Рефакторинг обработчиков. Часть 2 #21

src/handlers/ws_handler.erl

@@ -1,5 +1,18 @@
+%%%-------------------------------------------------------------------
+%%% @doc Пользовательский WebSocket-обработчик.
+%%%
+%%% Устанавливает WebSocket-соединение после проверки JWT-токена
+%%% и подписывает пользователя на обновления календарей.
+%%%
+%%% Поддерживаемые действия:
+%%% - subscribe   – подписаться на обновления календаря
+%%% - unsubscribe – отписаться от обновлений
+%%% - ping        – проверка соединения
+%%% @end
+%%%-------------------------------------------------------------------
 -module(ws_handler).
 -behaviour(cowboy_websocket).
+
 -export([init/2]).
 -export([websocket_init/1]).
 -export([websocket_handle/2]).
@@ -7,59 +20,73 @@
 -export([terminate/3]).
 
 -record(state, {
-  user_id :: binary() | undefined,
-  subscriptions = [] :: [binary()]
+  user_id       :: binary() | undefined,
+  subscriptions = [] :: [binary()]   % ← инициализация пустым списком
 }).
 
+%%%===================================================================
+%%% cowboy_websocket callback
+%%%===================================================================
+
+-spec init(cowboy_req:req(), any()) ->
+  {ok, cowboy_req:req(), undefined} |
+  {cowboy_websocket, cowboy_req:req(), #state{}}.
 init(Req, _Opts) ->
   Qs = cowboy_req:parse_qs(Req),
   case proplists:get_value(<<"token">>, Qs) of
     undefined ->
-      {ok, cowboy_req:reply(401, #{}, <<"Missing token">>, Req), undefined};
+      Req1 = cowboy_req:reply(401, #{}, <<"Missing token">>, Req),
+      {ok, Req1, undefined};
     Token ->
       case logic_auth:verify_jwt(Token) of
         {ok, UserId, _Role} ->
           {cowboy_websocket, Req, #state{user_id = UserId}};
         {error, _} ->
-          {ok, cowboy_req:reply(401, #{}, <<"Invalid token">>, Req), undefined}
+          Req1 = cowboy_req:reply(401, #{}, <<"Invalid token">>, Req),
+          {ok, Req1, undefined}
       end
   end.
 
-websocket_init(State) ->
-  pg:join(eventhub_ws, self()),
-  {ok, State}.
+%%%===================================================================
+%%% websocket callbacks
+%%%===================================================================
 
+-spec websocket_init(#state{}) -> {ok, #state{}}.
+websocket_init(#state{user_id = UserId} = State) ->
+  pg:join(eventhub_ws, self()),
+  io:format("[WS] User ~s connected~n", [UserId]),
+  {ok, State#state{subscriptions = []}}.
+
+-spec websocket_handle(term(), #state{}) ->
+  {ok, #state{}} | {reply, {text, binary()}, #state{}}.
 websocket_handle({text, Msg}, State) ->
-  io:format("WebSocket received: ~s~n", [Msg]),
+  io:format("[WS] Received: ~s~n", [Msg]),
   try jsx:decode(Msg, [return_maps]) of
     #{<<"action">> := <<"subscribe">>, <<"calendar_id">> := CalendarId} ->
-      io:format("Subscribe to calendar: ~s~n", [CalendarId]),
-      NewSubs = case lists:member(CalendarId, State#state.subscriptions) of
-                  true -> State#state.subscriptions;
-                  false -> [CalendarId | State#state.subscriptions]
-                end,
-      Reply = jsx:encode(#{status => <<"subscribed">>, calendar_id => CalendarId}),
-      io:format("Sending reply: ~s~n", [Reply]),
-      {reply, {text, Reply}, State#state{subscriptions = NewSubs}};
+      handle_subscribe(CalendarId, State);
+    #{<<"action">> := <<"unsubscribe">>, <<"calendar_id">> := CalendarId} ->
+      handle_unsubscribe(CalendarId, State);
     #{<<"action">> := <<"ping">>} ->
       {reply, {text, <<"{\"status\":\"pong\"}">>}, State};
     Other ->
-      io:format("Unknown action: ~p~n", [Other]),
+      io:format("[WS] Unknown action: ~p~n", [Other]),
       {ok, State}
   catch
     _:Error ->
-      io:format("Error parsing WebSocket message: ~p~n", [Error]),
+      io:format("[WS] Error parsing message: ~p~n", [Error]),
       {ok, State}
   end;
 websocket_handle(_Frame, State) ->
   {ok, State}.
 
+-spec websocket_info(term(), #state{}) ->
+  {ok, #state{}} | {reply, {text, binary()}, #state{}}.
 websocket_info({notification, Type, Data}, State) ->
   case should_notify(Type, Data, State) of
     true ->
       Msg = jsx:encode(#{
-        type => Type,
-        data => Data,
+        type      => Type,
+        data      => Data,
         timestamp => os:system_time(seconds)
       }),
       {reply, {text, Msg}, State};
@@ -69,15 +96,41 @@ websocket_info({notification, Type, Data}, State) ->
 websocket_info(_Info, State) ->
   {ok, State}.
 
-terminate(_Reason, _Req, _State) ->
+-spec terminate(term(), cowboy_req:req(), #state{}) -> ok.
+terminate(_Reason, _Req, #state{user_id = UserId}) ->
   pg:leave(eventhub_ws, self()),
+  io:format("[WS] User ~s disconnected~n", [UserId]),
   ok.
 
-should_notify(calendar_update, #{calendar_id := CalId}, State) ->
-  lists:member(CalId, State#state.subscriptions);
-should_notify(booking_update, #{user_id := UserId}, State) ->
-  UserId =:= State#state.user_id;
-should_notify(event_update, #{calendar_id := CalId}, State) ->
-  lists:member(CalId, State#state.subscriptions);
+%%%===================================================================
+%%% Внутренние функции
+%%%===================================================================
+
+-spec handle_subscribe(binary(), #state{}) -> {reply, {text, binary()}, #state{}}.
+handle_subscribe(CalendarId, #state{subscriptions = Subs} = State) ->
+  io:format("[WS] Subscribe to calendar: ~s~n", [CalendarId]),
+  NewSubs = case lists:member(CalendarId, Subs) of
+              true  -> Subs;
+              false -> [CalendarId | Subs]
+            end,
+  Reply = jsx:encode(#{status => <<"subscribed">>, calendar_id => CalendarId}),
+  {reply, {text, Reply}, State#state{subscriptions = NewSubs}}.
+
+-spec handle_unsubscribe(binary(), #state{}) -> {reply, {text, binary()}, #state{}}.
+handle_unsubscribe(CalendarId, #state{subscriptions = Subs} = State) ->
+  io:format("[WS] Unsubscribe from calendar: ~s~n", [CalendarId]),
+  NewSubs = lists:delete(CalendarId, Subs),
+  Reply = jsx:encode(#{status => <<"unsubscribed">>, calendar_id => CalendarId}),
+  {reply, {text, Reply}, State#state{subscriptions = NewSubs}}.
+
+-spec should_notify(atom(), map(), #state{}) -> boolean().
+should_notify(calendar_update, #{calendar_id := CalId}, #state{subscriptions = Subs}) ->
+  lists:member(CalId, Subs);
+should_notify(booking_update, #{user_id := UserId}, #state{user_id = UserId}) ->
+  true;
+should_notify(booking_update, _, _) ->
+  false;
+should_notify(event_update, #{calendar_id := CalId}, #state{subscriptions = Subs}) ->
+  lists:member(CalId, Subs);
 should_notify(_, _, _) ->
   true.