ctdo-trac/TracRendezVous/tracrendezvous/event/web_ui.py

# -*- coding: utf-8 -*-

import re, math

from datetime import datetime, timedelta, time
from os import mkdir
from os.path import join
from re import match, sub
from collections import defaultdict
from sqlite3 import IntegrityError
from operator import attrgetter

from trac.config import *
from trac.mimeview.api import Mimeview, IContentConverter, Context
from trac.core import Component, implements, TracError
from trac.resource import IResourceManager, Resource, get_resource_url
from trac.perm import PermissionError, IPermissionRequestor
from trac.search import ISearchSource, search_to_sql, shorten_result
from trac.util import get_reporter_id, Ranges
from trac.util.text import to_unicode
from trac.util.html import html
from trac.util.datefmt import get_timezone, utc, format_time, localtz
#from trac.util.translation import _, add_domain
from trac.web.chrome import INavigationContributor, ITemplateProvider, add_stylesheet, add_warning, add_notice, add_ctxtnav, add_script, add_link, Chrome
from trac.web import IRequestHandler
from trac.wiki import IWikiSyntaxProvider

from dateutil import rrule
from genshi.builder import tag
from genshi.template import TemplateLoader, NewTextTemplate
from tractags.api import TagSystem, ITagProvider
from tracrendezvous.location.model import ItemLocation
from tracrendezvous.event.model import Event, EventRRule, EventRDate
#from tracrendezvous.event.parse_ical import parse_ical
from ctdotools.utils import gen_wiki_page, validate_id, time_parse, datetime_parse, date_parse, get_tz

from trac.util.translation import domain_functions

add_domain, _, tag_ = domain_functions('tracrendezvous', ('add_domain', '_', 'tag_'))

import tracrendezvous

__all__ = ['EventModule','EventTagProvider']

class EventTagProvider(Component):
    """A tag provider using Events tag field as sources of tags.
    """
    implements(ITagProvider)

    # ITagProvider methods
    def get_taggable_realm(self):
        return 'event'

    def get_tagged_resources(self, req, tags):
        split_into_tags = TagSystem(self.env).split_into_tags
        db = self.env.get_db_cnx()
        cursor = db.cursor()
        args = []
        sql = "SELECT * FROM (SELECT e_id, tags, COALESCE(tags, '') as fields FROM events)"
        constraints = []
        if tags:
            constraints.append(
                "(" + ' OR '.join(["fields LIKE %s" for t in tags]) + ")")
            args += ['%' + t + '%' for t in tags]
        else:
            constraints.append("fields != ''")

        if constraints:
            sql += " WHERE %s" % " AND ".join(constraints)
        sql += " ORDER BY e_id"
        self.env.log.debug(sql)
        cursor.execute(sql, args)
        for row in cursor:
            id, ttags = row[0], ' '.join([f for f in row[1:-1] if f])
            event_tags = split_into_tags(ttags)
            tags = set([to_unicode(x) for x in tags])
            if (not tags or event_tags.intersection(tags)):
                yield Resource('event', id), event_tags

    def get_resource_tags(self, req, resource):
        if 'EVENTS_VIEW' not in req.perm(resource):
            return
        event = Event.fetch_one(self.env, resource.id)
        tags = self.__event_tags(event)
        return tags

    def set_resource_tags(self, req, resource, tags):
        req.perm.require('EVENTS_MODIFY', resource)
        split_into_tags = TagSystem(self.env).split_into_tags
        event = Event.fetch_one(self.env, resource.id)
        all_ = self.__event_tags(event)
        tags.difference_update(all_.difference(event.tags))
        event.tags = u' '.join(sorted(map(to_unicode, tags)))
        event.update()

    def remove_resource_tags(self, req, resource):
        req.perm.require('EVENTS_MODIFY', resource)
        event = Event.fetch_one(self.env, resource.id)
        event.tags = None
        event.update()

    # Private methods
    def __event_tags(self, rendezvous):
        return TagSystem(self.env).split_into_tags(rendezvous.tags)


class EventModule(Component):

    '''The web ui frontend for the event management system'''

