# Copyright (C) 1998-2017 by the Free Software Foundation, Inc.
#
# This file is part of GNU Mailman.
#
# GNU Mailman is free software: you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# GNU Mailman 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 General Public License for
# more details.
#
# You should have received a copy of the GNU General Public License along with
# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.

"""Send an acknowledgment of the successful post to the sender.

This only happens if the sender has set their AcknowledgePosts attribute.
"""

from mailman.core.i18n import _
from mailman.email.message import UserNotification
from mailman.interfaces.handler import IHandler
from mailman.interfaces.languages import ILanguageManager
from mailman.interfaces.template import ITemplateLoader
from mailman.utilities.string import expand, oneline
from public import public
from zope.component import getUtility
from zope.interface import implementer


@public
@implementer(IHandler)
class Acknowledge:
    """Send an acknowledgment."""

    name = 'acknowledge'
    description = _("""Send an acknowledgment of a posting.""")

    def process(self, mlist, msg, msgdata):
        """See `IHandler`."""
        # Extract the sender's address and find them in the user database
        sender = msgdata.get('original_sender', msg.sender)
        member = mlist.members.get_member(sender)
        if member is None or not member.acknowledge_posts:
            # Either the sender is not a member, in which case we can't know
            # whether they want an acknowlegment or not, or they are a member
            # who definitely does not want an acknowlegment.
            return
        # Okay, they are a member that wants an acknowledgment of their post.
        # Give them their original subject.  BAW: do we want to use the
        # decoded header?
        original_subject = msgdata.get(
            'origsubj', msg.get('subject', _('(no subject)')))
        # Get the user's preferred language.
        language_manager = getUtility(ILanguageManager)
        language = (language_manager[msgdata['lang']]
                    if 'lang' in msgdata
                    else member.preferred_language)
        # Now get the acknowledgement template.
        display_name = mlist.display_name                        # noqa: F841
        template = getUtility(ITemplateLoader).get(
            'list:user:notice:post', mlist,
            language=language.code)
        text = expand(template, mlist, dict(
            subject=oneline(original_subject, in_unicode=True),
            # For backward compatibility.
            list_name=mlist.list_name,
            ))
        # Craft the outgoing message, with all headers and attributes
        # necessary for general delivery.  Then enqueue it to the outgoing
        # queue.
        subject = _('$display_name post acknowledgment')
        usermsg = UserNotification(sender, mlist.bounces_address,
                                   subject, text, language)
        usermsg.send(mlist)