%%%-------------------------------------------------------------------
%%% @author anlicheng
%%% @copyright (C) 2024, <COMPANY>
%%% @doc
%%%
%%% @end
%%% Created : 07. 5月 2024 10:30
%%%-------------------------------------------------------------------
-module(endpoint_timer).
-author("anlicheng").
-include("endpoint.hrl").

-behaviour(gen_server).

%% API
-export([start_link/1]).
-export([task/3, ack/2, cleanup/1]).

%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).

-record(state, {
    retry_interval = 0,
    %% 定时器
    timer_map = #{}
}).

%%%===================================================================
%%% API
%%%===================================================================

task(Pid, Id, Task) when is_pid(Pid), is_integer(Id), is_function(Task, 0) ->
    gen_server:cast(Pid, {task, Id, Task}).

ack(Pid, Id) when is_pid(Pid), is_integer(Id) ->
    gen_server:cast(Pid, {ack, Id}).

cleanup(Pid) when is_pid(Pid) ->
    gen_server:cast(Pid, cleanup).

%% @doc Spawns the server and registers the local name (unique)
-spec(start_link(RetryInterval :: integer()) ->
    {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
start_link(RetryInterval) when is_integer(RetryInterval) ->
    gen_server:start_link(?MODULE, [RetryInterval], []).

%%%===================================================================
%%% gen_server callbacks
%%%===================================================================

%% @private
%% @doc Initializes the server
-spec(init(Args :: term()) ->
    {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
    {stop, Reason :: term()} | ignore).
init([RetryInterval]) ->
    {ok, #state{retry_interval = RetryInterval}}.

%% @private
%% @doc Handling call messages
-spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()},
    State :: #state{}) ->
    {reply, Reply :: term(), NewState :: #state{}} |
    {reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} |
    {noreply, NewState :: #state{}} |
    {noreply, NewState :: #state{}, timeout() | hibernate} |
    {stop, Reason :: term(), Reply :: term(), NewState :: #state{}} |
    {stop, Reason :: term(), NewState :: #state{}}).
handle_call(_Request, _From, State = #state{}) ->
    {reply, ok, State}.

%% @private
%% @doc Handling cast messages
-spec(handle_cast(Request :: term(), State :: #state{}) ->
    {noreply, NewState :: #state{}} |
    {noreply, NewState :: #state{}, timeout() | hibernate} |
    {stop, Reason :: term(), NewState :: #state{}}).
handle_cast({task, Id, Task}, State = #state{retry_interval = RetryInterval, timer_map = TimerMap}) ->
    TimerRef = erlang:start_timer(RetryInterval, self(), {repost_ticker, {Id, Task}}),
    {noreply, State#state{timer_map = maps:put(Id, TimerRef, TimerMap)}};

%% 取消
handle_cast({ack, Id}, State = #state{timer_map = TimerMap}) ->
    case maps:take(Id, TimerMap) of
        error ->
            {noreply, State};
        {TimerRef, NTimerMap} ->
            is_reference(TimerRef) andalso erlang:cancel_timer(TimerRef),
            {noreply, State#state{timer_map = NTimerMap}}
    end;

handle_cast(cleanup, State = #state{timer_map = TimerMap}) ->
    lists:foreach(fun({_, TimerRef}) -> catch erlang:cancel_timer(TimerRef) end, maps:to_list(TimerMap)),
    {noreply, State#state{timer_map = #{}}}.

%% @private
%% @doc Handling all non call/cast messages
-spec(handle_info(Info :: timeout() | term(), State :: #state{}) ->
    {noreply, NewState :: #state{}} |
    {noreply, NewState :: #state{}, timeout() | hibernate} |
    {stop, Reason :: term(), NewState :: #state{}}).
handle_info({timeout, _, {repost_ticker, {Id, Task}}}, State = #state{retry_interval = RetryInterval, timer_map = TimerMap}) ->
    Task(),
    TimerRef = erlang:start_timer(RetryInterval, self(), {repost_ticker, {Id, Task}}),

    {noreply, State#state{timer_map = maps:put(Id, TimerRef, TimerMap)}}.

%% @private
%% @doc This function is called by a gen_server when it is about to
%% terminate. It should be the opposite of Module:init/1 and do any
%% necessary cleaning up. When it returns, the gen_server terminates
%% with Reason. The return value is ignored.
-spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()),
    State :: #state{}) -> term()).
terminate(_Reason, _State = #state{}) ->
    ok.

%% @private
%% @doc Convert process state when code is changed
-spec(code_change(OldVsn :: term() | {down, term()}, State :: #state{},
    Extra :: term()) ->
    {ok, NewState :: #state{}} | {error, Reason :: term()}).
code_change(_OldVsn, State = #state{}, _Extra) ->
    {ok, State}.

%%%===================================================================
%%% Internal functions
%%%===================================================================