%-*-Mode:erlang;coding:utf-8;tab-width:4;c-basic-offset:4;indent-tabs-mode:()-*-
% ex: set ft=erlang fenc=utf-8 sts=4 ts=4 sw=4 et nomod:
%%%
%%%------------------------------------------------------------------------
%%% @doc
%%% ==CloudI IP Address Parsing==
%%% Use a fixed width format for simpler parsing, testing, and to allow
%%% better pattern matching within service names.
%%% @end
%%%
%%% MIT License
%%%
%%% Copyright (c) 2013-2017 Michael Truog <mjtruog at protonmail dot com>
%%%
%%% Permission is hereby granted, free of charge, to any person obtaining a
%%% copy of this software and associated documentation files (the "Software"),
%%% to deal in the Software without restriction, including without limitation
%%% the rights to use, copy, modify, merge, publish, distribute, sublicense,
%%% and/or sell copies of the Software, and to permit persons to whom the
%%% Software is furnished to do so, subject to the following conditions:
%%%
%%% The above copyright notice and this permission notice shall be included in
%%% all copies or substantial portions of the Software.
%%%
%%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
%%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
%%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
%%% FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
%%% DEALINGS IN THE SOFTWARE.
%%%
%%% @author Michael Truog <mjtruog at protonmail dot com>
%%% @copyright 2013-2017 Michael Truog
%%% @version 1.7.1 {@date} {@time}
%%%------------------------------------------------------------------------

-module(cloudi_ip_address).
-author('mjtruog at protonmail dot com').

%% external interface
-export([to_binary/1,
         to_string/1,
         from_binary/1,
         from_string/1]).

-type format_binary() ::
    <<_:120>> | <<_:312>>.
-type format_string() ::
    string().
-export_type([format_binary/0, format_string/0]).

%%%------------------------------------------------------------------------
%%% External interface functions
%%%------------------------------------------------------------------------

%%-------------------------------------------------------------------------
%% @doc
%% ===Create a binary string representation.===
%% @end
%%-------------------------------------------------------------------------

-spec to_binary(inet:ip_address()) -> format_binary().

to_binary({B1, B2, B3, B4}) ->
    [B1a, B1b, B1c] = int_to_dec_list_3(B1),
    [B2a, B2b, B2c] = int_to_dec_list_3(B2),
    [B3a, B3b, B3c] = int_to_dec_list_3(B3),
    [B4a, B4b, B4c] = int_to_dec_list_3(B4),
    <<B1a, B1b, B1c, $., B2a, B2b, B2c, $., B3a, B3b, B3c, $., B4a, B4b, B4c>>;
to_binary({S1, S2, S3, S4, S5, S6, S7, S8}) ->
    [S1a, S1b, S1c, S1d] = int_to_hex_list_4(S1),
    [S2a, S2b, S2c, S2d] = int_to_hex_list_4(S2),
    [S3a, S3b, S3c, S3d] = int_to_hex_list_4(S3),
    [S4a, S4b, S4c, S4d] = int_to_hex_list_4(S4),
    [S5a, S5b, S5c, S5d] = int_to_hex_list_4(S5),
    [S6a, S6b, S6c, S6d] = int_to_hex_list_4(S6),
    [S7a, S7b, S7c, S7d] = int_to_hex_list_4(S7),
    [S8a, S8b, S8c, S8d] = int_to_hex_list_4(S8),
    <<S1a, S1b, S1c, S1d, $:,
      S2a, S2b, S2c, S2d, $:,
      S3a, S3b, S3c, S3d, $:,
      S4a, S4b, S4c, S4d, $:,
      S5a, S5b, S5c, S5d, $:,
      S6a, S6b, S6c, S6d, $:,
      S7a, S7b, S7c, S7d, $:,
      S8a, S8b, S8c, S8d>>.

%%-------------------------------------------------------------------------
%% @doc
%% ===Create a list string representation.===
%% @end
%%-------------------------------------------------------------------------

-spec to_string(inet:ip_address()) -> format_string().

to_string({B1, B2, B3, B4}) ->
    [B1a, B1b, B1c] = int_to_dec_list_3(B1),
    [B2a, B2b, B2c] = int_to_dec_list_3(B2),
    [B3a, B3b, B3c] = int_to_dec_list_3(B3),
    [B4a, B4b, B4c] = int_to_dec_list_3(B4),
    [B1a, B1b, B1c, $., B2a, B2b, B2c, $., B3a, B3b, B3c, $., B4a, B4b, B4c];
to_string({S1, S2, S3, S4, S5, S6, S7, S8}) ->
    [S1a, S1b, S1c, S1d] = int_to_hex_list_4(S1),
    [S2a, S2b, S2c, S2d] = int_to_hex_list_4(S2),
    [S3a, S3b, S3c, S3d] = int_to_hex_list_4(S3),
    [S4a, S4b, S4c, S4d] = int_to_hex_list_4(S4),
    [S5a, S5b, S5c, S5d] = int_to_hex_list_4(S5),
    [S6a, S6b, S6c, S6d] = int_to_hex_list_4(S6),
    [S7a, S7b, S7c, S7d] = int_to_hex_list_4(S7),
    [S8a, S8b, S8c, S8d] = int_to_hex_list_4(S8),
    [S1a, S1b, S1c, S1d, $:,
     S2a, S2b, S2c, S2d, $:,
     S3a, S3b, S3c, S3d, $:,
     S4a, S4b, S4c, S4d, $:,
     S5a, S5b, S5c, S5d, $:,
     S6a, S6b, S6c, S6d, $:,
     S7a, S7b, S7c, S7d, $:,
     S8a, S8b, S8c, S8d].

