let module_inst = {
  interfaces =
    let AP = { # AP
          interface-mode = "trunk";
          vlans = [ "users" "admin" ];
        };
        off.interface-mode = "none";
    in {
        "ge-0/0/0" = off;
        "ge-0/0/1" = off;
        "ge-0/0/2" = off;
        "ge-0/0/3" = off;
        "ge-0/0/4" = off;
        "ge-0/0/5" = off;
        "ge-0/0/6" = off;
        "ge-0/0/7" = off;
        "ge-0/0/8" = off;
        "ge-0/0/9" = off;
        "ge-0/0/10" = off;
        "ge-0/0/11" = off;
        "ge-0/0/12" = AP;
        "ge-0/0/13" = AP;
        "ge-0/0/14" = AP;
        "ge-0/0/15" = AP;
        "ge-0/0/16" = AP;
        "ge-0/0/17" = AP;
        "ge-0/0/18" = off;
        "ge-0/0/19" = off;
        "ge-0/0/20" = off;
        "ge-0/0/21" = off;
        "ge-0/0/22" = off;
        "ge-0/0/23" = off;
        "ge-0/0/24" = off;
        "ge-0/0/25" = off;
        "ge-0/0/26" = off;
        "ge-0/0/27" = off;
        "ge-0/0/28" = off;
        "ge-0/0/29" = off;
        "ge-0/0/30" = off;
        "ge-0/0/31" = off;
        "ge-0/0/32" = off;
        "ge-0/0/33" = off;
        "ge-0/0/34" = off;
        "ge-0/0/35" = off;
        "ge-0/0/36" = off;
        "ge-0/0/37" = off;
        "ge-0/0/38" = off;
        "ge-0/0/39" = off;
        "ge-0/0/40" = off;
        "ge-0/0/41" = off;
        "ge-0/0/42" = off;
        "ge-0/0/43" = off;
        "ge-0/0/44" = off;
        "ge-0/0/45" = off;
        "ge-0/0/46" = off;
        "ge-0/0/47" = off;

        "ge-0/1/0" = { # upstream
          interface-mode = "trunk";
          vlans = [ "all" ];
          dhcp_trusted = true;
          management = true;
        };
        "ge-0/1/1" = off;
        "ge-0/1/2" = off;
        "ge-0/1/3" = off;

        "xe-0/1/0" = off;
        "xe-0/1/1" = off;
        "xe-0/1/2" = off;
        "xe-0/1/3" = off;

        "me0" = { # mgmt
          interface-mode = "none";
          management = true;
        };
      };
      vlans = {
        "users" = [ { begin = 3045; end = 4094; } ];
        "admin" = [ 3000 ];
      };
    };
  module = { lib, config, ... }: with lib; {
    # NOTE: dhcp should be configured at vlan level, but this is not very satisfying,
    # so this module tries to configured dhcp-trust on interfaces
    # -> this implies that interfaces change the config of their vlans
    options = {
      interfaces =
        let vlan_type = types.either (types.strMatching "[^\n\r]+") (types.ints.unsigned);
            interface = {config, ...}: {
              options = {
                interface-mode = mkOption { 
                  type = types.enum [ "trunk" "access" "none" ];
                  #TODO: default = if ;
                };
                vlans = mkOption {
                  type = types.listOf vlan_type;
                };
                dhcp_trusted = mkOption { type = types.bool; default = false; };
                management = mkOption { type = types.bool; default = false; };

                xmlGen = mkOption { type = types.uniq types.unspecified; };
              };
              config.vlans = lib.mkIf (config.interface-mode == "none") (lib.mkForce [ ]);
              config.xmlGen = name:
              let
                mgmt_fam = if config.management then "<inet><dhcp/></inet>" else "";
                eth_switch = if config.interface-mode == "none" then "" else ''
                    <ethernet-switching>
                      <interface-mode>${config.interface-mode}</interface-mode>
                      <vlan>${builtins.concatStringsSep "" (map (vlan: "<members>${builtins.toString vlan}</members>") config.vlans)}</vlan>
                    </ethernet-switching>'';
              in ''
                <interface>
                  <name>${name}</name>
                  <unit>
                    <name>0</name>
                    <family>
                      ${mgmt_fam}
                      ${eth_switch}
                    </family>
                  </unit>
                </interface>'';
            };
          in mkOption {
            type = types.attrsOf (types.submodule interface);
          };
        vlans = let
          range_type.options = {
            begin = mkOption { type = types.ints.unsigned; };
            end = mkOption { type = types.ints.unsigned; };
          };
          in mkOption {
            type = types.attrsOf (types.listOf (types.either types.ints.unsigned (types.submodule range_type)));
          };

      # NOTE, HACK: placeholder for now
      toplevel = mkOption {
        type = types.uniq types.anything;
      };
    };
    config.toplevel =
      let
        interfaces = builtins.attrValues (builtins.mapAttrs (name: mod: mod.xmlGen name) config.interfaces);
        # { vlan = { trust = [String]; notrust = [String]; } }
        interface_names = builtins.attrNames config.interfaces;
        vlan_map = inter: vlan:
          if builtins.isString vlan then
            if config.interfaces.${inter}.dhcp_trusted then
              { ${vlan}.trust = inter; }
            else
              { ${vlan}.notrust = inter; }
          else
            {};
        int_map = inter: map (vlan_map inter) config.interfaces.${inter}.vlans;
        vlan_trust_table =
          builtins.zipAttrsWith (vlan: values: builtins.zipAttrsWith (_: ints: ints ) values)
            (builtins.concatMap int_map interface_names);
        vlans = map (vlan:
          let ids = map (id:
                  let list = if builtins.isInt id then
                              builtins.toString id
                            else
                              "${builtins.toString id.begin}-${builtins.toString id.end}";
                  in ''<vlan-id-list>${list}</vlan-id-list>'')
                config.vlans.${vlan};
          in ''
            <vlan>
              <name>${vlan}</name>
              ${builtins.concatStringsSep "\n" ids}
            </vlan>'') (builtins.attrNames config.vlans);
      in [ ''
        <interfaces>
        ${builtins.concatStringsSep "\n" interfaces}
        </interfaces>
        <vlans>
        ${builtins.concatStringsSep "\n" vlans}
        </vlans>'' vlan_trust_table];
  };
in (import <nixpkgs/lib>).evalModules {
  modules = [ module module_inst ];
}