from trac.core import Component, implements
from announcerplugin.api import IAnnouncementSubscriber, istrue
from announcerplugin.api import IAnnouncementPreferenceProvider
from trac.ticket import model
from trac.web.chrome import add_warning
from trac.config import ListOption
import re

class JoinableGroupSubscriber(Component):
    implements(IAnnouncementSubscriber, IAnnouncementPreferenceProvider)
    
    joinable_groups = ListOption('announcer', 'joinable_groups', [], 
        doc="""Joinable groups represent 'opt-in' groups that users may 
        freely join. The name of the groups should be a simple alphanumeric 
        string. By adding the group name preceeded by @ (such as @sec for
        the sec group) to the CC field of a ticket, everyone in that group
        will receive an announcement when that ticket is changed.""")
    
    def get_subscription_realms(self):
        return ('ticket',)
    
    def get_subscription_categories(self, realm):
        if realm == "ticket":
            return('changed', 'created', 'attachment added')
        else:
            ()
    
    def get_subscriptions_for_event(self, event):
        if event.realm == 'ticket':
            if event.category in ('changed', 'created', 'attachment added'):
                cc = event.target['cc'] or ''
                for chunk in re.split('\s|,', cc):
                    chunk = chunk.strip()
                    if chunk.startswith('@'):
                        member = None
                        for member in self._get_membership(chunk[1:]):
                            self.log.debug(
                                "JoinableGroupSubscriber added '%s (%s)' " \
                                "because of opt-in to group: %s"%(member[1], \
                                member[2] and 'authenticated' or \
                                'not authenticated', chunk[1:]))
                            yield member
                        if member is None:
                            self.log.debug("JoinableGroupSubscriber found " \
                                    "no members for group: %s." % chunk[1:])
                            
    def _get_membership(self, group):
        db = self.env.get_db_cnx()
        cursor = db.cursor()
        cursor.execute("""
            SELECT sid, authenticated
              FROM session_attribute 
             WHERE name=%s
               AND value=%s
        """, ('announcer_joinable_group_' + group, "1"))
        for result in cursor.fetchall():
            if result[1] in (1, '1', True):
                authenticated = True
            else:
                authenticated = False
            yield ("email", result[0], authenticated, None)

    def get_announcement_preference_boxes(self, req):
        if req.authname == "anonymous" and 'email' not in req.session:
            return
        if self.joinable_groups:
            yield "joinable_groups", "Group Subscriptions"
        
    def render_announcement_preference_box(self, req, panel):
        cfg = self.config
        sess = req.session
        if req.method == "POST":
            for group in self.joinable_groups:
                group_opt = 'joinable_group_%s' % group
                result = req.args.get(group_opt, None)
                if result:
                    sess["announcer_" + group_opt] = '1'
                else:                    
                    if "announcer_" + group_opt in sess:
                        del sess["announcer_" + group_opt]
        groups = {}
        for group in self.joinable_groups:
            groups[group] = sess.get('announcer_joinable_group_%s' % group, None)
        data = dict(joinable_groups = groups)
        return "prefs_announcer_joinable_groups.html", data