flake.nix

{
  description = "A Nix-flake-based Java development environment and package";

  outputs = { self, nixpkgs }:
    let
      javaVersion = 22; # Change this value to update the whole stack

      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
      forEachSupportedSystem = f: nixpkgs.lib.genAttrs supportedSystems (system: f {
        pkgs = import nixpkgs { inherit system; overlays = [ self.overlays.default ]; };
      });
    in
    {
      overlays.default = final: prev: {
        jdk = prev."jdk${toString javaVersion}";
      };

      devShells = forEachSupportedSystem ({ pkgs }: {
        default = pkgs.mkShell {
          packages = with pkgs; [ jdk ];
        };
      });

      packages = forEachSupportedSystem ({ pkgs }: {
        default = pkgs.stdenv.mkDerivation {
          pname = "discord-counting-tools";
          version = "1.0.0";
          src = ./.;

          meta = {
            description = "A Java program to generate weird ways to count using a Discord bot";
            license = "agpl3Only";
          };

          buildInputs = [ pkgs.openjdk ];
          nativeBuildInputs = [ pkgs.makeWrapper ];

          buildPhase = ''
            					echo "Compiling Java sources..."
            					mkdir -p build
            					find src -name '*.java' > sources.txt
            					javac -d build @sources.txt
            				'';

          installPhase = ''
            					echo "Packaging into JAR..."
            					mkdir -p $out/lib
            					cd build
            					jar cf $out/lib/discord-counting-tools.jar .
            					mkdir -p $out/bin
            					makeWrapper ${pkgs.jre}/bin/java $out/bin/discord-counting-tools \
            						--add-flags "-cp $out/lib/discord-counting-tools.jar discordCountingTools.Main"
            					echo "Build Successful."
            				'';
        };
      });
    };
}