feat: discovery tops for empty GET /v1/search. Refs EventHub/EventHubBack#50

Co-authored-by: Cursor <cursoragent@cursor.com>

src/handlers/handler_search.erl

@@ -24,7 +24,7 @@ trails() ->
     #{
       path        => <<"/v1/search">>,
       method      => <<"GET">>,
-      description => <<"Search calendars and events">>,
+      description => <<"Search calendars and events. Empty query (auth only) returns discovery tops by rating; use q/tags/geo/from/to for filtered search.">>,
       tags        => [<<"Search">>],
       parameters  => [
         #{name => <<"type">>,  in => <<"query">>, schema => #{type => string, enum => [<<"calendar">>, <<"event">>]}, description => <<"Type of entities to search">>},

src/logic/logic_search.erl

@@ -16,6 +16,7 @@
 %% ─────────────────────────────────────────────────────────────────
 -define(DEFAULT_LIMIT, 20).
 -define(MAX_LIMIT, 100).
+-define(DISCOVERY_FETCH, 200).
 -define(EARTH_RADIUS_KM, 6371.0).
 
 %%%-------------------------------------------------------------------
@@ -36,6 +37,14 @@
 search(Type, Query, UserId, Params) ->
   Limit = min(maps:get(limit, Params, ?DEFAULT_LIMIT), ?MAX_LIMIT),
   Offset = maps:get(offset, Params, 0),
+  case is_discovery_request(Query, Params) of
+    true ->
+      discovery_search(Type, UserId, Params, Limit, Offset);
+    false ->
+      filtered_search(Type, Query, UserId, Params, Limit, Offset)
+  end.
+
+filtered_search(Type, Query, UserId, Params, Limit, Offset) ->
   case Type of
     <<"event">> ->
       {ok, Total, Events} = search_events(Query, UserId, Params, Limit, Offset),
@@ -52,6 +61,58 @@ search(Type, Query, UserId, Params) ->
       }}
   end.
 
+%% Пустой search (страница «Главная»): tops из stats_tops; иначе — полный scan.
+is_discovery_request(Query, Params) ->
+  QueryEmpty = Query =:= undefined orelse Query =:= <<>>,
+  QueryEmpty andalso
+    not maps:is_key(tags, Params) andalso
+    not maps:is_key(from, Params) andalso
+    not maps:is_key(to, Params) andalso
+    not maps:is_key(lat, Params) andalso
+    not maps:is_key(lon, Params) andalso
+    not maps:is_key(sort, Params).
+
+discovery_search(Type, UserId, Params, Limit, Offset) ->
+  case Type of
+    <<"event">> ->
+      {ok, Total, Events} = discovery_events(UserId, Params, Limit, Offset),
+      {ok, Total, #{<<"events">> => Events}};
+    <<"calendar">> ->
+      {ok, Total, Calendars} = discovery_calendars(UserId, Params, Limit, Offset),
+      {ok, Total, #{<<"calendars">> => Calendars}};
+    _ ->
+      {ok, EventsTotal, Events} = discovery_events(UserId, Params, Limit, Offset),
+      {ok, CalendarsTotal, Calendars} = discovery_calendars(UserId, Params, Limit, Offset),
+      {ok, EventsTotal + CalendarsTotal, #{
+        <<"events">> => Events,
+        <<"calendars">> => Calendars
+      }}
+  end.
+
+discovery_events(UserId, Params, Limit, Offset) ->
+  FetchN = max(Limit + Offset, ?DISCOVERY_FETCH),
+  Tops = core_event:get_top_events_by_rating(FetchN),
+  Accessible = filter_accessible_events(Tops, UserId),
+  case Accessible of
+    [] ->
+      search_events(undefined, UserId, Params, Limit, Offset);
+    Items ->
+      Total = length(Items),
+      {ok, Total, format_events(paginate(Items, Limit, Offset))}
+  end.
+
+discovery_calendars(UserId, Params, Limit, Offset) ->
+  FetchN = max(Limit + Offset, ?DISCOVERY_FETCH),
+  Tops = core_calendar:get_top_calendars_by_rating(FetchN),
+  Accessible = filter_accessible_calendars(Tops, UserId),
+  case Accessible of
+    [] ->
+      search_calendars(undefined, UserId, Params, Limit, Offset);
+    Items ->
+      Total = length(Items),
+      {ok, Total, format_calendars(paginate(Items, Limit, Offset))}
+  end.
+
 %% ============ Поиск событий ============
 
 -spec search_events(Query :: binary() | undefined,