#!/usr/bin/env python
#import iniparse as ip
#import  ConfigParser as cp
#smb_conf = ip.INIConfig(open('smb.conf'))
# Note - ConfigParser or Iniparser cannot parse smb.conf because of leading spaces in key values

import sys
import re


class SmbConf(object):
    def __init__(self, in_filename):
        self.conf = ''
        with open(in_filename) as in_file:
            self.conf  = in_file.read()

    def add_after_global_section(self, what):
        self.conf = self.conf.replace('[global]', '[global]' + '\n' + what)
        pass

    def replace_or_add_global_option(self, option, value):
        re_ = re.compile('(?m)^\s*%(option)s\s*=' % vars())
        expression = '%(option)s=%(value)s' % vars()
        if re_.findall(self.conf):
            self.conf = re.sub('(?m)^\s*%(option)s\s*=[^$]*' % vars(),
                               expression, self.conf)
        else:
            self.add_after_global_section(expression)

    def samba_home_user_patch(self):
        #https://wiki.archlinux.org/index.php/Samba#Creating_usershare_path
        self.replace_or_add_global_option('usershare path',   '/var/lib/samba/usershare')
        self.replace_or_add_global_option('usershare max shares',   '100')
        self.replace_or_add_global_option('usershare allow guests', 'yes')
        self.replace_or_add_global_option('usershare owner only',   'false')
        #self.replace_or_add_global_option('force user',             'nobody')
        self.replace_or_add_global_option('guest account',             'nobody')

        #essential for anonymous access from windows PC
        self.replace_or_add_global_option('map to guest',           'bad user')
        self.replace_or_add_global_option('workgroup',              'WORKGROUP')

    def output2file(self, out_filename):
        with open(out_filename, 'w') as f:
            f.write(self.conf)


in_filename = sys.argv[1]
out_filename = in_filename

if len(sys.argv)>2:
    out_filename = sys.argv[2]
    
smb = SmbConf(in_filename)
smb.samba_home_user_patch()
smb.output2file(out_filename)