depot/third_party/nixpkgs/pkgs/games/stockfish/default.nix

{ lib, stdenv, fetchurl, fetchFromGitHub }:

let
    # The x86-64-modern may need to be refined further in the future
    # but stdenv.hostPlatform CPU flags do not currently work on Darwin
    # https://discourse.nixos.org/t/darwin-system-and-stdenv-hostplatform-features/9745
    archDarwin = if stdenv.isx86_64 then "x86-64-modern" else "apple-silicon";
    arch = if stdenv.isDarwin then archDarwin else
           if stdenv.isx86_64 then "x86-64" else
           if stdenv.isi686 then "x86-32" else
           if stdenv.isAarch64 then "armv8" else
           "unknown";

    # These files can be found in src/evaluate.h
    nnueBigFile = "nn-1111cefa1111.nnue";
    nnueBig = fetchurl {
      name = nnueBigFile;
      url = "https://tests.stockfishchess.org/api/nn/${nnueBigFile}";
      sha256 = "sha256-ERHO+hERa3cWG9SxTatMUPJuWSDHVvSGFZK+Pc1t4XQ=";
    };
    nnueSmallFile = "nn-37f18f62d772.nnue";
    nnueSmall = fetchurl {
      name = nnueSmallFile;
      url = "https://tests.stockfishchess.org/api/nn/${nnueSmallFile}";
      sha256 = "sha256-N/GPYtdy8xB+HWqso4mMEww8hvKrY+ZVX7vKIGNaiZ0=";
    };
in

stdenv.mkDerivation rec {
  pname = "stockfish";
  version = "17";

  src = fetchFromGitHub {
    owner = "official-stockfish";
    repo = "Stockfish";
    rev = "sf_${version}";
    sha256 = "sha256-oXvLaC5TEUPlHjhm7tOxpNPY88QxYHFw+Cev3Q8NEeQ=";
  };

  postUnpack = ''
    sourceRoot+=/src
    cp "${nnueBig}" "$sourceRoot/${nnueBigFile}"
    cp "${nnueSmall}" "$sourceRoot/${nnueSmallFile}"
  '';

  makeFlags = [ "PREFIX=$(out)" "ARCH=${arch}" "CXX=${stdenv.cc.targetPrefix}c++" ];
  buildFlags = [ "build" ];

  enableParallelBuilding = true;

  meta = with lib; {
    homepage = "https://stockfishchess.org/";
    description = "Strong open source chess engine";
    mainProgram = "stockfish";
    longDescription = ''
      Stockfish is one of the strongest chess engines in the world. It is also
      much stronger than the best human chess grandmasters.
      '';
    maintainers = with maintainers; [ luispedro siraben thibaultd ];
    platforms = ["x86_64-linux" "i686-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin"];
    license = licenses.gpl3Only;
  };

}