#!/usr/bin/env python3

# http://inamidst.com/saxo/
# Created by Sean B. Palmer

import datetime
import decimal
import math as maths
import socket
import struct

import saxo

@saxo.pipe
def npl(args):
    server = "ntp1.npl.co.uk"
    client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    client.sendto(b"\x1B" + 47 * b"\x00", (server, 123))
    data, address = client.recvfrom(48)

    if data:
        buf = struct.unpack("B" * 48, data)
        d = decimal.Decimal
        value = d("0.0")
        for i in range(8):
            value += d(buf[32 + i]) * d(str(maths.pow(2, (3 - i) * 8)))
        value -= d(2208988800)
        # timestamp = str(d)

        a, b = str(value).split(".")
        f = "%Y-%m-%d %H:%M:%S"
        dt = datetime.datetime.utcfromtimestamp(value).strftime(f)
        return dt + "." + b[:6] + " UTC"
    return "No data was received from %s" % server