//
//  Copyright (C) 2016-2019 Greg Landrum
//
//   @@ All Rights Reserved @@
//  This file is part of the RDKit.
//  The contents are covered by the terms of the BSD license
//  which is included in the file license.txt, found at the root
//  of the RDKit source tree.
//
#include <RDGeneral/BoostStartInclude.h>
#include <boost/algorithm/string.hpp>
#include <boost/foreach.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/format.hpp>
#include <RDGeneral/BoostEndInclude.h>
#include <GraphMol/RDKitBase.h>
#include <GraphMol/RDKitQueries.h>
#include <iostream>
#include "SmilesWrite.h"
#include "SmilesParse.h"
#include "SmilesParseOps.h"

namespace SmilesParseOps {
using namespace RDKit;

namespace parser {
template <typename Iterator>
bool read_int(Iterator &first, Iterator last, unsigned int &res) {
  std::string num = "";
  while (first != last && *first >= '0' && *first <= '9') {
    num += *first;
    ++first;
  }
  if (num == "") {
    return false;
  }
  res = boost::lexical_cast<unsigned int>(num);
  return true;
}
template <typename Iterator>
bool read_int_pair(Iterator &first, Iterator last, unsigned int &n1,
                   unsigned int &n2, char sep = '.') {
  if (!read_int(first, last, n1)) {
    return false;
  }
  if (first >= last || *first != sep) {
    return false;
  }
  ++first;
  return read_int(first, last, n2);
}

template <typename Iterator>
std::string read_text_to(Iterator &first, Iterator last, std::string delims) {
  std::string res = "";
  Iterator start = first;
  // EFF: there are certainly faster ways to do this
  while (first != last && delims.find_first_of(*first) == std::string::npos) {
    if (*first == '&' && std::distance(first, last) > 2 &&
        *(first + 1) == '#') {
      // escaped char
      if (start != first) {
        res += std::string(start, first);
      }
      Iterator next = first + 2;
      while (next != last && *next >= '0' && *next <= '9') {
        ++next;
      }
      if (next == last || *next != ';') {
        throw RDKit::SmilesParseException(
            "failure parsing CXSMILES extensions: quoted block not terminated "
            "with ';'");
      }
      if (next > first + 2) {
        std::string blk = std::string(first + 2, next);
        res += (char)(boost::lexical_cast<int>(blk));
      }
      first = next + 1;
      start = first;
    } else {
      ++first;
    }
  }
  if (start != first) {
    res += std::string(start, first);
  }
  return res;
}

template <typename Iterator>
bool parse_atom_values(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first >= last || *first != ':') {
    return false;
  }
  ++first;
  unsigned int atIdx = 0;
  while (first != last && *first != '$') {
    std::string tkn = read_text_to(first, last, ";$");
    if (tkn != "") {
      mol.getAtomWithIdx(atIdx)->setProp(RDKit::common_properties::molFileValue,
                                         tkn);
    }
    ++atIdx;
    if (first != last && *first != '$') {
      ++first;
    }
  }
  if (first == last || *first != '$') {
    return false;
  }
  ++first;
  return true;
}

template <typename Iterator>
bool parse_atom_props(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first >= last) {
    return false;
  }
  while (first != last && *first != '|' && *first != ',') {
    unsigned int atIdx;
    if (read_int(first, last, atIdx)) {
      if (first == last || *first != '.') {
        return false;
      }
      ++first;
      std::string pname = read_text_to(first, last, ".");
      if (pname != "") {
        if (first == last || *first != '.') {
          return false;
        }
        ++first;
        std::string pval = read_text_to(first, last, ":|,");
        if (pval != "") {
          mol.getAtomWithIdx(atIdx)->setProp(pname, pval);
        }
      }
    }
    if (first != last && *first != '|' && *first != ',') {
      ++first;
    }
  }
  if (first != last && *first != '|' && *first != ',') {
    return false;
  }
  if (*first != '|') {
    ++first;
  }
  return true;
}