    Option("event", "upcoming_name", _(u"Upcoming Events"))
    Option("event", "upcoming_desc", _(u"Hier erfährst Du direkt, was in den nächsten 6 Monaten im Chaostreff los ist."))
    Option("event", "wiki_content", _(u"Feel free to fill this outer space with content descibing the actual event.[[BR]]If the event is recurrent, describe the overall topics or similarities here and put the date dependant stuff into the wikipages you find via the links on the right side."))
    implements(IRequestHandler,
                IResourceManager,
                IWikiSyntaxProvider,
                IContentConverter,
                IPermissionRequestor,
                INavigationContributor,
                ISearchSource,
                ITemplateProvider)
    m1 = re.compile(r'^/event/(\d+)$')
    m2 = re.compile(r'^/event/edit/(\d+)$')
    m3 = re.compile(r'^/event/recurrency/(\d+)$')
    m4 = re.compile(r'^/event/by-day/(\d{4})-(\d{1,2})-(\d{1,2})$')
    m5 = re.compile(r'^/event/new/(\d{4})-(\d{1,2})-(\d{1,2})$')
    m6 = re.compile(r'^/event/createpage/(\d+)/(\d{4})-(\d{1,2})-(\d{1,2})$')

    def __init__(self, parent=None):
        from pkg_resources import resource_filename
        locale_dir = resource_filename(tracrendezvous.__name__, 'locale')
        add_domain(self.env.path, locale_dir)

    # INavigationContributor methods
    def get_active_navigation_item(self, req):
        return 'event'

    def get_navigation_items(self, req):
        if "EVENTS_VIEW" in req.perm:
            yield ('mainnav', 'event', html.A(_('Upcoming Events'), href=req.href.event("upcoming")))

    def get_permission_actions(self):
        '''returns all permissions this component provides'''
        return ['EVENTS_ADD', 'EVENTS_DELETE', 'EVENTS_MODIFY', 'EVENTS_VIEW',
            ('EVENTS_ADMIN',
                ('EVENTS_ADD', 'EVENTS_DELETE', 'EVENTS_MODIFY', 'EVENTS_VIEW'))]

    def match_request(self, req):

        self.env.log.debug("EventModule.match_request %s\n" % req)

        key = req.path_info
        simple_paths = ("/event/upcoming", '/event', "/event/new")
        if key in simple_paths:
            return True
        m = self.m1.match(key)
        if m:
            req.args["e_id"] = int(m.group(1))
            return True
        m = self.m2.match(key)
        if m:
            req.args["e_id"] = int(m.group(1))
            return True
        m = self.m3.match(key)
        if m:
            req.args["e_id"] = int(m.group(1))
            return True
        m = self.m4.match(key)
        if m:
            req.args['arg_date'] = datetime(int(m.group(1)),int(m.group(2)),int(m.group(3)), 17, tzinfo=utc)
            return True
        m = self.m5.match(key)
        if m:
            req.args['arg_date'] = datetime(int(m.group(1)),int(m.group(2)),int(m.group(3)), 17, tzinfo=utc)
            return True
        m = self.m6.match(key)
        if m:
            req.args["e_id"] = int(m.group(1))
            req.args['arg_date'] = datetime(int(m.group(2)),int(m.group(3)),int(m.group(4)), tzinfo=utc)
            return True
        return False

    # ITemplateProvider methods
    def get_templates_dirs(self):
        from pkg_resources import resource_filename
        return [resource_filename(__name__, 'templates')]

    def get_htdocs_dirs(self):
        """Return a list of directories with static resources (such as style
        sheets, images, etc.)

        Each item in the list must be a `(prefix, abspath)` tuple. The
        `prefix` part defines the path in the URL that requests to these
        resources are prefixed with.

