subreddit.py

# The contents of this file are subject to the Common Public Attribution
# License Version 1.0. (the "License"); you may not use this file except in
# compliance with the License. You may obtain a copy of the License at
# http://code.reddit.com/LICENSE. The License is based on the Mozilla Public
# License Version 1.1, but Sections 14 and 15 have been added to cover use of
# software over a computer network and provide for limited attribution for the
# Original Developer. In addition, Exhibit A has been modified to be consistent
# with Exhibit B.
#
# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
# the specific language governing rights and limitations under the License.
#
# The Original Code is Reddit.
#
# The Original Developer is the Initial Developer.  The Initial Developer of the
# Original Code is CondeNet, Inc.
#
# All portions of the code written by CondeNet are Copyright (c) 2006-2010
# CondeNet, Inc. All Rights Reserved.
################################################################################
from __future__ import with_statement

from pylons import c, g
from pylons.i18n import _

from r2.lib.db.thing import Thing, Relation, NotFound
from account import Account
from printable import Printable
from r2.lib.db.userrel import UserRel
from r2.lib.db.operators import lower, or_, and_, desc
from r2.lib.memoize import memoize
from r2.lib.utils import tup, interleave_lists, last_modified_multi, flatten
from r2.lib.utils import timeago
from r2.lib.cache import sgm
from r2.lib.strings import strings, Score
from r2.lib.filters import _force_unicode
from r2.lib.db import tdb_cassandra
from r2.lib.cache import CL_ONE

import os.path
import random

class SubredditExists(Exception): pass

class Subreddit(Thing, Printable):
    # Note: As of 2010/03/18, nothing actually overrides the static_path
    # attribute, even on a cname. So c.site.static_path should always be
    # the same as g.static_path.
    _defaults = dict(static_path = g.static_path,
                     stylesheet = None,
                     stylesheet_rtl = None,
                     stylesheet_contents = '',
                     stylesheet_hash     = '0',
                     firsttext = strings.firsttext,
                     header = None,
                     header_size = None,
                     header_title = "",
                     allow_top = False, # overridden in "_new"
                     description = '',
                     images = {},
                     reported = 0,
                     valid_votes = 0,
                     show_media = False,
                     show_cname_sidebar = False,
                     css_on_cname = True,
                     domain = None,
                     over_18 = False,
                     mod_actions = 0,
                     sponsorship_text = "this reddit is sponsored by",
                     sponsorship_url = None,
                     sponsorship_img = None,
                     sponsorship_name = None,
                     # do we allow self-posts, links only, or any?
                     link_type = 'any', # one of ('link', 'self', 'any')
                     flair_enabled = True,
                     flair_position = 'right', # one of ('left', 'right')
                     link_flair_position = '', # one of ('', 'left', 'right')
                     flair_self_assign_enabled = False,
                     )
    _essentials = ('type', 'name', 'lang')
    _data_int_props = Thing._data_int_props + ('mod_actions', 'reported')

    sr_limit = 50
    gold_limit = 100
    DEFAULT_LIMIT = object()

    # note: for purposely unrenderable reddits (like promos) set author_id = -1
    @classmethod
    def _new(cls, name, title, author_id, ip, lang = g.lang, type = 'public',
             over_18 = False, **kw):
        with g.make_lock('create_sr_' + name.lower()):
            try:
                sr = Subreddit._by_name(name)
                raise SubredditExists
            except NotFound:
                if "allow_top" not in kw:
                    kw['allow_top'] = True
                sr = Subreddit(name = name,
                               title = title,
                               lang = lang,
                               type = type,
                               over_18 = over_18,
                               author_id = author_id,
                               ip = ip,
                               **kw)
                sr._commit()

                #clear cache
                Subreddit._by_name(name, _update = True)
                return sr


