#!/usr/bin/env python3
"""
munin US NOAA weather plugin (http://tgftp.nws.noaa.gov)

Draws relative humidity in %.
Copy/link file as 'weather_humidity_CODE', like: weather_humidity_LOWW for Austria, Vienna.

Get the code by going to http://tgftp.nws.noaa.gov, selecting your
location, and copying the code from the address bar of your browser; should
be something like CODE.html.

Linux users might need to adjust the shebang.
"""

import sys
from urllib.request import urlopen
import re

url = 'https://tgftp.nws.noaa.gov/data/observations/metar/decoded/%s.TXT'

re_hum = re.compile(r'Relative Humidity:\s*(\d+)%')


code = sys.argv[0][(sys.argv[0].rfind('_') + 1):]
if not code:
    sys.exit(1)
elif len(sys.argv) == 2 and sys.argv[1] == "autoconf":
    print("yes")
elif len(sys.argv) == 2 and sys.argv[1] == "config":
    print('graph_title Relative humidity at code %s' % code)
    print('graph_vlabel humidity in %')
    print('graph_category sensors')

    print('humidity.label Humidity')
    print('graph_args --base 1000 -l 0')
else:
    u = urlopen(url % code)
    txt = str(u.read())
    u.close()

    hum = re_hum.findall(txt)[0]
    print('humidity.value %s' % hum)