{
  description = "Advent of Code 2024: PHP";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
  };

  outputs =
    { nixpkgs, ... }:
    let
      pkgs = import nixpkgs {
        config.allowUnfree = true;
      };
    in
    {
      devShells.x86_64-linux.default =
        let
          phpVersion = "php84";

          phpPackage = pkgs.lib.attrByPath [ phpVersion ] null pkgs;
          phpPackages = pkgs.lib.attrByPath [ "${phpVersion}Packages" ] null pkgs;
          phpExtensions = pkgs.lib.attrByPath [ "${phpVersion}Extensions" ] null pkgs;
        in
        pkgs.mkShell {
          # build tools
          nativeBuildInputs = with pkgs; [
            phpPackage
            nodejs_18
          ];
          # dependencies
          buildInputs = with pkgs; [
            intelephense
            phpunit
            phpPackages.php-cs-fixer
            phpPackages.phpstan
            phpExtensions.xdebug

            gh # GitHub CLI
          ];
        };

    };
}