    _specials = {}

    @classmethod
    def _by_name(cls, names, stale=False, _update = False):
        #lower name here so there is only one cache
        names, single = tup(names, True)

        to_fetch = {}
        ret = {}

        for name in names:
            lname = name.lower()

            if lname in cls._specials:
                ret[name] = cls._specials[lname]
            else:
                to_fetch[lname] = name

        if to_fetch:
            def _fetch(lnames):
                q = cls._query(lower(cls.c.name) == lnames,
                               cls.c._spam == (True, False),
                               limit = len(lnames),
                               data=True)
                try:
                    srs = list(q)
                except UnicodeEncodeError:
                    print "Error looking up SRs %r" % (lnames,)
                    raise

                return dict((sr.name.lower(), sr._id)
                            for sr in srs)

            srs = {}
            srids = sgm(g.cache, to_fetch.keys(), _fetch, prefix='subreddit.byname', stale=stale)
            if srids:
                srs = cls._byID(srids.values(), data=True, return_dict=False, stale=stale)

            for sr in srs:
                ret[to_fetch[sr.name.lower()]] = sr

        if ret and single:
            return ret.values()[0]
        elif not ret and single:
            raise NotFound, 'Subreddit %s' % name
        else:
            return ret

    @classmethod
    @memoize('subreddit._by_domain')
    def _by_domain_cache(cls, name):
        q = cls._query(cls.c.domain == name,
                       limit = 1)
        l = list(q)
        if l:
            return l[0]._id

    @classmethod
    def _by_domain(cls, domain, _update = False):
        sr_id = cls._by_domain_cache(_force_unicode(domain).lower(),
                                     _update = _update)
        if sr_id:
            return cls._byID(sr_id, True)
        else:
            return None

    @property
    def moderators(self):
        return self.moderator_ids()

    @property
    def contributors(self):
        return self.contributor_ids()

    @property
    def banned(self):
        return self.banned_ids()

    @property
    def subscribers(self):
        return self.subscriber_ids()

    @property
    def flair(self):
        return self.flair_ids()

    def spammy(self):
        return self._spam

    def can_comment(self, user):
        if c.user_is_admin:
            return True
        elif self.is_banned(user):
            return False
        elif self.type in ('public','restricted'):
            return True
        elif self.is_moderator(user) or self.is_contributor(user):
            #private requires contributorship
            return True
        else:
            return False

    def can_submit(self, user, promotion=False):
        if c.user_is_admin:
            return True
        elif self.is_banned(user) and not promotion:
            return False
        elif self.type == 'public':
            return True
        elif self.is_moderator(user) or self.is_contributor(user):
            #restricted/private require contributorship
            return True
        else:
            return False

    def can_ban(self,user):
        return (user
                and (c.user_is_admin
                     or self.is_moderator(user)))

    def can_distinguish(self,user):
        return (user
                and (c.user_is_admin
                     or self.is_moderator(user)))

    def can_change_stylesheet(self, user):
        if c.user_is_loggedin:
            return c.user_is_admin or self.is_moderator(user)
        else:
            return False

    def is_special(self, user):
        return (user
                and (c.user_is_admin
                     or self.is_moderator(user)
                     or self.is_contributor(user)))

    def can_give_karma(self, user):
        return self.is_special(user)

    def should_ratelimit(self, user, kind):
        if c.user_is_admin or self.is_special(user):
            return False

        if kind == 'comment':
            rl_karma = g.MIN_RATE_LIMIT_COMMENT_KARMA
        else:
            rl_karma = g.MIN_RATE_LIMIT_KARMA

        return user.karma(kind, self) < rl_karma

    def can_view(self, user):
        if c.user_is_admin:
            return True
        
        if self.spammy():
            return False
        elif self.type in ('public', 'restricted', 'archived'):
            return True
        elif c.user_is_loggedin:
            #private requires contributorship
            return self.is_contributor(user) or self.is_moderator(user)

    def can_demod(self, bully, victim):
        # This works because the is_*() functions return the relation
        # when True. So we can compare the dates on the relations.
        bully_rel = self.is_moderator(bully)
        victim_rel = self.is_moderator(victim)
        if bully_rel is None or victim_rel is None:
            return False
        return bully_rel._date <= victim_rel._date

    @classmethod
    def load_subreddits(cls, links, return_dict = True, stale=False):
        """returns the subreddits for a list of links. it also preloads the
        permissions for the current user."""
        srids = set(l.sr_id for l in links
                    if getattr(l, "sr_id", None) is not None)
        subreddits = {}
        if srids:
            subreddits = cls._byID(srids, data=True, stale=stale)

        if subreddits and c.user_is_loggedin:
            # dict( {Subreddit,Account,name} -> Relationship )
            SRMember._fast_query(subreddits.values(), (c.user,),
                                 ('subscriber','contributor','moderator'),
                                 data=True, eager_load=True, thing_data=True)

        return subreddits if return_dict else subreddits.values()

