{ config, lib, ... }:

let
  inherit (lib)
    mapAttrsToList
    mkEnableOption
    mkOption
    optionalString
    ;

  inherit (lib.types)
    attrsOf
    either
    enum
    ints
    listOf
    str
    submodule
    ;

  interface =
    { name, config, ... }:
    let
      unit =
        { name, config, ... }:
        {
          options = {
            enable = mkEnableOption "this logical interface" // {
              default = true;
              example = false;
            };
            family = {
              ethernet-switching = {
                enable = mkEnableOption "the ethernet switching on this logical interface";
                interface-mode = mkOption {
                  type = enum [
                    "trunk"
                    "access"
                  ];
                  description = ''
                    Mode of operation for vlan addressing of this interface.
                    "trunk" means that the traffic is tagged, "access" means the
                    traffic is tagged by the switch.
                  '';
                };
                vlans = mkOption {
                  type = listOf (either str ints.unsigned);
                  default = [ ];
                  description = ''
                    Vlans that can be used on this interface.
                    Only one ID should be here for "access" mode of operation.
                  '';
                };
              };
              #TODO : DHCP
              inet = {
                enable = mkEnableOption "the IPv4 configuration of this logical interface";
                addresses = mkOption {
                  type = listOf str;
                  default = [ ];
                  description = ''
                    ipv4 addresses of this interface.
                  '';
                };
              };
              inet6 = {
                enable = mkEnableOption "the IPv6 configuration of this logical interface";
                addresses = mkOption {
                  type = listOf str;
                  default = [ ];
                  description = ''
                    ipv6 addresses of this interface.
                  '';
                };
              };
            };
            xml = mkOption {
              type = str;
              visible = false;
              readOnly = true;
            };
          };
          config.xml =
            let
              members = map (
                vlan: "<members>${builtins.toString vlan}</members>"
              ) config.family.ethernet-switching.vlans;
              eth = optionalString config.family.ethernet-switching.enable ''
                <ethernet-switching>
                  <interface-mode>${config.family.ethernet-switching.interface-mode}</interface-mode>
                  <vlan>${builtins.concatStringsSep "" members}</vlan>
                  <storm-control><profile-name>default</profile-name></storm-control>
                </ethernet-switching>
              '';

              addr4 = map (addr: "<name>${addr}</name>") config.family.inet.addresses;
              inet = optionalString config.family.inet.enable ''
                <inet>
                  <address>${builtins.concatStringsSep "" addr4}</address>
                </inet>
              '';

              addr6 = map (addr: "<name>${addr}</name>") config.family.inet6.addresses;
              inet6 = optionalString config.family.inet6.enable ''
                <inet6>
                  <address>${builtins.concatStringsSep "" addr6}</address>
                </inet6>
              '';
            in
            ''
              <unit>
                <name>${name}</name>
                ${optionalString (!config.enable) "<disable/>"}
                <family>
                  ${eth}${inet}${inet6}
                </family>
              </unit>'';
        };
    in
    {
      options = {
        enable = mkEnableOption "this physical interface";
        unit = mkOption {
          type = attrsOf (submodule unit);
          default = { };
          description = ''
            Configuration of the logical interfaces on this physical interface.
          '';
        };
        xml = mkOption {
          type = str;
          visible = false;
          readOnly = true;
        };
      };
      config.xml =
        let
          units = mapAttrsToList (_: unit: unit.xml) config.unit;
        in
        ''
          <interface>
            <name>${name}</name>
            ${optionalString (!config.enable) "<disable/>"}
            ${builtins.concatStringsSep "" units}
          </interface>
        '';
    };
in
{
  options = {
    interfaces = mkOption {
      type = attrsOf (submodule interface);
      description = ''
        The interfaces configuration.
      '';
    };
    netconf.xmls.interfaces = mkOption {
      type = str;
      visible = false;
      readOnly = true;
    };
  };
  config.netconf.xmls.interfaces = ''
    <interfaces operation="replace">
      ${builtins.concatStringsSep "" (mapAttrsToList (_: intf: intf.xml) config.interfaces)}
    </interfaces>
  '';
}