        The `abspath` is the absolute path to the directory containing the
        resources on the local file system.
        """
        from pkg_resources import resource_filename
        return [('hw', resource_filename(__name__, 'htdocs')),
            ('parent', resource_filename(tracrendezvous.__name__, 'htdocs'))]

    def process_request(self, req):

        query = req.path_info
        if "/event/upcoming" == query:
            return self.__display_upcoming_events(req)
        elif "/event/by-day" in query:
            return self.__display_events_by_day(req)
        elif "/event/new" in query:
            return self.__process_event(req)
        elif "/event/recurrency" in query:
            return self.__process_recurrency(req)
        elif "/event/edit" in query:
            return self.__process_event(req)
        elif "/event/createpage" in query:
            return self.__create_wiki_page(req)
        elif "/event" in query:
            return self.__display_events(req)
        else:
            return self.__display_upcoming_events(req)

    # IContentConverter methods
    def get_supported_conversions(self):
        #yield ('rss', _('RSS Feed'), 'xml',
        #'tracrendezvous.Event', 'application/rss+xml', 8)
        yield ('ical', _('Ical Feed'), 'ics',
               'tracrendezvous.Event', 'text/calendar', 8)

    def convert_content(self, req, mimetype, cal, key):
        #if key == 'rss':
        #return self._export_upcoming_events_rss(req, ticket)
        if key == 'ical':
            return self.__export_upcoming_events_ical(req, cal)

    # IResourceManager methods

    def get_resource_realms(self):
        yield 'event'

    def get_resource_description(self, resource, format=None, context=None,
                                 **kwargs):
        if format == 'compact':
            return 'Event #%s' % resource.id
        from tracrendezvous.event.model import Event
        event = Event.fetch_one(self.env, resource.id)
        # TODO: really UTC?
        return "Event #%d - %s (%s UTC - %s UTC)" % (event.e_id, event.name, event.time_begin, event.time_end)

    # ISearchSource methods

    def get_search_filters(self, req):
        if 'EVENTS_VIEW' in req.perm:
            yield ('event', _('Events'))

    def get_search_results(self, req, terms, filters):
        if not 'event' in filters:
            return
        db = self.env.get_db_cnx()
        sql_query, args = search_to_sql(db, ['e1.name','e1.author'],
                                        terms)
        cursor = db.cursor()
        cursor.execute("SELECT e1.e_id, e1.name, e1.author, e1.time_modified "
                       "FROM events e1 "
                       "WHERE " + sql_query, args)

        event_realm = Resource('event')
        for e_id, name, author, ts in cursor:
            event = event_realm(id=e_id)
            yield (get_resource_url(self.env, event, req.href),
                name,
                datetime.utcfromtimestamp(ts), author,
                _("Click the link"))

    # IWikiSyntaxProvider methods
    def get_wiki_syntax(self):
        return []

    def get_link_resolvers(self):
        yield ('event', self._format_event_link)

    # private methods
    def __process_recurrency(self, req):
        req.perm.require("EVENTS_MODIFY")
        e_id = req.args["e_id"]
        add_ctxtnav(req, _('Back to') +  _('Overview'), req.href.event())
        add_ctxtnav(req, _('Back to') + _('Event') + ' #%s' % e_id, req.href.event('edit', e_id))
        add_stylesheet (req, 'hw/css/ui.all.css')
        add_stylesheet (req, 'hw/css/event.css')
        add_script (req, 'hw/scripts/jquery-ui-1.6.custom.min.js')
        if req.session.has_key("edited"):
            #add_notice(req, tag.p(_("Recurrency rule created successfully. Back to "), tag.a(_("Event"), href=req.href.event(event.e_id))))
            del req.session["edited"]
            req.session.save()
        if req.session.has_key("added"):
            #add_notice(req, tag.p(_("Recurrency rule created successfully. Back to "), tag.a(_("Event"), href=req.href.event(event.e_id))))
            del req.session["added"]
            req.session.save()
        if req.session.has_key("event_added"):
            add_notice(req, tag.p(_("Event created successfully.") + _("Back to "), tag.a(_("Event"), href=req.href.event(event.e_id))))
            del req.session["event_added"]
            req.session.save()
        if req.session.has_key("deleted"):
            #add_notice(req, tag.p(_("Recurrency rule deleted successfully. Back to "), tag.a(_("Event"), href=req.href.event(event.e_id))))
            del req.session["deleted"]
            req.session.save()