    #rising uses this to know which subreddits to include, doesn't
    #work for all/friends atm
    def rising_srs(self):
        if c.default_sr or not hasattr(self, '_id'):
            user = c.user if c.user_is_loggedin else None
            sr_ids = self.user_subreddits(user)
        else:
            sr_ids = (self._id,)
        return sr_ids

    def get_links(self, sort, time):
        from r2.lib.db import queries
        return queries.get_links(self, sort, time)

    def get_spam(self):
        from r2.lib.db import queries
        return queries.get_spam(self)

    def get_reported(self):
        from r2.lib.db import queries
        return queries.get_reported(self)

    def get_trials(self):
        from r2.lib.db import queries
        return queries.get_trials(self)

    def get_modqueue(self):
        from r2.lib.db import queries
        return queries.get_modqueue(self)

    def get_all_comments(self):
        from r2.lib.db import queries
        return queries.get_sr_comments(self)

    @classmethod
    def get_modactions(cls, srs, mod=None, action=None):
        # Get a query that will yield ModAction objects with mod and action 
        from r2.models import ModAction
        return ModAction.get_actions(srs, mod=mod, action=action)

    @classmethod
    def add_props(cls, user, wrapped):
        names = ('subscriber', 'moderator', 'contributor')
        rels = (SRMember._fast_query(wrapped, [user], names) if c.user_is_loggedin else {})
        defaults = Subreddit.default_subreddits()
        target = "_top" if c.cname else None
        for item in wrapped:
            if not user or not user.has_subscribed:
                item.subscriber = item._id in defaults
            else:
                item.subscriber = bool(rels.get((item, user, 'subscriber')))
            item.moderator = bool(rels.get((item, user, 'moderator')))
            item.contributor = bool(item.type != 'public' and
                                    (item.moderator or
                                     rels.get((item, user, 'contributor'))))

            # Don't reveal revenue information via /r/lounge's subscribers
            if (g.lounge_reddit and item.name == g.lounge_reddit
                and not c.user_is_admin):
                item._ups = 0

            item.score = item._ups

            # override "voting" score behavior (it will override the use of
            # item.score in builder.py to be ups-downs)
            item.likes = item.subscriber or None
            base_score = item.score - (1 if item.likes else 0)
            item.voting_score = [(base_score + x - 1) for x in range(3)]
            item.score_fmt = Score.subscribers

            #will seem less horrible when add_props is in pages.py
            from r2.lib.pages import UserText
            item.usertext = UserText(item, item.description, target=target)


        Printable.add_props(user, wrapped)
    #TODO: make this work
    cache_ignore = set(["subscribers"]).union(Printable.cache_ignore)
    @staticmethod
    def wrapped_cache_key(wrapped, style):
        s = Printable.wrapped_cache_key(wrapped, style)
        s.extend([wrapped._spam])
        return s

    @classmethod
    def top_lang_srs(cls, lang, limit, filter_allow_top = False, over18 = True,
                     over18_only = False, ids=False, stale=False):
        from r2.lib import sr_pops
        lang = tup(lang)

        sr_ids = sr_pops.pop_reddits(lang, over18, over18_only, filter_allow_top = filter_allow_top)
        sr_ids = sr_ids[:limit]

        return (sr_ids if ids
                else Subreddit._byID(sr_ids, data=True, return_dict=False, stale=stale))

    @classmethod
    def default_subreddits(cls, ids = True, over18 = False, limit = g.num_default_reddits,
                           stale=True):
        """
        Generates a list of the subreddits any user with the current
        set of language preferences and no subscriptions would see.