template <typename Iterator>
bool parse_atom_labels(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first >= last || *first != '$') {
    return false;
  }
  ++first;
  unsigned int atIdx = 0;
  while (first != last && *first != '$') {
    std::string tkn = read_text_to(first, last, ";$");
    if (tkn != "") {
      mol.getAtomWithIdx(atIdx)->setProp(RDKit::common_properties::atomLabel,
                                         tkn);
    }
    ++atIdx;
    if (first != last && *first != '$') {
      ++first;
    }
  }
  if (first == last || *first != '$') {
    return false;
  }
  ++first;
  return true;
}

template <typename Iterator>
bool parse_coords(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first >= last || *first != '(') {
    return false;
  }

  auto *conf = new Conformer(mol.getNumAtoms());
  mol.addConformer(conf);
  ++first;
  unsigned int atIdx = 0;
  while (first != last && *first != ')') {
    RDGeom::Point3D pt;
    std::string tkn = read_text_to(first, last, ";)");
    if (tkn != "") {
      std::vector<std::string> tokens;
      boost::split(tokens, tkn, boost::is_any_of(std::string(",")));
      if (tokens.size() >= 1 && tokens[0].size()) {
        pt.x = boost::lexical_cast<double>(tokens[0]);
      }
      if (tokens.size() >= 2 && tokens[1].size()) {
        pt.y = boost::lexical_cast<double>(tokens[1]);
      }
      if (tokens.size() >= 3 && tokens[2].size()) {
        pt.z = boost::lexical_cast<double>(tokens[2]);
      }
    }

    conf->setAtomPos(atIdx, pt);
    ++atIdx;
    if (first != last && *first != ')') {
      ++first;
    }
  }
  if (first == last || *first != ')') {
    return false;
  }
  ++first;
  return true;
}

template <typename Iterator>
bool parse_coordinate_bonds(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first >= last || *first != 'C') {
    return false;
  }
  ++first;
  if (first >= last || *first != ':') {
    return false;
  }
  ++first;
  while (first != last && *first >= '0' && *first <= '9') {
    unsigned int aidx;
    unsigned int bidx;
    if (read_int_pair(first, last, aidx, bidx)) {
      Bond *bnd = nullptr;
      for (auto bond : mol.bonds()) {
        unsigned int smilesIdx;
        if (bond->getPropIfPresent("_cxsmilesBondIdx", smilesIdx) &&
            smilesIdx == bidx) {
          bnd = bond;
          break;
        }
      }
      if (!bnd ||
          (bnd->getBeginAtomIdx() != aidx && bnd->getEndAtomIdx() != aidx)) {
        BOOST_LOG(rdWarningLog) << "BOND NOT FOUND! " << bidx
                                << " involving atom " << aidx << std::endl;
        return false;
      }
      bnd->setBondType(Bond::DATIVE);
      if (bnd->getBeginAtomIdx() != aidx) {
        unsigned int tmp = bnd->getBeginAtomIdx();
        bnd->setBeginAtomIdx(aidx);
        bnd->setEndAtomIdx(tmp);
      }
    } else {
      return false;
    }
    if (first < last && *first == ',') {
      ++first;
    }
  }
  return true;
}

template <typename Iterator>
bool parse_unsaturation(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first + 1 >= last || *first != 'u') {
    return false;
  }
  ++first;
  if (first >= last || *first != ':') {
    return false;
  }
  ++first;
  while (first < last && *first >= '0' && *first <= '9') {
    unsigned int idx;
    if (!read_int(first, last, idx)) {
      return false;
    }
    auto atom = mol.getAtomWithIdx(idx);
    if (!atom->hasQuery()) {
      atom = QueryOps::replaceAtomWithQueryAtom(&mol, atom);
    }
    atom->expandQuery(makeAtomUnsaturatedQuery(), Queries::COMPOSITE_AND);
    if (first < last && *first == ',') {
      ++first;
    }
  }
  return true;
}

