%%%-------------------------------------------------------------------
%%% @author anlicheng
%%% @copyright (C) 2025, <COMPANY>
%%% @doc
%%%
%%% @end
%%% Created : 13. 8月 2025 16:41
%%%-------------------------------------------------------------------
-module(service_model).
-author("anlicheng").
-include("efka_tables.hrl").

-behaviour(gen_server).

%% API
-export([start_link/0]).

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

-define(SERVER, ?MODULE).
-define(TAB, service).

-record(state, {

}).

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

insert(Service = #service{}) ->
    gen_server:call(?SERVER, {insert, Service}).

change_status(ServiceId, NewStatus) when is_binary(ServiceId), is_integer(NewStatus) ->
    gen_server:call(?SERVER, {change_status, ServiceId, NewStatus}).

-spec set_config(ServiceId :: binary(), ConfigJson :: binary()) -> ok | {error, Reason :: any()}.
set_config(ServiceId, ConfigJson) when is_binary(ServiceId), is_binary(ConfigJson) ->
    gen_server:call(?SERVER, {set_config, ServiceId, ConfigJson}).

-spec get_config_json(ServiceId :: binary()) -> error | {ok, ConfigJson :: binary()}.
get_config_json(ServiceId) when is_binary(ServiceId) ->
    gen_server:call(?SERVER, {get_config_json, ServiceId}).

-spec get_status(ServiceId :: binary()) -> Status :: integer().
get_status(ServiceId) when is_binary(ServiceId) ->
    gen_server:call(?SERVER, {get_status, ServiceId}).

-spec get_service(ServiceId :: binary()) -> error | {ok, Service :: #service{}}.
get_service(ServiceId) when is_binary(ServiceId) ->
    gen_server:call(?SERVER, {get_service, ServiceId}).

-spec get_all_services() -> [#service{}].
get_all_services() ->
    gen_server:call(?SERVER, get_all_services).

-spec get_all_service_ids() -> [ServiceId :: binary()].
get_all_service_ids() ->
    gen_server:call(?SERVER, get_all_service_ids).

-spec get_running_services() -> {ok, [#service{}]} | {error, Reason :: term()}.
get_running_services() ->
    gen_server:call(?SERVER, get_running_services).

%% @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, DetsDir} = application:get_env(efka, dets_dir),
    File = DetsDir ++ "service.dets",
    {ok, ?TAB} = dets:open_file(?TAB, [{file, File}, {type, bag}, {keypos, 2}]),
    {ok, #state{}}.

%% @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({insert, Service}, _From, State = #state{}) ->
    ok = dets:insert(?TAB, Service),
    {reply, ok, State};

handle_call({change_status, ServiceId, NewStatus}, _From, State = #state{}) ->
    case dets:lookup(?TAB, ServiceId) of
        [] ->
            {reply, {error, <<"service not found">>}, State};
        [OldService] ->
            NewService = OldService#service{status = NewStatus},
            ok = dets:insert(?TAB, NewService),
            {reply, ok, State}
    end;

handle_call({set_config, ServiceId, ConfigJson}, _From, State = #state{}) ->
    case dets:lookup(?TAB, ServiceId) of
        [] ->
            {reply, {error, <<"service not found">>}, State};
        [OldService] ->
            NewService = OldService#service{config_json = ConfigJson},
            ok = dets:insert(?TAB, NewService),
            {reply, ok, State}
    end;

handle_call({get_config_json, ServiceId}, _From, State = #state{}) ->
    case dets:lookup(?TAB, ServiceId) of
        [] ->
            {reply, error, State};
        [#service{config_json = ConfigJson}] ->
            {reply, {ok, ConfigJson}, State}
    end;

handle_call({get_status, ServiceId}, _From, State = #state{}) ->
    case dets:lookup(?TAB, ServiceId) of
        [] ->
            {reply, 0, State};
        [#service{status = Status}] ->
            {reply, Status, State}
    end;

handle_call(get_all_services, _From, State = #state{}) ->
    Items = dets:foldl(fun(Record, Acc) -> [Record|Acc] end, [], ?TAB),
    {reply, lists:reverse(Items), State};

handle_call(get_running_services, _From, State = #state{}) ->
    Items = dets:foldl(fun(Record, Acc) -> [Record|Acc] end, [], ?TAB),
    RunningItems = lists:filter(fun(#service{status = Status}) -> Status =:= 1 end, lists:reverse(Items)),
    {reply, RunningItems, 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(_Request, State = #state{}) ->
    {noreply, State}.

%% @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 = dets:close(?TAB),
    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
%%%===================================================================