        session_tzname, selected_tz = get_tz(req.session.get('tz', self.env.config.get("trac", "default_timezone") or None))

        event = Event.fetch_one(self.env, e_id)
        if not event:
            raise TracError(_("Event not found"))
        try:
            period = EventRRule.fetch_by_event(self.env, e_id)[0]
            exists = True
        except IndexError:
            period = EventRRule(self.env, e_id=event.e_id)
            exists = False
        freq = 0
        if req.method == "POST":
            if req.args.has_key("save"):
                is_valid = True
                is_periodic = req.args.has_key("is_periodic")
                if event.is_periodic and not is_periodic:
                    EventRRule.delete(self.env, event.e_id)
                    EventRDate.delete(self.env, event.e_id)
                    event.is_periodic = False
                    event.update()
                    req.redirect(req.href.event("recurrency", event.e_id))
                elif not event.is_periodic and is_periodic:
                    event.is_periodic = True
                    event.update()
                def get_bymonth(req, name, period):
                    try:
                        period.bymonth = int(req.args[name])
                        if not (0 <= period.bymonth < 12):
                            raise Exception()
                    except Exception:
                        add_warning(req, _("Wrong Value for 'month'."))
                        raise
                def get_bymonthday(req, name, period):
                    try:
                        period.bymonthday = int(req.args[name])
                        if not (-33 <= period.bymonthday < 32):
                            raise Exception()
                    except Exception, e:
                        add_warning(req, _("Wrong Value for 'monthday'."))
                        raise
                def get_byweekday(req, name, period):
                    try:
                        period.byweekday = set((int(req.args[name]),))
                        if filter(lambda x: not (0 <= x < 7), period.byweekday):
                            raise Exception()
                    except Exception, e:
                        add_warning(req, _("Wrong Value for 'weekday'."))
                        raise
                def get_byweekdayocc(req, name, period):
                    byweekdayocc = req.args[name]
                    if byweekdayocc:
                        try:
                            period.byweekdayocc = int(byweekdayocc)
                        except Exception, e:
                            add_warning(req, _("Wrong Value for 'weekday occurence'."))
                            raise
                    else:
                        period.byweekdayocc = None
                def get_interval(req, name, period):
                    try:
                        period.interval = int(req.args[name])
                        if not (0 <= period.interval < 1000):
                            raise Exception()
                    except Exception, e:
                        add_warning(req, _("Wrong Value for interval"))
                        raise

                # std parameters
                count = req.args["count"]
                if count:
                    try:
                        period.count = int(count)
                    except Exception, e:
                        is_valid = False
                        add_warning(req, _("Wrong Value for count"))
                else:
                    period.count = None
                until_date = req.args["until_date"]
                if until_date:
                    try:
                        until = date_parse(until_date)
                        period.until = datetime.combine(until, time(12,tzinfo=utc))
                    except Exception, e:
                        add_warning(req, _("Wrong Value for until_date or until_time"))
                        raise
                else:
                    period.until = None

