/*
  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
  Copyright (C) 2004-2024 The Stockfish developers (see AUTHORS file)

  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 "benchmark.h"

#include <cstdlib>
#include <fstream>
#include <iostream>
#include <vector>

namespace {

// clang-format off
const std::vector<std::string> Defaults = {
  "setoption name UCI_Chess960 value false",
  "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
  "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 10",
  "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - - 0 11",
  "4rrk1/pp1n3p/3q2pQ/2p1pb2/2PP4/2P3N1/P2B2PP/4RRK1 b - - 7 19",
  "rq3rk1/ppp2ppp/1bnpb3/3N2B1/3NP3/7P/PPPQ1PP1/2KR3R w - - 7 14 moves d4e6",
  "r1bq1r1k/1pp1n1pp/1p1p4/4p2Q/4Pp2/1BNP4/PPP2PPP/3R1RK1 w - - 2 14 moves g2g4",
  "r3r1k1/2p2ppp/p1p1bn2/8/1q2P3/2NPQN2/PPP3PP/R4RK1 b - - 2 15",
  "r1bbk1nr/pp3p1p/2n5/1N4p1/2Np1B2/8/PPP2PPP/2KR1B1R w kq - 0 13",
  "r1bq1rk1/ppp1nppp/4n3/3p3Q/3P4/1BP1B3/PP1N2PP/R4RK1 w - - 1 16",
  "4r1k1/r1q2ppp/ppp2n2/4P3/5Rb1/1N1BQ3/PPP3PP/R5K1 w - - 1 17",
  "2rqkb1r/ppp2p2/2npb1p1/1N1Nn2p/2P1PP2/8/PP2B1PP/R1BQK2R b KQ - 0 11",
  "r1bq1r1k/b1p1npp1/p2p3p/1p6/3PP3/1B2NN2/PP3PPP/R2Q1RK1 w - - 1 16",
  "3r1rk1/p5pp/bpp1pp2/8/q1PP1P2/b3P3/P2NQRPP/1R2B1K1 b - - 6 22",
  "r1q2rk1/2p1bppp/2Pp4/p6b/Q1PNp3/4B3/PP1R1PPP/2K4R w - - 2 18",
  "4k2r/1pb2ppp/1p2p3/1R1p4/3P4/2r1PN2/P4PPP/1R4K1 b - - 3 22",
  "3q2k1/pb3p1p/4pbp1/2r5/PpN2N2/1P2P2P/5PP1/Q2R2K1 b - - 4 26",
  "6k1/6p1/6Pp/ppp5/3pn2P/1P3K2/1PP2P2/3N4 b - - 0 1",
  "3b4/5kp1/1p1p1p1p/pP1PpP1P/P1P1P3/3KN3/8/8 w - - 0 1",
  "2K5/p7/7P/5pR1/8/5k2/r7/8 w - - 0 1 moves g5g6 f3e3 g6g5 e3f3",
  "8/6pk/1p6/8/PP3p1p/5P2/4KP1q/3Q4 w - - 0 1",
  "7k/3p2pp/4q3/8/4Q3/5Kp1/P6b/8 w - - 0 1",
  "8/2p5/8/2kPKp1p/2p4P/2P5/3P4/8 w - - 0 1",
  "8/1p3pp1/7p/5P1P/2k3P1/8/2K2P2/8 w - - 0 1",
  "8/pp2r1k1/2p1p3/3pP2p/1P1P1P1P/P5KR/8/8 w - - 0 1",
  "8/3p4/p1bk3p/Pp6/1Kp1PpPp/2P2P1P/2P5/5B2 b - - 0 1",
  "5k2/7R/4P2p/5K2/p1r2P1p/8/8/8 b - - 0 1",
  "6k1/6p1/P6p/r1N5/5p2/7P/1b3PP1/4R1K1 w - - 0 1",
  "1r3k2/4q3/2Pp3b/3Bp3/2Q2p2/1p1P2P1/1P2KP2/3N4 w - - 0 1",
  "6k1/4pp1p/3p2p1/P1pPb3/R7/1r2P1PP/3B1P2/6K1 w - - 0 1",
  "8/3p3B/5p2/5P2/p7/PP5b/k7/6K1 w - - 0 1",
  "5rk1/q6p/2p3bR/1pPp1rP1/1P1Pp3/P3B1Q1/1K3P2/R7 w - - 93 90",
  "4rrk1/1p1nq3/p7/2p1P1pp/3P2bp/3Q1Bn1/PPPB4/1K2R1NR w - - 40 21",
  "r3k2r/3nnpbp/q2pp1p1/p7/Pp1PPPP1/4BNN1/1P5P/R2Q1RK1 w kq - 0 16",
  "3Qb1k1/1r2ppb1/pN1n2q1/Pp1Pp1Pr/4P2p/4BP2/4B1R1/1R5K b - - 11 40",
  "4k3/3q1r2/1N2r1b1/3ppN2/2nPP3/1B1R2n1/2R1Q3/3K4 w - - 5 1",

