-module(qdate).

-export([
	to_string/1,
	to_string/2,
	to_date/1,
	to_now/1,
	to_unixtime/1
]).

%% Exported for API compatibility with ec_date
-export([
	format/1,format/2,
	nparse/1,
	parse/1
]).


to_string(Format) ->
	to_string(Format, now()).

to_string(Format, Date) ->
	ec_date:format(Format,to_date(Date)).

format(Format) ->
	to_string(Format).

format(Format, Date) ->
	to_string(Format, Date).

parse(String) ->
	to_date(String).

nparse(String) ->
	to_now(String).

to_date(Unixtime) when is_integer(Unixtime) ->
	unixtime_to_date(Unixtime);
to_date(DateString) when is_list(DateString) ->
	ec_date:parse(DateString);
to_date(Now = {_,_,_}) ->
	calendar:now_to_datetime(Now);
to_date(Date = {{_,_,_},{_,_,_}}) ->
	Date.


to_unixtime(Unixtime) when is_integer(Unixtime) ->
	Unixtime;
to_unixtime(ToParse) ->
	Date = to_date(ToParse),
	calendar:datetime_to_gregorian_seconds(Date).


to_now(Now = {_,_,_}) ->
	Now;
to_now(ToParse) ->
	Unixtime = to_unixtime(ToParse),
	unixtime_to_now(Unixtime).


unixtime_to_now(T) when is_integer(T) ->
	MegaSec = floor(T/1000000),
	Secs = T - MegaSec*1000000,
	{MegaSec,Secs,0}.

unixtime_to_date(T) ->
	Now = unixtime_to_now(T),
	calendar:now_to_datetime(Now).

floor(N) when N >= 0 ->
	trunc(N);
floor(N) when N < 0 ->
	Int = trunc(N),
	if
		Int==N -> Int;
		true -> Int-1
	end.