{
  lib,
  ...
}:
let
  inherit (import ../../data) machines;

  mkKnownHost =
    name:
    { publicKey, domains, ... }:
    {
      inherit publicKey;
      extraHostNames = map (domain: "${name}.${domain}") domains;
    };

  mkBuilder =
    {
      system,
      systems ? [ system ],
      sshUser ? "nixremote",
      protocol ? "ssh-ng",
      ...
    }@builder:
    builder
    // {
      inherit
        sshUser
        systems
        protocol
        ;
    };

  mkBuildMachine =
    hostName: machine:
    (mkBuilder machine.builder)
    // {
      inherit hostName;
    };
in
{
  programs.ssh.knownHosts = lib.mapAttrs mkKnownHost machines;
  nix = {
    distributedBuilds = true;

    buildMachines = lib.mapAttrsToList mkBuildMachine (lib.filterAttrs (n: v: v ? builder) machines);

    settings = {
      connect-timeout = 1;
    };
  };
}