-module(avz).
%%-author('Maxim Sokhatsky').

-include_lib("avz/include/avz.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/metainfo.hrl").
-include_lib("kvs/include/user.hrl").


-export([
  sha/1,
  update/2,
  coalesce/2,
  merge/2,
  callbacks/1,
  sdk/1,
  buttons/1,
  event/1,
  api_event/3,
  login_user/1,
  login/2,
  version/0
]).


sha(Pass) -> crypto:hmac(wf:config(n4u,hmac,sha256),n2o_secret:secret(),wf:to_binary(Pass)).
update({K,V},P) -> wf:setkey(K,1,case P of undefined -> []; _P -> _P end,{K,V}).

coalesce(X,undefined) -> X;
coalesce(_,Y) -> Y.
merge(A,B) -> list_to_tuple([ coalesce(X,Y) || {X,Y} <- lists:zip(tuple_to_list(A),tuple_to_list(B)) ]).

callbacks(Methods) -> [ M:callback()     || M <- Methods].
sdk(Methods)       -> [ M:sdk()          || M <- Methods].
buttons(Methods)   -> [ M:login_button() || M <- Methods].

event(init) -> [];
event(logout) -> wf:user(undefined), wf:redirect(?LOGIN_PAGE);
event(to_login) -> wf:redirect(?LOGIN_PAGE);
event({register, #user{}=U}) -> kvs:put(U#user{id=kvs:next_id("user", 1)}), login_user(U); % sample
event({login, #user{}=U, N}) -> Updated = merge(U,N), kvs:put(Updated), login_user(Updated); % sample
event({error, E}) -> (?CTX#cx.module):event({login_failed, E});
event({Method,Event}) -> Method:event({Method,Event});
event(Ev) ->  wf:info(?MODULE,"Page Event ~p",[Ev]).

api_event(gLogin, Args, Term) -> google:api_event(gLogin, Args, Term);
api_event(gLoginFail, Args, Term) -> google:api_event(gLoginFail, Args, Term);
api_event(fbLogin, Args, Term)   -> facebook:api_event(fbLogin, Args, Term);
api_event(winLogin, Args, Term)  -> microsoft:api_event(winLogin, Args, Term);
api_event(Name, Args, Term)      -> wf:info(?MODULE,"Unknown API event: ~p ~p ~p",[Name, Args, Term]).

login_user(User) -> wf:user(User), wf:redirect(?AFTER_LOGIN).
login(_Key, [{error, E}|_Rest])-> wf:info(?MODULE,"Auth Error: ~p", [E]);
login(Key, Args) ->
  LoginFun = fun(K) ->
    Index = proplists:get_value(Key:index(K), Args),
    case kvs:index(user,K,Index) of
      [Exists|_] ->
        RegData = Key:registration_data(Args, Key, Exists),
        (?CTX#cx.module):event({login, Exists, RegData}),
        true;
      _ -> false end end,
  
  Keys = [K || M<-kvs:modules(),T<-(M:metainfo())#schema.tables, T#table.name==user, K<-T#table.keys],
  LoggedIn = lists:any(LoginFun, Keys),
  if (LoggedIn =:= true) -> ok; true -> 
    RegData = Key:registration_data(Args, Key, #user{}),
    (?CTX#cx.module):event({register, RegData})
  end.

version() -> proplists:get_value(vsn,element(2,application:get_all_key(?MODULE))).