// $Id$
//
//  Copyright (C) 2002-2011 Greg Landrum and Rational Discovery LLC
//
//   @@ 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/BadFileException.h>
#include <RDGeneral/FileParseException.h>
#include <RDGeneral/StreamOps.h>
#include <RDGeneral/RDLog.h>
#include "MolSupplier.h"
#include "FileParsers.h"
#include <GraphMol/SmilesParse/SmilesParse.h>
#include <boost/tokenizer.hpp>
typedef boost::tokenizer<boost::char_separator<char> > tokenizer;

#include <fstream>
#include <iostream>
#include <sstream>
#include <string>
#include <cstdlib>

namespace RDKit {
SmilesMolSupplier::SmilesMolSupplier() { init(); }

SmilesMolSupplier::SmilesMolSupplier(const std::string &fileName,
                                     const std::string &delimiter,
                                     int smilesColumn, int nameColumn,
                                     bool titleLine, bool sanitize) {
  init();

  // FIX: this binary mode of opening file is here because of a bug in VC++ 6.0
  // the function "tellg" does not work correctly if we do not open it this way
  // Need to check if this has been fixed in VC++ 7.0
  auto *tmpStream = new std::ifstream(fileName.c_str(), std::ios_base::binary);

  if (!tmpStream || (!(*tmpStream)) || (tmpStream->bad())) {
    std::ostringstream errout;
    errout << "Bad input file " << fileName;
    throw BadFileException(errout.str());
  }
  dp_inStream = static_cast<std::istream *>(tmpStream);
  CHECK_INVARIANT(dp_inStream, "bad instream");
  CHECK_INVARIANT(!(dp_inStream->eof()), "early EOF");

  d_delim = delimiter;
  df_sanitize = sanitize;
  df_title = titleLine;
  d_smi = smilesColumn;
  d_name = nameColumn;
  df_end = false;

  // if(d_title) processTitleLine();
  this->checkForEnd();
  POSTCONDITION(dp_inStream, "bad instream");
}

SmilesMolSupplier::SmilesMolSupplier(std::istream *inStream, bool takeOwnership,
                                     const std::string &delimiter,
                                     int smilesColumn, int nameColumn,
                                     bool titleLine, bool sanitize) {
  CHECK_INVARIANT(inStream, "bad instream");
  CHECK_INVARIANT(!(inStream->eof()), "early EOF");

  init();
  dp_inStream = inStream;
  df_owner = takeOwnership;
  d_delim = delimiter;
  df_sanitize = sanitize;
  df_title = titleLine;
  d_smi = smilesColumn;
  d_name = nameColumn;
  df_end = false;
  this->checkForEnd();
  POSTCONDITION(dp_inStream, "bad instream");
}

SmilesMolSupplier::~SmilesMolSupplier() {
  if (df_owner && dp_inStream) {
    delete dp_inStream;
  }
}

void SmilesMolSupplier::init() {
  dp_inStream = nullptr;
  df_owner = true;
  df_end = false;

  d_len = -1;
  d_next = -1;
  d_line = -1;
  d_molpos.clear();
  d_lineNums.clear();
}

void SmilesMolSupplier::setData(const std::string &text,
                                const std::string &delimiter, int smilesColumn,
                                int nameColumn, bool titleLine, bool sanitize) {
  if (dp_inStream && df_owner) delete dp_inStream;
  init();

  dp_inStream = new std::stringstream(text);

  d_delim = delimiter;
  df_sanitize = sanitize;
  df_title = titleLine;
  d_smi = smilesColumn;
  d_name = nameColumn;
  df_end = false;

  this->checkForEnd();
  POSTCONDITION(dp_inStream, "bad instream");
}

// ensures that there is a line available to be read
// from the file:
void SmilesMolSupplier::checkForEnd() {
  PRECONDITION(dp_inStream, "no stream");
  int pos = this->skipComments();
  if (pos != -1) {
    d_line = -1;
    dp_inStream->seekg(0);
    df_end = false;
  }
}

void SmilesMolSupplier::reset() {
  PRECONDITION(dp_inStream, "no stream");
  dp_inStream->clear();

  df_end = 0;
  if (d_molpos.size() > 0) {
    dp_inStream->seekg(d_molpos.front());
    d_next = 0;
    d_line = 0;
  } else {
    dp_inStream->seekg(0);
    d_next = -1;
    d_line = -1;
  }
}

