/****************************************************************************************[Dimacs.h]
Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
Copyright (c) 2007-2010, Niklas Sorensson

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
**************************************************************************************************/

#ifndef SLIME_Dimacs_h
#define SLIME_Dimacs_h

#include <stdio.h>

#include "ParseUtils.h"
#include "SolverTypes.h"

namespace SLIME {

//=================================================================================================
// DIMACS Parser:

template <class B, class Solver>
static void readClause(B &in, Solver &S, vec<Lit> &lits) {
  int parsed_lit, var;
  lits.clear();
  for (;;) {
    parsed_lit = parseInt(in);
    if (parsed_lit == 0)
      break;
    var = abs(parsed_lit) - 1;
    while (var >= S.nVars())
      S.newVar();
    lits.push((parsed_lit > 0) ? mkLit(var) : ~mkLit(var));
  }
}

template <class B, class Solver>
static void parse_DIMACS_main(B &in, Solver &S) {
  vec<Lit> lits;
  int vars = 0;
  int clauses = 0;
  int cnt = 0;
  for (;;) {
    skipWhitespace(in);
    if (*in == EOF)
      break;
    else if (*in == 'p') {
      if (eagerMatch(in, "p cnf")) {
        vars = parseInt(in);
        clauses = parseInt(in);
      } else {
        printf("PARSE ERROR! Unexpected char: %d\n", *in), exit(3);
      }
    } else if (*in == 'c' || *in == 'p')
      skipLine(in);
    else {
      cnt++;
      readClause(in, S, lits);
      S.addClause_(lits);
    }
  }
  if (vars != S.nVars())
    fprintf(stderr,
            "WARNING! DIMACS header mismatch: wrong number of variables.\n");
  if (cnt != clauses)
    fprintf(stderr,
            "WARNING! DIMACS header mismatch: wrong number of clauses.\n");
}

// Inserts problem into solver.
//
template <class Solver>
static void parse_DIMACS(FILE *input_stream, Solver &S) {
  StreamBuffer in(input_stream);
  parse_DIMACS_main(in, S);
}

//=================================================================================================

//=================================================================================================
} // namespace SLIME

#endif
