{ pkgs, lib, config, ipv4, ... }:
with builtins;
let
  inherit (builtins.extraBuiltins) pass-to-file;
  inherit (config) networking users;
  netIPv4        = ipv4;
  netIPv4Gateway = "80.67.180.134";
  #netIPv6        = "2001:912:400:104::35";
  #netIPv6Gateway = "2001:912:400:104::1";
  lanIPv4        = "192.168.1.214";
  lanNet         = "192.168.1.0/24";
  lanIPv4Gateway = "192.168.1.1";
in
{
imports = [
  networking/nftables.nix
];
boot.initrd.network = {
  enable = true;
  ssh = {
    enable = true;
    # To prevent ssh from freaking out because a different host key is used,
    # a different port for dropbear is useful
    # (assuming the same host has also a normal sshd running)
    port = 2222;
    authorizedKeys = users.users.root.openssh.authorizedKeys.keys;
  };
  # This will automatically load the zfs password prompt on login
  # and kill the other prompt so boot can continue
  # The pkill zfs kills the zfs load-key from the console
  # allowing the boot to continue.
  postCommands = ''
    echo >>/root/.profile "zfs load-key -a && pkill zfs"
  '';
};

/* WARNING: using ipconfig (the ip= kernel parameter) IS NOT RELIABLE:
   a 91.216.110.35/32 becomes a 91.216.110.35/8
boot.kernelParams = map
  (ip: "ip=${ip.clientIP}:${ip.serverIP}:${ip.gatewayIP}:${ip.netmask}:${ip.hostname}:${ip.device}:${ip.autoconf}")
  [ { clientIP = netIPv4; serverIP = "";
      gatewayIP = networking.defaultGateway.address;
      netmask = "255.255.255.255";
      hostname = ""; device = networking.defaultGateway.interface;
      autoconf = "off";
    }
    { clientIP = lanIPv4; serverIP = "";
      gatewayIP = "";
      netmask = "255.255.255.0";
      hostname = ""; device = "enp2s0";
      autoconf = "off";
    }
  ];
*/
/* DIY network config, but a right one */
boot.initrd.preLVMCommands = ''
  set -x

  # IPv4 net
  ip link set enp1s0 up
  ip address add ${netIPv4}/32 dev enp1s0
  ip route add ${netIPv4Gateway} dev enp1s0
  ip route add default via ${netIPv4Gateway} dev enp1s0

  # IPv4 lan
  ip link set enp2s0 up
  ip address add ${lanIPv4}/32 dev enp2s0
  ip route add ${lanIPv4Gateway} dev enp2s0
  ip route add ${lanNet} dev enp2s0 src ${lanIPv4} proto kernel
    # NOTE: ${lanIPv4}/24 would not work with initrd's ip, hence ${lanNet}

  # IPv6 net
  #ip -6 address add ''${netIPv6} dev enp1s0
  #ip -6 route add ''${netIPv6Gateway} dev enp1s0
  #ip -6 route add default via ''${netIPv6Gateway} dev enp1s0

  ip -4 address
  ip -4 route
  #ip -6 address
  #ip -6 route

  set +x

  # Since boot.initrd.network's preLVMCommands won't set hasNetwork=1
  # we have to run the postCommands ourselves.
  ${config.boot.initrd.network.postCommands}
'';

# Workaround https://github.com/NixOS/nixpkgs/issues/56822
#boot.initrd.kernelModules = [ "ipv6" ];

# Useless without an out-of-band access, and unsecure
# (though / may still be encrypted at this point).
# boot.kernelParams = [ "boot.shell_on_fail" ];

# Disable IPv6 entirely until it's available
boot.kernel.sysctl = {
  "net.ipv6.conf.enp1s0.disable_ipv6" = 1;
};

services.knot.extraConfig = lib.mkBefore ''
  server:
    listen: ${netIPv4}@53
    #listen: ::@53
'';

networking = rec {
  hostName   = "mermet";
  domainBase = "sourcephile";
  domain     = "${domainBase}.fr";
  
  useDHCP = false;
  defaultGateway = {
    address = netIPv4Gateway;
    interface = "enp1s0";
  };
  /*
  defaultGateway6 = {
    address = netIPv6Gateway;
    interface = "enp1s0";
  };
  */
  #nameservers = [ ];
  nftables.ruleset = ''
    add rule inet filter input  iifname "enp1s0" goto net2fw
    add rule inet filter output oifname "enp1s0" goto fw2net
    
    add rule inet filter input  iifname "enp2s0" goto lan2fw
    add rule inet filter output oifname "enp2s0" goto fw2lan
  '';
  interfaces.enp1s0 = {
    useDHCP = false;
    ipv4.addresses = [ { address = netIPv4; prefixLength = 32; } ];
    ipv4.routes    = [ { address = networking.defaultGateway.address; prefixLength = 32; } ];

    /*
    ipv6.addresses = [ { address = netIPv6; prefixLength = 64; }
                       { address = "fe80::1"; prefixLength = 10; }
                     ];
    ipv6.routes    = [ { address = networking.defaultGateway6.address; prefixLength = 64; } ];
    */
  };
  interfaces.enp2s0 = {
    useDHCP = false;
    ipv4.addresses = [ { address = lanIPv4; prefixLength = 24; } ];
    /*
    # FIXME: remove this /1 hack when the machine will be racked at PTT
    ipv4.routes    = [ { address = "0.0.0.0";   prefixLength = 1; via = "192.168.1.1"; }
                       { address = "128.0.0.0"; prefixLength = 1; via = "192.168.1.1"; }
                       ];
    */
    /*
    ipv6.addresses = [ { address = "fe80::1"; prefixLength = 10; } ];
    ipv6.routes    = [ ];
    */
  };
  interfaces.enp3s0 = {
    useDHCP = false;
  };
};
}