#!/usr/bin/env python

import sys
import os
import re

def scan(interface):
    '''Returns [{bssid, essid, enckey, channel, quality}, ...]'''
    if os.system("/sbin/ifconfig %s up" % interface) != 0:
        raise Exception('Failed bringing up interface')

    pipe = os.popen("/sbin/iwlist %s scan" % interface, 'r')
    result = []

    hasap = False
    appattern = re.compile('Cell ([0-9]+)')
    
    patterns = {'bssid': re.compile('Address:\s?([0-9a-fA-F\:]{17})\s*$'),
                'essid': re.compile('ESSID:\s?"([^"]*)"'),
                'enckey': re.compile('Encryption key:\s?([A-Za-z]+)'),
                'channel': re.compile('Channel:\s?([0-9]+)'),
                'quality': re.compile('Quality[=:]([0-9]+)/100')}

    filters = {'bssid': lambda s: s.lower(),
               'enckey': lambda s: s.lower() == 'on',
               'channel': lambda s: int(s),
               'quality': lambda s: int(s)}

    for line in pipe:
        if not appattern.search(line):
            if not hasap:
                continue
        else:
            if hasap and params['bssid'] != None:
                result.append(params)
            else:
                hasap = True
            
            params = {'bssid': None, 'essid': None, 'enckey': None,
                      'channel': None, 'quality': None}            
        
        for key, pattern in patterns.items():
            match = pattern.search(line)
            if match:
                value = match.group(1)
                if filters.has_key(key):
                    value = filters[key](value)
                params[key] = value
        
    if hasap and params['bssid'] != None:
        result.append(params)

    return result

def show_scanlist(lst):
    lst.sort(lambda a, b: cmp(a['quality'], b['quality']))
    columns = [('bssid', 20), ('essid', 20), ('enckey', 8),
               ('channel', 9), ('quality', 9)]
    
    formats = {'enckey': lambda v: v and 'on' or 'off',
               'quality': lambda v: "%d%%" % v}
    
    line = ' ' * 5
    for name, width in columns:
        line += (' ' * width + name)[-width:]
    print line
    
    for n, params in enumerate(lst):
        line = '%2d   ' % (n + 1)
        for name, width in columns:
            value = params[name]
            
            if formats.has_key(name):
                value = formats[name](value)
            
            line += (' ' * width + str(value))[-width:]
        
        print line

def netsettings_toas(interface):
    os.system("/sbin/ifconfig %s 195.148.186.185 netmask 255.255.255.0" % interface)
    os.system("/sbin/route add default gateway 195.148.186.1 dev %s" % interface)
    open("/etc/resolv.conf", "w").write("nameserver 86.50.0.40\nnameserver 193.166.234.15\n")

def netsettings_dhcp(interface):
    if os.system("/sbin/dhclient %s" % interface) != 0:
        raise Exception("DHCP failed")

# TUT

import urllib
import re

def tut_login(user, password):
    # Get posturl
    loginpage = urllib.urlopen("https://signin.public.tut.fi/").read()
    posturl = re.search('''<form .* action=['"]([^'"]+)['"].*>''', loginpage).group(1)
    posturl = "https://signin.public.tut.fi/" + posturl
    # Login
    params = urllib.urlencode({'user': user, 'pass': password, 'login': 'login'})
    data = urllib.urlopen(posturl, params).read()
    return 'Logged in' in data

def netsettings_tut(interface):
    user = 'aimonen'
    password = open("/etc/tutpass", "r").readline().strip()
    netsettings_dhcp(interface)
    if not tut_login(user, password):
        raise Exception("TUT login failed")

def set_wlanparam(interface, param, value):
    status = os.system("/sbin/iwconfig %s %s %s" % (interface, param, value))
    if status != 0:
        raise Exception('Failed setting wlan parameter')

wepkeys = { .. }

if __name__ == '__main__':
    
    interface = 'ra0'
    
    scanresult = scan(interface)
    show_scanlist(scanresult)
    
    print ""
    
    while True:
        sid = raw_input("Select AP: ")
        try:
            params = scanresult[int(sid) - 1]
            break
        except IndexError:
            continue
        except ValueError:
            continue

    if params['enckey'] and not wepkeys.has_key(params['essid']):
        print "No wep key for %s" % params['essid']
        sys.exit(1)

    print "Connecting to %s" % params['bssid']

    os.system("killall -q dhclient")

    if params['enckey']:
        set_wlanparam(interface, 'key', wepkeys[params['essid']])
    else:
        set_wlanparam(interface, 'key', 'off')

    set_wlanparam(interface, 'ap', params['bssid'])

    if params['essid'] == 'luola':
        netsettings_toas(interface)
    elif params['essid'] == 'TUT':
        netsettings_tut(interface)
    else:
        netsettings_dhcp(interface)