Aggregator prototype

grabthar.erl

% By Grabthar's Hammer you will be avenged.
-module(grabthar). 

-export([start_link/3]).

-record(state, {
    customer_id,
    timer,
    threshold,
    current = 1,
    pending = queue:new()
}).

start_link(CustomerId, Threshold, Timeout) ->
    Pid = spawn_link(fun() -> 
                Tref = erlang:send_after(Timeout, self(), release_pending),
                loop(#state{threshold=Threshold, timer=Tref, customer_id = CustomerId}) 
            end),
        {ok, Pid}.

loop(State) ->
    receive 
        {add_notification, N} ->
            NewState = case State#state.current > State#state.threshold of
                true ->
                    State#state{ pending = queue:in(N, State#state.pending) };
                false ->
                    error_logger:format("~p", [N]),
                    State#state{ current = State#state.current + 1 }
            end,
            loop(NewState);
        
        time_remaining ->
            error_logger:format("~p", [erlang:read_timer(State#state.timer)]),
            loop(State);

        queue_len ->
            error_logger:format("~p", [queue:len(State#state.pending)]),
            loop(State);

        release_pending ->
            error_logger:format("~p", [queue:to_list(State#state.pending)])

    end.