        An optional kw argument 'limit' is defaulted to g.num_default_reddits
        """

        # we'll let these be unordered for now
        auto_srs = []
        if g.automatic_reddits:
            auto_srs = map(lambda sr: sr._id,
                           Subreddit._by_name(g.automatic_reddits, stale=stale).values())

        srs = cls.top_lang_srs(c.content_langs, limit + len(auto_srs),
                               filter_allow_top = True,
                               over18 = over18, ids = True,
                               stale=stale)

        rv = []
        for sr in srs:
            if len(rv) >= limit:
                break
            if sr in auto_srs:
                continue
            rv.append(sr)

        rv = auto_srs + rv

        return rv if ids else Subreddit._byID(rv, data=True, return_dict=False, stale=stale)

    @classmethod
    @memoize('random_reddits', time = 1800)
    def random_reddits(cls, user_name, sr_ids, limit):
        """This gets called when a user is subscribed to more than 50
        reddits. Randomly choose 50 of those reddits and cache it for
        a while so their front page doesn't jump around."""
        return random.sample(sr_ids, limit)

    @classmethod
    def random_reddit(cls, limit = 1000, over18 = False):
        srs = cls.top_lang_srs(c.content_langs, limit,
                               filter_allow_top = False,
                               over18 = over18,
                               over18_only = over18,
                               ids=True)
        return (Subreddit._byID(random.choice(srs))
                if srs else Subreddit._by_name(g.default_sr))

    @classmethod
    def user_subreddits(cls, user, ids=True, over18=False, limit=DEFAULT_LIMIT,
                        stale=False):
        """
        subreddits that appear in a user's listings. If the user has
        subscribed, returns the stored set of subscriptions.
        
        limit - if it's Subreddit.DEFAULT_LIMIT, limits to 50 subs
                (100 for gold users)
                if it's None, no limit is used
                if it's an integer, then that many subs will be returned

        Otherwise, return the default set.
        """
        # Limit the number of subs returned based on user status,
        # if no explicit limit was passed
        if limit is Subreddit.DEFAULT_LIMIT:
            if user and user.gold:
                # Goldies get extra subreddits
                limit = Subreddit.gold_limit
            else:
                limit = Subreddit.sr_limit
        
        # note: for user not logged in, the fake user account has
        # has_subscribed == False by default.
        if user and user.has_subscribed:
            sr_ids = Subreddit.reverse_subscriber_ids(user)

            if limit and len(sr_ids) > limit:
                sr_ids.sort()
                sr_ids = cls.random_reddits(user.name, sr_ids, limit)
            return sr_ids if ids else Subreddit._byID(sr_ids,
                                                      data=True,
                                                      return_dict=False,
                                                      stale=stale)
        else:
            return cls.default_subreddits(ids = ids, over18=over18,
                                          limit=g.num_default_reddits,
                                          stale=stale)

    @classmethod
    @memoize('subreddit.special_reddits')
    def special_reddits_cache(cls, user_id, query_param):
        reddits = SRMember._query(SRMember.c._name == query_param,
                                  SRMember.c._thing2_id == user_id,
                                  #hack to prevent the query from
                                  #adding it's own date
                                  sort = (desc('_t1_ups'), desc('_t1_date')),
                                  eager_load = True,
                                  thing_data = True,
                                  limit = 100)

        return [ sr._thing1_id for sr in reddits ]

    # Used to pull all of the SRs a given user moderates or is a contributor
    # to (which one is controlled by query_param)
    @classmethod
    def special_reddits(cls, user, query_param, _update=False):
        return cls.special_reddits_cache(user._id, query_param, _update=_update)

    def is_subscriber_defaults(self, user):
        if user.has_subscribed:
            return self.is_subscriber(user)
        else:
            return self in self.default_subreddits(ids = False)

    @classmethod
    def subscribe_defaults(cls, user):
        if not user.has_subscribed:
            for sr in cls.user_subreddits(None, False,
                                          limit = g.num_default_reddits):
                #this will call reverse_subscriber_ids after every
                #addition. if it becomes a problem we should make an
                #add_multiple_subscriber fn
                if sr.add_subscriber(user):
                    sr._incr('_ups', 1)
            user.has_subscribed = True
            user._commit()

    @classmethod
    def submit_sr_names(cls, user):
        """subreddit names that appear in a user's submit page. basically a
        sorted/rearranged version of user_subreddits()."""
        srs = cls.user_subreddits(user, ids = False)
        names = [s.name for s in srs if s.can_submit(user)]
        names.sort(key=str.lower)