%%-------------------------------------------------------------------------
%% @doc
%% ===Parse a binary string representation.===
%% @end
%%-------------------------------------------------------------------------

-spec from_binary(format_binary()) ->
    inet:ip_address().

from_binary(<<B1a, B1b, B1c, $., B2a, B2b, B2c, $.,
              B3a, B3b, B3c, $., B4a, B4b, B4c>>) ->
    {erlang:list_to_integer([B1a, B1b, B1c]),
     erlang:list_to_integer([B2a, B2b, B2c]),
     erlang:list_to_integer([B3a, B3b, B3c]),
     erlang:list_to_integer([B4a, B4b, B4c])};
from_binary(<<S1a, S1b, S1c, S1d, $:, S2a, S2b, S2c, S2d, $:,
              S3a, S3b, S3c, S3d, $:, S4a, S4b, S4c, S4d, $:,
              S5a, S5b, S5c, S5d, $:, S6a, S6b, S6c, S6d, $:,
              S7a, S7b, S7c, S7d, $:, S8a, S8b, S8c, S8d>>) ->
    {erlang:list_to_integer([S1a, S1b, S1c, S1d], 16),
     erlang:list_to_integer([S2a, S2b, S2c, S2d], 16),
     erlang:list_to_integer([S3a, S3b, S3c, S3d], 16),
     erlang:list_to_integer([S4a, S4b, S4c, S4d], 16),
     erlang:list_to_integer([S5a, S5b, S5c, S5d], 16),
     erlang:list_to_integer([S6a, S6b, S6c, S6d], 16),
     erlang:list_to_integer([S7a, S7b, S7c, S7d], 16),
     erlang:list_to_integer([S8a, S8b, S8c, S8d], 16)}.

%%-------------------------------------------------------------------------
%% @doc
%% ===Parse a binary string representation.===
%% @end
%%-------------------------------------------------------------------------

-spec from_string(format_string()) ->
    inet:ip_address().

from_string([B1a, B1b, B1c, $., B2a, B2b, B2c, $.,
             B3a, B3b, B3c, $., B4a, B4b, B4c]) ->
    {erlang:list_to_integer([B1a, B1b, B1c]),
     erlang:list_to_integer([B2a, B2b, B2c]),
     erlang:list_to_integer([B3a, B3b, B3c]),
     erlang:list_to_integer([B4a, B4b, B4c])};
from_string([S1a, S1b, S1c, S1d, $:, S2a, S2b, S2c, S2d, $:,
             S3a, S3b, S3c, S3d, $:, S4a, S4b, S4c, S4d, $:,
             S5a, S5b, S5c, S5d, $:, S6a, S6b, S6c, S6d, $:,
             S7a, S7b, S7c, S7d, $:, S8a, S8b, S8c, S8d]) ->
    {erlang:list_to_integer([S1a, S1b, S1c, S1d], 16),
     erlang:list_to_integer([S2a, S2b, S2c, S2d], 16),
     erlang:list_to_integer([S3a, S3b, S3c, S3d], 16),
     erlang:list_to_integer([S4a, S4b, S4c, S4d], 16),
     erlang:list_to_integer([S5a, S5b, S5c, S5d], 16),
     erlang:list_to_integer([S6a, S6b, S6c, S6d], 16),
     erlang:list_to_integer([S7a, S7b, S7c, S7d], 16),
     erlang:list_to_integer([S8a, S8b, S8c, S8d], 16)}.

%%%------------------------------------------------------------------------
%%% Private functions
%%%------------------------------------------------------------------------

int_to_dec_list_3(Value0)
    when is_integer(Value0), Value0 >= 0, Value0 =< 255 ->
    C1 = (Value0 rem 10) + $0,
    Value1 = Value0 div 10,
    C2 = (Value1 rem 10) + $0,
    Value2 = Value1 div 10,
    C3 = Value2 + $0,
    [C3, C2, C1].

int_to_hex_list_4(Value0)
    when is_integer(Value0), Value0 >= 0, Value0 =< 65535 ->
    C1 = int_to_hex(Value0 rem 16),
    Value1 = Value0 div 16,
    C2 = int_to_hex(Value1 rem 16),
    Value2 = Value1 div 16,
    C3 = int_to_hex(Value2 rem 16),
    Value3 = Value2 div 16,
    C4 = int_to_hex(Value3),
    [C4, C3, C2, C1].

-compile({inline, [{int_to_hex,1}]}).

int_to_hex(I) when 0 =< I, I =< 9 ->
    I + $0;
int_to_hex(I) when 10 =< I, I =< 15 ->
    (I - 10) + $a.