{
  lib,
  config,
  pkgs,
  ...
}:
with lib; let
  haCfg = config.pub-solar.home-assistant;
  cfg = config.pub-solar.home-assistant.mqtt;
in {
  config = mkIf (haCfg.enable && cfg.enable) {
    networking.firewall.allowedTCPPorts = [
      1883 # mosquitto
    ];

    services.mosquitto = {
      enable = true;
      listeners = [{users = cfg.users;}];
    };
  };
}