template <typename Iterator>
bool parse_ring_bonds(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first >= last || *first != 'r' || first + 1 >= last ||
      *(first + 1) != 'b' || first + 2 >= last || *(first + 2) != ':') {
    return false;
  }
  first += 3;
  while (first < last && *first >= '0' && *first <= '9') {
    unsigned int n1;
    if (!read_int(first, last, n1)) {
      return false;
    }
    // check that we can read at least two more characters:
    if (first + 1 >= last || *first != ':') {
      return false;
    }
    ++first;
    unsigned int n2;
    bool gt = false;
    if (*first == '*') {
      ++first;
      n2 = 0xDEADBEEF;
      mol.setProp(common_properties::_NeedsQueryScan, 1);
    } else {
      if (!read_int(first, last, n2)) {
        return false;
      }
      switch (n2) {
        case 0:
        case 2:
        case 3:
          break;
        case 4:
          gt = true;
          break;
        default:
          BOOST_LOG(rdWarningLog)
              << "unrecognized rb value: " << n2 << std::endl;
          return false;
      }
    }
    auto atom = mol.getAtomWithIdx(n1);
    if (!atom->hasQuery()) {
      atom = QueryOps::replaceAtomWithQueryAtom(&mol, atom);
    }
    if (!gt) {
      atom->expandQuery(makeAtomRingBondCountQuery(n2), Queries::COMPOSITE_AND);
    } else {
      auto q = static_cast<ATOM_EQUALS_QUERY *>(new ATOM_LESSEQUAL_QUERY);
      q->setVal(n2);
      q->setDescription("AtomRingBondCount");
      q->setDataFunc(queryAtomRingBondCount);
      atom->expandQuery(q, Queries::COMPOSITE_AND);
    }
    if (first < last && *first == ',') {
      ++first;
    }
  }
  return true;
}

template <typename Iterator>
bool parse_linknodes(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  // these look like: |LN:1:1.3.2.6,4:1.4.3.6|
  // that's two records:
  //   1:1.3.2.6: 1-3 repeats, atom 1-2, 1-6
  //   4:1.4.3.6: 1-4 repeats, atom 4-4, 4-6
  // which maps to the property value "1 3 2 2 3 2 7|1 4 2 5 4 5 7"
  // If the linking atom only has two neighbors then the outer atom
  // specification (the last two digits) can be left out. So for a molecule
  // where atom 1 has bonds only to atoms 2 and 6 we could have
  // |LN:1:1.3|
  // instead of
  // |LN:1:1.3.2.6|
  if (first >= last || *first != 'L' || first + 1 >= last ||
      *(first + 1) != 'N' || first + 2 >= last || *(first + 2) != ':') {
    return false;
  }
  first += 3;
  std::string accum = "";
  while (first < last && *first >= '0' && *first <= '9') {
    unsigned int atidx;
    if (!read_int(first, last, atidx)) {
      return false;
    }
    // check that we can read at least two more characters:
    if (first + 1 >= last || *first != ':') {
      return false;
    }
    ++first;
    unsigned int startReps;
    if (!read_int(first, last, startReps)) {
      return false;
    }
    ++first;
    unsigned int endReps;
    if (!read_int(first, last, endReps)) {
      return false;
    }
    unsigned int idx1;
    unsigned int idx2;
    if (first < last && *first == '.') {
      ++first;
      if (!read_int(first, last, idx1)) {
        return false;
      }
      ++first;
      if (!read_int(first, last, idx2)) {
        return false;
      }
    } else if (mol.getAtomWithIdx(atidx)->getDegree() == 2) {
      auto nbrs = mol.getAtomNeighbors(mol.getAtomWithIdx(atidx));
      idx1 = *nbrs.first;
      nbrs.first++;
      idx2 = *nbrs.first;
    } else {
      return false;
    }
    if (first < last && *first == ',') {
      ++first;
    }

