Расширена общая статистика по дням: Отзывы, Календари, Жалобы, Тикеты, Подписки #22

src/core/core_subscription.erl

@@ -4,6 +4,7 @@
 -export([update_status/2, check_expired/0]).
 -export([list_subscriptions/0, create_subscription/1, update_subscription/2, delete_subscription/1]).
 -export([count_subscription/0]).
+-export([count_subscriptions_by_date/2]).
 
 -define(TRIAL_DAYS, 30).
 
@@ -292,4 +293,25 @@ parse_iso_datetime(Other) -> Other.
 %%%-------------------------------------------------------------------
 -spec count_subscription() -> non_neg_integer().
 count_subscription() ->
-  mnesia:table_info(subscription, size).
+  mnesia:table_info(subscription, size).
+
+%%%-------------------------------------------------------------------
+%%% @doc Подсчёт подписок, созданных в заданном временном диапазоне.
+%%% @end
+%%%-------------------------------------------------------------------
+-spec count_subscriptions_by_date(From :: calendar:datetime(), To :: calendar:datetime()) ->
+  [{{pos_integer(), pos_integer(), pos_integer()}, non_neg_integer()}].
+count_subscriptions_by_date(From, To) ->
+  All = mnesia:dirty_match_object(#subscription{_ = '_'}),
+  Filtered = lists:filter(fun(S) -> S#subscription.created_at >= From andalso
+    S#subscription.created_at =< To end, All),
+  Counts = lists:foldl(fun(S, Acc) ->
+    Day = date_part(S#subscription.created_at),
+    case lists:keyfind(Day, 1, Acc) of
+      false -> [{Day, 1} | Acc];
+      {Day, C} -> lists:keyreplace(Day, 1, Acc, {Day, C+1})
+    end
+                       end, [], Filtered),
+  lists:sort(Counts).
+
+date_part({{Y,M,D}, _}) -> {Y,M,D}.