/*
  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad

  Stockfish 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.

  Stockfish 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/>.
*/

#if !defined(SEARCH_H_INCLUDED)
#define SEARCH_H_INCLUDED

#include <cstring>
#include <vector>

#include "types.h"

class Position;
struct SplitPoint;

namespace Search {

/// The Stack struct keeps track of the information we need to remember from
/// nodes shallower and deeper in the tree during the search. Each search thread
/// has its own array of Stack objects, indexed by the current ply.

struct Stack {
  SplitPoint* sp;
  int ply;
  Move currentMove;
  Move excludedMove;
  Move bestMove;
  Move killers[2];
  Depth reduction;
  Value eval;
  Value evalMargin;
  int skipNullMove;
};


/// The LimitsType struct stores information sent by GUI about available time
/// to search the current move, maximum depth/time, if we are in analysis mode
/// or if we have to ponder while is our opponent's side to move.

struct LimitsType {

  LimitsType() {  memset(this, 0, sizeof(LimitsType)); }
  bool useTimeManagement() const { return !(maxTime | maxDepth | maxNodes | infinite); }

  int time, increment, movesToGo, maxTime, maxDepth, maxNodes, infinite, ponder;
};


/// The SignalsType struct stores volatile flags updated during the search
/// typically in an async fashion, for instance to stop the search by the GUI.

struct SignalsType {
  bool stopOnPonderhit, firstRootMove, stop, failedLowAtRoot;
};

extern volatile SignalsType Signals;
extern LimitsType Limits;
extern std::vector<Move> RootMoves;
extern Position RootPosition;

extern void init();
extern int64_t perft(Position& pos, Depth depth);
extern void think();

} // namespace

#endif // !defined(SEARCH_H_INCLUDED)