{ pkgs, config, factsGenerator, ... }:
let
  publicKey = machine: (builtins.readFile "${config.clanCore.clanDir}/machines/${machine}/facts/wireguard.wg0.pub");
in
{
  networking.firewall.allowedUDPPorts = [ 51820 ];
  clanCore.facts.services.wireguard = factsGenerator.wireguard { name = "wg0"; };
  boot.kernel.sysctl."net.ipv4.ip_forward" = true;

  # Enable WireGuard
  networking.wg-quick.interfaces = {
    # Hub and Spoke Setup
    # https://www.procustodibus.com/blog/2020/11/wireguard-hub-and-spoke-config/
    wg0 = {
      address = [ "10.100.0.1/32" ];
      listenPort = 51820; # to match firewall allowedUDPPorts (without this wg uses random port numbers)
      privateKeyFile = config.clanCore.facts.services.wireguard.secret."wireguard.wg0.key".path;
      mtu = 1280;

      postUp = ''
        ${pkgs.iptables}/bin/iptables -A FORWARD -i wg0 -j ACCEPT
      '';
      postDown = ''
        ${pkgs.iptables}/bin/iptables -D FORWARD -i wg0 -j ACCEPT
      '';

      peers = [
        # server
        # ------
        # start at 1
        {
          # chungus
          publicKey = publicKey "chungus";
          allowedIPs = [ "10.100.0.2/32" ];
        }
        # desktops
        # --------
        # start at 10
        {
          # cream
          publicKey = publicKey "cream";
          allowedIPs = [ "10.100.0.6/32" ]; # todo : change ip
        }
        {
          # cherry
          publicKey = publicKey "cherry";
          allowedIPs = [ "10.100.0.7/32" ]; # todo : change ip
        }
        # mobil devices
        # -------------
        # start at 100
        {
          # iphone palo
          publicKey = "ICeZLWYzF+nTffMV0+8yfW1WJsUQNhNbKQ4rRbn5hDs=";
          allowedIPs = [ "10.100.0.101/32" ];
        }
        {
          # ipad palo
          publicKey = "wN81/4K2d5tcxqrxnjOpKw9YpAkPdp0/8cCN1B7icVo=";
          allowedIPs = [ "10.100.0.102/32" ];
        }
        {
          # iphone tina
          publicKey = "8f8fYGymH3Tq8d14B2+ijMiHwocEbUIXSZji3U29IhA=";
          allowedIPs = [ "10.100.0.103/32" ];
        }
      ];
    };
  };
}