{
  config,
  lib,
  pkgs,
  ...
}:
let

  cfg = config.services.mail-quota-warning;

in
{

  options = {
    services.mail-quota-warning = {

      enable = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = ''
          Enable mail-quota-warning daemon.
        '';
      };

      settings = lib.mkOption {
        type = lib.types.submodule {
          freeformType = with lib.types; attrsOf anything;
          options = {
            CHECK_INTERVAL_DAYS = lib.mkOption {
              default = 7;
              type = lib.types.int;
              description = ''
                Interval of days in which a warning message will be
                delivered.
              '';
            };
            QUOTA_WARNING_THRESHOLD_PERCENT = lib.mkOption {
              default = 80;
              type = lib.types.int;
              description = ''
                Threshold of used mailbox space in percent after which
                a warning message will be delivered.
              '';
            };
          };
        };
        default = { };
        description = ''
          Extra options which should be used by the mailbox quota warning script.
        '';
        example = lib.literalExpression ''
          {
            CHECK_INTERVAL_DAYS = 7;
            QUOTA_WARNING_THRESHOLD_PERCENT = 80;
          }
        '';
      };

      secretFile = lib.mkOption {
        type = lib.types.nullOr (lib.types.pathWith {
          inStore = false;
          absolute = true;
        });
        default = null;
        example = "/run/keys/mail-quota-warning-secrets";
        description = ''
          A YAML file containing secrets, see example config file
          in the repository.
        '';
      };

      interval = lib.mkOption {
        type = lib.types.str;
        default = "*:00,30:00";
        description = ''
          How often we run the sync. Default is half an hour.

          The format is described in
          {manpage}`systemd.time(7)`.
        '';
      };

    };
  };

  config = lib.mkIf cfg.enable {


  # FIXME maybe move this to an external module
  systemd.services.tlsa-cloudflare-update = {
    description = "Check and update TLSA/DANE record for mx1 from Stalwart ACME Cert";
  
    after = [ "network-online.target" "stalwart-mail.service" "agenix.service" ];
    wants = [ "network-online.target" "stalwart-mail.service" "agenix.service" ];
  
    serviceConfig = {
      Type = "oneshot";
      User = "stalwart-mail";
      Group = "stalwart-mail";
      EnvironmentFile = config.age.secrets.gotlsaflare-cloudflare-token.path;
      RuntimeDirectory = "stalwart-tlsa";
    };

    environment = {
      DOMAIN = "project-insanity.org";
      SUBDOMAIN = "mx1";
      PORT = "25";
      ACME_PROVIDER_ID = "cloudflare3";
    };

    path = with pkgs; [
      bash
      coreutils
      openssl
      dnsutils
      gotlsaflare
      rocksdb.tools
      gawk
    ];

    script = ''
      set -eu

      TLSA_RECORD="_$PORT._tcp.$SUBDOMAIN.$DOMAIN"
      DB_PATH="/var/lib/stalwart-mail/db"
      TEMP_RAW="/run/stalwart-tlsa/cert.bundle"
      TEMP_CRT="/run/stalwart-tlsa/cert.crt"

      echo "Starting TLSA update process for $DOMAIN"

      ldb --db="$DB_PATH" --column_family=s get "acme.$ACME_PROVIDER_ID.cert" | base64 -d > "$TEMP_RAW"

      if [ ! -s "$TEMP_RAW" ]; then
        echo "ERROR: ACME certificate extraction failed"
        exit 1
      fi

      openssl x509 -in "$TEMP_RAW" -out "$TEMP_CRT"

      LOCAL_HASH=$(openssl x509 -in "$TEMP_CRT" -pubkey -noout | openssl pkey -pubin -outform DER | openssl sha256 | awk '{print tolower($2)}')
      echo "Local hash: $LOCAL_HASH"

      UPSTREAM_HASH=$(dig +nosplit +short TLSA "$TLSA_RECORD" | awk '{print tolower($4)}' | head -n1)
      echo "Upstream hash: $UPSTREAM_HASH"

      if [ "$LOCAL_HASH" = "$UPSTREAM_HASH" ]; then
        echo "Hashes match. DNS is up to date."
        exit 0
      fi

      echo "Hashes differ! Updating Cloudflare..."
      gotlsaflare update \
        --url "$DOMAIN" \
        --subdomain "$SUBDOMAIN" \
        --tcp"$PORT" \
        --cert "$TEMP_CRT"

      echo "TLSA update completed successfully."
    '';
  };

  systemd.timers.tlsa-cloudflare-update = {
    description = "Run TLSA check and update every 15 minutes";
    wantedBy = [ "timers.target" ];
    timerConfig = {
      OnBootSec = "2m";
      OnUnitActiveSec = "15m";
      Unit = "tlsa-cloudflare-update.service";
    };
  };

    systemd.services."mail-quota-warning" = {
      description = "mail-quota-warning script";
      after = [ "network.target" ];
      wants = [ "network-online.target" ];
      environment = {
        PYTHONUNBUFFERED = "1";
      }
      // lib.mapAttrs (_: v: toString v) cfg.settings;
      serviceConfig = {
        Type = "simple";
        LoadCredential = lib.optionalString (cfg.secretFile != null) "secrets.yaml:${cfg.secretFile}";
        ExecStart = "${lib.getExe pkgs.mail-quota-warning} --config \${CREDENTIALS_DIRECTORY}/secrets.yaml";
        WorkingDirectory = "%S/mail-quota-warning";
        StateDirectory = "mail-quota-warning";

        # hardening
        AmbientCapabilities = "";
        CapabilityBoundingSet = "";
        DevicePolicy = "closed";
        DynamicUser = true;
        LockPersonality = true;
        MemoryDenyWriteExecute = true;
        NoNewPrivileges = true;
        PrivateDevices = true;
        PrivateTmp = true;
        PrivateUsers = true;
        ProcSubset = "pid";
        ProtectClock = true;
        ProtectControlGroups = true;
        ProtectHome = true;
        ProtectHostname = true;
        ProtectKernelLogs = true;
        ProtectKernelModules = true;
        ProtectKernelTunables = true;
        ProtectProc = "invisible";
        ProtectSystem = "strict";
        RemoveIPC = true;
        RestrictAddressFamilies = [
          "AF_INET"
          "AF_INET6"
        ];
        RestrictNamespaces = true;
        RestrictRealtime = true;
        RestrictSUIDSGID = true;
        SystemCallArchitectures = "native";
        SystemCallFilter = [
          "@system-service"
          "~@privileged"
        ];
        UMask = "0077";
      };
    };

    systemd.timers.mail-quota-warning = {
      timerConfig = {
        OnCalendar = [
          ""
          cfg.interval
        ];
      };
      wantedBy = [ "timers.target" ];
    };

  };

  meta = {
    maintainers = with lib.maintainers; [ onny ];
  };

}