ROMol *SmilesMolSupplier::processLine(std::string inLine) {
  ROMol *res = nullptr;

  try {
    // -----------
    // tokenize the input line:
    // -----------
    boost::char_separator<char> sep(d_delim.c_str(), "",
                                    boost::keep_empty_tokens);
    tokenizer tokens(inLine, sep);
    STR_VECT recs;
    for (tokenizer::iterator tokIter = tokens.begin(); tokIter != tokens.end();
         ++tokIter) {
      std::string rec = strip(*tokIter);
      recs.push_back(rec);
    }
    if (recs.size() <= static_cast<unsigned int>(d_smi)) {
      std::ostringstream errout;
      errout << "ERROR: line #" << d_line << "does not contain enough tokens\n";
      throw FileParseException(errout.str());
    }

    // -----------
    // get the smiles and create a molecule
    // -----------
    SmilesParserParams params;
    params.sanitize = df_sanitize;
    params.allowCXSMILES = false;
    params.parseName = false;
    res = SmilesToMol(recs[d_smi], params);
    if (!res) {
      std::stringstream errout;
      errout << "Cannot create molecule from : '" << recs[d_smi] << "'";
      throw SmilesParseException(errout.str());
    }

    // -----------
    // get the name (if there's a name column)
    // -----------
    if (d_name == -1) {
      // if no name defaults it to the line number we read it from string
      std::ostringstream tstr;
      tstr << d_line;
      std::string mname = tstr.str();
      res->setProp(common_properties::_Name, mname);
    } else {
      if (d_name >= static_cast<int>(recs.size())) {
        BOOST_LOG(rdWarningLog) << "WARNING: no name column found on line "
                                << d_line << std::endl;
      } else {
        res->setProp(common_properties::_Name, recs[d_name]);
      }
    }

    // -----------
    // read in the properties
    // -----------
    unsigned int iprop = 0;
    for (unsigned int col = 0; col < recs.size(); col++) {
      if (static_cast<int>(col) == d_smi || static_cast<int>(col) == d_name)
        continue;
      std::string pname, pval;
      if (d_props.size() > col) {
        pname = d_props[col];
      } else {
        pname = "Column_";
        std::stringstream ss;
        ss << col;
        pname += ss.str();
      }

      pval = recs[col];
      res->setProp(pname, pval);
      iprop++;
    }

  } catch (const SmilesParseException &pe) {
    // Couldn't parse the passed in smiles
    // Simply print out a message
    BOOST_LOG(rdErrorLog) << "ERROR: Smiles parse error on line " << d_line
                          << "\n";
    BOOST_LOG(rdErrorLog) << "ERROR: " << pe.message() << "\n";
    res = nullptr;
  } catch (const MolSanitizeException &se) {
    // We couldn't sanitize the molecule
    //  write out an error message
    BOOST_LOG(rdErrorLog) << "ERROR: Could not sanitize molecule on line "
                          << d_line << std::endl;
    BOOST_LOG(rdErrorLog) << "ERROR: " << se.message() << "\n";
    res = nullptr;
  } catch (...) {
    //  write out an error message
    BOOST_LOG(rdErrorLog) << "ERROR: Could not process molecule on line "
                          << d_line << std::endl;
    res = nullptr;
  }

  return res;
}

// --------------------------------------------------
//
//  Returns the next available line in the input stream.
//
//  Side-effects:
//    - If EOF is hit without reading anything, the df_end
//      flag will be set.
//    - If a real line is read, our d_line counter is
//      incremented
//
// --------------------------------------------------
std::string SmilesMolSupplier::nextLine() {
  PRECONDITION(dp_inStream, "bad stream");
  if (df_end) return "";
  std::string tempStr = getLine(dp_inStream);

  if (tempStr == "") {
    // got an empty string, check to see if we hit EOF:
    if (dp_inStream->eof()) {
      // yes, set our flag:
      df_end = true;
    }
  } else if (dp_inStream->eof()) {
    // we got some data before hitting EOF. So clear the
    // flag on inStream
    dp_inStream->clear();
  }
  d_line++;
  return tempStr;
}

