/*********************                                                        */
/*! \file regexp_operation.h
 ** \verbatim
 ** Original author: Tianyi Liang
 ** Major contributors: none
 ** Minor contributors (to current version): none
 ** This file is part of the CVC4 project.
 ** Copyright (c) 2009-2013  New York University and The University of Iowa
 ** See the file COPYING in the top-level source directory for licensing
 ** information.\endverbatim
 **
 ** \brief Symbolic Regular Expresion Operations
 **
 ** Symbolic Regular Expression Operations
 **/

#include "cvc4_private.h"

#ifndef __CVC4__THEORY__STRINGS__REGEXP__OPERATION_H
#define __CVC4__THEORY__STRINGS__REGEXP__OPERATION_H

#include <vector>
#include <set>
#include <algorithm>
#include "util/hash.h"
#include "util/regexp.h"
#include "theory/theory.h"
#include "theory/rewriter.h"
//#include "context/cdhashmap.h"

namespace CVC4 {
namespace theory {
namespace strings {

class RegExpOpr {
	typedef std::pair< Node, CVC4::String > PairNodeStr;
	typedef std::set< Node > SetNodes;
	typedef std::pair< Node, Node > PairNodes;

private:
	unsigned d_card;
    Node d_emptyString;
    Node d_true;
    Node d_false;
	Node d_emptySingleton;
	Node d_emptyRegexp;
	Node d_zero;
	Node d_one;

	char d_char_start;
	char d_char_end;
	Node d_sigma;
	Node d_sigma_star;
	
	std::map< PairNodes, Node > d_simpl_cache;
	std::map< PairNodes, Node > d_simpl_neg_cache;
	std::map< Node, Node > d_compl_cache;
	std::map< Node, std::pair< int, Node > > d_delta_cache;
	std::map< PairNodeStr, Node > d_dv_cache;
	std::map< PairNodeStr, std::pair< Node, int > > d_deriv_cache;
	std::map< Node, bool > d_cstre_cache;
	std::map< Node, std::pair< std::set<unsigned>, std::set<Node> > > d_cset_cache;
	std::map< Node, std::pair< std::set<unsigned>, std::set<Node> > > d_fset_cache;
	std::map< PairNodes, Node > d_inter_cache;
	//bool checkStarPlus( Node t );
	void simplifyPRegExp( Node s, Node r, std::vector< Node > &new_nodes );
	void simplifyNRegExp( Node s, Node r, std::vector< Node > &new_nodes );
	std::string niceChar( Node r );
	int gcd ( int a, int b );
	Node mkAllExceptOne( char c );

	void getCharSet( Node r, std::set<unsigned> &pcset, SetNodes &pvset );
	Node intersectInternal( Node r1, Node r2, std::map< unsigned, std::set< PairNodes > > cache, bool &spflag );
	void firstChars( Node r, std::set<unsigned> &pcset, SetNodes &pvset );

	//TODO: for intersection
	bool follow( Node r, CVC4::String c, std::vector< char > &vec_chars );

public:
	RegExpOpr();

	bool checkConstRegExp( Node r );
    void simplify(Node t, std::vector< Node > &new_nodes, bool polarity);
	int delta( Node r, Node &exp );
	int derivativeS( Node r, CVC4::String c, Node &retNode );
	Node derivativeSingle( Node r, CVC4::String c );
	bool guessLength( Node r, int &co );
	Node intersect(Node r1, Node r2, bool &spflag);

	std::string mkString( Node r );
};

}/* CVC4::theory::strings namespace */
}/* CVC4::theory namespace */
}/* CVC4 namespace */

#endif /* __CVC4__THEORY__STRINGS__REGEXP__OPERATION_H */