        #add the current site to the top (default_sr)
        if g.default_sr in names:
            names.remove(g.default_sr)
            names.insert(0, g.default_sr)

        if c.lang in names:
            names.remove(c.lang)
            names.insert(0, c.lang)

        return names

    @property
    def path(self):
        return "/r/%s/" % self.name


    def keep_item(self, wrapped):
        if c.user_is_admin:
            return True

        user = c.user if c.user_is_loggedin else None
        return self.can_view(user)

    def get_images(self):
        """
        Iterator over list of (name, url) pairs which have been
        uploaded for custom styling of this subreddit. 
        """
        for name, img in self.images.iteritems():
            if name != "/empties/":
                yield (name, img)
    
    def get_num_images(self):
        if '/empties/' in self.images:
            return len(self.images) - 1
        else:
            return len(self.images)
    
    def add_image(self, name, url, max_num = None):
        """
        Adds an image to the subreddit's image list.  The resulting
        number of the image is returned.  Note that image numbers are
        non-sequential insofar as unused numbers in an existing range
        will be populated before a number outside the range is
        returned.

        raises ValueError if the resulting number is >= max_num.

        The Subreddit will be _dirty if a new image has been added to
        its images list, and no _commit is called.
        """
        if max_num is not None and self.get_num_images() >= max_num:
            raise ValueError, "too many images"
        
        # copy and blank out the images list to flag as _dirty
        l = self.images
        self.images = None
        # update the dictionary and rewrite to images attr
        l[name] = url
        self.images = l

    def del_image(self, name):
        """
        Deletes an image from the images dictionary assuming an image
        of that name is in the current dictionary.

        The Subreddit will be _dirty if image has been removed from
        its images list, and no _commit is called.
        """
        if self.images.has_key(name):
            l = self.images
            self.images = None

            del l[name]
            self.images = l

    def __eq__(self, other):
        if type(self) != type(other):
            return False

        if isinstance(self, FakeSubreddit):
            return self is other

        return self._id == other._id

    def __ne__(self, other):
        return not self.__eq__(other)

    @staticmethod
    def user_mods_all(user, srs):
        # Get moderator SRMember relations for all in srs
        # if a relation doesn't exist there will be a None entry in the
        # returned dict
        mod_rels = SRMember._fast_query(srs, user, 'moderator', data=False)
        if None in mod_rels.values():
            return False
        else:
            return True

    @staticmethod
    def get_all_mod_ids(srs):
        from r2.lib.db.thing import Merge
        srs = tup(srs)
        queries = [SRMember._query(SRMember.c._thing1_id == sr._id,
                                   SRMember.c._name == 'moderator') for sr in srs]
        merged = Merge(queries)
        # sr_ids = [sr._id for sr in srs]
        # query = SRMember._query(SRMember.c._thing1_id == sr_ids, ...)
        # is really slow
        return [rel._thing2_id for rel in list(merged)]

class FakeSubreddit(Subreddit):
    over_18 = False
    _nodb = True

    def __init__(self):
        Subreddit.__init__(self)
        self.title = ''
        self.link_flair_position = 'left'

    def is_moderator(self, user):
        return c.user_is_loggedin and c.user_is_admin

    def can_view(self, user):
        return True

    def can_comment(self, user):
        return False

    def can_submit(self, user, promotion=False):
        return False

    def can_change_stylesheet(self, user):
        return False

    def is_banned(self, user):
        return False

    def get_all_comments(self):
        from r2.lib.db import queries
        return queries.get_all_comments()

    def spammy(self):
        return False

class FriendsSR(FakeSubreddit):
    name = 'friends'
    title = 'friends'

    @classmethod
    @memoize("get_important_friends", 5*60)
    def get_important_friends(cls, user_id, max_lookup = 500, limit = 100):
        a = Account._byID(user_id, data = True)
        # friends are returned chronologically by date, so pick the end of the list
        # for the most recent additions
        friends = Account._byID(a.friends[-max_lookup:], return_dict = False,
                                data = True)

