#!/usr/bin/env python
# -*- coding: utf-8 -*-
###################################################
# File name: update_passwords.py                  #
# Author: Martin Uribe                            #
# Date created: 03/17/2017                        #
# Date last modified: 03/23/2017                  #
# Python Version: 2.6.5                           #
###################################################
"""Script for updating the passwords of RIDS user accounts.

You have the option of updating the passwords for all of your RIDS accounts.
This incules both the UNIX and RIDS passwords. The changes are pushed out
for each environment, which takes time so make sure that you actually want
to update them all.

Optionally you have the choice of updating a single account. You must
specify the user that you want to update.
"""
import getopt
import os
import sys

__version__ = '1.0.1'

__author__ = 'Martin Uribe'
__email__ = 'martin.uribe AT mywork.com'


def change_all(accounts):
    """Used for updating all of your RIDS accounts at once.

    This function calls update_pass() while looping through all of your RIDS
    accounts.

    :param accounts: List of all of your accounts on the system
    :return: None
    """
    for account in accounts:
        env = get_env(account, accounts)
        update_pass(account, env)


def update_pass(user, env):
    """Used to make the actual changes to your accounts.

    It will run the UNIX passwd command against the user account. It will
    then change its working directory to that of the environment to which
    the account belongs to and push out the updated password with the
    user_unix2rids perl script.

    :param user: String containing the user account to modify
    :param env: String containing the environment that the account belongs to
    :return: None
    """
    push_update = 'sr -u apache ./user_unix2rids -update %s' % user
    change_passwd = 'sr passwd %s' % user
    env_path = '/usr/' + env + '/bin'

    if os.path.isdir(env_path):
        os.chdir(env_path)
        print '[%s] %s:' % (env.upper(), user)
        # actually modify the system
        os.system(change_passwd)
        os.system(push_update)
    else:
        print '%s does not exist!' % env.upper()


def get_accounts(user):
    """Used to get all of your the RIDS accounts.

    These accounts are based on the account from which you are currently
    logged in with or the account that you specified at the command line
    with the --user flag.

    :param user: String containing the user account to modify
    :return: Dictionary of user accounts associated with the user provided
    """
    with open('/etc/passwd', 'r') as p:
        # just had to play around with dictionary comprehensions :D
        accounts = dict((line.split(':')[0], line.split(':')[-1].split('/')[2].strip()) for line in p if user in line)
    return accounts


def get_env(user, accounts):
    """Used to get the environment of the account.

    I've made the assumption here that any account that doesn't have
    startExt as its shell is an env1 account for the Field Engineer,
    who is the one most likely to be using this script.

    :param user: String containing the user account to look up
    :param accounts: Dictionary of accounts used to look-up the env for the account
    :return: String of the environment that the account belongs to
    """
    env = accounts[user]
    if 'env' not in env:
        env = 'env1'
    return env


def info(user):
    """Used to display information on how to run this program

    Displays a more detailed explanation of how to run the script and
    details all of the flags that it can accept.

    :return: None
    """
    print '\nThis script will change the passwords for the given user account(s)'
    print 'on the system. If an optional argument is used, both the user and the'
    print 'env options must be provided.\n'
    print '    -h, --help: This help info'
    print '    -a, --all : Make changes to all of your accounts'
    print '    -u, --user: The username of the account that you want to modify'
    print '\n   examples: ' + sys.argv[0] + ' -u ' + user
    print '             ' + sys.argv[0] + ' --user ' + user


def main(argv):
    """Main entry point to the program

    This function puts it all together.

    :param argv: List of arguments that were past in when the script was ran
    :return: None
    """
    import getpass

    usage = 'USAGE: ' + sys.argv[0] + ' --help --all [--user <user>]'
    user = getpass.getuser()
    accounts = get_accounts(user)
    flags = len(argv)
    run_all = False

    if 0 <= flags <= 2:
        try:
            opts, args = getopt.getopt(argv, 'hau:', ['help', 'all', 'user='])
        except getopt.GetoptError:
            # some funky stuff was put in, get out now!
            print 'Invalid argument used!'
            print usage
            sys.exit(2)

        # cycle through the options
        for opt, arg in opts:
            if opt in ('-h', '--help'):
                print usage
                info(user)
                sys.exit()
            elif opt in ('-a', '--all'):
                run_all = True
            elif opt in ('-u', '--user'):
                user = arg

        # update the password for all env accounts or just one
        if run_all:
            # last chance to back out
            print 'Updating ALL accounts for %s: ' % user
            choice = raw_input('Are you sure (y/n)? ').lower()
            if 'y' in choice:
                change_all(accounts)
            else:
                print 'OK, bye!'
                sys.exit()
        elif user in accounts:
            env = get_env(user, accounts)

            # give the user a final chance to change their mind
            print 'Updating account %s in %s: ' % (user, env)
            choice = raw_input('Are you sure (y/n)? ').lower()
            if 'y' in choice:
                update_pass(user, env)
            else:
                print 'OK, bye!'
                sys.exit()
        else:
            # user account specified was not found
            print '%s is not a valid account!' % user
            sys.exit()
    else:
        # point them in the right direction
        print usage
        sys.exit()


if __name__ == '__main__':
    main(sys.argv[1:])