Пагинация, фильтры и сортировки Часть 1 #20

src/handlers/admin/admin_handler_event_by_id.erl

@@ -113,12 +113,14 @@ convert_field({<<"location">>, Val}) -> {location, Val};
 convert_field({<<"tags">>, Val}) -> {tags, Val};
 convert_field({<<"capacity">>, Val}) -> {capacity, Val};
 convert_field({<<"online_link">>, Val}) -> {online_link, Val};
-convert_field({<<"status">>, Val}) -> {status, Val};
+convert_field({<<"status">>, Val}) ->
+  try binary_to_existing_atom(Val, utf8) of
+    Atom -> {status, Atom}
+  catch
+    error:badarg -> {status, Val}   % fallback, но лучше залогировать
+  end;
 convert_field(Other) -> Other.
 
-%% event_to_json, datetime_to_iso8601, parse_datetime, parse_datetime_binary
-%% берутся те же, что и в admin_handler_events.erl (можно вынести в общий модуль,
-%% но для простоты дублируем).
 event_to_json(Event) ->
   LocationJson = case Event#event.location of
                    undefined -> null;

src/handlers/admin/admin_handler_events.erl

@@ -6,37 +6,51 @@
 
 init(Req, _Opts) ->
   case cowboy_req:method(Req) of
-    <<"GET">> ->
-      list_all_events(Req);
-    _ ->
-      send_error(Req, 405, <<"Method not allowed">>)
+    <<"GET">> -> list_all_events(Req);
+    _ -> send_error(Req, 405, <<"Method not allowed">>)
   end.
 
-%% GET /v1/admin/events
 list_all_events(Req) ->
   case auth_admin(Req) of
     {ok, _AdminId, Req1} ->
-      Filters = parse_filters(Req1),
-      {ok, Events} = logic_event:list_all_events(Filters),
+      Params = parse_admin_event_search(Req1),
+      {ok, Total, Events} = logic_event:search_events(Params),
       Json = [event_to_json(E) || E <- Events],
-      send_json(Req1, 200, Json);
+      Limit = maps:get(limit, Params, 50),
+      Offset = maps:get(offset, Params, 0),
+      RangeEnd = min(Offset + Limit - 1, Total - 1),
+      Headers = #{
+        <<"content-type">> => <<"application/json">>,
+        <<"content-range">> => iolist_to_binary(
+          io_lib:format("items ~B-~B/~B", [Offset, RangeEnd, Total])),
+        <<"x-total-count">> => integer_to_binary(Total),
+        <<"access-control-expose-headers">> => <<"Content-Range, X-Total-Count">>
+      },
+      Body = jsx:encode(Json),
+      cowboy_req:reply(200, Headers, Body, Req1),
+      {ok, Body, []};
     {error, Code, Msg, Req1} ->
       send_error(Req1, Code, Msg)
   end.
 
-%% --- Вспомогательные функции ---
-
-parse_filters(Req) ->
+parse_admin_event_search(Req) ->
   Qs = cowboy_req:parse_qs(Req),
-  lists:filtermap(
-    fun
-      ({<<"from">>, Val}) -> {true, {from, parse_datetime_binary(Val)}};
-      ({<<"to">>, Val}) -> {true, {to, parse_datetime_binary(Val)}};
-      (_) -> false
-    end,
-    Qs
-  ).
+  #{
+    from => parse_datetime_qs(proplists:get_value(<<"from">>, Qs)),
+    to   => parse_datetime_qs(proplists:get_value(<<"to">>, Qs)),
+    status => proplists:get_value(<<"status">>, Qs, undefined),
+    calendar_id => proplists:get_value(<<"calendar_id">>, Qs, undefined),
+    title => proplists:get_value(<<"title">>, Qs, undefined),
+    q     => proplists:get_value(<<"q">>, Qs, undefined),
+    limit  => parse_int_qs(proplists:get_value(<<"limit">>, Qs), 50),
+    offset => parse_int_qs(proplists:get_value(<<"offset">>, Qs), 0),
+    sort   => proplists:get_value(<<"sort">>, Qs, <<"created_at">>),
+    order  => proplists:get_value(<<"order">>, Qs, <<"desc">>)
+  }.
 
+%%--------------------------------------------------------------------
+%% Вспомогательные функции
+%%--------------------------------------------------------------------
 auth_admin(Req) ->
   case handler_auth:authenticate(Req) of
     {ok, AdminId, Req1} ->
@@ -48,7 +62,14 @@ auth_admin(Req) ->
       {error, Code, Msg, Req1}
   end.
 
-%% Сериализация события (полностью скопирована из handler_event_by_id.erl)
+parse_int_qs(undefined, Default) -> Default;
+parse_int_qs(Bin, Default) ->
+  try binary_to_integer(Bin) catch _:_ -> Default end.
+
+parse_datetime_qs(undefined) -> undefined;
+parse_datetime_qs(Bin) ->
+  case parse_datetime(Bin) of {ok, Dt} -> Dt; _ -> undefined end.
+
 event_to_json(Event) ->
   LocationJson = case Event#event.location of
                    undefined -> null;
@@ -97,12 +118,6 @@ datetime_to_iso8601({{Year, Month, Day}, {Hour, Minute, Second}}) ->
 datetime_to_iso8601(undefined) ->
   undefined.
 
-parse_datetime_binary(Str) ->
-  case parse_datetime(Str) of
-    {ok, Dt} -> Dt;
-    _ -> undefined
-  end.
-
 parse_datetime(Str) ->
   try
     [DateStr, TimeStr] = string:split(Str, "T"),
@@ -119,12 +134,6 @@ parse_datetime(Str) ->
   catch _:_ -> {error, invalid_format}
   end.
 
-send_json(Req, Status, Data) ->
-  Body = jsx:encode(Data),
-  Headers = #{<<"content-type">> => <<"application/json">>},
-  cowboy_req:reply(Status, Headers, Body, Req),
-  {ok, Body, []}.
-
 send_error(Req, Status, Message) ->
   Body = jsx:encode(#{error => Message}),
   cowboy_req:reply(Status, #{<<"content-type">> => <<"application/json">>}, Body, Req),