                # selective parameters
                try:
                    freq = int(req.args["freq"])
                except KeyError:
                    add_warning(req, _("Please select one of the recurrency types"))
                    is_valid = False
                if freq == 0:
                    period.freq = rrule.YEARLY
                    period.byweekday = list()
                    period.byweekdayocc = None
                    period.byyearday = None
                    try:
                        get_interval(req, "yearinterval", period)
                        get_bymonthday(req, "monthday-yearly-0", period)
                        get_bymonth(req, "monthname-yearly-0", period)
                    except Exception:
                        is_valid = False
                elif freq == 1:
                    period.freq = rrule.YEARLY
                    get_interval(req, "yearinterval", period)
                    period.bymonthday = None
                    period.byyearday = None
                    try:
                        get_byweekdayocc(req, "dayocc-yearly-1", period)
                        get_byweekday(req, "weekday-yearly-1", period)
                        get_bymonth(req, "monthname-yearly-1", period)
                    except Exception:
                        is_valid = False
                elif freq == 2:
                    period.freq = rrule.YEARLY
                    try:
                        get_interval(req, "yearinterval", period)
                    except Exception:
                        is_valid = False
                    period.bymonthday = None
                    period.bymonth = None
                    period.byweekday = list()
                    period.byweekdayocc = None
                    try:
                        period.byyearday = int(req.args["yearday"])
                        if not (0 <= period.byyearday < 366):
                          raise Exception()
                    except Exception, e:
                        add_warning(req, _("Wrong Value for 'weekday'."))
                        is_valid = False
                elif freq == 3:
                    period.freq = rrule.MONTHLY
                    try:
                        get_interval(req, "monthinterval", period)
                        get_bymonthday(req, "monthday-monthly-0", period)
                    except Exception:
                        is_valid = False
                    period.byweekday = None
                    period.byweekdayocc = None
                    period.byyearday = None
                    period.bymonth = None
                elif freq == 4:
                    period.freq = rrule.MONTHLY
                    period.byyearday = None
                    period.bymonth = None
                    period.bymonthday = None
                    try:
                        get_interval(req, "monthinterval", period)
                        get_byweekdayocc(req, "dayocc-monthly-1", period)
                        get_byweekday(req, "weekday-monthly-1", period)
                    except Exception:
                        is_valid = False
                elif freq == 5:
                    period.freq = rrule.WEEKLY
                    try:
                        get_interval(req, "weekinterval", period)
                    except Exception:
                        is_valid = False
                    period.byweekday = list()
                    period.byweekdayocc = None
                    period.byyearday = None
                    period.bymonth = None
                    period.bymonthday = None
                    try:
                        weekdays = set(map(int, req.args["weekday-weekly"]))
                        if any(map(lambda x: not (0 <= x < 7), weekdays)):
                            is_valid = False
                        if weekdays != period.byweekday:
                            period.byweekday = weekdays
                    except KeyError:
                        add_warning(req, _("Any days selected."))
                        is_valid = False
                elif freq == 6:
                    period.freq = rrule.DAILY
                    try:
                        get_interval(req, "dayinterval", period)
                    except Exception:
                        is_valid = False
                    period.byweekday = None
                    period.byweekdayocc = None
                    period.byyearday = None
                    period.bymonth = None
                    period.bymonthday = None
                if is_valid:
                    if exists:
                        period.update()
                    else:
                        period.commit()
                    req.redirect(req.href.event("recurrency", e_id))
            elif req.args.has_key("exception-add"):
                try:
                    exception = datetime_parse("%s 12:00" % req.args["exception-name"], selected_tz)
                    exception = exception.replace(hour=event.time_begin.hour, minute=event.time_begin.minute)
                except ValueError:
                    add_warning(req, _("Wrong recurrency exception date format"))
                    req.redirect(req.href.event("recurrency", e_id))
                rdate = EventRDate(self.env, 0, event.e_id, True, exception)
                rdate.commit()
                req.session["added"] = True
                req.redirect(req.href.event("recurrency", e_id))
            elif req.args.has_key("exception-edit"):
                for k in req.args.iterkeys():
                    try:
                        marker, erd_id  = k.split(":", 1)
                    except Exception,e:
                        continue
                    try:
                        erd_id = int(erd_id)
                        validate_id(erd_id)
                    except ValueError,e:
                        continue
                    if marker != "exception":
                        continue
                    rdate = EventRDate.fetch_one(self.env, erd_id)
                    try:
                        exception = datetime_parse("%s 12:00" % req.args["exception-name"], selected_tz)
                        exception = exception.replace(hour=event.time_begin.hour, minute=event.time_begin.minute)
                    except KeyError:
                        add_warning(req, _("You have to specify a valid recurrency exception date for that operation!"))
                        req.redirect(req.href.event("recurrency", e_id))
                    if exception:
                        rdate.erd_datetime = exception
                        rdate.update()
                        req.session["edited"] = True
                        req.redirect(req.href.event("recurrency", e_id))
                req.redirect(req.href.event("recurrency", e_id))
            elif req.args.has_key("exception-delete"):
                for k in req.args.iterkeys():
                    try:
                        marker, erd_id  = k.split(":", 1)
                    except Exception,e:
                        continue
                    try:
                        erd_id = int(erd_id)
                        validate_id(erd_id)
                    except ValueError,e:
                        continue
                    if marker != "exception":
                        continue
                    EventRDate.delete(self.env, erd_id)
                    req.session["deleted"] = True
                req.redirect(req.href.event("recurrency", e_id))
        else:
            if period.bymonthday!=None and period.bymonth!=None:
                freq = 0
            elif period.byweekday and period.bymonth!=None:
                freq = 1
            elif period.byyearday!=None:
                freq = 2
            elif period.bymonthday!=None:
                freq = 3
            elif period.byweekdayocc!=None and period.byweekday:
                freq = 4
            elif period.freq == rrule.WEEKLY:
                freq = 5
            elif period.freq == rrule.DAILY:
                freq = 6
        exceptions = EventRDate.fetch_by_event(self.env, event.e_id)
        return "recur_edit.html", {
            "event" : event,
            "freq" : freq,
            "period" : period,
            "session_tzname" : session_tzname,
            "selected_tz" : selected_tz,
            "exceptions" : exceptions,
            "default_location" : self.config.getint("location", "default_location"),
            "locations" : ItemLocation.fetch_all(self.env),
            "month_names" : EventRRule.month_names,
            "day_names" : EventRRule.day_names,
            "weekday_names" : EventRRule.weekday_names,
            "monthday_names" : EventRRule.monthday_names}, None

