%%%-------------------------------------------------------------------
%%% @author Evgeny Khramtsov <ekhramtsov@process-one.net>
%%% @copyright (C) 2016, Evgeny Khramtsov
%%% @doc
%%%
%%% @end
%%% Created : 13 Apr 2016 by Evgeny Khramtsov <ekhramtsov@process-one.net>
%%%-------------------------------------------------------------------
-module(mod_last_mnesia).
-behaviour(mod_last).

%% API
-export([init/2, import/2, get_last/2, store_last_info/4, remove_user/2]).

-include("mod_last.hrl").
-include("logger.hrl").

%%%===================================================================
%%% API
%%%===================================================================
init(_Host, _Opts) ->
    ejabberd_mnesia:create(?MODULE, last_activity,
			[{disc_copies, [node()]},
			 {attributes,
			  record_info(fields, last_activity)}]),
    update_table().

get_last(LUser, LServer) ->
    case mnesia:dirty_read(last_activity, {LUser, LServer}) of
	[] ->
	    not_found;
	[#last_activity{timestamp = TimeStamp,
			status = Status}] ->
	    {ok, TimeStamp, Status}
    end.

store_last_info(LUser, LServer, TimeStamp, Status) ->
    US = {LUser, LServer},
    F = fun () ->
		mnesia:write(#last_activity{us = US,
					    timestamp = TimeStamp,
					    status = Status})
	end,
    mnesia:transaction(F).

remove_user(LUser, LServer) ->
    US = {LUser, LServer},
    F = fun () -> mnesia:delete({last_activity, US}) end,
    mnesia:transaction(F).

import(_LServer, #last_activity{} = LA) ->
    mnesia:dirty_write(LA).

%%%===================================================================
%%% Internal functions
%%%===================================================================
update_table() ->
    Fields = record_info(fields, last_activity),
    case mnesia:table_info(last_activity, attributes) of
      Fields ->
          ejabberd_config:convert_table_to_binary(
            last_activity, Fields, set,
            fun(#last_activity{us = {U, _}}) -> U end,
            fun(#last_activity{us = {U, S}, status = Status} = R) ->
                    R#last_activity{us = {iolist_to_binary(U),
                                          iolist_to_binary(S)},
                                    status = iolist_to_binary(Status)}
            end);
      _ ->
	  ?INFO_MSG("Recreating last_activity table", []),
	  mnesia:transform_table(last_activity, ignore, Fields)
    end.