/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program 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.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef STARK_MOVEMENT_SHORTEST_PATH_H
#define STARK_MOVEMENT_SHORTEST_PATH_H

#include "common/list.h"
#include "common/hashmap.h"

namespace Stark {

namespace Resources {
class FloorEdge;
}

/**
 * Find the shortest path between two nodes in a graph
 *
 * This is an implementation of Dijsktra's search algorithm
 */
class ShortestPath {
public:
	typedef Common::List<const Resources::FloorEdge *> NodeList;

	/** Computes the shortest path between the start and the goal graph nodes */
	NodeList search(const Resources::FloorEdge *start, const Resources::FloorEdge *goal);

private:
	typedef Common::HashMap<const Resources::FloorEdge *, const Resources::FloorEdge *> NodePrecedenceMap;
	typedef Common::HashMap<const Resources::FloorEdge *, float> NodeCostMap;

	const Resources::FloorEdge *popEdgeWithLowestCost(NodeList &frontier, const NodeCostMap &costSoFar) const;

	NodeList rebuildPath(const Resources::FloorEdge *start, const Resources::FloorEdge *goal,
	                                    const NodePrecedenceMap &cameFrom) const;
};

} // End of namespace Stark

#endif // STARK_MOVEMENT_SHORTEST_PATH_H