#! /usr/bin/python

import sys
import optparse
import hmac
import time
import select
from ctf import teams, pointscli
import os
from urllib import quote

basedir = None
flagsdir = None

key = 'My First Shared Secret (tm)'
def hexdigest(s):
    return hmac.new(key, s.encode('utf-8')).hexdigest()

def auth():
    # Pretend to be in.tcpmuxd
    while True:
        line = sys.stdin.readline()
        if not line:
            return
        line = line.strip().lower()

        if line == 'tcpmux':
            sys.stdout.write('+Okay, fine.\r\n')
            sys.stdout.flush()
            continue
        elif line == 'help':
            sys.stdout.write('tcpmux\r\n')
        elif ':::' in line:
            # Authentication
            cat, passwd = line.split(':::')
            if passwd == hexdigest(cat):
                return cat
            else:
                sys.stdout.write('-Blow me.\r\n')
        else:
            sys.stdout.write('-Blow me.\r\n')
        return

def award(cat, team):
    qcat = quote(cat, '')
    fn = os.path.join(flagsdir, qcat)
    f = open(fn, 'w')
    f.write(team)
    f.close()
    pointscli.award(cat, team, 1)
    print('+%s' % team)
    sys.stdout.flush()

def run():
    cat = auth()
    if not cat:
        return

    now = time.time()
    next_award = now - (now % 60)
    flag = teams.house

    while True:
        now = time.time()
        while now >= next_award:
            next_award += 60
            award(cat, flag)

        timeout = next_award - now
        r, w, x = select.select([sys.stdin], [], [], timeout)
        if r:
            line = sys.stdin.readline()
            if not line:
                break
            new_flag = line.strip() or teams.house
            if new_flag != flag:
                # Award a point if the flag is captured
                flag = new_flag
                award(cat, flag)

def main():
    p = optparse.OptionParser(usage='%prog [options] FLAGSDIR')
    p.add_option('-a', '--auth', dest='cat', default=None,
                 help='Generate authentication for the given category')
    opts, args = p.parse_args()
    if opts.cat:
        print('%s:::%s' % (opts.cat, hexdigest(opts.cat.encode('utf-8'))))
    elif len(args) != 1:
        p.error('Wrong number of arguments')
    else:
        global flagsdir
        flagsdir = args[0]
        run()

if __name__ == '__main__':
    main()