#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# TODO:
# - check if everything is filled in (computers, params, preparation)
# - improve scoring
# - test
# - switch to a real SSH/SFTP client to properly handle filenames


instructions = {
    'si':u"""
Ustvari dva navidezna računalnika s slikama diskov 
- SimpleArbiter s sliko diska simpleArbiterDhcp in 
SmallStudent s sliko diska student-entrance2.

Na SimpleArbiter se lahko prijaviš z uporabniškim imenom tester in geslom test.
Na SmallStudent se lahko prijaviš kot root z geslom kaboom.

Poskrbi, da bo SmallStudent s SimpleArbiter dostopen na naslovu {testip}.

Na SmallStudent ustvari uporabnika {testuser} z geslom {passwd}.

Na SmallStudent je nekje v domačem imeniku uporabnika "bilbo" skrita datoteka, ki vsebuje niz {magicstr}.
Skopiraj jo v domači imenik {testuser} in poimenuj {dstfile}.
Poskrbi, da bo lastnik {testuser}, skupina pa naj ostane nespremenjena.
Brati naj jo ima pravico samo lastnik, pisati lastnik in skupina, poganjati nihče.
V {dstfile} zamenjaj vse vrstice oblike poXYZlz, kjer so XYZ poljubni znaki, tako, da bo namesto XYZ niz "kaka".

Napiši program v poljubnem programskem jeziku, ki kot argument sprejme število B med 0 in 7.
Program naj prebere znak s standardnega izhoda. 
Če je B-ti bit v znaku nastavljen na 1, naj izpiše "ta".
Če je B-ti bit nastavljen na 0, naj program izpiše "ti".
Program poimenuj {progname} in ga spravi v domači imenik {testuser}.
""",
    'en': u'''
Create two virtual machines
- SimpleArbiter using simpleArbiterDhcp as the disk image and
SmallStudent using student-entrance2 as its disk.

You can log in as testr on SimpleArbiter with the password test.
You can log in as root on SimpleStudent with the password kaboom.

Make sure that SmallStudent is accessible from SimpleArbiter on IP {testip}.

Create a user {testuser} with the password {passwd} on SmallStudent.

There is a file containing {magicstr} hidden somewhere in the home directory of
user "bilbo".
Copy the into the home directory of user bilbo and name it {dstfile}.
Change the owner to {testuser} and leave the group unchanged.
Make sure only the owner has the right to read it, only the owner and group members have the right to write to it and noone has the right to execute it.
In {dstfile}, replace all lines of the form poXYZlz where XYZ are arbitrary characters so that XYZ is replaced by "kaka".

Write a program in any programming language.
The program should accept a single argument, B, which is a number between 0 and 7.
It should read a character from standard input and output "ta" if B-th bit in this character is
set to 1. If B-th bit is not set, the program should output "ti".
Name the program {progname} and place it in the home directory of {testuser}.
''',
}

instructions = {'si': 'Potrpite.', 'en': 'Have patience.'}

computers = {
    'SimpleArbiter': {
        'disks': [
            {
                'name': 'simpleArbiterDhcpGW',
            },
        ],
        'network_interfaces': [
            {
                'network': 'net1',
            },
            {
                'network': 'net2',
            },
        ],
        'flavor': 'm1.tiny',
        'config_drive': False,
    },
    'SmallStudent': {
        'disks': [
            {
                'name': 'student-entrance2',
            },
        ],
        'network_interfaces': [
            {
                'network': 'net2',
            },
        ],
        'flavor': 'm1.tiny',
        'config_drive': False, 
    }
}

networks = {
    'net1': {
        'public': True,
    },
    'net2': {
        'public': False,
    }
}

params_meta = {
    'testip': {
        'descriptions': {
            'si': 'IP SmallStudent',
            'en': 'IP SmallStudent',
        },
        'w': False,
        'public': True,
        'type': 'IP',
        'generated': True,
    },
    'testuser': {
        'descriptions': {
            'si': 'Uporabnik na SmallStudent',
            'en': 'Username on SmallStudent',
        },
        'w': False,
        'public': True,
        'type': 'username',
        'generated': True,
    },
    'passwd': {
        'descriptions': {
            'si': 'Geslo na SmallStudent',
            'en': 'Password on SmallStudent',
        },
        'w': False,
        'public': True,
        'type': None,
        'generated': True,

