from datetime import datetime
import re
from leap.email.smtp.smtprelay import (
    SMTPFactory,
    #SMTPDelivery, # an object
    EncryptedMessage,
)
from leap.email.smtp import tests
from twisted.test import proto_helpers
from twisted.mail.smtp import User


# some regexps
IP_REGEX = "(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}" + \
    "([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])"
HOSTNAME_REGEX = "(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*" + \
    "([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])"
IP_OR_HOST_REGEX = '(' + IP_REGEX + '|' + HOSTNAME_REGEX + ')'


class TestSmtpRelay(tests.OpenPGPTestCase):

    EMAIL_DATA = ['HELO relay.leap.se',
                  'MAIL FROM: <user@leap.se>',
                  'RCPT TO: <leap@leap.se>',
                  'DATA',
                  'From: User <user@leap.se>',
                  'To: Leap <leap@leap.se>',
                  'Date: ' + datetime.now().strftime('%c'),
                  'Subject: test message',
                  '',
                  'This is a secret message.',
                  'Yours,',
                  'A.',
                  '',
                  '.',
                  'QUIT']

    def assertMatch(self, string, pattern, msg=None):
        if not re.match(pattern, string):
            msg = self._formatMessage(msg, '"%s" does not match pattern "%s".'
                                           % (string, pattern))
            raise self.failureException(msg)

    def test_relay_accepts_valid_email(self):
        """
        Test if SMTP server responds correctly for valid interaction.
        """

        SMTP_ANSWERS = ['220 ' + IP_OR_HOST_REGEX +
                        ' NO UCE NO UBE NO RELAY PROBES',
                        '250 ' + IP_OR_HOST_REGEX + ' Hello ' +
                        IP_OR_HOST_REGEX + ', nice to meet you',
                        '250 Sender address accepted',
                        '250 Recipient address accepted',
                        '354 Continue']
        proto = SMTPFactory(self._gpg).buildProtocol(('127.0.0.1', 0))
        transport = proto_helpers.StringTransport()
        proto.makeConnection(transport)
        for i, line in enumerate(self.EMAIL_DATA):
            proto.lineReceived(line + '\r\n')
            self.assertMatch(transport.value(),
                             '\r\n'.join(SMTP_ANSWERS[0:i + 1]))
        proto.setTimeout(None)

    def test_message_encrypt(self):
        proto = SMTPFactory(self._gpg).buildProtocol(('127.0.0.1', 0))
        user = User('leap@leap.se', 'relay.leap.se', proto, 'leap@leap.se')
        m = EncryptedMessage(user, self._gpg)
        for line in self.EMAIL_DATA[4:12]:
            m.lineReceived(line)
        m.parseMessage()
        m.encrypt()
        decrypted = str(self._gpg.decrypt(m.cyphertext))
        self.assertEqual('\n'.join(self.EMAIL_DATA[9:12]), decrypted)