// Copyright (C) 2012 Laboratoire de Recherche et Developpement de
// l'Epita (LRDE).
//
// This file is part of Spot, a model checking library.
//
// Spot is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// Spot 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, see <http://www.gnu.org/licenses/>.

#ifndef SPOT_TGBAALGOS_ISWEAKSCC_HH
# define SPOT_TGBAALGOS_ISWEAKSCC_HH

#include "scc.hh"

namespace spot
{
  /// \addtogroup tgba_misc
  /// @{

  /// \brief Whether the SCC number \a scc in \a map is weak.
  ///
  /// An SCC is weak if either its cycles are all accepting, or they
  /// are all non-accepting.
  ///
  /// The scc_map \a map should have been built already.  The absence
  /// of accepting cycle is easy to check (the scc_map can tell
  /// whether the SCC is non-accepting already).  Similarly, an SCC in
  /// which all transitions belong to all acceptance sets is
  /// necessarily weak.
  /// For other accepting SCCs, this function enumerates all cycles in
  /// the given SCC (it stops if it find a non-accepting cycle).
  bool is_weak_scc(scc_map& map, unsigned scc, bool easydetect = true);

  /// \brief Whether the SCC number \a scc in \a map is complete
  ///
  /// A SCC is complete iff for all states for all label there exist
  /// a transition that stay into this SCC.
  bool
  is_complete_scc(const tgba *a, scc_map& map, unsigned scc);

  /// \brief Whether the SCC number \a scc in \a map is syntactically weak.
  ///
  /// An SCC is syntactically weak iff the lowest label of states inside 
  /// this SCC corresponds to an obligation label
  ///
  /// Work only on tgba where labels are formula 
  /// 
  /// The scc_map \a map should have been built already.  The absence
  /// of accepting cycle is easy to check (the scc_map can tell
  /// whether the SCC is non-accepting already).  Similarly, an SCC in
  /// which all transitions belong to all acceptance sets is
  /// necessarily weak.
  /// For other accepting SCCs, this function enumerates all cycles in
  /// the given SCC (it stops if it find a non-accepting cycle).
  bool is_syntactic_weak_scc(const tgba *a, scc_map& map, unsigned scc);

  /// \brief wether a SCC is syntactically characterized by a gurarantee 
  /// formula
  ///
  /// Work only on tgba where labels are formula 
  bool is_syntactic_terminal_scc(const tgba *a, scc_map& map, unsigned scc);

  /// \brief wether a SCC is terminal using an heuristic
  ///
  /// The heuristic try to characterize the SCC by loking if the SCC 
  /// is complete and all cycle are fully accepting ( all transitions 
  /// have all acceptance conditions)
  bool
  is_terminal_heuristic (const tgba *a, scc_map& map, unsigned scc);

  /// \brief wether a SCC is weak using an heuristic
  /// 
  /// The heuristic looks if all path are fully accepting 
  bool
  is_weak_heuristic(scc_map& map, unsigned scc);

  /// @}
}


#endif // SPOT_TGBAALGOS_ISWEAKSCC_HH