#!/usr/bin/python

# modem:
#
# * upstream and downstream power levels
# * downstream signal to noise ratio
# * downstream error counts
#
# The values are retrieved from the cable modem's status web pages at
# 192.168.100.1. So, this plugin must be installed on a munin node
# which can access those pages.
#
# To install, place this plugin in the node's plugins directory,
# /etc/munin/plugins and restart munin-node.
#
# Developed and tested with:
# firmware:         D30CM-OSPREY-2.4.0.1-GA-02-NOSH
# hardware version: 1
#
# Copyright 2020 Nathaniel Clark <nathaniel.clark@misrule.us>

"""
=head1 NAME

arris-sb6183 - Health monitoring plugin for Arris SB6183 Cable Modem

=head1 CONFIGURATION

Make sure 192.168.100.1 is accessible through your firewall.

To have this register with munin as it's own host set the "env.hostname" in config.
Also ensure that the hostname set is listed in munin.conf.

[arris*]
env.hostname modem

=head1 VERSION

0.0.1

=head1 AUTHOR

Nathaniel Clark <nathaniel.clark@misrule.us>

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

 #%# family=contrib
 #%# capabilities=autoconf

=cut
"""

import re
import os
import sys
import requests
from lxml import html


URL = os.getenv("url", "http://192.168.100.1/RgConnect.asp")
HOSTNAME = os.getenv("hostname", None)
UPCOUNT = int(os.getenv("up", 4))
DOWNCOUNT = int(os.getenv("down", 16))

if len(sys.argv) == 2:
    if sys.argv[1] == "config":
        if HOSTNAME:
            print("host_name {0}\n".format(HOSTNAME))

        # POWER
        print("multigraph arris_power")
        print("graph_title Arris Power (dBmV)")
        print("graph_vlabel Power (dBmV)")
        print("graph_category network")
        for i in range(1, DOWNCOUNT + 1):
            print("down_{0}.label Down Ch {1}".format(i, i))
            print("down_{0}.type GAUGE".format(i))
            print("down_{0}.draw LINE1".format(i))
        for i in range(1, UPCOUNT + 1):
            print("up_{0}.label Up Ch {1}".format(i, i))
            print("up_{0}.type GAUGE".format(i))
            # print("up_{0}.draw LINE1".format(i))

        for i in range(1, DOWNCOUNT + 1):
            name = "down_{0}".format(i)
            print("\nmultigraph arris_power.{0}".format(name))
            print("graph_title Downstream Power for Channel {0} (dBmV)".format(i))
            print("graph_category network")
            print("power.label dBmV")
            print("power.type GAUGE")
            print("power.draw LINE1")
        for i in range(1, UPCOUNT + 1):
            name = "up_{0}".format(i)
            print("\nmultigraph arris_power.{0}".format(name))
            print("graph_title Upstream Power for Channel {0} (dBmV)".format(i))
            print("graph_category network")
            print("power.label dBmV")
            print("power.type GAUGE")
            print("power.draw LINE1")

        # SNR
        print("\nmultigraph arris_snr")
        print("graph_title Arris Signal-to-Noise Ratio (dB)")
        print("graph_vlabel SNR (dB)")
        print("graph_category network")
        for i in range(1, DOWNCOUNT + 1):
            print("down_{0}.label Ch {1}".format(i, i))
            print("down_{0}.type GAUGE".format(i))
            print("down_{0}.draw LINE1".format(i))

        for i in range(1, DOWNCOUNT + 1):
            name = "down_{0}".format(i)
            print("\nmultigraph arris_snr.{0}".format(name))
            print("graph_title SNR on Channel {0} (dB)".format(i))
            print("graph_vlabel SNR (dB)")
            print("graph_category network")
            print("snr.label dB")
            print("snr.type GAUGE")
            print("snr.draw LINE1")

