{
  config,
  inputs,
  lib,
  pkgs,
  ...
}:
with lib; let
  cfg = config.custom.containers.headscale;
in {
  options.custom.containers.headscale.enable = mkOption {default = false;};

  config = mkIf cfg.enable {
    age.secrets = let
      secret = filename: {
        file = "${inputs.self}/secrets/${filename}";
      };
    in {
      "${config.custom.profile}/headscale/.env" = secret "${config.custom.profile}/headscale/.env";
    };

    #?? arion-headscale pull
    environment.shellAliases.arion-headscale = "sudo arion --prebuilt-file ${config.virtualisation.arion.projects.headscale.settings.out.dockerComposeYaml}";

    virtualisation.arion.projects.headscale.settings.services = {
      # https://headscale.net/
      # https://github.com/juanfont/headscale
      # BUG: Does not support generic DoH/DoT
      # https://github.com/juanfont/headscale/issues/1312
      headscale.service = {
        command = "serve";
        container_name = "headscale";
        env_file = [config.age.secrets."${config.custom.profile}/headscale/.env".path];
        image = "headscale/headscale:v0.23.0-beta.4";
        restart = "unless-stopped";

        ports = [
          "9999:9999"
          "9090:9090"
        ];

        volumes = [
          "${config.custom.containers.directory}/headscale/config:/etc/headscale"
          "${config.custom.containers.directory}/headscale/data:/var/lib/headscale"

          # Minimum config.yaml
          # https://github.com/juanfont/headscale/blob/main/config-example.yaml
          # https://github.com/juanfont/headscale/blob/main/integration/hsic/config.go
          "${pkgs.writeText "config.yaml" ''
            noise:
              private_key_path: /var/lib/headscale/noise_private.key
          ''}:/etc/headscale/config.yaml"
        ];
      };
    };
  };
}