flake.nix

{
  description = "Global FHS environment for your daily computing needs.";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
    utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, utils }: utils.lib.eachDefaultSystem (system: let 
    pkgs = import nixpkgs {
      inherit system;
    };
  in {
    devShells.default = let 
    script = pkgs.writeShellScriptBin "test-vm" ''
      timeout() {
        seq 1 5 | while read r; do
          echo x
          sleep 1
        done | awk '
        NR < 5 {
          printf "\r(press CTRL-C to cancel) Starting vm in %d\033[0K", 6 - NR
        }
        NR > 4 {
          printf "\rStarting vm in %d\033[0K", 6 - NR
        }
        END {
          printf "\rStarting vm\033[0K\n"
        }
        '
      }
      
      run-vm() {
        pushd test &>/dev/null
        nix flake update -v --inputs-from ../ 2>&1 | awk '
        {
          printf "\rUpdating flake"
        }
        END {
          printf "\rDone\033[0K\n"
        }
        '
        nixos-shell --flake .#
        popd &>/dev/null
      }
      
      test-vm() {
        run-vm
        timeout
        test-vm
      }

      test-vm
    '';
    in pkgs.mkShell {
      packages = with pkgs; [
        nixos-shell
        ncurses
        script
        gawk
        jq
      ];
      shellHook = ''
        echo -e "\033[31mRun test-vm to test your code\033[0m"
      '';
      NIX_PATH="nixpkgs=${nixpkgs}";
    };
  }) // {
    nixosModules = rec {
      nixos-fhs = import ./module;
      default = nixos-fhs;
    };
  };
}