// --------------------------------------------------
//
//  Returns the position of the beginning of the next
//  non-comment line in the input stream. -1 is returned if
//  no line could be read;
//
//  Side-effects:
//    - If EOF is hit without finding a valid line, the df_end
//      flag will be set.
//    - Our d_line counter is incremented for each line read
//
long int SmilesMolSupplier::skipComments() {
  PRECONDITION(dp_inStream, "bad stream");
  if (this->atEnd()) return -1;

  std::streampos prev = dp_inStream->tellg();
  std::string tempStr = this->nextLine();
  if (!df_end) {
    // if we didn't immediately hit EOF, loop until we get a valid line:
    while ((tempStr[0] == '#') || (strip(tempStr).size() == 0)) {
      prev = dp_inStream->tellg();
      tempStr = this->nextLine();
      if (this->atEnd()) break;
    }
  }
  // if we hit EOF without getting a proper line, return -1:
  if (tempStr.empty() || (tempStr[0] == '#') || (strip(tempStr).size() == 0)) {
    return -1;
  }
  return static_cast<long int>(prev);
}

// --------------------------------------------------
//
//  Reads and processes the title line
//
void SmilesMolSupplier::processTitleLine() {
  PRECONDITION(dp_inStream, "bad stream");
  int pos = this->skipComments();
  if (pos >= 0) {
    dp_inStream->seekg(pos);

    std::string tempStr = getLine(dp_inStream);
    boost::char_separator<char> sep(d_delim.c_str(), "",
                                    boost::keep_empty_tokens);
    tokenizer tokens(tempStr, sep);
    for (tokenizer::iterator tokIter = tokens.begin(); tokIter != tokens.end();
         ++tokIter) {
      std::string pname = strip(*tokIter);
      d_props.push_back(pname);
    }
  }
}

std::string SmilesMolSupplier::getItemText(unsigned int idx) {
  PRECONDITION(dp_inStream, "no stream");
  unsigned int holder = d_next;
  bool endHolder = df_end;
  // this throws the relevant exception if we go too far:
  moveTo(idx);
  std::string res = getLine(dp_inStream);
  d_next = holder;
  df_end = endHolder;
  return res;
}

// --------------------------------------------------
//
//  Moves to the position of a particular entry in the
//  stream.
//
//  If insufficient entries are present, a FileParseException
//    will be thrown
//
void SmilesMolSupplier::moveTo(unsigned int idx) {
  PRECONDITION(dp_inStream, "bad instream");
  // get the easy situations (boundary conditions) out of the
  // way first:
  if (d_len > -1 && idx >= static_cast<unsigned int>(d_len)) {
    df_end = true;
    std::ostringstream errout;
    errout << "ERROR: Index error (idx = " << idx << "): "
           << "ran out of lines\n";
    throw FileParseException(errout.str());
  }

  // dp_inStream->seekg() is called for all idx values
  // and earlier calls to next() may have put the stream into a bad state
  dp_inStream->clear();

  // -----------
  // Case 1: we have already read the particular entry:
  //
  // Set the stream position and return
  // -----------
  if (!d_molpos.empty() && d_molpos.size() > idx) {
    dp_inStream->clear();  // clear the EOF tag if it has been set
    df_end = false;
    dp_inStream->seekg(d_molpos[idx]);
    d_next = idx;
    d_line = d_lineNums[idx];
    return;
  }

  // -----------
  // Case 2: we haven't read the entry, so move forward until
  //   we've gone far enough.
  // -----------
  if (d_molpos.empty()) {
    // if we are just starting out, process the title line
    dp_inStream->seekg(0);
    if (df_title) this->processTitleLine();
  } else {
    // move to the last position we've seen:
    dp_inStream->seekg(d_molpos.back());
    // read that line:
    std::string tmp = getLine(dp_inStream);
  }

