import os
import sys
import getpass
from fedora.client.fas2 import AccountSystem
from fedora.client.fas2 import CLAError
from fedora.client import AuthError, ServerError
from OpenSSL import crypto
import urlgrabber
import datetime

# This file was modified from the fedora_cert section in fedora-packager written
# by Dennis Gilmore (https://fedorahosted.org/fedora-packager/)


# Define our own error class
class fedora_cert_error(Exception):
    pass

def _open_cert():
    """
    Read in the certificate so we dont duplicate the code 
    """
     # Make sure we can even read the thing.
    cert_file = os.path.join(os.path.expanduser('~'), ".koji", "client.crt")
    if not os.access(cert_file, os.R_OK):
        raise fedora_cert_error("""!!!    cannot read your ~/.fedora.cert file   !!!
!!! Ensure the file is readable and try again !!!""")
    raw_cert = open(cert_file).read()
    my_cert = crypto.load_certificate(crypto.FILETYPE_PEM, raw_cert)
    return my_cert

def verify_cert():
    """
    Check that the user cert is valid. 
    things to check/return
    not revoked
    Expiry time warn if less than 21 days
    """
    my_cert = _open_cert()
    serial_no = my_cert.get_serial_number()
    valid_until = my_cert.get_notAfter()[:8]
    crl = urlgrabber.urlread("https://admin.fedoraproject.org/ca/crl.pem")
    dateFmt = '%Y%m%d'
    delta = datetime.datetime.now() + datetime.timedelta(days=21)
    warn = datetime.datetime.strftime(delta, dateFmt)

    print 'cert expires: %s-%s-%s' % (valid_until[:4], valid_until[4:6], valid_until[6:8])

    if valid_until < warn:
        print 'WARNING: Your cert expires soon.'


def certificate_expired():
    """
    Check to see if ~/.fedora.cert is expired
    Returns True or False

    """
    my_cert = _open_cert()

    if my_cert.has_expired():
        return True
    else:
        return False

def read_user_cert():
    """
    Figure out the Fedora user name from ~/.fedora.cert

    """
    my_cert = _open_cert()

    subject = str(my_cert.get_subject())
    subject_line = subject.split("CN=")
    cn_parts = subject_line[1].split("/")
    username = cn_parts[0]
    return username

def create_user_cert(username=None):
    if not username:
        username = raw_input('FAS Username: ')
    password = getpass.getpass('FAS Password: ')
    try:
        fas = AccountSystem('https://admin.fedoraproject.org/accounts/', username=username, password=password)
    except AuthError:
        raise fedora_cert_error("Invalid username/password.")

    try:
        cert = fas.user_gencert()
        fas.logout()
    except CLAError:
        fas.logout()
        raise fedora_cert_error("""You must sign the CLA before you can generate your certificate.\n
To do this, go to https://admin.fedoraproject.org/accounts/cla/""")
    cert_file = os.path.join(os.path.expanduser('~'), ".fedora.cert")
    try:
        FILE = open(cert_file,"w")
        FILE.write(cert)
        FILE.close()
    except:
        raise fedora_cert_error("""Can not open cert file for writing.
Please paste certificate into ~/.fedora.cert\n\n%s""" % cert)