feat: calendar follow API (POST/DELETE follow, GET following). Refs EventHub/EventHubFront#9

src/handlers/handler_user_following.erl

@@ -0,0 +1,55 @@
+%%%-------------------------------------------------------------------
+%%% @doc Список календарей, которые пользователь отслеживает (follow).
+%%%
+%%% GET /v1/user/following
+%%% @end
+%%%-------------------------------------------------------------------
+-module(handler_user_following).
+-behaviour(cowboy_handler).
+
+-export([init/2]).
+-export([trails/0]).
+
+-include("records.hrl").
+
+-spec init(cowboy_req:req(), any()) -> {ok, cowboy_req:req(), any()}.
+init(Req0, _State) ->
+  case cowboy_req:method(Req0) of
+    <<"GET">> -> list_following(Req0);
+    _         -> handler_utils:send_error(Req0, 405, <<"Method not allowed">>)
+  end.
+
+-spec trails() -> [map()].
+trails() ->
+  [
+    #{
+      path        => <<"/v1/user/following">>,
+      method      => <<"GET">>,
+      description => <<"List calendars the current user follows">>,
+      tags        => [<<"Calendars">>],
+      responses => #{
+        200 => #{
+          description => <<"Array of followed calendars">>,
+          content => #{<<"application/json">> => #{schema => #{
+            type  => array,
+            items => #{type => object}
+          }}}
+        },
+        401 => #{description => <<"Unauthorized">>}
+      }
+    }
+  ].
+
+-spec list_following(cowboy_req:req()) -> {ok, cowboy_req:req(), any()}.
+list_following(Req) ->
+  case handler_utils:auth_user(Req) of
+    {ok, UserId, Req1} ->
+      {ok, Calendars} = logic_calendar_follow:list_following_calendars(UserId),
+      Response = [
+        maps:put(following, true, handler_utils:calendar_to_json(C))
+        || C <- Calendars
+      ],
+      handler_utils:send_json(Req1, 200, Response);
+    {error, Code, Message, Req1} ->
+      handler_utils:send_error(Req1, Code, Message)
+  end.