    if (!accum.empty()) {
      accum += "|";
    }
    accum += (boost::format("%d %d 2 %d %d %d %d") % startReps % endReps %
              (atidx + 1) % (idx1 + 1) % (atidx + 1) % (idx2 + 1))
                 .str();
  }
  mol.setProp(common_properties::molFileLinkNodes, accum);
  return true;
}

template <typename Iterator>
bool parse_variable_attachments(Iterator &first, Iterator last,
                                RDKit::RWMol &mol) {
  // these look like: CO*.C1=CC=NC=C1 |m:2:3.5.4|
  // that corresponds to replacing the bond to atom 2 with bonds to atom 3, 5,
  // or 4
  //
  if (first >= last || *first != 'm' || first + 1 >= last ||
      *(first + 1) != ':') {
    return false;
  }
  first += 2;

  while (first < last && *first >= '0' && *first <= '9') {
    unsigned int at1idx;
    if (!read_int(first, last, at1idx)) {
      return false;
    }
    if (mol.getAtomWithIdx(at1idx)->getDegree() != 1) {
      BOOST_LOG(rdWarningLog)
          << "position variation bond to atom with more than one bond"
          << std::endl;
      return false;
    }
    if (first < last && *first == ':') {
      ++first;
    } else {
      BOOST_LOG(rdWarningLog) << "improperly formatted m: block" << std::endl;
      return false;
    }
    std::vector<std::string> others;
    while (first < last && *first >= '0' && *first <= '9') {
      unsigned int aidx;
      if (!read_int(first, last, aidx)) {
        return false;
      }
      others.push_back((boost::format("%d") % (aidx + 1)).str());
      if (first < last && *first == '.') {
        ++first;
      }
    }
    std::string endPts = (boost::format("(%d") % others.size()).str();
    for (auto idx : others) {
      endPts += " " + idx;
    }
    endPts += ")";

    for (auto nbri : boost::make_iterator_range(
             mol.getAtomBonds(mol.getAtomWithIdx(at1idx)))) {
      auto bnd = mol[nbri];
      bnd->setProp(common_properties::_MolFileBondEndPts, endPts);
      bnd->setProp(common_properties::_MolFileBondAttach, std::string("ANY"));
    }
    if (first < last && *first == ',') {
      ++first;
    }
  }
  return true;
}
template <typename Iterator>
bool parse_substitution(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first >= last || *first != 's' || first + 1 >= last ||
      *(first + 1) != ':') {
    return false;
  }
  first += 2;
  while (first < last && *first >= '0' && *first <= '9') {
    unsigned int n1;
    if (!read_int(first, last, n1)) {
      return false;
    }
    // check that we can read at least two more characters:
    if (first + 1 >= last || *first != ':') {
      return false;
    }
    ++first;
    unsigned int n2;
    if (*first == '*') {
      ++first;
      n2 = 0xDEADBEEF;
      mol.setProp(common_properties::_NeedsQueryScan, 1);
    } else {
      if (!read_int(first, last, n2)) {
        return false;
      }
    }
    auto atom = mol.getAtomWithIdx(n1);
    if (!atom->hasQuery()) {
      atom = QueryOps::replaceAtomWithQueryAtom(&mol, atom);
    }
    atom->expandQuery(makeAtomNonHydrogenDegreeQuery(n2),
                      Queries::COMPOSITE_AND);
    if (first < last && *first == ',') {
      ++first;
    }
  }
  return true;
}

template <typename Iterator>
bool processRadicalSection(Iterator &first, Iterator last, RDKit::RWMol &mol,
                           unsigned int numRadicalElectrons) {
  if (first >= last) {
    return false;
  }
  ++first;
  if (first >= last || *first != ':') {
    return false;
  }
  ++first;
  unsigned int atIdx;
  if (!read_int(first, last, atIdx)) {
    return false;
  }
  mol.getAtomWithIdx(atIdx)->setNumRadicalElectrons(numRadicalElectrons);
  while (first < last && *first == ',') {
    ++first;
    if (first < last && (*first < '0' || *first > '9')) {
      return true;
    }
    if (!read_int(first, last, atIdx)) {
      return false;
    }
    mol.getAtomWithIdx(atIdx)->setNumRadicalElectrons(numRadicalElectrons);
  }
  if (first >= last) {
    return false;
  }
  return true;
}

