% coding: utf-8
% Copyright 2008 Grégory Burri
%
% This file is part of Euphorik.
%
% Euphorik is free software: you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation, either version 3 of the License, or
% (at your option) any later version.
%
% Euphorik is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with Euphorik.  If not, see <http://www.gnu.org/licenses/>.
%
% Module with some useful stuffs.


-module(euphorik_common).
-author("Greg Burri <greg.burri@gmail.com>").
-export([
   ceiling/1,
   delta_date_ms/2,
   delta_date_minute/2,
   serialize_ip/1,
   unserialize_ip/1
]).


% Arrondi un float à l'entier supérieur.
% Bizarre, cette fonction n'existe pas dans la stdlib.
% Pas utilisé mais bon ca me fait de la peine de l'enlever.
ceiling(X) ->
   T = trunc(X),
   case (X - T) of
      Neg when Neg < 0 -> T;
      Pos when Pos > 0 -> T + 1;
      _ -> T
   end.


% Retourne la difference entre deux timestamp (erlang:now()) en miliseconde
delta_date_ms(D1, D2) ->
   1000000000 * abs(element(1, D1) - element(1, D2)) + 1000 * abs(element(2, D1) - element(2, D2)) + trunc(abs(element(3, D1) - element(3, D2)) / 1000).


% Retourne la différence entre deux timestamp (erlang:now) en minutes
delta_date_minute(D1, D2) ->
   trunc(delta_date_ms(D1, D2) / 1000 / 60).


serialize_ip(undefined) ->
   "<unknown IP>";
serialize_ip(IP) ->
   lists:flatten(io_lib:format("~w.~w.~w.~w", tuple_to_list(IP))).


unserialize_ip(IP) ->
   case io_lib:fread("~d.~d.~d.~d", IP) of
      {ok, [A, B, C, D], []} -> {A, B, C, D};
      _  -> erreur
   end.