-module(myapp_events2).
-behaviour(gen_server).

%-include_lib("stdlib/include/qlc.hrl").

-export([start_link/0]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).

-export([add_task/4, delete_task/2]).
-export([add_task_b/4, delete_task_b/2]).
-export([check_ets_count/0, check_ets_count2/0]).


-define(IS_STRING(S), (is_list(S) andalso S /= [] andalso is_integer(hd(S)))).


add_task(Task_Id, Proc_Id, Type, Time)
when ?IS_STRING(Task_Id), is_integer(Proc_Id), ((Type =:= static) orelse (Type =:= dynamic)), is_integer(Time) ->
  Time2 = case Type of
    dynamic ->
      erlang:system_time(second) + Time; % Timestamp_Now + Time
    _ ->
      % static
      Time
  end,
  gen_server:cast(?MODULE, {add_task, {{Task_Id, Proc_Id}, Time2}}),
  ok.

delete_task(Task_Id, Proc_Id)
when ?IS_STRING(Task_Id), is_integer(Proc_Id) ->
  gen_server:cast(?MODULE, {delete_task, {Task_Id, Proc_Id}}),
  ok.


add_task_b(Task_Id, Proc_Id, Type, Time)
when ?IS_STRING(Task_Id), is_integer(Proc_Id), ((Type =:= static) orelse (Type =:= dynamic)), is_integer(Time) ->
  Time2 = case Type of
    dynamic ->
      erlang:system_time(second) + Time; % Timestamp_Now + Time
    _ ->
      % static
      Time
  end,
  gen_server:call(?MODULE, {add_task, {{Task_Id, Proc_Id}, Time2}}).

delete_task_b(Task_Id, Proc_Id)
when ?IS_STRING(Task_Id), is_integer(Proc_Id) ->
  gen_server:call(?MODULE, {delete_task, {Task_Id, Proc_Id}}).




start_link() ->
  gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).


init([]) ->
  %ets:new(events_time_table, [bag, named_table, { keypos, 2 }, private, {write_concurrency, true}, {read_concurrency, true}]), % Key = Time
  %ets:new(events_table, [ordered_set, named_table, { keypos, 1 }, private, {write_concurrency, true}, {read_concurrency, true}]),
  
  %ets:new(events_time_table, [bag, named_table, { keypos, 2 }, private]), % Key = Time
  
  %ets:new(events_time_table, [ordered_set, named_table, { keypos, 2 }, private]), % Key = Time
  %ets:new(events_table, [ordered_set, named_table, { keypos, 1 }, private]), % Key = {Task_Id, Proc_Id}
  
  ets:new(events_time_table, [ordered_set, named_table, { keypos, 1 }, private]), % Key = {Time, Task_Id, Proc_Id}
  ets:new(events_table, [ordered_set, named_table, { keypos, 1 }, private]), % Key = {Task_Id, Proc_Id}
  
  %erlang:send_after(100, self(), check_time_process),
  self() ! check_time_process,
  State = [],
  {ok, State}.


handle_call({add_task, {{Task_Id, Proc_Id}=V0, Time}=V}, _From, State) ->
  %true = ets:insert(events_time_table, V),
  %true = ets:insert(events_table, V),
  
  case ets:lookup(events_table, V0) of
    [{{Task_Id, Proc_Id}, Time0}] ->
      ets:delete_object(events_time_table, {{Time0, Task_Id, Proc_Id}}),
      true = ets:insert(events_time_table, {{Time, Task_Id, Proc_Id}});
    [] ->
      true = ets:insert(events_time_table, {{Time, Task_Id, Proc_Id}});
    Z ->
      io:format("~p~n", [Z]),
      true = ets:insert(events_time_table, {{Time, Task_Id, Proc_Id}})
  end,
  true = ets:insert(events_table, V),
  
  %io:format("add/update: ~p ~p~n", [Task_Id, Proc_Id]),
  {reply, ok, State};


handle_call({delete_task, {Task_Id, Proc_Id}=V}, _From, State) ->
  %qlc:e(qlc:q([
  %  {ets:delete_object(events_time_table, X), ets:delete(events_table, V)}
  %  || {{Task_Id0, Proc_Id0}, _Time} = X <- ets:table(events_table),
  %  Task_Id0 =:= Task_Id, Proc_Id0 =:= Proc_Id ])), % [{true,true}] | [] % повільно
  
  %qlc:e(qlc:q([
  %  {ets:delete_object(events_time_table, X), ets:delete(events_table, V)}
  %  || X <- ets:lookup(events_table, V) ])), % [{true,true}] | []
  
