iocaine/nix/nixos-module.nix

# SPDX-FileCopyrightText: 2025 Gergely Nagy
# SPDX-FileContributor: Gergely Nagy
#
# SPDX-License-Identifier: MIT
{ self }:
{
  config,
  lib,
  pkgs,
  ...
}:
let
  cfg = config.services.iocaine;
  defaultPackage = self.packages.${pkgs.hostPlatform.system}.iocaine;
  tomlFormat = pkgs.formats.toml { };
  configFile = tomlFormat.generate "iocaine.toml" cfg.config;
in
{
  options.services.iocaine = {
    enable = lib.mkEnableOption "iocaine, the deadliest poison known to AI";
    package = lib.mkOption {
      type = lib.types.package;
      default = defaultPackage;
      description = "The iocaine package to use.";
    };
    config = lib.mkOption {
      inherit (tomlFormat) type;
      default = { };
      description = "THe configuration for iocaine.";
    };
  };

  config = lib.mkIf cfg.enable {
    assertions = [
      {
        assertion = cfg.config.sources.markov or null != null;
        message = ''
          You have to define at least one Markov source (`services.iocaine.config.sources.markov`) for iocaine.
        '';
      }
      {
        assertion = cfg.config.sources.words or null != null;
        message = ''
          You have to define a word list source (`services.iocaine.config.sources.words`) for iocaine.
        '';
      }
    ];

    systemd.services.iocaine = {
      description = "iocaine, the deadliest poison known to AI";
      restartTriggers = [ configFile ];
      wantedBy = [ "multi-user.target" ];
      after = [ "network.target" ];
      environment = {
        HOME = "%S/home";
      };

      serviceConfig = {
        Type = "simple";
        ExecStart = "${pkgs.lib.getExe cfg.package} --config-file ${configFile}";
        Restart = "on-failure";
        DynamicUser = true;

        StateDirectory = "iocaine";
        WorkingDirectory = "/var/lib/iocaine";

        ProtectSystem = "strict";
        SystemCallArchitectures = "native";
        MemoryDenyWriteExecute = true;
        NoNewPrivileges = true;
        PrivateTmp = true;
        PrivateDevices = true;
        RestrictAddressFamilies = [
          "AF_INET"
          "AF_INET6"
        ];
        RestrictNamespaces = true;
        RestrictRealtime = true;
        DevicePolicy = "closed";
        ProtectClock = true;
        ProtectHostname = true;
        ProtectProc = "invisible";
        ProtectControlGroups = true;
        ProtectKernelModules = true;
        ProtectKernelTunables = true;
        LockPersonality = true;
      };
    };
  };
}