    },
    'magicstr':{
        'descriptions': {
            'si': 'Niz v iskani datoteki',
            'en': 'String in the file you need to find',
        },
        'w': False,
        'public': True,
        'type': None,
        'generated': True,

    },
    'dstfile':{
        'descriptions': {
            'si': 'Ciljno ime datoteke',
            'en': 'Destination filename',
        },
        'w': False,
        'public': True,
        'type': 'filename',
        'generated': True,
    },
    'progname':{
        'descriptions': {
            'si': 'Ime programa',
            'en': 'Program filename',
        },
        'w': False,
        'public': True,
        'type': 'filename',
        'generated': True,
    },
    'pubseed':{
        'descriptions': {
            'si': 'Nekaj nepredvidenega',
            'en': 'A random seed',
        },
        'w': False,
        'public': True,
        'type': None,
        'generated': True,
    },
    'rndseed':{
        'descriptions': {
            'si': 'random seed za skrito datoteko',
            'en': 'random seed for hiding the file',
        },
        'w': False,
        'public': False,
        'type': None,
        'generated': True,
    },
}

def task(testip, testuser, passwd, magicstr, dstfile, progname, pubseed):
    from pexpect import pxssh
    import random
    N_TITA = 40
    target = pxssh.pxssh()
    target.login(testip, testuser, passwd)
    target.sendline('ls -l ~/{}'.format(dstfile))
    target.prompt()
    dst_ls = target.before
    target.sendline('cat ~/{}'.format(dstfile))
    target.prompt()
    dst_file_contents = target.before
    target.sendline('ls ~/'.format(dstfile))
    target.prompt()
    home_ls = target.before
    results = {
        'dst_ls': dst_ls,
        'dst_file_contents': dst_file_contents,
        'home_ls': home_ls,
    }
    tita_return = ""
    r = random.Random(pubseed)
    for i in range(N_TITA):
        b = r.randint(0, 7)
        x = oct(r.randint(37, 127)).replace('o', '')
        target.sendline('echo -e "\\{}" | ~/{} {}'.format(x, progname, b))
        target.prompt()
        tita_return += target.before
    results['tita_return'] = tita_return
    target.logout()
    return results

def gen_params(user_id, params_meta):
    import random
    params = dict()
    r = random.Random(user_id)
    params['testip'] = kpov_random_helpers.IPv4_addr_gen(r, 
                            network = '10.94.80.0/19', n_generated=1)[0]
    params['testuser'] = kpov_random_helpers.default_generators['username'](r)
    params['passwd'] = kpov_random_helpers.alnum_gen(r, 8)
    params['magicstr'] = "".join([r.choice("qwerztlpoQWERTPOL") for i in range(10)])
    params['dstfile'] = kpov_random_helpers.default_generators['filename'](r)
    params['progname'] = kpov_random_helpers.default_generators['filename'](r)
    while params['dstfile'] == params['progname']:
        params['progname'] = kpov_random_helpers.default_generators['filename'](r)
    params['pubseed'] = kpov_random_helpers.alnum_gen(r, 8)
    params['rndseed'] = kpov_random_helpers.alnum_gen(r, 8)
    return params


