{ config, pkgs, lib, ... }:
let
  cfg = config.services.gickup;
  format = pkgs.formats.yaml { };
in
{
  options.services.gickup = {
    enable = lib.mkEnableOption "gickup, a git repository mirroring service";
    package = lib.mkPackageOption pkgs "gickup" { };

    gitPackage = lib.mkPackageOption pkgs "git" { };
    gitLfsPackage = lib.mkPackageOption pkgs "git-lfs" { };

    settings = lib.mkOption {
      type = lib.types.submodule {
        freeformType = format.type;
      };
    };
  };

  config = lib.mkIf cfg.enable {
    users.users.gickup = {
      isSystemUser = true;
      group = "gickup";
      home = "/var/lib/gickup";
    };

    users.groups.gickup = { };

    systemd.services.gickup = {
      description = "Gickup git repository mirroring service";
      wantedBy = [ "multi-user.target" ];
      after = [ "network.target" ];

      path = [
        cfg.gitPackage
        cfg.gitLfsPackage
      ];

      serviceConfig = {
        ExecStart = utils.escapeSystemdExecArgs [
          (lib.getExe cfg.package)
          (format.generate "gickup-settings.conf" cfg.settings)
        ];

        StateDirectory = "gickup";
        WorkingDirectory = "gickup";
        RuntimeDirectory = "gickup";
        RuntimeDirectoryMode = "0700";

        # Hardening options
        AmbientCapabilities = [];
        LockPersonality = true;
        NoNewPrivileges = true;
        PrivateDevices = true;
        PrivateMounts = 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"
          "~@resources"
          "~@privileged"
        ];
        UMask = "0002";
        CapabilityBoundingSet = [];
      };
    };
  };
}