template <typename Iterator>
bool parse_radicals(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first >= last || *first != '^') {
    return false;
  }
  while (*first == '^') {
    ++first;
    if (first >= last) {
      return false;
    }
    if (*first < '1' || *first > '7') {
      return false;  // these are the values that are allowed to be there
    }
    switch (*first) {
      case '1':
        if (!processRadicalSection(first, last, mol, 1)) {
          return false;
        }
        break;
      case '2':
      case '3':
      case '4':
        if (!processRadicalSection(first, last, mol, 2)) {
          return false;
        }
        break;
      case '5':
      case '6':
      case '7':
        if (!processRadicalSection(first, last, mol, 3)) {
          return false;
        }
        break;
      default:
        BOOST_LOG(rdWarningLog)
            << "Radical specification " << *first << " ignored.";
    }
  }
  return true;
}

template <typename Iterator>
bool parse_enhanced_stereo(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  StereoGroupType group_type = StereoGroupType::STEREO_ABSOLUTE;
  if (*first == 'a') {
    group_type = StereoGroupType::STEREO_ABSOLUTE;
  } else if (*first == 'o') {
    group_type = StereoGroupType::STEREO_OR;
  } else if (*first == '&') {
    group_type = StereoGroupType::STEREO_AND;
  }
  ++first;

  // OR and AND groups carry a group number
  if (group_type != StereoGroupType::STEREO_ABSOLUTE) {
    unsigned int group_id = 0;
    read_int(first, last, group_id);
  }

  if (first >= last || *first != ':') {
    return false;
  }
  ++first;

  std::vector<Atom *> atoms;
  while (first != last && *first >= '0' && *first <= '9') {
    unsigned int aidx;
    if (read_int(first, last, aidx)) {
      Atom *atom = mol.getAtomWithIdx(aidx);
      if (!atom) {
        BOOST_LOG(rdWarningLog)
            << "Atom " << aidx << " not found!" << std::endl;
        return false;
      }
      atoms.push_back(atom);
    } else {
      return false;
    }

    if (first < last && *first == ',') {
      ++first;
    }
  }

  std::vector<StereoGroup> mol_stereo_groups(mol.getStereoGroups());
  mol_stereo_groups.emplace_back(group_type, std::move(atoms));
  mol.setStereoGroups(std::move(mol_stereo_groups));

  return true;
}

template <typename Iterator>
bool parse_it(Iterator &first, Iterator last, RDKit::RWMol &mol) {
  if (first >= last || *first != '|') {
    return false;
  }
  ++first;
  while (first < last && *first != '|') {
    typename Iterator::difference_type length = std::distance(first, last);
    if (*first == '(') {
      if (!parse_coords(first, last, mol)) {
        return false;
      }
    } else if (*first == '$') {
      if (length > 4 && *(first + 1) == '_' && *(first + 2) == 'A' &&
          *(first + 3) == 'V' && *(first + 4) == ':') {
        first += 4;
        if (!parse_atom_values(first, last, mol)) {
          return false;
        }
      } else {
        if (!parse_atom_labels(first, last, mol)) {
          return false;
        }
      }
    } else if (length > 9 && std::string(first, first + 9) == "atomProp:") {
      first += 9;
      if (!parse_atom_props(first, last, mol)) {
        return false;
      }
    } else if (*first == 'C') {
      if (!parse_coordinate_bonds(first, last, mol)) {
        return false;
      }
    } else if (*first == '^') {
      if (!parse_radicals(first, last, mol)) {
        return false;
      }
    } else if (*first == 'a' || *first == 'o' ||
               (*first == '&' && first + 1 < last && first[1] != '#')) {
      if (!parse_enhanced_stereo(first, last, mol)) {
        return false;
      }
    } else if (*first == 'r' && first + 1 < last && first[1] == 'b') {
      if (!parse_ring_bonds(first, last, mol)) {
        return false;
      }
    } else if (*first == 'L' && first + 1 < last && first[1] == 'N') {
      if (!parse_linknodes(first, last, mol)) {
        return false;
      }
    } else if (*first == 'u') {
      if (!parse_unsaturation(first, last, mol)) {
        return false;
      }
    } else if (*first == 's') {
      if (!parse_substitution(first, last, mol)) {
        return false;
      }
    } else if (*first == 'm') {
      if (!parse_variable_attachments(first, last, mol)) {
        return false;
      }
    } else {
      ++first;
    }
    // if(first < last && *first != '|') ++first;
  }
  if (first >= last || *first != '|') {
    return false;
  }
  ++first;  // step past the last '|'
  return true;
}
}  // namespace parser