  // 5-man positions
  "8/8/8/8/5kp1/P7/8/1K1N4 w - - 0 1",     // Kc2 - mate
  "8/8/8/5N2/8/p7/8/2NK3k w - - 0 1",      // Na2 - mate
  "8/3k4/8/8/8/4B3/4KB2/2B5 w - - 0 1",    // draw

  // 6-man positions
  "8/8/1P6/5pr1/8/4R3/7k/2K5 w - - 0 1",   // Re5 - mate
  "8/2p4P/8/kr6/6R1/8/8/1K6 w - - 0 1",    // Ka2 - mate
  "8/8/3P3k/8/1p6/8/1P6/1K3n2 b - - 0 1",  // Nd2 - draw

  // 7-man positions
  "8/R7/2q5/8/6k1/8/1P5p/K6R w - - 0 124", // Draw

  // Mate and stalemate positions
  "6k1/3b3r/1p1p4/p1n2p2/1PPNpP1q/P3Q1p1/1R1RB1P1/5K2 b - - 0 1",
  "r2r1n2/pp2bk2/2p1p2p/3q4/3PN1QP/2P3R1/P4PP1/5RK1 w - - 0 1",
  "8/8/8/8/8/6k1/6p1/6K1 w - -",
  "7k/7P/6K1/8/3B4/8/8/8 b - -",

  // Chess 960
  "setoption name UCI_Chess960 value true",
  "bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w HFhf - 0 1 moves g2g3 d7d5 d2d4 c8h3 c1g5 e8d6 g5e7 f7f6",
  "nqbnrkrb/pppppppp/8/8/8/8/PPPPPPPP/NQBNRKRB w KQkq - 0 1",
  "setoption name UCI_Chess960 value false"
};
// clang-format on

}  // namespace

namespace Stockfish::Benchmark {

// Builds a list of UCI commands to be run by bench. There
// are five parameters: TT size in MB, number of search threads that
// should be used, the limit value spent for each position, a file name
// where to look for positions in FEN format, and the type of the limit:
// depth, perft, nodes and movetime (in milliseconds). Examples:
//
// bench                            : search default positions up to depth 13
// bench 64 1 15                    : search default positions up to depth 15 (TT = 64MB)
// bench 64 1 100000 default nodes  : search default positions for 100K nodes each
// bench 64 4 5000 current movetime : search current position with 4 threads for 5 sec
// bench 16 1 5 blah perft          : run a perft 5 on positions in file "blah"
std::vector<std::string> setup_bench(const std::string& currentFen, std::istream& is) {

    std::vector<std::string> fens, list;
    std::string              go, token;

    // Assign default values to missing arguments
    std::string ttSize    = (is >> token) ? token : "16";
    std::string threads   = (is >> token) ? token : "1";
    std::string limit     = (is >> token) ? token : "13";
    std::string fenFile   = (is >> token) ? token : "default";
    std::string limitType = (is >> token) ? token : "depth";

    go = limitType == "eval" ? "eval" : "go " + limitType + " " + limit;

    if (fenFile == "default")
        fens = Defaults;

    else if (fenFile == "current")
        fens.push_back(currentFen);

    else
    {
        std::string   fen;
        std::ifstream file(fenFile);

        if (!file.is_open())
        {
            std::cerr << "Unable to open file " << fenFile << std::endl;
            exit(EXIT_FAILURE);
        }

        while (getline(file, fen))
            if (!fen.empty())
                fens.push_back(fen);

        file.close();
    }

    list.emplace_back("setoption name Threads value " + threads);
    list.emplace_back("setoption name Hash value " + ttSize);
    list.emplace_back("ucinewgame");

    for (const std::string& fen : fens)
        if (fen.find("setoption") != std::string::npos)
            list.emplace_back(fen);
        else
        {
            list.emplace_back("position fen " + fen);
            list.emplace_back(go);
        }

    return list;
}

}  // namespace Stockfish