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

Draws pressure in hPa.
Copy/link file as 'weather_pressure_CODE', like: weather_pressure_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
import urllib
import re

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

re_hpa = re.compile('Pressure.*\((\d+) hPa\)')


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 Atmospheric pressure at code %s' % code)
    print('graph_vlabel Pressure in hPa')
    print('graph_category sensors')

    print('pressure.label Pressure')
    print('pressure.type GAUGE')
    print('graph_args --base 1000 -l 850 -u 1050 --rigid')
    print('graph_scale no')
else:
    u = urllib.urlopen(url % code)
    txt = u.read()
    u.close()

    hpa = re_hpa.findall(txt)[0]
    print('pressure.value %s' % hpa)