namespace {
template <typename Q>
void addquery(Q *qry, std::string symbol, RDKit::RWMol &mol, unsigned int idx) {
  PRECONDITION(qry, "bad query");
  auto *qa = new QueryAtom(0);
  qa->setQuery(qry);
  qa->setNoImplicit(true);
  mol.replaceAtom(idx, qa);
  if (symbol != "") {
    mol.getAtomWithIdx(idx)->setProp(RDKit::common_properties::atomLabel,
                                     symbol);
  }
  delete qa;
}
void processCXSmilesLabels(RDKit::RWMol &mol) {
  for (RDKit::ROMol::AtomIterator atIt = mol.beginAtoms();
       atIt != mol.endAtoms(); ++atIt) {
    std::string symb = "";
    if ((*atIt)->getPropIfPresent(RDKit::common_properties::atomLabel, symb)) {
      if (symb == "star_e") {
        /* according to the MDL spec, these match anything, but in MARVIN they
        are "unspecified end groups" for polymers */
        addquery(makeAtomNullQuery(), symb, mol, (*atIt)->getIdx());
      } else if (symb == "Q_e") {
        addquery(makeQAtomQuery(), symb, mol, (*atIt)->getIdx());
      } else if (symb == "QH_p") {
        addquery(makeQHAtomQuery(), symb, mol, (*atIt)->getIdx());
      } else if (symb == "AH_p") {  // this seems wrong...
        /* According to the MARVIN Sketch, AH is "any atom, including H" -
        this would be "*" in SMILES - and "A" is "any atom except H".
        The CXSMILES docs say that "A" can be represented normally in SMILES
        and that "AH" needs to be written out as AH_p. I'm going to assume that
        this is a Marvin internal thing and just parse it as they describe it.
        This means that "*" in the SMILES itself needs to be treated
        differently, which we do below. */
        addquery(makeAHAtomQuery(), symb, mol, (*atIt)->getIdx());
      } else if (symb == "X_p") {
        addquery(makeXAtomQuery(), symb, mol, (*atIt)->getIdx());
      } else if (symb == "XH_p") {
        addquery(makeXHAtomQuery(), symb, mol, (*atIt)->getIdx());
      } else if (symb == "M_p") {
        addquery(makeMAtomQuery(), symb, mol, (*atIt)->getIdx());
      } else if (symb == "MH_p") {
        addquery(makeMHAtomQuery(), symb, mol, (*atIt)->getIdx());
      }
    } else if ((*atIt)->getAtomicNum() == 0 && (*atIt)->getSymbol() == "*") {
      addquery(makeAAtomQuery(), "", mol, (*atIt)->getIdx());
    }
  }
}

