-module(facebook).
%%-author('Andrii Zadorozhnii').

-include_lib("avz/include/avz.hrl").
-include_lib("nitro/include/nitro.hrl").
-include_lib("n4u/include/wf.hrl"). %% todo unbind avz -- todo avz usage example without nitro and n4u (n2o v4.4 fork) framework
-include_lib("kvs/include/user.hrl").


-export([
  sdk/0,               % JavaScript for page embedding for JavaScript based login methods
  login_button/0,      % HTML Button for page embedding
  event/1,             % Page Event for HTTP redirect based login methods
  api_event/3,         % Page Event for JavaScript based login methods
  email_prop/2,
  callback/0,          % Callback part of HTTP redirect based login methods
  registration_data/3, % Process Parameters
  
  index/1
]).


-define(FB_APP_ID,    application:get_env(avz, fb_id,        [])).


callback() -> ok.
event({facebook,_Event}) -> wf:wire("fb_login();"), ok.
api_event(fbLogin, Args, _Term) -> {JSArgs} = ?AVZ_JSON:decode(list_to_binary(Args)), avz:login(facebook, JSArgs).

registration_data(Props, facebook, Ori)->
    Id = proplists:get_value(<<"id">>, Props),
    BirthDay = case proplists:get_value(<<"birthday">>, Props) of
        undefined -> {1, 1, 1970};
        BD -> list_to_tuple([list_to_integer(X) || X <- string:tokens(binary_to_list(BD), "/")]) end,
    Email = proplists:get_value(<<"email">>, Props),
    [UserName|_] = string:tokens(binary_to_list(Email),"@"),
    Cover = case proplists:get_value(<<"cover">>,Props) of undefined -> ""; {P} -> case proplists:get_value(<<"source">>,P) of undefined -> ""; C -> binary_to_list(C) end end,
    Ori#user{   display_name = UserName,
                images = avz:update({fb_cover,Cover},avz:update({fb_avatar,"https://graph.facebook.com/" ++ binary_to_list(Id) ++ "/picture?type=large"},Ori#user.images)),
                email = Email,
                names = proplists:get_value(<<"first_name">>, Props),
                surnames = proplists:get_value(<<"last_name">>, Props),
                tokens = avz:update({facebook,Id},Ori#user.tokens),
                birth = {element(3, BirthDay), element(1, BirthDay), element(2, BirthDay)},
                register_date = os:timestamp(),
                status = ok }.

index(K) -> wf:to_binary(K).
email_prop(Props, _) -> proplists:get_value(<<"email">>, Props).

login_button() -> 
  #link{id=loginfb, body=[<<"Facebook">>], postback={facebook,loginClick}}.

sdk() ->
    wf:wire(#api{name=fbLogin, tag=fb}),
    [ #dtl{bind_script=false, file="facebook_sdk", ext="dtl", folder="priv/static/js",
        bindings=[{appid, ?FB_APP_ID}] } ].