# Copyright (C) 1998-2007 by the Free Software Foundation, Inc.
#
# This program 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 2
# of the License, or (at your option) any later version.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
# USA.

"""Calculate the regular (i.e. non-digest) recipients of the message.

This module calculates the non-digest recipients for the message based on the
list's membership and configuration options.  It places the list of recipients
on the `recips' attribute of the message.  This attribute is used by the
SendmailDeliver and BulkDeliver modules.
"""

from Mailman import Errors
from Mailman import Message
from Mailman import Utils
from Mailman.MemberAdaptor import ENABLED
from Mailman.configuration import config
from Mailman.i18n import _



def process(mlist, msg, msgdata):
    # Short circuit if we've already calculated the recipients list,
    # regardless of whether the list is empty or not.
    if msgdata.has_key('recips'):
        return
    # Should the original sender should be included in the recipients list?
    include_sender = 1
    sender = msg.get_sender()
    try:
        if mlist.getMemberOption(sender, config.DontReceiveOwnPosts):
            include_sender = 0
    except Errors.NotAMemberError:
        pass
    # Support for urgent messages, which bypasses digests and disabled
    # delivery and forces an immediate delivery to all members Right Now.  We
    # are specifically /not/ allowing the site admins password to work here
    # because we want to discourage the practice of sending the site admin
    # password through email in the clear. (see also Approve.py)
    missing = []
    password = msg.get('urgent', missing)
    if password is not missing:
        if mlist.Authenticate((config.AuthListModerator,
                               config.AuthListAdmin),
                              password):
            recips = mlist.getMemberCPAddresses(mlist.getRegularMemberKeys() +
                                                mlist.getDigestMemberKeys())
            msgdata['recips'] = recips
            return
        else:
            # Bad Urgent: password, so reject it instead of passing it on.  I
            # think it's better that the sender know they screwed up than to
            # deliver it normally.
            realname = mlist.real_name
            text = _("""\
Your urgent message to the %(realname)s mailing list was not authorized for
delivery.  The original message as received by Mailman is attached.
""")
            raise Errors.RejectMessage, Utils.wrap(text)
    # Calculate the regular recipients of the message
    recips = [mlist.getMemberCPAddress(m)
              for m in mlist.getRegularMemberKeys()
              if mlist.getDeliveryStatus(m) == ENABLED]
    # Remove the sender if they don't want to receive their own posts
    if not include_sender:
        try:
            recips.remove(mlist.getMemberCPAddress(sender))
        except (Errors.NotAMemberError, ValueError):
            # Sender does not want to get copies of their own messages (not
            # metoo), but delivery to their address is disabled (nomail).  Or
            # the sender is not a member of the mailing list.
            pass
    # Handle topic classifications
    do_topic_filters(mlist, msg, msgdata, recips)
    # Bookkeeping
    msgdata['recips'] = recips



def do_topic_filters(mlist, msg, msgdata, recips):
    if not mlist.topics_enabled:
        # MAS: if topics are currently disabled for the list, send to all
        # regardless of ReceiveNonmatchingTopics
        return
    hits = msgdata.get('topichits')
    zaprecips = []
    if hits:
        # The message hit some topics, so only deliver this message to those
        # who are interested in one of the hit topics.
        for user in recips:
            utopics = mlist.getMemberTopics(user)
            if not utopics:
                # This user is not interested in any topics, so they get all
                # postings.
                continue
            # BAW: Slow, first-match, set intersection!
            for topic in utopics:
                if topic in hits:
                    # The user wants this message
                    break
            else:
                # The user was interested in topics, but not any of the ones
                # this message matched, so zap him.
                zaprecips.append(user)
    else:
        # The semantics for a message that did not hit any of the pre-canned
        # topics is to troll through the membership list, looking for users
        # who selected at least one topic of interest, but turned on
        # ReceiveNonmatchingTopics.
        for user in recips:
            if not mlist.getMemberTopics(user):
                # The user did not select any topics of interest, so he gets
                # this message by default.
                continue
            if not mlist.getMemberOption(user,
                                         config.ReceiveNonmatchingTopics):
                # The user has interest in some topics, but elects not to
                # receive message that match no topics, so zap him.
                zaprecips.append(user)
            # Otherwise, the user wants non-matching messages.
    # Prune out the non-receiving users
    for user in zaprecips:
        recips.remove(user)