/*
 * This file is part of the program ltl2dstar (http://www.ltl2dstar.de/).
 * Copyright (C) 2005-2007 Joachim Klein <j.klein@ltl2dstar.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as 
 *  published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#ifndef LTLSAFETYAUTOMATA_H
#define LTLSAFETYAUTOMATA_H

/** @file
 * Provide wrapper to the scheck tool.
 */

#include "APSet.hpp"
#include "LTLFormula.hpp"
#include "DBA2DRA.hpp"
#include "common/TempFile.hpp"
#include "common/Exceptions.hpp"
#include "parsers/parser_interface.hpp"


#include <memory>

/**
 * Wrapper to the external scheck tool that can convert (co)safe LTL formulas
 * to determinstic Büchi automata.
 */
class LTLSafetyAutomata {
public:
  /** Constructor */
  LTLSafetyAutomata(bool only_syntactically_safe=true) 
    : _only_syn(only_syntactically_safe) {}

  /** 
   * Generate a DRA for an LTL formula using scheck
   * @param ltl the formula
   * @param scheck_path the path to the scheck executable
   * @return a shared_ptr to the generated DRA (on failure returns a ptr to 0)
   */
  template <class DRA>
  typename DRA::shared_ptr 
  ltl2dra(LTLFormula& ltl, const std::string& scheck_path) {
    LTLFormula_ptr ltl_;
    LTLFormula *ltl_for_scheck=0;
    
    bool safe=false;
    
    if (ltl.isSafe()) {
      safe=true;
      ltl_=ltl.negate();
      ltl_for_scheck=ltl_.get();
    } else if (ltl.isCoSafe()) {
      ltl_for_scheck=&ltl;
    } else {
      if (_only_syn) {
	// Not syntactically safe -> abort
	typename DRA::shared_ptr p;
	return p;
      }
    }

    //    std::cerr<< "Calling scheck with " 
    //	     <<ltl_for_scheck->toStringPrefix() << " : " << safe << std::endl;

    std::auto_ptr<NBA_t> nba(ltl2dba(*ltl_for_scheck, 
				     scheck_path,
				     _only_syn));
    
    if (nba.get()==0) {
      typename DRA::shared_ptr p;
      return p;
    }
    
    //    nba->print(std::cerr);
    
    // safe -> negate DRA
    return DBA2DRA::dba2dra<NBA_t,DRA>(*nba,safe);
    //    return dba2dra<DRA>(*nba, safe);
    // nba is auto-destructed
  }
  

  
private:
  /** Only check syntactically safe formulas */
  bool _only_syn;
  
  typedef NBA<APElement, EdgeContainerExplicit_APElement> NBA_t;

  /** 
   * Generate a DRA for an LTL formula using scheck
   * @param ltl the formula
   * @param scheck_path the path to the scheck executable
   * @param only_syn don't use check for pathological formulas
   * @return a shared_ptr to the generated DRA (on failure returns a ptr to 0)
   */
  NBA_t *ltl2dba(LTLFormula& ltl, const std::string& scheck_path, bool only_syn=true) {
    THROW_EXCEPTION(Exception, "Unsupported code path, please use the original source.");
    return 0;
  }
  
};

#endif