{ lib, config, pkgs, ... }:
{
  options.swarselmodules.nix-index = lib.mkEnableOption "nix-index settings";
  config = lib.mkIf config.swarselmodules.nix-index {
    programs.nix-index =
      let
        commandNotFound = pkgs.runCommandLocal "command-not-found.sh" { } ''
          mkdir -p $out/etc/profile.d
          cat > $out/etc/profile.d/command-not-found.sh <<'EOF'
          # Adapted from https://github.com/bennofs/nix-index/blob/master/command-not-found.sh
          command_not_found_handle() {
              if [ -n "''${MC_SID-}" ] || ! [ -t 1 ]; then
                  >&2 echo "$1: command not found"
                  return 127
              fi

              echo -n "searching nix-index..."
              ATTRS=$(@nix-locate@ --minimal --no-group --type x --type s --whole-name --at-root "/bin/$1")

              case $(echo -n "$ATTRS" | grep -c "^") in
              0)
                  >&2 echo -ne "$(@tput@ el1)\r"
                  >&2 echo "$1: command not found"
                  ;;
              *)
                  >&2 echo -ne "$(@tput@ el1)\r"
                  >&2 echo "The program ‘$(@tput@ setaf 4)$1$(@tput@ sgr0)’ is currently not installed."
                  >&2 echo "It is provided by the following derivation(s):"
                  while read -r ATTR; do
                      ATTR=''${ATTR%.out}
                      >&2 echo "  $(@tput@ setaf 12)nixpkgs#$(@tput@ setaf 4)$ATTR$(@tput@ sgr0)"
                  done <<< "$ATTRS"
                  ;;
              esac

              return 127
          }

          command_not_found_handler() {
              command_not_found_handle "$@"
              return $?
          }
          EOF

          substitute $out/etc/profile.d/command-not-found.sh        \
            $out/etc/profile.d/command-not-found.sh                 \
            --replace-fail @nix-locate@ ${pkgs.nix-index}/bin/nix-locate \
            --replace-fail @tput@ ${pkgs.ncurses}/bin/tput
        '';
      in

      {

        enable = true;
        package = pkgs.symlinkJoin {
          name = "nix-index";
          paths = [ commandNotFound ];
        };
      };
    programs.nix-index-database.comma.enable = true;
  };
}