#!/usr/bin/python
# vim: set fileencoding=utf-8 :
#
# Munin plugin to monitor the runtime vs. the off time of a
# pelletronic/pelletronic touch 2.0
#
# Copyright 2013 Guido Guenther <agx@sigxcpu.org>
#
# Licesnse: GPLv3
#
# depends: python-requests
#
# FIXME: This currently doesn't probe the connected systems
#
#%# capabilities=autoconf
#%# family=contrib

import requests
import os
import re
import sys
import json

username = os.getenv('username', 'oekofen')
password = os.getenv('password', username)
debug = os.getenv('debug')
url = os.getenv('url')

# The items we want to fetch:
items = { "off": "CAPPL:FA[0].L_sillstandszeit",
          "on": "CAPPL:FA[0].L_brennerlaufzeit_anzeige",
        }

def canon(name):
    return re.sub(r"[^a-zA-Z0-9_]", "_", name)

def print_config(url):
    print """graph_title Pellematic runtime coefficent
graph_vlabel Coefficient
graph_category Heating
graph_info This graph shows the amount of time the oven did not run versus the time the oven did run
graph_period hour

coefficient.label runtime coefficient
coefficient.type GAUGE
coefficient.draw LINE1
coefficient.warning 0.9
coefficient.critical 0.95

ontime.label burner on hours
ontime.type GAUGE
ontime.graph no

offtime.label burner off hours
offtime.type GAUGE
offtime.graph no
"""

def fetch_raw(url):
    # Perform authentication and get the cookie
    auth_formdata = {'language': 'en',
                     'username': username,
                     'password': password,
                     'submit': 'Login',
                     }
    r = requests.post(url, data=auth_formdata)

    pksession = r.cookies['pksession']
    cookies = { 'pksession': pksession,
                'language': 'en' }
    params = { 'action': 'get',
               'attr': '1',
             }

    # These are the headers used by the supplied application
    # It mostly doesn't matter what we pass but the backend
    # breaks with a lua error without a Accept-Language header:
    headers = {'Accept': 'application/json',
               'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
               'Accept-Language': 'en',
              }

    # The items to fetch are passed as simple json string
    payload = json.dumps(items.values())
    r = requests.post(url,
                      data=payload,
                      params=params,
                      cookies=cookies,
                      headers=headers)

    if hasattr(r.json, '__call__'):
        ret = r.json()
    else: # in requests 0.12 json isn't a callable
        ret = r.json

    if debug:
        print >>sys.stderr, ret

    return ret

def fetch_values(url):
    out = fetch_raw(url)
    on = 0.0
    off = 1.0
    
    for item in out:
        if item['name'] == items['off']:
            off = float(item['value'])
        if item['name'] == items['on']:
            on = float(item['value'])
    
    print "coefficient.value %f" % (on/off)
    print "ontime.value %f" % on
    print "offtime.value %f" % off



def main(args):
    if not url:
        print >>sys.stderr, "No url configured"
        return 1
    if len(args) > 1:
        if args[1] in [ 'autoconf', 'detect' ]:
            try:
                fetch_raw(url)
                print "yes"
                return 0
            except:
                print "no"
                return 1
        elif args[1] == 'config':
            try:
                print_config(url)
            except Exception as e:
                print >>sys.stderr, "Failed to fetch config: '%s'" % e
                return 1
            return 0
    try:
        fetch_values(url)
    except Exception as e:
        print >>sys.stderr, "Failed to fetch values: '%s'" % e
        return 1
    return 0

if __name__ == "__main__":
    sys.exit(main(sys.argv))