:- module(sockets, [socket_client_open/3,
                    socket_server_open/2,
                    socket_server_accept/4,
                    socket_server_close/1,
                    current_hostname/1]).

:- use_module(library(error)).


socket_client_open(Addr, Stream, Options) :-
    (  var(Addr) ->
       throw(error(instantiation_error, socket_client_open/3))
    ;
       true
    ),
    must_be(var, Stream),
    must_be(list, Options),
    (  Addr = Address:Port,
       atom(Address),
       ( atom(Port) ; integer(Port) ) ->
       true
    ;
       throw(error(type_error(socket_address, Addr), socket_client_open/3))
    ),
    builtins:parse_stream_options(Options,
                                  [Alias, EOFAction, Reposition, Type],
                                  socket_client_open/3),
    '$socket_client_open'(Address, Port, Stream, Alias, EOFAction, Reposition, Type).


socket_server_open(Addr, ServerSocket) :-
    must_be(var, ServerSocket),
    (  ( integer(Addr) ; var(Addr) ) ->
       '$socket_server_open'([], Addr, ServerSocket)
    ;
       Addr = Address:Port,
       must_be(atom, Address),
       can_be(integer, Port),
       '$socket_server_open'(Address, Port, ServerSocket)
    ).


socket_server_accept(ServerSocket, Client, Stream, Options) :-
    must_be(var, Client),
    must_be(var, Stream),
    builtins:parse_stream_options(Options,
                                  [Alias, EOFAction, Reposition, Type],
                                  socket_server_accept/4),
    '$socket_server_accept'(ServerSocket, Client, Stream, Alias, EOFAction, Reposition, Type).


socket_server_close(ServerSocket) :-
    '$socket_server_close'(ServerSocket).


current_hostname(HostName) :-
    '$current_hostname'(HostName).