#!/usr/bin/python
"""Checks if specified programs are present
with correct version on a Windows server
using wmi protocol
"""

import argparse
import socket
import sys
import wmi_client_wrapper as wmi

def main():
    """Gets options from command line
    and checks if specified programs are present
    with correct version.
    """

    options = get_options()
    programs = dict(item.split(":") for item in options.programs.split(";"))
    address = get_host_ip_address(options.computer)
    query = "SELECT Name,Version FROM Win32_Product"
    errors = []
    wmic = wmi.WmiClientWrapper(
        username=r"<USER_NAME>",
        password="<PASSWORD>",
        host=address
    )

    query_result = perform_wmi_query(wmic, query)
    # monitored_programs = []
    for program_name, program_version in programs.iteritems():
        tmp = [x for x in query_result if x['Name'] == program_name]
        if tmp:
            wmi_program = tmp[0]
            if wmi_program['Version'] != program_version:
                errors.append("""Program {0} version is not valid.
                              Found {1} expected {2}""".format(program_name,
                                                               wmi_program['Version'],
                                                               program_version))
        else:
            errors.append("Program {0} not found on system.".format(program_name))

    if errors:
        delimiter = '\n'
        error = delimiter.join(errors)
        print "CRITICAL - some programs have incorrect versions or do not exits.\n{0}".format(error)
        sys.exit(2)
    else:
        print "OK - All requires programs are ok."
        sys.exit(0)




def perform_wmi_query(wmic, query):
    """Preforms wmi query

    Arguments:
        wmic {WmiClientWrapper} -- wmi object uset to connect to server
        query {String} -- query to be run on the server

    Returns:
        [String] -- Output of the query
    """

    try:
        output = wmic.query(query)
    except:
        print "Error connecting to host"
        sys.exit(3)
    return output


def get_host_ip_address(hostname):
    """Gets ip address from DNS hostname

    Arguments:
        hostname {String} -- DNS hostname

    Returns:
        String -- IP address
    """

    try:
        addres = socket.gethostbyname(hostname)
    except:
        print "Error, hostname not valid."
        sys.exit(3)
    return addres

def get_options():
    """Parse command line arguments.

    Returns:
        [String] -- Parameters as List
    """
    parser = argparse.ArgumentParser()
    parser.add_argument('--computer', help='Slave name.', required=True)
    parser.add_argument('--programs',
                        help='Programs in format <program>:<version> ; sepparated.',
                        required=True)
    return parser.parse_args()

if __name__ == "__main__":
    main()