  %%ets:fun2ms(fun({{A,B},C}) when A =:= X andalso B =:= Y -> {{A,B},C} end).
  %%[{{{'$1','$2'},'$3'}, [{'andalso',{'=:=','$1',{const,"2"}}, {'=:=','$2',{const,2}}}], [{{{{'$1','$2'}},'$3'}}]}]
  %case ets:select(events_table, [{{{'$1','$2'},'$3'},
  %  [{'andalso',{'=:=','$1',{const, Task_Id}}, {'=:=','$2',{const, Proc_Id}}}],
  %  [{{{{'$1','$2'}},'$3'}}]}] ) of
  %  
  %  [X] ->
  %    ets:delete_object(events_time_table, X),
  %    ets:delete(events_table, V);
  %  _ -> ok
  %end,
  
  %case ets:lookup(events_table, V) of
  %  [X] ->
  %    ets:delete_object(events_time_table, X),
  %    ets:delete(events_table, V);
  %  _ -> ok
  %end,
  
  %case ets:match_object(events_table, {{Task_Id, Proc_Id}, '$3'}) of
  %  [X] ->
  %    ets:delete_object(events_time_table, X),
  %    ets:delete(events_table, V);
  %  _ -> ok
  %end,
  
  %case ets:match_object(events_table, {{Task_Id, Proc_Id}, '$3'}) of
  case ets:lookup(events_table, V) of
    [{{Task_Id, Proc_Id}, Time}] ->
      ets:delete_object(events_time_table, {{Time, Task_Id, Proc_Id}}),
      ets:delete(events_table, V);
    _ -> ok
  end,
  
  %io:format("deleted: ~p ~p~n", [Task_Id, Proc_Id]),
  {reply, ok, State};


handle_call(_Req, _From, State) ->
  {reply, not_handled, State}.


handle_cast({add_task, {{_Task_Id, _Proc_Id}, _Time}=_V}, State) ->
  %ets:insert(events_table, V),
  %io:format("add/update: ~p ~p~n", [Task_Id, Proc_Id]),
  {noreply, State};


handle_cast({delete_task, {_Task_Id, _Proc_Id}=_V}, State) ->
  %ets:delete(events_table, V),
  %io:format("deleted: ~p ~p~n", [Task_Id, Proc_Id]),
  {noreply, State};


handle_cast(_Req, State) ->
  {noreply, State}.


handle_info(check_time_process, State) ->
  erlang:send_after(1000, self(), check_time_process),
  
  %Timestamp_Now = erlang:system_time(second),
  
  %%ets:fun2ms(fun({{A,B},C}) when C =< Timestamp_Now -> {{A,B},C} end).
  %%[{{{'$1','$2'},'$3'}, [{'=<','$3',{const,1642507256}}], [{{{{'$1','$2'}},'$3'}}]}]
  
  %L = ets:select(events_table, [{{{'$1','$2'},'$3'}, [{'=<','$3',{const, Timestamp_Now}}], [{{{{'$1','$2'}},'$3'}}]}] ),
  
  %lists:foldl(fun({{Task_Id0, Proc_Id0}=V, _Time0}, ok) ->
     % send_to_rabbitmq({call_timer, Proc_Id0, Task_Id0}),
  %   ets:delete(events_table, V),
     %io:format("tick: ~p ~p~n", [Task_Id0, Proc_Id0]),
  %   ok
  %  end, ok, L),
  
  
  ok = check_time_h(ets:first(events_time_table), false, erlang:system_time(second) ),
  
  %erlang:send_after(1000, self(), check_time_process),
  {noreply, State};


handle_info(_Request, State) ->
  {noreply, State}.


terminate(_Reason, _State) ->
  ok.

code_change(_OldVsn, State, _Extra) -> 
  {ok, State}.


%check_time_h(Key, Prev_Key, Timestamp_Now)
check_time_h('$end_of_table', Prev_Key, _Timestamp_Now) ->
  case Prev_Key of
    false -> ok;
    _ ->
      ets:delete_object(events_time_table, {Prev_Key}),
      ok
  end;
check_time_h({Time, Task_Id, Proc_Id}=Key, Prev_Key, Timestamp_Now) ->
  case Prev_Key of
    false -> ok;
    _ ->
      ets:delete_object(events_time_table, {Prev_Key}),
      ok
  end,
  
  if Time =< Timestamp_Now ->
      % send_to_rabbitmq({call_timer, Proc_Id, Task_Id}),
      ets:delete(events_table, {Task_Id, Proc_Id}),
      check_time_h(ets:next(events_time_table, Key), Key, Timestamp_Now);
      
    true -> ok
  end.

check_ets_count() -> ets:info(events_table, 'size').
check_ets_count2() -> ets:info(events_time_table, 'size').