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

Draws temperature/dew point in C.
Copy/link file as 'weather_temp_CODE', like: weather_temp_LOWW for Austria, Vienna.

Get the code by going to https://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_C = re.compile(r'Temperature:\s*[0-9]*\s*[F]*\s*\((-?\d+\.?\d?) C\)')
re_DewC = re.compile(r'Dew.*:\s*[0-9]*\s*[F]*\s*\((-?\d+\.?\d?) C\)')

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 Temperature and Dew Point at code %s' % code)
    print('graph_vlabel Temperature and Dew Point in C')
    print('graph_category sensors')
    print('temperature.label Temperature')
    print('dewpoint.label Dew Point')
    print('graph_args --base 1000 -l 0')
else:
    u = urlopen(url % code)
    txt = str(u.read())
    u.close()

    C = re_C.findall(txt)[0]
    DewC = re_DewC.findall(txt)[0]
    print('temperature.value %s' % C)
    print('dewpoint.value %s' % DewC)