/*

Stockfish, a UCI chess playing engine derived from Glaurung 2.1

Copyright (C) 2004-2008 Tord Romstad (Glaurung author)

Copyright (C) 2008-2013 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/>.

*/

#include <cassert>

#include <iomanip>

#include <sstream>

#include <stack>

#include "movegen.h"

#include "notation.h"

#include "position.h"

using namespace std;

static const char* PieceToChar[COLOR_NB] = { " PNBRQK", " pnbrqk" };

/// score_to_uci() converts a value to a string suitable for use with the UCI

/// protocol specifications:

///

/// cp <x> The score from the engine's point of view in centipawns.

/// mate <y> Mate in y moves, not plies. If the engine is getting mated

/// use negative values for y.

string score_to_uci(Value v, Value alpha, Value beta) {

stringstream s;

if (abs(v) < VALUE_MATE_IN_MAX_PLY)

s << "cp " << v * 100 / int(PawnValueMg);

else

s << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;

s << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : "");

return s.str();

}

/// move_to_uci() converts a move to a string in coordinate notation

/// (g1f3, a7a8q, etc.). The only special case is castling moves, where we print

/// in the e1g1 notation in normal chess mode, and in e1h1 notation in chess960

/// mode. Internally castle moves are always coded as "king captures rook".

const string move_to_uci(Move m, bool chess960) {

Square from = from_sq(m);

Square to = to_sq(m);

if (m == MOVE_NONE)

return "(none)";

if (m == MOVE_NULL)

return "0000";

if (type_of(m) == CASTLE && !chess960)

to = (to > from ? FILE_G : FILE_C) | rank_of(from);

string move = square_to_string(from) + square_to_string(to);

if (type_of(m) == PROMOTION)

move += PieceToChar[BLACK][promotion_type(m)]; // Lower case

return move;

}

/// move_from_uci() takes a position and a string representing a move in

/// simple coordinate notation and returns an equivalent legal Move if any.

Move move_from_uci(const Position& pos, string& str) {

if (str.length() == 5) // Junior could send promotion piece in uppercase

str[4] = char(tolower(str[4]));

for (MoveList<LEGAL> ml(pos); !ml.end(); ++ml)

if (str == move_to_uci(ml.move(), pos.is_chess960()))

return ml.move();

return MOVE_NONE;

}

/// move_to_san() takes a position and a legal Move as input and returns its

/// short algebraic notation representation.

const string move_to_san(Position& pos, Move m) {

if (m == MOVE_NONE)

return "(none)";

if (m == MOVE_NULL)

return "(null)";

assert(MoveList<LEGAL>(pos).contains(m));

Bitboard others, b;

string san;

Color us = pos.side_to_move();

Square from = from_sq(m);

Square to = to_sq(m);

Piece pc = pos.piece_on(from);

PieceType pt = type_of(pc);

if (type_of(m) == CASTLE)

san = to > from ? "O-O" : "O-O-O";

else

{

if (pt != PAWN)

{

san = PieceToChar[WHITE][pt]; // Upper case

// Disambiguation if we have more then one piece of type 'pt' that can

// reach 'to' with a legal move.

others = b = (pos.attacks_from(pc, to) & pos.pieces(us, pt)) ^ from;

while (b)

{

Move move = make_move(pop_lsb(&b), to);

if (!pos.pl_move_is_legal(move, pos.pinned_pieces()))

others ^= from_sq(move);

}

if (others)

{

if (!(others & file_bb(from)))

san += file_to_char(file_of(from));

else if (!(others & rank_bb(from)))

san += rank_to_char(rank_of(from));

else

san += square_to_string(from);

}

}

else if (pos.is_capture(m))

san = file_to_char(file_of(from));

if (pos.is_capture(m))

san += 'x';

san += square_to_string(to);

if (type_of(m) == PROMOTION)

san += string("=") + PieceToChar[WHITE][promotion_type(m)];

}

if (pos.move_gives_check(m, CheckInfo(pos)))

{

StateInfo st;

pos.do_move(m, st);

san += MoveList<LEGAL>(pos).size() ? "+" : "#";

pos.undo_move(m);

}

return san;

}

/// pretty_pv() formats human-readable search information, typically to be

/// appended to the search log file. It uses the two helpers below to pretty

/// format time and score respectively.

static string time_to_string(int64_t msecs) {

const int MSecMinute = 1000 * 60;

const int MSecHour = 1000 * 60 * 60;

int64_t hours = msecs / MSecHour;

int64_t minutes = (msecs % MSecHour) / MSecMinute;

int64_t seconds = ((msecs % MSecHour) % MSecMinute) / 1000;

stringstream s;

if (hours)

s << hours << ':';

s << setfill('0') << setw(2) << minutes << ':' << setw(2) << seconds;

return s.str();

}

static string score_to_string(Value v) {

stringstream s;

if (v >= VALUE_MATE_IN_MAX_PLY)

s << "#" << (VALUE_MATE - v + 1) / 2;

else if (v <= VALUE_MATED_IN_MAX_PLY)

s << "-#" << (VALUE_MATE + v) / 2;

else

s << setprecision(2) << fixed << showpos << float(v) / PawnValueMg;

return s.str();

}

string pretty_pv(Position& pos, int depth, Value value, int64_t msecs, Move pv[]) {

const int64_t K = 1000;

const int64_t M = 1000000;

std::stack<StateInfo> st;

Move* m = pv;

string san, padding;

size_t length;

stringstream s;

s << setw(2) << depth

<< setw(8) << score_to_string(value)

<< setw(8) << time_to_string(msecs);

if (pos.nodes_searched() < M)

s << setw(8) << pos.nodes_searched() / 1 << " ";

else if (pos.nodes_searched() < K * M)

s << setw(7) << pos.nodes_searched() / K << "K ";

else

s << setw(7) << pos.nodes_searched() / M << "M ";

padding = string(s.str().length(), ' ');

length = padding.length();

while (*m != MOVE_NONE)

{

san = move_to_san(pos, *m);

if (length + san.length() > 80)

{

s << "\n" + padding;

length = padding.length();

}

s << san << ' ';

length += san.length() + 1;

st.push(StateInfo());

pos.do_move(*m++, st.top());

}

while (m != pv)

pos.undo_move(*--m);

return s.str();

}