%%%---------------------------------------------------------------------
%%% Copyright 2024 William Fank Thomé
%%%
%%% Licensed under the Apache License, Version 2.0 (the "License");
%%% you may not use this file except in compliance with the License.
%%% You may obtain a copy of the License at
%%%
%%%     http://www.apache.org/licenses/LICENSE-2.0
%%%
%%% Unless required by applicable law or agreed to in writing, software
%%% distributed under the License is distributed on an "AS IS" BASIS,
%%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%%% See the License for the specific language governing permissions and
%%% limitations under the License.
%%%---------------------------------------------------------------------
-module(doctest_md).
-moduledoc false.

% API functions
-export([code_blocks/1]).

-define(CODE_BLOCK_RE,
    "(?ms)^(```[`]*)erlang\\s*\\n" % ```erlang
    "(.*?)"                        %  <erlang-code>
    "(?:\\n^(\\1)(\\s+|\\n|$))"    %  ```
).

%%%=====================================================================
%%% API functions
%%%=====================================================================

% TODO: Check how to use shell_docs_markdown:parse_md/1.
%       It can simplify the capture of the code blocks,
%       but it's only available since OTP-27-rc3.
code_blocks(Markdown) when is_list(Markdown); is_binary(Markdown) ->
    case re:run(Markdown, ?CODE_BLOCK_RE, [
        global, {capture, all_but_first, binary}
    ]) of
        {match, Groups} ->
            {ok, [CodeBlock || [_, CodeBlock, _, _] <- Groups]};
        nomatch ->
            none
    end.

%%%=====================================================================
%%% Internal functions
%%%=====================================================================

% nothing here yet!