// -*- coding: utf-8 -*-
// Copyright (C) 2014 Laboratoire de Recherche et Développement 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/>.

#include <algorithm>
#include <numeric>
#include "randomize.hh"
#include "misc/random.hh"

namespace spot
{
  SPOT_API void
  randomize(tgba_digraph_ptr& aut, bool randomize_states,
	    bool randomize_transitions)
  {
    if (!randomize_states && !randomize_transitions)
      return;
    auto& g = aut->get_graph();
    if (randomize_states)
      {
	unsigned n = g.num_states();
	std::vector<unsigned> nums(n);
	std::iota(nums.begin(), nums.end(), 0);
	std::random_shuffle(nums.begin(), nums.end(), spot::mrand);
	g.rename_states_(nums);
	aut->set_init_state(nums[aut->get_init_state_number()]);
      }
    if (randomize_transitions)
      {
	g.remove_dead_transitions_();
	auto& v = g.transition_vector();
	std::random_shuffle(v.begin() + 1, v.end(), spot::mrand);
      }

    typedef tgba_digraph::graph_t::trans_storage_t tr_t;
    g.sort_transitions_([](const tr_t& lhs, const tr_t& rhs)
			{ return lhs.src < rhs.src; });
    g.chain_transitions_();
  }
}
