# kpov_util should be imported by add_assignment.py

instructions = {
    'si':"""
Postavi dva navidezna računalnika - SimpleArbiter z diska SimpleArbiterVPN ter
VPNClient1. Poskrbite, da bosta povezana med seboj in v Internet.
Na VPNClient1 namestite OpenVPN in program za nadzor nad virtualnimi napravami
(s katerim kreirate napravo tap).

Na strežniku SimpleArbiterVPN že teče VPN strežnik in uporablja skrivnost, 
ki jo najdete tudi na VPNClient1 v domačem imeniku uporabnika student.
Na VPNClient1 vzpostavite VPN tako, da napišete primerno datoteko z 
nastavitvami. VPNClient1 na navideznem lokalnem omrežju nastavite naslov
{IP_VPNClient1}

Nato poskrbite, da bo na VPNClient1 na navideznem omrežju prek NFS omogočen
dostop do imenika /home/test/{DIRNAME}.
V ta imenik skopirajte datoteke, ki so prek SMB dostopne na SimpleArbiter.
""",
	'en':"""
Setup two virtual machines - SimpleArbiterVPN and a VPN client (VPNClient1). 
Set the client's network up so that it has access to the internal network and
the internet.
On VPNClient1, install OpenVPN and a program for supervising virtual devices 
(which you will use to create a tap device). On the VPN, set the IP for 
VPNClient1 to {IP_VPNClient1}.

An OpenVPN server is already running on SimpleArbiterVPN. Use the secret 
available on VPNClient1 in the home directory of user student to connect to 
the VPN server on SimpleArbiterVPN. To do that, you will have to write your
own OpenVPN configuration file. 

After you have set up the VPN, make the directory
/home/test/{DIRNAME} on VPNClient1 available over NFS from SimpleArbiter over
your VPN. Copy files that are available from SimpleArbiter over SMB to
/home/test/{DIRNAME}.
"""
}

computers = {
    'SimpleArbiter': {
        'disks': [
            {
                'name': 'simpleArbiterDhcpGWVPN',
            },
        ],
        'network_interfaces': [
            {
                'network': 'test-net'
            },
            {
                'network': 'net1'
            }
        ],
        'flavor': 'm1.tiny',
        'config_drive': False
    },
    'VPNClient1': {
        'disks': [
            {   'name': 'student-VPNClient1',
            },
        ],
        'network_interfaces': [
            {
                'network': 'net1'
            }
        ],
        'flavor': 'm1.tiny',
        'config_drive': False
    },
}

networks = {
    'test-net': {
        'public': True
    },
    # Used for the VPN tunnel
    'net1': {
        'public': False
    }
}

#Tukaj sem generiral tri parametre, prosil bi če se upoštevajo pri Tasku. 
params_meta = {
    'IP_SimpleArbiterVPN': {'descriptions':{'si':'IP za SimpleArbiter na VPN'}, 'w': False, 'public': True, 'type': 'IP', 'generated': True}, 
    'IP_VPNClient1': {'descriptions':{'si':'IP klienta na VPN'}, 'w': False, 'public': True, 'type': 'IP', 'generated': True},
    'IP_LANClient1': {'descriptions':{'si':'IP klienta na LAN'}, 'w': True, 'public': True, 'type': 'IP', 'generated': False},
    'DIRNAME': {'descriptions':{'si':'Imenik, dostopen prek NFS'}, 'w': False, 'public': True, 'type': 'IP', 'generated': True},
    'secret_random_seed': {'descriptions':{'si':'Seme za skrivnost'}, 'w': False, 'public': False, 'type': None, 'generated': True},
}

def task(IP_SimpleArbiterVPN, IP_VPNClient1, IP_LANClient1, DIRNAME):
    import collections
    from pexpect import pxssh    # Used to set up an SSH connection to a remote machine
    import pexpect  # Allows the script to spawn a child application and control it as if a human were typing commands

    # The necessary things we need to check if the task was performed correctly
    results = collections.defaultdict(str)
    
    # VPNClient1
    sC1 = pxssh.pxssh(encoding='utf-8')
    sC1.login(IP_LANClient1, 'student', 'vaje')
    
    # sA
    results['SimpleArbiter_ifconfig'] = pexpect.run(
        'ifconfig -a', encoding='utf-8', env={'PATH': '/bin:/sbin'})
    results['SimpleArbiter_route'] = pexpect.run(
        'route -n', encoding='utf-8', env={'PATH': '/bin:/sbin'})
    
    # Pings each of the clients
    # 10.8.0.6 and 10.8.0.10 are the first two default addresses distributed by OpenVPN
    # Will output everything ping outputs (set to ping 3 times)
    results['SimpleArbiter_ping_C1'] = pexpect.run(
        'ping -c 3 {}'.format(IP_VPNClient1), encoding='utf-8')
    results['SimpleArbiter_traceroute'] = pexpect.run(
        'traceroute {}'.format(IP_VPNClient1), encoding='utf-8')
    sC1.sendline('cat /etc/exports')
    sC1.prompt()
    output = sC1.before
    results['VPNClient1_nfs_access_control_list'] = output
    results['SimpleArbiter_mount'] = pexpect.run(
        'sudo mount {}:/home/test/{} /mnt'.format(IP_VPNClient1, DIRNAME), encoding='utf-8')
    results['SimpleArbiter_mount_result'] = pexpect.run(
        'sudo mount', encoding='utf-8')
    results['SimpleArbiter_ls'] = pexpect.run(
        'ls /mnt', encoding='utf-8')
    pexpect.run(
        'sudo umount /mnt', encoding='utf-8')

