%%%-------------------------------------------------------------------
%%% @author Arkadiusz
%%% @copyright (C) 2021, <COMPANY>
%%% @doc
%%% @end
%%%-------------------------------------------------------------------
-module(pollution_gen_server).

-behaviour(gen_server).

-export([start_link/0, crash/0, start/0, stop/0]).
-export([init/1, handle_call/3,terminate/2, code_change/3]).
-export([addStation/2, addValue/4, removeValue/3, getOneValue/3, getStationMean/2, getDailyMean/2, getDailyMaxMean/2, getDailyMinMean/2, getMinimumDistanceStations/2]).
-define(SERVER, ?MODULE).

%%%===================================================================
%%% Spawning and gen_server implementation
%%%===================================================================

start() ->
  start_link().

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

init([]) ->
  {ok, pollution:createMonitor()}.

%%% client API
addStation(StationName, Coordinates) ->
  gen_server:call(?SERVER, [addStation, StationName, Coordinates])
.

addValue(Station, Date, Type, Value) ->
  gen_server:call(?SERVER, [addValue, Station, Date, Type, Value])
.

removeValue(Station, Date, Type) ->
  gen_server:call(?SERVER, [removeValue, Station, Date, Type])
.

getOneValue(Station, Date, Type) ->
  gen_server:call(?SERVER, [getOneValue, Station, Date, Type])
.

getStationMean(Station, Type) ->
  gen_server:call(?SERVER, [getStationMean, Station, Type])
.

getDailyMean(Type, DateTime) ->
  gen_server:call(?SERVER, [getDailyMean, Type, DateTime])
.

getDailyMaxMean(Type, DateTime) ->
  gen_server:call(?SERVER, [getDailyMaxMean, Type, DateTime])
.

getDailyMinMean(Type, DateTime) ->
  gen_server:call(?SERVER, [getDailyMinMean, Type, DateTime])
.

getMinimumDistanceStations(Coords, Distance) ->
  gen_server:call(?SERVER, [getMinimumDistanceStations, Coords, Distance])
.

handle_call([addStation, StationName, Coordinates], _From, Monitor) ->
  NewMonitor = pollution:addStation(StationName, Coordinates, Monitor),
  {reply, checkMonitor(NewMonitor == Monitor), NewMonitor};

handle_call([addValue, Station, Date, Type, Value], _From, Monitor) ->
  NewMonitor = pollution:addValue(Station, Date, Type, Value, Monitor),
  {reply, checkMonitor(NewMonitor == Monitor), NewMonitor};

handle_call([removeValue, Station, Date, Type], _From, Monitor) ->
  NewMonitor = pollution:removeValue(Station, Date, Type, Monitor),
  {reply, checkMonitor(NewMonitor == Monitor), NewMonitor};

handle_call([getOneValue, Station, Date, Type], _From, Monitor) ->
  Value = pollution:getOneValue(Station, Date, Type, Monitor),
  {reply, Value, Monitor};

handle_call([getStationMean, Station, Type], _From, Monitor) ->
  StationMean = pollution:getStationMean(Station, Type, Monitor),
  {reply, StationMean, Monitor};

handle_call([getDailyMean, Type, DateTime], _From, Monitor) ->
  DailyMean = pollution:getDailyMean(Type, DateTime, Monitor),
  {reply, DailyMean, Monitor};

handle_call([getDailyMaxMean, Type, DateTime], _From, Monitor) ->
  DailyMaxMean = pollution:getDailyMaxMean(Type, DateTime, Monitor),
  {reply, DailyMaxMean, Monitor};

handle_call([getDailyMinMean, Type, DateTime], _From, Monitor) ->
  DailyMinMean = pollution:getDailyMinMean(Type, DateTime, Monitor),
  {reply, DailyMinMean, Monitor};

handle_call([getMinimumDistanceStations, Coords, Distance], _From, Monitor) ->
  MinimumDistanceStations = pollution:getMinimumDistanceStations(Coords, Distance, Monitor),
  {reply, MinimumDistanceStations, Monitor}
.

crash() ->
  1/0
.

stop() ->
  terminate(1, 1).

terminate(_Reason, _State) ->
  ok.

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

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

checkMonitor(true) -> error;
checkMonitor(false) -> ok
.