# Adapted and simplified from https://nixos.wiki/wiki/Mailman
{
  config,
  lib,
  ...
}: let
  inherit
    (lib)
    mkIf
    mkEnableOption
    mkOption
    ;
  inherit (lib.types) nonEmptyStr;
  cfg = config.services.mathebau-mailman;
in {
  options.services.mathebau-mailman = {
    enable = mkEnableOption "mathebau mailman service";
    hostName = mkOption {
      type = nonEmptyStr;
    };
    siteOwner = mkOption {
      type = nonEmptyStr;
    };
  };

  config = mkIf cfg.enable {
    services = {
      postfix = {
        enable = true;
        relayDomains = ["hash:/var/lib/mailman/data/postfix_domains"];
        sslCert = config.security.acme.certs.${cfg.hostName}.directory + "/full.pem";
        sslKey = config.security.acme.certs.${cfg.hostName}.directory + "/key.pem";
        config = {
          transport_maps = ["hash:/var/lib/mailman/data/postfix_lmtp"];
          local_recipient_maps = ["hash:/var/lib/mailman/data/postfix_lmtp"];
          proxy_interfaces = "130.83.2.184";
          smtputf8_enable = "no"; # HRZ does not know SMTPUTF8
        };
        relayHost = "mailout.hrz.tu-darmstadt.de"; # Relay to HRZ
      };
      mailman = {
        enable = true;
        inherit (cfg) siteOwner;
        hyperkitty.enable = true;
        webHosts = [cfg.hostName];
        serve.enable = true; #
      };
      nginx.virtualHosts.${cfg.hostName} = {
        enableACME = true;
        forceSSL = false;
      };
    };

    environment.persistence.${config.impermanence.name} = {
      directories = [
        "/var/lib/acme" # Persist TLS keys and account
        "/var/lib/mailman"
        "/var/lib/mailman-web"
      ];
    };

    security.acme.defaults.email = cfg.siteOwner;
    security.acme.acceptTerms = true;

    networking.firewall.allowedTCPPorts = [25 80 443];
  };
}