        # if we don't have a last visit for your friends, we don't
        # care about them
        last_visits = last_modified_multi(friends, "submitted")
        friends = [x for x in friends if x in last_visits]

        # sort friends by most recent interactions
        friends.sort(key = lambda x: last_visits[x], reverse = True)
        return [x._id for x in friends[:limit]]

    def get_links(self, sort, time):
        from r2.lib.db import queries
        from r2.models import Link
        from r2.controllers.errors import UserRequiredException

        if not c.user_is_loggedin:
            raise UserRequiredException

        friends = self.get_important_friends(c.user._id)

        if not friends:
            return []

        if g.use_query_cache:
            # with the precomputer enabled, this Subreddit only supports
            # being sorted by 'new'. it would be nice to have a
            # cleaner UI than just blatantly ignoring their sort,
            # though
            sort = 'new'
            time = 'all'

            friends = Account._byID(friends, return_dict=False)

            crs = [queries.get_submitted(friend, sort, time)
                   for friend in friends]
            return queries.MergedCachedResults(crs)

        else:
            q = Link._query(Link.c.author_id == friends,
                            sort = queries.db_sort(sort),
                            data = True)
            if time != 'all':
                q._filter(queries.db_times[time])
            return q

    def get_all_comments(self):
        from r2.lib.db import queries
        from r2.models import Comment
        from r2.controllers.errors import UserRequiredException

        if not c.user_is_loggedin:
            raise UserRequiredException

        friends = self.get_important_friends(c.user._id)

        if not friends:
            return []

        if g.use_query_cache:
            # with the precomputer enabled, this Subreddit only supports
            # being sorted by 'new'. it would be nice to have a
            # cleaner UI than just blatantly ignoring their sort,
            # though
            sort = 'new'
            time = 'all'

            friends = Account._byID(friends,
                                    return_dict=False)

            crs = [queries.get_comments(friend, sort, time)
                   for friend in friends]
            return queries.MergedCachedResults(crs)

        else:
            q = Comment._query(Comment.c.author_id == friends,
                               sort = desc('_date'),
                               data = True)
            return q

class AllSR(FakeSubreddit):
    name = 'all'
    title = 'all'

    def get_links(self, sort, time):
        from r2.lib import promote
        from r2.models import Link
        from r2.lib.db import queries
        q = Link._query(Link.c.sr_id > 0,
                        sort = queries.db_sort(sort),
                        read_cache = True,
                        write_cache = True,
                        cache_time = 60,
                        data = True,
                        filter_primary_sort_only=True)
        if time != 'all':
            q._filter(queries.db_times[time])
        return q

    def get_all_comments(self):
        from r2.lib.db import queries
        return queries.get_all_comments()

    def rising_srs(self):
        return None


class _DefaultSR(FakeSubreddit):
    #notice the space before reddit.com
    name = ' reddit.com'
    path = '/'
    header = g.default_header_url

    def get_links_sr_ids(self, sr_ids, sort, time):
        from r2.lib.db import queries
        from r2.models import Link

        if not sr_ids:
            return []
        else:
            srs = Subreddit._byID(sr_ids, data=True, return_dict = False)

        if g.use_query_cache:
            results = [queries.get_links(sr, sort, time)
                       for sr in srs]
            return queries.merge_results(*results)
        else:
            q = Link._query(Link.c.sr_id == sr_ids,
                            sort = queries.db_sort(sort), data=True)
            if time != 'all':
                q._filter(queries.db_times[time])
            return q

    def get_links(self, sort, time):
        user = c.user if c.user_is_loggedin else None
        sr_ids = Subreddit.user_subreddits(user)
        return self.get_links_sr_ids(sr_ids, sort, time)

    @property
    def title(self):
        return _(g.short_description)

# This is the base class for the instantiated front page reddit
class DefaultSR(_DefaultSR):
    def __init__(self):
        _DefaultSR.__init__(self)
        try:
            self._base = Subreddit._by_name(g.default_sr, stale=True)
        except NotFound:
            self._base = None

    @property
    def _fullname(self):
        return "t5_6"

    @property
    def header(self):
        return (self._base and self._base.header) or _DefaultSR.header

    @property
    def header_title(self):
        return (self._base and self._base.header_title) or ""

