#!/usr/bin/env python
#
# Authors:
# rafael@postgresql.org.es / http://www.postgresql.org.es/
#
# Copyright (c) 2015 USIT-University of Oslo
#
# sms_send: Custom alertscript to send SMS notifications from Zabbix
# to a SMS service.
#
# sms_send is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# sms_send is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with sms_send.  If not, see <http://www.gnu.org/licenses/>.
#

import sys
import os
import urllib2
import urllib
from datetime import datetime

# ###################################################################
# Method: send_sms_message()
# Parameters: phone_number, message
#
# Used to send the notification to a SMS service via HTTPS
# ###################################################################

def send_sms_message(phone_number, message):

    log_file = '/var/log/zabbixsrv/zabbix_sms_send.log'

    try:
        sms_server_url = 'https://sms.uio.no/sms/send'
        locale_code  = 'USIT'

        auth_info = get_auth_info()
        username = auth_info[0]
        password = auth_info[1]

        #
        # Definition of the parameters that will be sent to sms.uio.no
        #

        parameters = {'b':username,'p':password,'s':locale_code,'t':phone_number,'m':message}
        encoded_parameters = urllib.urlencode(parameters)

        req = urllib2.Request(sms_server_url,encoded_parameters)
        response = urllib2.urlopen(req,timeout=5)
        output = response.read()

        #
        # Very simple log file with the output from the sms gateway.
        #

        with open(log_file,'a') as file:
            file.write('[' + str(datetime.now()) + ']\n')
            file.write(output)
            file.write('\n')

    except Exception as e:

        with open(log_file,'a') as file:
            file.write('[' + str(datetime.now()) + ']\n')
            file.write(e)
            file.write('\n')

        sys.exit(1)


# ####################################################################
# Method: get_auth_info()
#
# Used to get the username and password information needed to log into
# the SMS service.  This information can be found in the
# .zabbix_sms_send_auth file in the home directory of the user running
# this script.
#
# We use this auth file to avoid having to define the username and
# password information in this script.
# #####################################################################

def get_auth_info():
    
    auth_info = []
    auth_file = os.getenv('HOME') + '/.zabbix_send_sms_auth'

    if os.path.isfile(auth_file):

        try:
            os.chmod(auth_file,0400)
            
            with open(auth_file,'r') as file:
                for line in file:

                    #
                    # Format of the file: username::password
                    #
                    auth_info= line.split('::')

            auth_info[1] = auth_info[1].replace('\n','')
            return auth_info

        except Exception as e:
            raise Exception("[ERROR]: %s\n" % e)

    else:
        raise Exception("[ERROR]: The file with auth information: %s does not exist" % auth_file)
            

# ############################################
# MAIN
# ############################################

if __name__ == '__main__':

    try:
        if len(sys.argv) == 4:
            phone_number = sys.argv[1]
            subject = sys.argv[2]
            message = sys.argv[3]
            
            #
            # We send only the subject of the notification. We could
            # also merge the subject and the message if we want to get
            # all the information by SMS.
            #

            send_sms_message(phone_number,subject)

        else:
            print "Error: Wrong number of parameters"
            print 'Format: ' + sys.argv[0] + ' <phone number> <subject> <message>'        
            sys.exit(1)

    except Exception as e:
        print e
        sys.exit(1)