    # Ping the VPN server
    sC1.sendline('ping -c 3 {0}'.format( IP_SimpleArbiterVPN ))
    sC1.prompt()
    results['VPNClient1_ping_VPN_server'] = sC1.before

    sC1.sendline('/sbin/ifconfig -a')
    sC1.prompt()
    results['VPNClient1_ifconfig'] = sC1.before
 
    sC1.sendline('ps xa')
    sC1.prompt()
    results['VPNClient1_ps'] = sC1.before
    sC1.logout()

    return results

def gen_params(user_id, params_meta):
    params = dict()
    #Tukaj sem generiral te tri parametre (ime skupne skrivnosti je heidi )
    #(ime imenika kjer naj bo shranjena skupna skrivnost naj bo openvpn)
    #(HASH bo naključno generiran niz iz user_id s katerim se bo preverjalo plagiatorstvo)
    import random
    r = random.Random(user_id)
    net = kpov_util.IPv4_subnet_gen(r, '10.168.0.0/16', 24)
    params['IP_VPNClient1'], params['IP_SimpleArbiterVPN'] = kpov_util.IPv4_addr_gen(r, net, 2)
    params['DIRNAME'] = kpov_util.fname_gen(r, extension=False)
    params['secret_random_seed']=str(r.random())
    return params


def task_check(results, params):
    import re
    score = 0
    hints = [] 

    IP_SA = params['IP_SimpleArbiterVPN'].replace('.', '\.')
    IP_C1 = params['IP_VPNClient1'].replace('.', '\.')
    rs = r"tap0: flags=.* mtu 1500\r\n +inet {}".format(IP_SA)
    if re.search(rs,
            results['SimpleArbiter_ifconfig']):
        score += 1
    else:
        hints.append("ifconfig on SimpleArbiter not OK")
    
    if re.search(
            "PING.*\r\n64 bytes from {}: icmp_seq=[0-9]+ ttl=64 time=[0-9.]* ms".format(IP_C1),
            results['SimpleArbiter_ping_C1']):
        score += 1
    else:
        hints.append("ping from server not OK")
    rs = "1 +{0} \({0}\)".format(IP_C1)
    if re.search(rs, results['SimpleArbiter_traceroute']):
        score += 1
    else:
        hints.append("traceroute not OK")
    if results['VPNClient1_nfs_access_control_list'].find(
        '/home/test/' + params['DIRNAME'] + ' ') >= 0:
        score += 1
    if results['SimpleArbiter_mount_result'].find(
            '{}:/home/test/{} on /mnt type nfs'.format(
            params['IP_VPNClient1'], params['DIRNAME'])):
        score += 1
    else:
        hints.append("mount not OK")

    # get r into the correct state
    r = random.Random(params['secret_random_seed'])
    s = "\n".join(["".join([r.choice("0123456789abcdef") for i in range(32)])
        for i in range(16)])
    keyfile = kpov_util.fname_gen(r, extension=False)

    # now check the filenames
    fnames_ok = True
    for i in range(3):
        fname = kpov_util.fname_gen(r, False)
        foo = kpov_util.fortune(r, 4096)
        pos = results['SimpleArbiter_ls'].find(fname + '.txt')
        fnames_ok = fnames_ok and pos >= 0
    if fnames_ok:
        score += 2
    else:
        hints.append("shared filenames not OK:")

    # Ping the VPN server
    if re.search(
            "PING.*\r\n64 bytes from {}: icmp_seq=[0-9]+ ttl=64 time=[0-9.]* ms".format(IP_SA), 
            results['VPNClient1_ping_VPN_server']):
        score += 1
    else:
        hints.append("ping from client not OK")

    rs = r"tap0: flags=.* mtu 1500\r\n +inet {}".format(IP_C1)
    if re.search(rs, results['VPNClient1_ifconfig']):
        score += 1
    else:
        hints.append("ifconfig on VPNClient1 not OK")
 
    if results['VPNClient1_ps'].find('openvpn') > 0:
        score += 1
    else:
        hints.append("openvpn not found running on VPNClient")
    return score, hints

def prepare_disks(templates, task_params, global_params):
    #guestmount -a d -m /dev/VG/LV -m /dev/sda1:/boot --ro /mnt
    #asistent je pocasnela :) 
    import random
    r = random.Random(task_params['secret_random_seed'])
    s = "\n".join([
        "".join([r.choice("0123456789abcdef") for i in range(32)])
        for i in range(16)])
    s = """#
# 2048 bit OpenVPN static key
#
-----BEGIN OpenVPN Static key V1-----
{}
-----END OpenVPN Static key V1-----
""".format(s)
    keyfile = kpov_util.fname_gen(r, extension=False) + ".key"
    templates['simpleArbiterDhcpGWVPN'].write("/etc/openvpn/secret.key", s)
    netaddr_s = """auto tap0
iface tap0 inet static
    openvpn server
    pre-up tunctl -t tap0
    address {}
    netmask 255.255.255.0
""".format(task_params['IP_SimpleArbiterVPN'])
    templates['simpleArbiterDhcpGWVPN'].write_append("/etc/network/interfaces", netaddr_s) 
    for i in range(3):
        fname = kpov_util.fname_gen(r, False)
        templates['simpleArbiterDhcpGWVPN'].write(
            "/srv/smb/" + fname + '.txt',
            kpov_util.fortune(r, 4096))
    write_default_config(templates['simpleArbiterDhcpGWVPN'], global_params)
    templates['student-VPNClient1'].write("/home/student/" + keyfile, s)
    # uid, gid (student = )
    templates['student-VPNClient1'].chown(1000, 1000, "/home/student/" + keyfile)