
        i++;
        workingDirs.push_back(argv[i]);
      } else if (argv[i] == "--pop-working-directory") {
        workingDirs.pop_back();
      } else if (!ifMzn2Fzn() ? s2out.processOption(i, argv, workingDirs.back())
                              : false) {  // NOLINT: Allow repeated empty if
        // Processed by Solns2Out
      } else if ((!isMznMzn || _isMzn2fzn) &&
                 _flt.processOption(i, argv,
                                    workingDirs.back())) {  // NOLINT: Allow repeated empty if
        // Processed by Flattener
      } else if ((_supportsA || _supportsI) && cop.get("-a --all --all-solns --all-solutions")) {
        _flagAllSatisfaction = true;
        _flagIntermediate = true;
      } else if ((_supportsA || _supportsI) &&
                 cop.get("-i --intermediate --intermediate-solutions")) {
        _flagIntermediate = true;
      } else if (cop.getOption("-n-i --no-intermediate --no-intermediate-solutions")) {
        _flagIntermediate = false;
      } else if (_supportsA && cop.get("--all-satisfaction")) {
        _flagAllSatisfaction = true;
      } else if (cop.get("--disable-all-satisfaction")) {
        _flagAllSatisfaction = false;
      } else if (_sf != nullptr &&
                 _sf->processOption(_siOpt, i, argv)) {  // NOLINT: Allow repeated empty if
        // Processed by Solver Factory
      } else {
        std::string executable_name(argv[0]);
        executable_name = executable_name.substr(executable_name.find_last_of("/\\") + 1);
        _log << executable_name << ": Unrecognized option or bad format `" << argv[i] << "'"
             << endl;
        return OPTION_ERROR;
      }
    }
    return OPTION_OK;
  }
  for (i = 1; i < argc; ++i) {
    if (argv[i] == "--push-working-directory") {
      i++;
      workingDirs.push_back(argv[i]);
    } else if (argv[i] == "--pop-working-directory") {
      workingDirs.pop_back();
    } else if (s2out.processOption(i, argv, workingDirs.back())) {
      // Processed by Solns2Out
    } else {
      std::string executable_name(argv[0]);
      executable_name = executable_name.substr(executable_name.find_last_of("/\\") + 1);
      _log << executable_name << ": Unrecognized option or bad format `" << argv[i] << "'" << endl;
      return OPTION_ERROR;
    }
  }
  return OPTION_OK;
}

void MznSolver::flatten(const std::string& modelString, const std::string& modelName) {
  _flt.setFlagVerbose(flagCompilerVerbose);
  _flt.setFlagStatistics(flagCompilerStatistics);
  _flt.setFlagTimelimit(flagOverallTimeLimit);
  _flt.flatten(modelString, modelName);
}

SolverInstance::Status MznSolver::solve() {
  {  // To be able to clean up flatzinc after PrcessFlt()
    GCLock lock;
    getSI()->processFlatZinc();
  }
  SolverInstance::Status status = getSI()->solve();
  GCLock lock;
  if (!getSI()->getSolns2Out()->fStatusPrinted) {
    getSI()->getSolns2Out()->evalStatus(status);
  }
  if (_siOpt->printStatistics) {
    getSI()->printStatistics();
  }
  if (flagStatistics) {
    getSI()->getSolns2Out()->printStatistics(_os);
  }
  return status;
}

SolverInstance::Status MznSolver::run(const std::vector<std::string>& args0,
                                      const std::string& model, const std::string& exeName,
                                      const std::string& modelName) {
  using namespace std::chrono;
  steady_clock::time_point startTime = steady_clock::now();
  std::vector<std::string> args = {exeName};
  for (const auto& a : args0) {
    args.push_back(a);
  }
  switch (processOptions(args)) {
    case OPTION_FINISH:
      return SolverInstance::NONE;
    case OPTION_ERROR:
      printUsage();
      _os << "More info with \"" << exeName << " --help\"\n";
      return SolverInstance::ERROR;
    case OPTION_OK:
      break;
  }
  if (flagIsSolns2out &&
      (ifMzn2Fzn() || _sf == nullptr || _sf->getId() != "org.minizinc.mzn-mzn") &&
      !_flt.hasInputFiles() && model.empty()) {
    // We are in solns2out mode
    while (std::cin.good()) {
      string line;
      getline(std::cin, line);
      line += '\n';  // need eols as in t=raw stream
      s2out.feedRawDataChunk(line.c_str());
    }
    return SolverInstance::NONE;
  }

  if (!ifMzn2Fzn() && _sf->getId() == "org.minizinc.mzn-mzn") {
    Env env;
    _si = _sf->createSI(env, _log, _siOpt);
    _si->setSolns2Out(&s2out);
    {  // To be able to clean up flatzinc after PrcessFlt()
      GCLock lock;
      _si->options()->verbose = getFlagVerbose();
      _si->options()->printStatistics = getFlagStatistics();
    }
    _si->solve();
    return SolverInstance::NONE;
  }

  try {
    flatten(model, modelName);
  } catch (Timeout&) {
    s2out.evalStatus(SolverInstance::UNKNOWN);
    return SolverInstance::UNKNOWN;
  }

  if (!ifMzn2Fzn() && flagOverallTimeLimit != 0) {
    steady_clock::time_point afterFlattening = steady_clock::now();
    milliseconds passed = duration_cast<milliseconds>(afterFlattening - startTime);
    milliseconds time_limit(flagOverallTimeLimit);
    if (passed > time_limit) {
      s2out.evalStatus(getFltStatus());
      return SolverInstance::UNKNOWN;
    }
    int time_left = (time_limit - passed).count();
    std::vector<std::string> timeoutArgs(2);
    timeoutArgs[0] = "--solver-time-limit";
    std::ostringstream oss;
    oss << time_left;
    timeoutArgs[1] = oss.str();
    int i = 0;
    _sf->processOption(_siOpt, i, timeoutArgs);
  }

  if (SolverInstance::UNKNOWN == getFltStatus()) {
    if (!ifMzn2Fzn()) {  // only then
      // Special handling of basic stdFlags
      auto* solve_item = _flt.getEnv()->model()->solveItem();
      bool is_sat_problem =
          solve_item != nullptr ? solve_item->st() == SolveI::SolveType::ST_SAT : true;
      if (is_sat_problem && _flagAllSatisfaction) {
        if (_supportsA) {
          std::vector<std::string> a_flag = {"-a"};
          int i = 0;
          _sf->processOption(_siOpt, i, a_flag);
        } else {
          // Solver does not support -a
          _log << "WARNING: Solver does not support all solutions for satisfaction problems."
               << endl;
        }
      }
      if (!is_sat_problem && _flagIntermediate) {
        std::vector<std::string> i_flag(1);
        i_flag[0] = _supportsI ? "-i" : "-a";  // Fallback to -a if -i is not supported
        int i = 0;
        _sf->processOption(_siOpt, i, i_flag);
      }

      // GCLock lock;                  // better locally, to enable cleanup after ProcessFlt()
      addSolverInterface();
      return solve();
    }
    return SolverInstance::NONE;
  }
  if (!ifMzn2Fzn()) {
    s2out.evalStatus(getFltStatus());
  }
  return getFltStatus();
  //  Add evalOutput() here?   TODO
}