#
# Copyright (c) 2014 ThoughtWorks, Inc.
#
# Pixelated is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Pixelated is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with Pixelated. If not, see <http://www.gnu.org/licenses/>.
from StringIO import StringIO
from email.utils import parseaddr
from leap.mail.outgoing.service import OutgoingMail

from twisted.internet.defer import Deferred, fail
from twisted.mail.smtp import SMTPSenderFactory
from twisted.internet import reactor, defer
from pixelated.support.functional import flatten


class SMTPDownException(Exception):
    def __init__(self):
        Exception.__init__(self, "Couldn't send mail now, try again later.")


class MailSender(object):

    def __init__(self, account_email_address, keymanager, cert_path, remote_smtp_host, remote_smtp_port):
        self._from = account_email_address
        self._keymanager = keymanager
        self._cert_path = cert_path
        self._remote_smtp_host = remote_smtp_host
        self._remote_smtp_port = remote_smtp_port

    def sendmail(self, mail):
        recipients = flatten([mail.to, mail.cc, mail.bcc])
        outgoing_mail = self._create_outgoing_mail()
        deferreds = []

        for recipient in recipients:
            deferreds.append(outgoing_mail.send_message(mail.to_smtp_format(), recipient))

        return defer.gatherResults(deferreds)

    def _create_outgoing_mail(self):
        return OutgoingMail(self._from, self._keymanager, self._cert_path, self._cert_path, self._remote_smtp_host, self._remote_smtp_port)


class LocalSmtpMailSender(object):

    def __init__(self, account_email_address, smtp):
        self.smtp = smtp
        self.account_email_address = account_email_address

    def sendmail(self, mail):
        if self.smtp.ensure_running():
            recipients = flatten([mail.to, mail.cc, mail.bcc])
            result_deferred = Deferred()
            sender_factory = SMTPSenderFactory(
                fromEmail=self.account_email_address,
                toEmail=set([parseaddr(recipient)[1] for recipient in recipients]),
                file=StringIO(mail.to_smtp_format()),
                deferred=result_deferred)

            reactor.connectTCP('localhost', self.smtp.local_smtp_port_number,
                               sender_factory)

            return result_deferred
        return fail(SMTPDownException())