:- use_module(library(dcg/basics)).
:- use_module(library(unicode)).

:- set_prolog_flag(double_quotes, codes).

cr_lf	     --> "\r\n". % [13, 10].
tab	     --> "\t". % [9].
null	     --> [0].

call_with_arg1(Arg, Callable) :- call(Callable, Arg).

ascii([C]) :- between(0, 127, C).
ascii_string([]).
ascii_string([C|Cs]) :- ascii([C]), ascii_string(Cs).

contains_substring([], []).
contains_substring(_, []).
contains_substring([X|Xs], [Y|Ys]) :-
    (X = Y -> contains_substring(Xs, Ys)
    ; contains_substring(Xs, [Y|Ys])), !.

ascii_contains_substring([], []).
ascii_contains_substring(Xs, []) :- ascii_string(Xs).
ascii_contains_substring([X|Xs], [Y|Ys]) :-
    ascii([X]),
    (X = Y -> ascii_contains_substring(Xs, Ys)
    ; ascii_contains_substring(Xs, [Y|Ys])), !.

unascii([C|Cs]) -->
    [C|Cs],
    {
	\+ascii_contains_substring([C|Cs], "\r\n"),
	\+ascii_contains_substring([C|Cs], "\t"),
	\+ascii_contains_substring([C|Cs], [0])
    }.

unascii_without([C|Cs], ExcludedSubStrings), [C|Cs] -->
    {
	\+maplist(
	    ascii_contains_substring([C|Cs]),
	    ExcludedSubStrings)
    },
    unascii([C|Cs]), !.

    
last_line --> ".", cr_lf.
last_line(L) :- phrase(last_line, L).

text_block(Blk) -->
    {
	last_line(L),
	\+ascii_contains_substring(Blk, L)
    }, Blk.

type(T) --> { T = [_] }, unascii(T).

red_type --> "+".

user_name([]) --> [].
user_name(U)  --> unascii(U).

selector([]) --> [].
selector(S)  --> unascii(S).

host_part([H|Hs]) --> string_without(".\t", [H|Hs]).
host([H])	  --> host_part(H).
host([H|Hs])	  --> host_part(H), ".", host(Hs).

port(P) --> digits(P), { number_codes(N, P), N >= 0, N =< 65536 }.

dir_entity(
    [type-Type, user-User, selector-Selector, host-Host, port-Port]
) -->
    type(Type), user_name(User),
    tab,
    selector(Selector),
    tab,
    host(Host),
    tab,
    port(Port), cr_lf.
dir_entity(
    [type-"+", user-User, selector-Selector, host-Host, port-Port]
) -->
    red_type, user_name(User),
    tab,
    selector(Selector),
    tab,
    host(Host),
    tab,
    port(Port), cr_lf.
dir_entity([]) --> [].

menu_entity([]) --> last_line.
menu_entity([D|Ds]) --> dir_entity(D), dir_entity(Ds), last_line.