    @property
    def header_size(self):
        return (self._base and self._base.header_size) or None

    @property
    def stylesheet_contents(self):
        return self._base.stylesheet_contents if self._base else ""

    @property
    def sponsorship_url(self):
        return self._base.sponsorship_url if self._base else ""

    @property
    def sponsorship_text(self):
        return self._base.sponsorship_text if self._base else ""

    @property
    def sponsorship_img(self):
        return self._base.sponsorship_img if self._base else ""



class MultiReddit(_DefaultSR):
    name = 'multi'
    header = ""

    def __init__(self, sr_ids, path):
        _DefaultSR.__init__(self)
        self.real_path = path
        self.sr_ids = sr_ids

        srs = Subreddit._byID(self.sr_ids, return_dict=False)
        self.banned_sr_ids = []
        self.kept_sr_ids = []
        for sr in srs:
            if sr._spam:
                self.banned_sr_ids.append(sr._id)
            else:
                self.kept_sr_ids.append(sr._id)

    @property
    def path(self):
        return '/r/' + self.real_path

    def get_links(self, sort, time):
        return self.get_links_sr_ids(self.kept_sr_ids, sort, time)

    def rising_srs(self):
        return self.kept_sr_ids

    def get_all_comments(self):
        from r2.lib.db.queries import get_sr_comments, merge_results
        srs = Subreddit._byID(self.kept_sr_ids, return_dict=False)
        results = [get_sr_comments(sr) for sr in srs]
        return merge_results(*results)

class RandomReddit(FakeSubreddit):
    name = 'random'
    header = ""

class RandomNSFWReddit(FakeSubreddit):
    name = 'randnsfw'
    header = ""

class ModContribSR(_DefaultSR):
    name  = None
    title = None
    query_param = None
    real_path = None

    @property
    def path(self):
        return '/r/' + self.real_path

    @property
    def sr_ids(self):
        if c.user_is_loggedin:
            return Subreddit.special_reddits(c.user, self.query_param)
        else:
            return []

    def rising_srs(self):
        return self.sr_ids

    def get_links(self, sort, time):
        return self.get_links_sr_ids(self.sr_ids, sort, time)

class ModSR(ModContribSR):
    name  = "communities you moderate"
    title = "communities you moderate"
    query_param = "moderator"
    real_path = "mod"

class ContribSR(ModContribSR):
    name  = "contrib"
    title = "communities you're approved on"
    query_param = "contributor"
    real_path = "contrib"

class SubSR(FakeSubreddit):
    stylesheet = 'subreddit.css'
    #this will make the javascript not send an SR parameter
    name = ''

    def can_view(self, user):
        return True

    def can_comment(self, user):
        return False

    def can_submit(self, user, promotion=False):
        return True

    @property
    def path(self):
        return "/reddits/"

class DomainSR(FakeSubreddit):
    @property
    def path(self):
        return '/domain/' + self.domain

    def __init__(self, domain):
        FakeSubreddit.__init__(self)
        self.domain = domain
        self.name = domain 
        self.title = domain + ' ' + _('on reddit.com')

    def get_links(self, sort, time):
        from r2.lib.db import queries
        # TODO: once the lists are precomputed properly, this can be
        # switched over to use the non-_old variety.
        return queries.get_domain_links(self.domain, sort, time)

Frontpage = DefaultSR()
Sub = SubSR()
Friends = FriendsSR()
Mod = ModSR()
Contrib = ContribSR()
All = AllSR()
Random = RandomReddit()
RandomNSFW = RandomNSFWReddit()

Subreddit._specials.update(dict(friends = Friends,
                                randnsfw = RandomNSFW,
                                random = Random,
                                mod = Mod,
                                contrib = Contrib,
                                all = All))

class SRMember(Relation(Subreddit, Account)): pass
Subreddit.__bases__ += (UserRel('moderator', SRMember),
                        UserRel('contributor', SRMember),
                        UserRel('subscriber', SRMember, disable_ids_fn = True),
                        UserRel('banned', SRMember))

class SubredditPopularityByLanguage(tdb_cassandra.View):
    _use_db = True
    _value_type = 'pickle'
    _connection_pool = 'main'
    _read_consistency_level = CL_ONE