-module(idna_unicode_data).

-export([combining_class/1,
         compat/1,
         composition/2,
         lowercase/1]).

-define(COMBINING_CLASS, 1).
-define(DECOMPOSITION, 2).
-define(LOWERCASE_MAPPING, 3).

combining_class(C) ->
    case lookup(C) of
        false -> 0;
        Props ->
            erlang:list_to_integer(element(?COMBINING_CLASS, Props))
    end.

compat(C) ->
    lookup(C, fun(Props) ->
                case element(?DECOMPOSITION, Props) of
                    [] -> undefined;
                    Val ->
                        Tokens = string:tokens(Val, " "),
                        CodePoints = dehex(case hd(Val) of
                                    $< -> tl(Tokens);
                                    _ -> Tokens
                                end),
                        CodePoints
                end
        end).

composition(A, B) ->
    Key = lists:flatten([hex(A), " ", hex(B)]),
    case decomposition(Key) of
        false -> undefined;
        Val -> erlang:list_to_integer(Val, 16)
    end.


lowercase(C) ->
    lookup(C, fun(Props) ->
                case element(?LOWERCASE_MAPPING, Props) of
                    [] -> C;
                    Hex -> erlang:list_to_integer(Hex, 16)
                end
        end).

%% --------------------
%% helper functions
%% --------------------

hex(Codepoint) ->
  string:right(erlang:integer_to_list(Codepoint, 16), 4, $0).

dehex(Strings) ->
  [erlang:list_to_integer(String, 16) || String <- Strings].

lookup(Codepoint) ->
    lookup1(hex(Codepoint)).

lookup(Codepoint, Fun) ->
    case lookup(Codepoint) of
        false -> {error, bad_codepoint};
        Props -> Fun(Props)
    end.


%% GENERATED