def task_check(results, params):
    import os
    import re
    N_TITA = 40
    hints = []
    score = 0
    hidden_contents = params['magicstr']
    r = random.Random(params['rndseed'])
    for i in range(1000):
        start = "".join([r.choice(["po", "p0", "no", "ko", "fo", "qo"]) for i in range(20)])
        mid = "".join([r.choice("uiasdfghjkyxcvbnm1234567890ASDFGHJKYZXCVBNM") for i in range(60)])
        end = r.choice(["lz", "1z", "Iz", "iz", "l2", "I2", "12"])
        if start[:2] == "po" and end == "lz":
              start = "po"
              mid = "kaka"
        x = start + mid + end
        hidden_contents += x + "\r\n"
    expected_contents = hidden_contents
    #expected_contents = re.sub(r"^po.*lz\r$", 
    #                           r"pokakalz\r", 
    #                           hidden_contents, 
    #                           re.MULTILINE)
    expected_contents = "cat ~/{}\r\n".format(params['dstfile']) + expected_contents
    if results["dst_file_contents"] == expected_contents:
        score += 3
    else:
        diff_pos = ""
        for i, c in enumerate(results["dst_file_contents"]):
            if len(expected_contents) < i or c != expected_contents[i]:
                start = max(0, i-10)
                end = min(len(expected_contents), len(results["dst_file_contents"]), i+20)
                diff_pos = (i, results["dst_file_contents"][start:end])
                break
        hints += ["wrong file contents\n" + str(diff_pos[1])]
        #hints += ["wrong file contents"]
    expected_ls = u"ls -l ~/{dstfile}\r\n-rw--w---- 1 {testuser} bilbo .*{dstfile}\r\n".format(**params)
    if re.match(expected_ls, results["dst_ls"]):
        score += 3
    else:
        hints += [u"missing file or wrong user/permissions\n" + results["dst_ls"]]
    if results["home_ls"].find(params['progname']) > -1:
        score += 2
    else:
        hints += ["missing program"]
    expected_tita = u""
    r = random.Random(params['pubseed'])
    for i in range(N_TITA):
        b = r.randint(0, 7)
        x_i = r.randint(37, 127)
        x = oct(x_i).replace('o', '')
        expected_tita += u'echo -e "\\{}" | ~/{} {}\r\n'.format(x, params['progname'], b)
        if x_i & (1 << b):
            expected_tita += u"ta\r\n"
        else:
            expected_tita += u"ti\r\n"
    if results["tita_return"] == expected_tita:
        score += 2
    else:
        hints += [u"program output incorrect\n" + results["tita_return"]]
    return score, hints


def prepare_disks(templates, task_params, global_params):
    import random
    import os
    #print "Haha!"
    #print params
    #print templates
    d = templates['student-entrance2']
    # first create the file contents to make it easyer to check.
    hidden_contents = task_params['magicstr']
    r = random.Random(task_params['rndseed'])
    for i in range(1000):
        x = "".join([r.choice(["po", "p0", "no", "ko", "fo", "qo"]) for i in range(20)])
        x += "".join([r.choice("uiasdfghjkyxcvbnm1234567890ASDFGHJKYZXCVBNM") for i in range(60)])
        x += r.choice(["lz", "1z", "Iz", "iz", "l2", "I2", "12"])
        hidden_contents += x + "\n"
    # create hidden file
    dir_list = ['Qlipper', 'Thunar', 'blender', 'autostart', 'kazam', 'mc', 'netsurf', 'pulse', 'qupzilla', 'radare2', 'teamviewer', 'texstudio', 'vlc']
    ending_list = ['rc', '.conf', '']
    start_list = ['net', 'dev', 'doc', 'lib', 'time', 'conf']
    r.shuffle(dir_list)
    file_letters = ["mod", "co"]
    for potential_dir in dir_list:
        try:
            potential_dir = os.path.join('/home/bilbo/.config', potential_dir)
            d.mkdir(potential_dir)
            d.chown(1001, 1001, potential_dir)
        except:
            pass
        for i in range(r.randint(2, 20)):
            rndstr2 = r.choice(start_list) + \
                r.choice(file_letters) + r.choice(ending_list)
            hidden_file_name = os.path.join(potential_dir, 
                                   rndstr2)
            d.write(hidden_file_name, hidden_contents)
            d.chown(1001, 1001, hidden_file_name)
            file_letters = ["stamp", "", "dev", "re"]
            hidden_contents = "".join([r.choice("asdfghjkyxcvbnm1234567890 \n") for j in range(10000)])
        file_letters = file_letters + ["mod", "co"]
    # TODO create some additional files 
    
    write_default_config(templates['simpleArbiterDhcpGW'], global_params)
    # finish here
    # rename