}  // end of anonymous namespace

void parseCXExtensions(RDKit::RWMol &mol, const std::string &extText,
                       std::string::const_iterator &first) {
  // BOOST_LOG(rdWarningLog) << "parseCXNExtensions: " << extText << std::endl;
  if (extText.empty() || extText[0] != '|') {
    return;
  }
  first = extText.begin();
  bool ok = parser::parse_it(first, extText.end(), mol);
  if (!ok) {
    throw RDKit::SmilesParseException("failure parsing CXSMILES extensions");
  }
  processCXSmilesLabels(mol);
}
}  // end of namespace SmilesParseOps

namespace RDKit {
namespace SmilesWrite {
namespace {
std::string quote_string(const std::string &txt) {
  // FIX
  return txt;
}

std::string get_enhanced_stereo_block(
    const ROMol &mol, const std::vector<unsigned int> &atomOrder) {
  std::stringstream res;
  // we need a map from original atom idx to output idx:
  std::vector<unsigned int> revOrder(mol.getNumAtoms());
  for (unsigned i = 0; i < atomOrder.size(); ++i) {
    revOrder[atomOrder[i]] = i;
  }
  std::vector<unsigned int> absAts;
  std::vector<std::vector<unsigned int>> orGps;
  std::vector<std::vector<unsigned int>> andGps;

  // we want this to be canonical (future proofing)
  for (const auto &sg : mol.getStereoGroups()) {
    std::vector<unsigned int> aids;
    aids.reserve(sg.getAtoms().size());
    for (const auto at : sg.getAtoms()) {
      aids.push_back(revOrder[at->getIdx()]);
    }
    switch (sg.getGroupType()) {
      case StereoGroupType::STEREO_ABSOLUTE:
        absAts.insert(absAts.end(), aids.begin(), aids.end());
        break;
      case StereoGroupType::STEREO_OR:
        std::sort(aids.begin(), aids.end());
        orGps.push_back(aids);
        break;
      case StereoGroupType::STEREO_AND:
        std::sort(aids.begin(), aids.end());
        andGps.push_back(aids);
        break;
    }
  }
  if (!absAts.empty()) {
    res << "a:";
    std::sort(absAts.begin(), absAts.end());
    for (auto aid : absAts) {
      res << aid << ",";
    }
  }
  if (!orGps.empty()) {
    std::sort(orGps.begin(), orGps.end());
    unsigned int gIdx = 1;
    for (const auto &gp : orGps) {
      res << "o" << gIdx++ << ":";
      for (auto aid : gp) {
        res << aid << ",";
      }
    }
  }
  if (!andGps.empty()) {
    std::sort(andGps.begin(), andGps.end());
    unsigned int gIdx = 1;
    for (const auto &gp : andGps) {
      res << "&" << gIdx++ << ":";
      for (auto aid : gp) {
        res << aid << ",";
      }
    }
  }
  std::string resStr = res.str();
  if (!resStr.empty() && resStr.back() == ',') {
    resStr.pop_back();
  }
  return resStr;
}

std::string get_value_block(const ROMol &mol,
                            const std::vector<unsigned int> &atomOrder,
                            const std::string &prop) {
  std::string res = "";
  bool first = true;
  for (auto idx : atomOrder) {
    if (!first) {
      res += ";";
    } else {
      first = false;
    }
    std::string lbl;
    if (mol.getAtomWithIdx(idx)->getPropIfPresent(prop, lbl)) {
      res += quote_string(lbl);
    }
  }
  return res;
}
std::string get_radical_block(const ROMol &mol,
                              const std::vector<unsigned int> &atomOrder) {
  std::string res = "";
  std::map<unsigned int, std::vector<unsigned int>> rads;
  for (unsigned int i = 0; i < atomOrder.size(); ++i) {
    auto idx = atomOrder[i];
    auto nrad = mol.getAtomWithIdx(idx)->getNumRadicalElectrons();
    if (nrad) {
      rads[nrad].push_back(i);
    }
  }
  if (rads.size()) {
    for (const auto &pr : rads) {
      switch (pr.first) {
        case 1:
          res += "^1:";
          break;
        case 2:
          res += "^2:";
          break;
        case 3:
          res += "^5:";
          break;
        default:
          BOOST_LOG(rdWarningLog) << "unsupported number of radical electrons "
                                  << pr.first << std::endl;
      }
      for (auto aidx : pr.second) {
        res += boost::str(boost::format("%d,") % aidx);
      }
    }
  }
  return res;
}
std::string get_coords_block(const ROMol &mol,
                             const std::vector<unsigned int> &atomOrder) {
  std::string res = "";
  const auto &conf = mol.getConformer();
  bool first = true;
  for (auto idx : atomOrder) {
    const auto &pt = conf.getAtomPos(idx);
    if (!first) {
      res += ";";
    } else {
      first = false;
    }
    res += boost::str(boost::format("%g,%g,") % pt.x % pt.y);
    if (conf.is3D()) {
      auto zc = boost::str(boost::format("%g") % pt.z);
      if (zc != "0") {
        res += zc;
      }
    }
  }
  return res;
}

