% vim: syntax=prolog

:- use_module(library(clpz)).
:- use_module(library(format)).
:- use_module(library(charsio)).
:- use_module(library(serialization/abnf)).

make_ip4(A, B, C, D, Addr) :-
  A #>= 0, A #=< 255,
  B #>= 0, B #=< 255,
  C #>= 0, C #=< 255,
  D #>= 0, D #=< 255,
  Addr #= ((A * 2^24) + (B * 2^16) + (C * 2^8) + D),
  ip4(Addr).

ip4(Addr) :- Addr >= 0, Addr < 2^32.

ip4_range(Addr, Range) :-
  ip4(Addr),
  Range in 0..32.

ip_format(ip4(Addr), Str) :-
  make_ip4(A, B, C, D, Addr),
  phrase(format_("~w.~w.~w.~w", [A, B, C, D]), Str).

ip_format(ip4_range(Addr, Range), Str) :-
  make_ip4(A, B, C, D, Addr),
  phrase(format_("~w.~w.~w.~w/~w", [A, B, C, D, Range]), Str).

hexd(D) --> abnf_hexdig(D).
hexd('a') --> "a".
hexd('b') --> "b".
hexd('c') --> "c".
hexd('d') --> "d".
hexd('e') --> "e".
hexd('f') --> "f".

int_(N)    --> abnf_digit(D), { number_chars(V, [D]) }, int_(V, N).
int_(N, N) --> [].
int_(A, N) --> abnf_digit(D), { number_chars(V, [D]), A1 is A*10+V }, int_(A1, N).

xint_(N)    --> hexd(D), { number_chars(V, ['0', 'x', D]) }, xint_(V, N).
xint_(N, N) --> [].
xint_(A, N) --> hexd(D), { number_chars(V, ['0', 'x', D]), A1 is A*16+V }, xint_(A1, N).

%ip4_num(V) --> int_(Ds, Ds), { number_chars(V, Ds), V >= 0, V =< 255 }.
ip4_num(V) --> int_(V), { V >= 0, V =< 255 }.

ip4_syntax(A, B, C, D) --> ip4_num(A), ".", ip4_num(B), ".", ip4_num(C), ".", ip4_num(D).
ip4_range_syntax(A, B, C, D, R) -->
  ip4_syntax(A, B, C, D), "/", 
  int_(R), { R >= 0, R =< 32 }.

ip4_parse(Str, Ip) :-
  phrase(ip4_syntax(A, B, C, D), Str),
  make_ip4(A, B, C, D, Addr),
  Ip = ip4(Addr).

ip4_range_parse(Str, IpR) :-
  phrase(ip4_range_syntax(A, B, C, D, Range), Str),
  make_ip4(A, B, C, D, Addr),
  IpR = ip4_range(Addr, Range).

make_ip6(A, B, C, D, E, F, G, H, Addr) :-
  A #>= 0, A #=< 65335,
  B #>= 0, B #=< 65335,
  C #>= 0, C #=< 65335,
  D #>= 0, D #=< 65335,
  E #>= 0, E #=< 65335,
  F #>= 0, F #=< 65335,
  G #>= 0, G #=< 65335,
  H #>= 0, H #=< 65335,
  Addr #=
      (A * 2^56) + (B * 2^48) + (C * 2^40) + (D * 2^32) + 
      (E * 2^24) + (F * 2^16) + (G * 2^8) + H,
  ip6(Addr).

ip6(Addr) :- Addr >= 0, Addr < 2^128.

ip6_syntax(A, B, C, D, E, F, G, H) -->
  ip6_num(A), ":",
  ip6_num(B), ":",
  ip6_num(C), ":",
  ip6_num(D), ":",
  ip6_num(E), ":",
  ip6_num(F), ":",
  ip6_num(G), ":",
  ip6_num(H).
ip6_num(D) --> xint_(D), { D >= 0, D =< 65535 }.

ip6_parse(Str, Ip) :-
  phrase(ip6_syntax(A, B, C, D, E, F, G, H), Str),
  make_ip6(A, B, C, D, E, F, G, H, Addr),
  Ip = ip6(Addr).

ip_parse(Str, Obj) :-
  (
    phrase(ip4_syntax(A, B, C, D), Str)
    -> make_ip4(A, B, C, D, Addr),
       Obj = ip4(Addr)
    ; (
        phrase(ip4_range_syntax(A, B, C, D, R), Str)
        -> make_ip4(A, B, C, D, Ip),
           Obj = ip4_range(Ip, R)
        ;  phrase(ip6_syntax(A, B, C, D, E, F, G, H), Str),
           make_ip6(A, B, C, D, E, F, G, H, Addr),
           Obj = ip6(Addr)
      )
  ).