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

let
  hostRole = config.site.hosts.${hostName}.role;
  networkPort = 25826;
  upstreamTypesDb = pkgs.stdenv.mkDerivation {
    name = "types.db";
    src = config.services.collectd.package.src;
    phases = [ "unpackPhase" "installPhase" ];
    installPhase = "cp src/types.db $out";
  };
  customTypesDb = builtins.toFile "types.db" ''
    stations                value:GAUGE:0:U
  '';
in
{
  services.collectd = {
    enable = true;
    buildMinimalPackage = true;

    extraConfig = ''
      TypesDB "${upstreamTypesDb}" "${customTypesDb}"
    '';

    plugins = lib.mkMerge [ {
      interface = "";
      conntrack = "";
      # TODO: dhcpcount
    } (lib.optionalAttrs (hostName == "stats") {
      network = ''
       Listen "::" "${toString networkPort}"
       Forward true
       Server "${config.site.net.serv.hosts4.spaceapi}" "${toString networkPort}"
       Server "${config.site.net.serv.hosts4.grafana}" "${toString networkPort}"
      '';
    }) (lib.optionalAttrs (hostName != "stats") {
      network = ''
        Server "${config.site.net.serv.hosts6.dn42.stats}" "${toString networkPort}"
      '';
    }) (lib.optionalAttrs (hostRole == "server") {
      irq = "";
      cpu = "";
      load = "";
      memory = "";
      swap = "";
      entropy = "";
      disk = "";
      df = "";
      processes = "";
      hddtemp = "";
      sensors = "";
      thermal = "";
    }) (lib.optionalAttrs config.services.dhcpd4.enable {
      exec =
        let
          maxTimeout = builtins.foldl' (maxTimeout: net:
            let
              dhcpConf = config.site.net.${net}.dhcp;
            in
              if dhcpConf != null &&
                 dhcpConf.server == hostName &&
                 dhcpConf.time > maxTimeout
              then dhcpConf.time
              else maxTimeout
          ) 180 (builtins.attrNames config.site.net);
        in ''
          Exec "collectd" "${pkgs.ruby}/bin/ruby" "${./dhcpcount.rb}" "${toString maxTimeout}"
        '';
    }) ];
  };
}