std::string get_atom_props_block(const ROMol &mol,
                                 const std::vector<unsigned int> &atomOrder) {
  std::vector<std::string> skip = {common_properties::atomLabel,
                                   common_properties::molFileValue,
                                   common_properties::molParity};
  std::string res = "";
  unsigned int which = 0;
  for (auto idx : atomOrder) {
    const auto atom = mol.getAtomWithIdx(idx);
    bool includePrivate = false, includeComputed = false;
    for (const auto &pn : atom->getPropList(includePrivate, includeComputed)) {
      if (std::find(skip.begin(), skip.end(), pn) == skip.end()) {
        if (res.size() == 0) {
          res += "atomProp";
        }
        res +=
            boost::str(boost::format(":%d.%s.%s") % which % quote_string(pn) %
                       quote_string(atom->getProp<std::string>(pn)));
      }
    }
    ++which;
  }
  return res;
}

void appendToCXExtension(const std::string &addition, std::string &base) {
  if (!addition.empty()) {
    if (base.size() > 1) {
      base += ",";
    }
    base += addition;
  }
}

}  // namespace
std::string getCXExtensions(const ROMol &mol) {
  std::string res = "|";
  // we will need atom ordering. Get that now:
  const std::vector<unsigned int> &atomOrder =
      mol.getProp<std::vector<unsigned int>>(
          common_properties::_smilesAtomOutputOrder);
  bool needLabels = false;
  bool needValues = false;
  for (auto idx : atomOrder) {
    const auto at = mol.getAtomWithIdx(idx);
    if (at->hasProp(common_properties::atomLabel)) {
      needLabels = true;
    }
    if (at->hasProp(common_properties::molFileValue)) {
      needValues = true;
    }
  }
  if (mol.getNumConformers()) {
    res += "(" + get_coords_block(mol, atomOrder) + ")";
  }
  if (needLabels) {
    if (res.size() > 1) {
      res += ",";
    }
    res += "$" + get_value_block(mol, atomOrder, common_properties::atomLabel) +
           "$";
  }
  if (needValues) {
    if (res.size() > 1) {
      res += ",";
    }
    res += "$_AV:" +
           get_value_block(mol, atomOrder, common_properties::molFileValue) +
           "$";
  }
  auto radblock = get_radical_block(mol, atomOrder);
  if (radblock.size()) {
    if (res.size() > 1) {
      res += ",";
    }
    res += radblock;
    if (res.back() == ',') {
      res.erase(res.size() - 1);
    }
  }

  const auto atomblock = get_atom_props_block(mol, atomOrder);
  appendToCXExtension(atomblock, res);

  const auto stereoblock = get_enhanced_stereo_block(mol, atomOrder);
  appendToCXExtension(stereoblock, res);

  if (res.size() > 1) {
    res += "|";
  } else {
    res = "";
  }
  return res;
}
}  // namespace SmilesWrite
}  // namespace RDKit