test_method.erl

-module(test_method).
%-compile([export_all, nowarn_export_all]).


% standard callbacks
-export([init/2, allowed_methods/2, content_types_provided/2, content_types_accepted/2, resource_exists/2]).


% custom callbacks
-export([method_jsone/2]).
-export([create_jsone/2]).
-export([create_jsone2/4]).
-export([valid_path/1]).


init(Req, Opts) ->
  {cowboy_rest, Req, Opts}.


allowed_methods(Req, State) ->
  {[<<"GET">>, <<"POST">>], Req, State}.
  %{[<<"POST">>], Req, State}.


content_types_provided(Req, State) ->
  {[
    { {<<"text">>, <<"plain">>, []}, method_jsone},
    { {<<"text">>, <<"html">>, []}, method_jsone}
    %{ {<<"application">>, <<"json">>, []}, method_jsone}
  ], Req, State}.


content_types_accepted(Req, State) ->
  { [{ {<<"application">>, <<"x-www-form-urlencoded">>, []}, create_jsone}], Req, State}.


resource_exists(Req, State) ->
  io:format("resource_exists State: ~p~n", [State]),
  {ok, Params, Req2} = cowboy_req:read_urlencoded_body(Req),
  io:format("Id: ~p~n",[Params]),
  case lists:keyfind(<<"path">>, 1, Params) of
    false -> {false, Req2, [{path, <<>>} | State]};
    {_, Path} -> {valid_path(Path), Req2, [{path, Path} | State]}
  end.


create_jsone(Req, State) ->
  % io:format("~p~n", ["cowboy read_urlencoded_body:"]),
  % io:format("~p~n", [cowboy_req:read_urlencoded_body(Req)]),
  % {ok, [{<<"test_id">>, Value}], Req2} = cowboy_req:read_urlencoded_body(Req),
  % io:format("~p~n",["value:"]),
  % io:format("~p~n",[Value]),
  % io:format("~p~n",["method:"]),
  % io:format("~p~n",[cowboy_req:method(Req2)]),
  % io:format("~p~n",["system variables from sys.config:"]),
  % io:format("~p~n",[application:get_env(p2_core, pgs_user, undefined)]),
  
  % Some_Id = <<"777">>,
  {path, Path} = lists:keyfind(path, 1, State),
  io:format("create_jsone: ~p~n", [Path]),
  ?MODULE:create_jsone2(cowboy_req:method(Req), Path, Req, State).

% helper
create_jsone2(<<"POST">>, Some_Id, Req2, State) ->
  Req3 = cowboy_req:set_resp_body(["Hello world! path: ", Some_Id], Req2),
  {true, Req3, State};
create_jsone2(_, _, Req2, State) ->
  {true, Req2, State}.

% cowboy_req:binding(test_id, Req, undefined) % get value from router bind,, https://ninenines.eu/docs/en/cowboy/2.4/manual/cowboy_req.binding/
% #{lang := Lang} = cowboy_req:match_qs([{lang, [], plain}], Req), % get_params,, https://ninenines.eu/docs/en/cowboy/2.4/manual/cowboy_req.match_qs/
% {ok, [{<<"paste">>, Value}], Req2} = cowboy_req:read_urlencoded_body(Req), % post_params,, https://ninenines.eu/docs/en/cowboy/2.4/manual/cowboy_req.read_urlencoded_body/

method_jsone(Req, not_found) ->
  { <<"{\"status\":\"error\", \"error_message\":\"invalid data\"}">>, Req, not_found};
method_jsone(Req, Id) ->
  { <<"{\"status\":\"ok\", \"data\":[{\"id\":\"", Id/binary, "\"}]}">>, Req, Id}.


% %%%%%%%%%%%%%%%%%%%%%%%55
valid_path(<<>>) -> true;
valid_path(<<$., _T/binary>>) -> false;
valid_path(<<$/, _T/binary>>) -> false;
valid_path(<<_Char, T/binary>>) -> valid_path(T).



% Escape some HTML characters that might make a fuss
escape_html_chars(Bin) ->
  << <<(escape_html_char(B))/binary>> || <<B>> <= Bin >>.

escape_html_char($<) -> <<"&lt;">>;
escape_html_char($>) -> <<"&gt;">>;
escape_html_char($&) -> <<"&amp;">>;
escape_html_char(C) -> <<C>>.