{ config, options, lib, pkgs, ... }:
with lib;
with lib.custom;
let
    cfg = config.modules.shell.gnupg;
in {
    options.modules.shell.gnupg = with types; {
        enable   = mkBoolOpt false;
        cacheTTL = mkOpt int 3600;  # 1hr
    };

    config = mkIf cfg.enable {
        environment.variables.GNUPGHOME = "$XDG_CONFIG_HOME/gnupg";

        programs.gnupg.agent.enable = true;

        user.packages = [
            pkgs.tomb
        ];

        # HACK Without this config file you get "No pinentry program" on 20.03.
        #      programs.gnupg.agent.pinentryFlavor doesn't appear to work, and this
        #      is cleaner than overriding the systemd unit.
        home.configFile."gnupg/gpg-agent.conf" = {
            text = ''
                default-cache-ttl ${toString cfg.cacheTTL}
                pinentry-program ${pkgs.pinentry.gtk2}/bin/pinentry
            '';
        };
    };
}