  // the stream pointer is now at the last thing we read in
  while (d_molpos.size() <= idx) {
    int nextP = this->skipComments();
    if (nextP < 0) {
      std::ostringstream errout;
      errout << "ERROR: Index error (idx = " << idx << "): "
             << "ran out of lines\n";
      throw FileParseException(errout.str());
    } else {
      d_molpos.push_back(nextP);
      d_lineNums.push_back(d_line);
      if (d_molpos.size() == idx + 1 && df_end) {
        // boundary condition: we could read the point we were looking for
        // but not the next one.
        // indicate that we've reached EOF:
        dp_inStream->clear();
        dp_inStream->seekg(0, std::ios_base::end);
        d_len = d_molpos.size();
        break;
      }
    }
  }

  POSTCONDITION(d_molpos.size() > idx, "not enough lines");
  dp_inStream->seekg(d_molpos[idx]);
  d_next = idx;
  return;
}

// ----------------------------------------------------------------------
//
//  Grabs and returns the next molecule from the input stream.
//  After processing the line, the file is advanced to the next
//  position in the file (skipping blank and comment lines).
//
//  Throws a FileParseException if EOF has already been hit.
//
ROMol *SmilesMolSupplier::next() {
  PRECONDITION(dp_inStream, "no stream");
  ROMol *res = nullptr;

  if (d_next < 0) {
    d_next = 0;
  }

  // This throws an exception if it fails:
  moveTo(d_next);
  CHECK_INVARIANT(static_cast<int>(d_molpos.size()) > d_next,
                  "bad index length");

  // ---------
  // if we get here we can just build the molecule:
  // ---------
  // set the stream to the relevant position:
  dp_inStream->clear();  // clear the EOF tag if it has been set
  dp_inStream->seekg(d_molpos[d_next]);
  d_line = d_lineNums[d_next];
  // grab the line:
  std::string inLine = getLine(dp_inStream);
  // and process it:
  res = this->processLine(inLine);

  // if we don't already know the length of the supplier,
  // check if we can read another line:
  if (d_len < 0 && this->skipComments() < 0) {
    d_len = d_molpos.size();
  }

  // make sure the line number is correct:
  if (d_next < static_cast<int>(d_lineNums.size())) {
    d_line = d_lineNums[d_next];
  }

  ++d_next;
  // if we just hit the last one, simulate EOF:
  if (d_len > 0 && d_next == d_len) {
    df_end = true;
  }
  return res;
}

// ----------------------------------------------------------------------
//
//  Grabs and returns a particular molecule from the input stream.
//
//  Raises a FileParseException on failure.
//
ROMol *SmilesMolSupplier::operator[](unsigned int idx) {
  PRECONDITION(dp_inStream, "no stream");

  // ---------
  // move to the appropriate location in the file:
  // ---------
  moveTo(idx);

  // ---------
  // and then pull the molecule:
  // ---------
  ROMol *res = next();

  return res;
}

// ----------------------------------------------------------------------
//
//  Returns the number of entries in the input stream
//
unsigned int SmilesMolSupplier::length() {
  PRECONDITION(dp_inStream, "no stream");
  // return the number of molecule lines in the file
  if (d_len > 0) {
    return d_len;
  } else {
    std::streampos oPos = dp_inStream->tellg();
    if (d_molpos.size()) {
      // we've already read some molecules, go to the last
      // one and read it in to initialize our location:
      dp_inStream->seekg(d_molpos.back());
      // skip that line and then continue:
      this->skipComments();
    } else {
      // process the title line if need be:
      if (df_title) this->processTitleLine();
    }
    int pos = this->skipComments();
    while (pos >= 0) {
      d_molpos.push_back(pos);
      d_lineNums.push_back(d_line);
      pos = this->skipComments();
    }
    // now remember to set the stream to its original position:
    dp_inStream->seekg(oPos);
    d_len = d_molpos.size();
    return d_len;
  }
}

bool SmilesMolSupplier::atEnd() { return df_end; }
}