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

with lib;

let
hasIface = iface: elem iface (numbers.api.hostIfaces config.networking.hostName);
strIfHasIface = iface: s: if hasIface iface then s else "";
attrsetIfHasIface = iface: as: if hasIface iface then as else {};
eltIfHasIface = iface: elt: if hasIface iface then [ elt ] else [];

in

{
  imports = [
    #./pgpool.nix
    ./udp514.nix
  ];

  services.udp514-journal.enable = true;
  services.coredns = {
    enable = true;
    config = ''
      . {
        ${strIfHasIface "sec0" "bind sec0"}
        ${strIfHasIface "lan0" "bind lan0"}
        whoami
      }
    '';
  };

  #services.postgresql = {
  #  enable = true;
  #  dataDir = "/srv/pgdata";
  #  settings = {
  #    default_transaction_isolation = "repeatable read";
  #  };
  #  authentication = ''
  #    host all all 10.127.1.2/29 trust
  #  '';
  #  enableTCPIP = true;
  #};

  #systemd.tmpfiles.rules = [
  #  "d /srv/pgdata 775 postgres postgres -"
  #];

  #services.pgpool = {
  #  enable = true;
  #  config = ''
  #    backend_clustering_mode = 'snapshot_isolation'
  #    backend_hostname0 = '10.127.1.2'
  #    backend_port0 = 5432
  #    backend_weight0 = 1
  #    backend_data_directory0 = '/srv/pgdata'
  #    backend_flag0 = ALLOW_TO_FAILOVER
  #    backend_hostname1 = '10.127.1.3'
  #    backend_port1 = 5432
  #    backend_weight1 = 1
  #    backend_data_directory1 = '/srv/pgdata'
  #    backend_flag1 = ALLOW_TO_FAILOVER
  #    listen_address = '*'
  #    logging_collector = true
  #    log_destination = 'syslog,stderr'
  #    log_min_messages = 'INFO'
  #  '';
  #};

  services.k3s = {
    enable = true;
    tokenFile = "/etc/k3s.token";
    #serverAddr =
    #  mkIf (config.networking.hostName != "snorlax")
    #    "https://${(numbers.api.hostIface "snorlax" "sec0").ip}:6443";
    #clusterInit = config.networking.hostName == "snorlax";
    extraFlags = (
    " --datastore-endpoint=nats://localhost:4222?noEmbed=true&bucket=k0-kine&replicas=2,nats://10.127.1.2:4222,nats://10.127.1.3:4222,nats://10.127.1.4:4222"+
    " --disable=traefik"+
    " --disable=local-storage"+
    " --cluster-cidr=10.128.0.0/16"+
    " --flannel-backend=host-gw"+
    (strIfHasIface "sec0" " --node-ip=${(numbers.api.hostIface config.networking.hostName "sec0").ip}")+
    (strIfHasIface "lan0" " --node-external-ip=${(numbers.api.hostIface config.networking.hostName "lan0").ip}")+
    "");
    #"--node-ip=${config.systemd.network
  };
  
  systemd.services.nats-datadir = {
    requiredBy = [ "nats.service" ];
    before = [ "nats.service" ];
    serviceConfig = {
      Type = "oneshot";
      ExecStart = pkgs.writeScript "nats-datadir" ''
        #!${pkgs.bash}/bin/bash
        ${pkgs.coreutils}/bin/mkdir -p /srv/nats
        ${pkgs.coreutils}/bin/chown -R nats:nats /srv/nats
        ${pkgs.coreutils}/bin/chmod 750 /srv/nats
      '';
    };
  };

  systemd.services.nats.unitConfig.Requires = [ "systemd-tmpfiles-resetup.service" ];
  systemd.services.nats.unitConfig.After = [ "systemd-tmpfiles-resetup.service" ];

  services.nats = {
    enable = true;
    serverName = config.networking.hostName;
    dataDir = "/srv/nats";
    jetstream = true;
    settings = {
      cluster = {
        name = "cascade";
        no_advertise = true;
        port = 6222;
        routes = [
          "nats://10.127.1.2:6222"
          "nats://10.127.1.3:6222"
          "nats://10.127.1.4:6222"
        ];
      };
      http_port = 8222;
    };
  };

  networking.firewall.allowedUDPPorts = [ 53 5432 9898 9999 6443 4222 6222 8222 ];
  networking.firewall.allowedTCPPorts = [ 53 5432 9898 9999 6443 4222 6222 8222 ];
}