use fmt;
use time;
use os;
use strconv;
use strings;

type parseerror = strconv::error;

export fn main() void = {
	if (len(os::args) != 2) {
		os::exit(os::status::FAILURE);
	};

	let timestr = os::args[1];
	let i = time::now(time::clock::REALTIME);
	let spl = strings::split(timestr, ":");
	defer free(spl);

	let li = if (len(spl) > 2) {
		fmt::fatal("Duration format: m or m:s");
	} else {
		yield match (parsetime(i, spl)) {
		case let inst: time::instant =>
			yield inst;
		case let e: parseerror =>
			fmt::fatal(strerror(e));
		};
	};

	fmt::printfln("<t:{}:R>", time::unix(li))!;
};

fn strerror(e: parseerror) str = {
	return strconv::strerror(e);
};

fn parsetime(clk: time::instant, spl: []str) (time::instant | parseerror) = {
	return if (len(spl) == 2) {
		let m = strconv::stoi64(spl[0])?;
		let s = strconv::stoi64(spl[1])?;
		let d = (m * time::MINUTE) + (s * time::SECOND);
		yield time::add(clk, d);
	} else {
		let m = strconv::stoi64(spl[0])?;
		let d = m * time::MINUTE;
		yield time::add(clk, d);
	};

};