#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Quick way to monitor Apache mod_status. Designed for use with Zabbix.
"""

import sys
import urllib2
import argparse


def get_url(url):
    """ Uses urllib2 to request Apache mod_status """
    try:
        conn = urllib2.urlopen(url)
        response = conn.read()
        conn.close()
        return response

    except urllib2.HTTPError:
        print "Error getting URL"


def parse_scoreboard(scoreboard):
    """ Parses scoreboard """

    keys = {
        '_': 'WaitingForConnection',
        'S': 'StartingUp',
        'R': 'ReadingRequest',
        'W': 'SendingReply',
        'K': 'KeepaliveRead',
        'D': 'DNSLookup',
        'C': 'ClosingConnection',
        'L': 'Logging',
        'G': 'GracefullyFinishing',
        'I': 'Idle',
        '.': 'OpenSlot'
    }

    scores = {}
    for score in scoreboard:
        if score in keys:
            if score in scores:
                scores[keys[score]] += 1
            else:
                scores[keys[score]] = 1

    return scores


def get_status(url=None):
    """ Returns an Apache performance stat or list all of them """

    if url is None:
        url = 'http://localhost/server-status'

    stats_text = get_url('{}?auto'.format(url))
    status = {}
    for line in stats_text.split("\n"):
        if ':' in line:
            key, value = line.split(':')
            if key == 'Scoreboard':
                for sk, sv in parse_scoreboard(value.strip()).iteritems():
                    status[sk] = sv
            else:
                status[key.strip().replace(' ', '_')] = float(value.strip())

    return status


def output_status(status, stat=None):
    """ Output function """
    if stat in status:
        print status[stat]
    else:
        print
        for key, value in status.iteritems():
            print "{:<30}{:<20}".format(key, value)
        print


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('--version', action='version', version='%(prog)s 1.0')
    parser.add_argument('-u', '--url', help='URL to query stats', default='http://localhost/server-status')
    parser.add_argument('-s', '--stat', help='Return the value for a specific statistic', default=None)
    parser.add_argument('-l', '--list', help='List all available Apache mod_status stats', action='store_true')
    args = parser.parse_args()

    if args.list:
        srv_status = get_status(args.url)
        output_status(srv_status, args.stat)
    else:
        srv_status = get_status(args.url)
        output_status(srv_status, stat=args.stat)