{ config, lib, pkgs, ... }:
with lib;
let
  cfg = config.nyxs-nix.services.vrrp;
in
{
  options.nyxs-nix.services.vrrp = with types; {
    enable = mkEnableOption "Enable the vrrp quotes service";

    ip = mkOption {
      type = str;
      default = "10.5.0.5/24";
      description = "Virtual IP address";
    };

    priority = mkOption {
      type = int;
      default = 0;
      description = "Priority of the system in the vrrp pool";
    };

    interface = mkOption {
      type = str;
      default = "eth0";
      description = "interface for vrrp communication";
    };

    id = mkOption {
      type = int;
      default = 1;
      description = "virtual router config id";
    };

    peers = mkOption {
      type = nullOr (listOf str);
      default = null;
      description = "List of ips for the other vrrp instancess";
    };
  };

  config = mkIf cfg.enable {
    # networking.firewall.extraCommands = ''
    #   iptables -I INPUT 1 -i vrrp.6 -p tcp --dport 22 -j ACCEPT
    #   iptables -I INPUT 2 -i vrrp.6 -p tcp -j DROP
    # '';

    # networking.vlans."eth0.6" = {
    #   id = 6;
    #   interface = "eth0";
    # };

    # networking.interfaces."eth0.6" = {
    #   ipv4.routes = [
    #      {
    #       address = "10.5.1.0";
    #       prefixLength = 24;
    #       via = "10.5.1.1";
    #     }
    #     {
    #       address = "0.0.0.0";
    #       prefixLength = 0;
    #       via = "10.5.1.1";
    #     }
    #   ];
    # };

    services.keepalived = {
      enable = true;

      openFirewall = true;

      extraGlobalDefs = ''
        use_symlink_paths true
      '';
      
      vrrpInstances.VIP_1 = {
        state = "BACKUP";
        interface = cfg.interface;
        virtualRouterId = cfg.id;
        priority = cfg.priority;
        virtualIps = [
          {
            addr = cfg.ip;
            scope = "global";
          }
        ];
        unicastPeers = mkIf (cfg.peers != null) cfg.peers;
        # useVmac = true;
        # vmacXmitBase = true;
        trackScripts = ["track_nginx"];
      };
      vrrpScripts = {
        track_nginx = {
          script = "${pkgs.systemd}/bin/systemctl is-active nginx";
          interval = 1;
          timeout = 2;
          rise = 2;
          fall = 2;
          weight = 0;
          user = "root";
        };
      };
    };
  };
}