%%%-------------------------------------------------------------------
%%% @author aresei
%%% @copyright (C) 2023, <COMPANY>
%%% @doc
%%%
%%% @end
%%% Created : 06. 9月 2023 16:37
%%%-------------------------------------------------------------------
-module(aircon_args).
-author("aresei").

-behaviour(gen_server).

%% API
-export([start_link/0]).
-export([get_metric/0, get_param/0, push_metric/1, push_param/1, get_device_uuid/1]).

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

-define(SERVER, ?MODULE).

-record(state, {
    %% #{device_id => device_uuid}, 下发的时候是：serial
    metrics = #{},
    param = #{}
}).

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

-spec get_param() -> {ok, Param :: #{}}.
get_param() ->
    gen_server:call(?MODULE, get_param).

-spec get_metric() -> {ok, Metric :: map()}.
get_metric() ->
    gen_server:call(?MODULE, get_metric).

-spec get_device_uuid(DeviceId :: binary()) -> error | {ok, DeviceUUID :: binary()}.
get_device_uuid(DeviceId) when is_binary(DeviceId) ->
    gen_server:call(?MODULE, {get_device_uuid, DeviceId}).

-spec push_param(Param :: map()) -> no_return().
push_param(Param) when is_map(Param) ->
    gen_server:cast(?MODULE, {push_param, Param}).

-spec push_metric(Metrics :: list()) -> no_return().
push_metric(Metrics) when is_list(Metrics) ->
    gen_server:cast(?MODULE, {push_metric, Metrics}).

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

%%%===================================================================
%%% 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([]) ->
    {ok, Metrics} = efka_client:request_metric(),
    try convert_metric(Metrics) of
        {ok, MetricMap} ->
            logger:debug("[aircon_args] init load metric_map: ~p", [MetricMap]),
            {ok, Param} = efka_client:request_param(),

            {ok, #state{metrics = MetricMap, param = Param}}
    catch
        _:Error:Stack->
            logger:warning("[aircon_args] request_metric get error: ~p, stack: ~p", [Error, Stack]),
            {ok, #state{metrics = #{}, param = #{}}}
    end.

%% @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(get_param, _From, State = #state{param = Param}) ->
    {reply, {ok, Param}, State};
handle_call({get_device_uuid, DeviceId}, _From, State = #state{metrics = Metrics}) when is_map(Metrics) ->
    Result = maps:find(DeviceId, Metrics),
    {reply, Result, State};
handle_call({get_device_uuid, _DeviceId}, _From, State) ->
    {reply, error, State};

handle_call(get_metric, _From, State = #state{metrics = Metrics}) ->
    {reply, {ok, Metrics}, 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({push_param, Param}, State = #state{}) ->
    {noreply, State#state{param = Param}};
handle_cast({push_metric, Metrics}, State = #state{}) ->
    try convert_metric(Metrics) of
        {ok, MetricMap} ->
            logger:debug("[aircon_args] push metric_map: ~p", [MetricMap]),
            {noreply, State#state{metrics = MetricMap}}
    catch _:_ ->
        {noreply, State}
    end.

%% @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(_Info, State = #state{}) ->
    {noreply, State}.

%% @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
%%%===================================================================

-spec convert_metric(Metrics :: list()) -> {ok, map()}.
convert_metric(Metrics) when is_list(Metrics) ->
    MetricTuples = lists:flatmap(fun
                                     (#{<<"serial">> := DeviceId, <<"device_uuid">> := DeviceUUID}) ->
                                         [{DeviceId, DeviceUUID}];
                                     (_) ->
                                         []
                                 end, Metrics),
    {ok, maps:from_list(MetricTuples)}.