-module(dhcp_handler).

-export([init/1, discover/4, request/4, release/3]).

-ignore_xref([behaviour_info/1]).
-type state() :: any().
-type server_id() :: dhcp:ip().

-callback init() ->
    {ok, state(), server_id()}.

-callback discover(ReplyPkg, RequestPkg, state()) ->
    {ok, state()} |
    {ok, {offer, IP, Netmask, ReplyPkg}, state()} |
    {ok, {offer, IP, Netmask, GW, ReplyPkg}, state()} |
    {ok, {offer, IP, Netmask, [GW], ReplyPkg}, state()} |
    {ok, ReplyPkg, state()} |
    {error, any()} when ReplyPkg::dhcp:package(),
                        RequestPkg::dhcp:package(),
                        IP::dhcp:ip(),
                        Netmask::dhcp:ip(),
                        GW::dhcp:ip().


-callback request(ReplyPkg, RequestPkg, state()) ->
    {ok, state()} |
    {ok, {ack, ReplyPkg}, state()} |
    {ok, {ack, IP, Netmask, ReplyPkg}, state()} |
    {ok, {ack, IP, Netmask, GW, ReplyPkg}, state()} |
    {ok, {ack, IP, Netmask, [GW], ReplyPkg}, state()} |
    {ok, {nck, ReplyPkg}, state()} |
    {ok, ReplyPkg, state()} |
    {error, any()} when ReplyPkg::dhcp:package(),
                        RequestPkg::dhcp:package(),
                        IP::dhcp:ip(),
                        Netmask::dhcp:ip(),
                        GW::dhcp:ip().

-callback release(RequestPkg, state()) ->
    {ok, state()} |
    {error, any()} when RequestPkg::dhcp:package().


init(Handler) ->
    Handler:init().

request(Handler, ReplyPkg, RequestPkg, State) ->
    Handler:request(ReplyPkg, RequestPkg, State).

discover(Handler, ReplyPkg, RequestPkg, State) ->
    Handler:discover(ReplyPkg, RequestPkg, State).

release(Handler, RequestPkg, State) ->
    Handler:release(RequestPkg, State).