        # ERRORS
        print("\nmultigraph arris_error")
        print("graph_title Arris Channel Errors")
        print("graph_category network")
        print("graph_args --base 1000")
        print("graph_vlabel errors/sec")
        print("graph_category network")
        print("corr.label Corrected")
        print("corr.type DERIVE")
        print("corr.min 0")
        print("uncr.label Uncorrectable")
        print("uncr.type DERIVE")
        print("uncr.min 0")
        print("uncr.warning 1")

        for i in range(1, DOWNCOUNT + 1):
            name = "down_{0}".format(i)
            print("\nmultigraph arris_error.{0}".format(name))
            print("graph_title Channel {0} Errors".format(i))
            print("graph_args --base 1000")
            print("graph_vlabel errors/sec")
            print("graph_category network")
            print("corr.label Correctable")
            print("corr.type DERIVE")
            print("corr.min 0")
            print("uncr.label Uncorrectable")
            print("uncr.type DERIVE")
            print("uncr.min 0")
            print("uncr.warning 1")

        sys.exit(0)

    if sys.argv[1] == "autoconfig":
        try:
            page = requests.get(URL)
        except:
            print("no (no router)")
        else:
            if page.status_code == 200:
                print("yes")
            else:
                print("no (Bad status code: %d)" % page.status_code)
        sys.exit(0)

rxblank = re.compile(r"[\x00\n\r\t ]+", re.MULTILINE)
rxcomment = re.compile(r"<!--.*?-->")
rxscript = re.compile(r"<script.*?</script>", re.MULTILINE)

page = requests.get(URL)
data = rxscript.sub("", rxcomment.sub("", rxblank.sub(" ", page.text)))
dom = html.fromstring(data)

arr = dom.xpath('//table[contains(@class, "simpleTable")]')
downstream = arr[1]
upstream = arr[2]

trs = downstream.findall("tr")
# drop title
trs.pop(0)

headings = ["".join(x.itertext()).strip() for x in trs.pop(0).findall("td")]
# ['Channel', 'Lock Status', 'Modulation', 'Channel ID', 'Frequency', 'Power', 'SNR', 'Corrected', 'Uncorrectables']

mapper = lambda x, y: (x, y)

# Summation Graphs
correct = 0
uncorr = 0
power = {"up": ["U"] * UPCOUNT, "down": ["U"] * DOWNCOUNT}
snr = ["U"] * DOWNCOUNT
for row in trs:
    data = dict(
        map(
            mapper, headings, ["".join(x.itertext()).strip() for x in row.findall("td")]
        )
    )
    uncorr += int(data["Uncorrectables"])
    correct += int(data["Corrected"])

    channel = int(data["Channel"])

    print("multigraph arris_power.down_{0}".format(channel))
    value = data["Power"].split(" ")[0]
    print("power.value {0}".format(value))
    power["down"][channel - 1] = value

    print("multigraph arris_snr.down_{0}".format(channel))
    value = data["SNR"].split(" ")[0]
    print("snr.value {0}".format(value))
    snr[channel - 1] = value

    print("multigraph arris_error.down_{0}".format(channel))
    print("corr.value {0}".format(data["Corrected"]))
    print("uncr.value {0}".format(data["Uncorrectables"]))

# Fill missing
for i in range(len(trs), DOWNCOUNT):
    print("multigraph arris_power.down_{0}".format(i + 1))
    print("power.value U")

    print("multigraph arris_snr.down_{0}".format(i + 1))
    print("snr.value U")

    print("multigraph arris_error.down_{0}".format(i + 1))
    print("corr.value U")
    print("uncr.value U")

print("multigraph arris_error")
print("corr.value {0}".format(correct))
print("uncr.value {0}".format(uncorr))

print("multigraph arris_snr")
for i in range(0, DOWNCOUNT):
    print("down_{0}.value {1}".format(i + 1, snr[i]))

trs = upstream.findall("tr")
# drop title
trs.pop(0)

headings = ["".join(x.itertext()).strip() for x in trs.pop(0).findall("td")]
# ['Channel', 'Lock Status', 'US Channel Type', 'Channel ID', 'Symbol Rate', 'Frequency', 'Power']
for row in trs:
    data = dict(
        map(
            mapper, headings, ["".join(x.itertext()).strip() for x in row.findall("td")]
        )
    )
    channel = int(data["Channel"])
    print("multigraph arris_power.up_{0}".format(channel))
    value = data["Power"].split(" ")[0]
    print("power.value {0}".format(value))
    power["up"][channel - 1] = value

# Fill missing
for i in range(len(trs), UPCOUNT):
    print("multigraph arris_power.up_{0}".format(i + 1))
    print("power.value U")

print("multigraph arris_power")
for i in range(0, DOWNCOUNT):
    print("down_{0}.value {1}".format(i + 1, power["down"][i]))
for i in range(0, UPCOUNT):
    print("up_{0}.value {1}".format(i + 1, power["up"][i]))