    def __process_event(self, req):
        '''process add, change and delete rendezvous'''
        if 'EVENTS_ADD' not in req.perm and 'EVENTS_MODIFY' not in req.perm and 'EVENTS_DELETE' not in req.perm:
            raise PermissionError()
        add_stylesheet (req, 'hw/css/event.css')
        add_stylesheet (req, 'hw/css/ui.all.css')
        add_script (req, 'hw/scripts/jquery-ui-1.6.custom.min.js')
        # set information after redirects
        if req.session.has_key("edited"):
            add_notice(req, tag.p(_("Event edited successfully. Back to "), tag.a(_("Overview"), href=req.href.event())))
            del req.session["edited"]
            req.session.save()
        if req.session.has_key("added"):
            add_notice(req, tag.p(_("Event created successfully. Back to "), tag.a(_("Overview"), href=req.href.event())))
            del req.session["added"]
            req.session.save()
        if req.session.has_key("deleted"):
            add_notice(req, tag.p(_("Event deleted successfully. Back to "), tag.a(_("Overview"), href=req.href.event())))
            del req.session["deleted"]
            req.session.save()
        myenv = self.env
        date_now = utc.localize(datetime.utcnow())
        session_tzname, selected_tz = get_tz(req.session.get('tz', self.config.get("trac", "default_timezone") or None))

        if req.args.has_key("e_id"):
            event = Event.fetch_one(myenv, req.args["e_id"])
            if not event:
                raise TracError(_("Event not found"))
            add_ctxtnav(req, _('Events Overview'), req.href.event())
            add_ctxtnav(req, _('Upcoming Events'), req.href.event("upcoming"))
            add_ctxtnav(req, _('Add New Event'), req.href.event("new"))
        else:
            try:
                pi = req.path_info
                crap, new_date = pi.split("new/", 1)
                year, month, day = re.match("(\d{4})-(\d{1,2})-(\d{1,2})", new_date).groups()
                new_date = utc.localize(datetime(int(year), int(month), int(day), 17, tzinfo=selected_tz))
            except ValueError:
                new_date = date_now
            event = Event(myenv, 0, "", req.authname, date_now, date_now, new_date, selected_tz.normalize(new_date + timedelta(0, 10800)), 1)
            add_ctxtnav(req, _('Events Overview'), req.href.event())
            add_ctxtnav(req, _('Upcoming Events'), req.href.event("upcoming"))

        if req.method == "POST":
            if req.args.has_key("delete"):
                req.perm.require("EVENTS_DELETE")
                EventRRule.delete(myenv, event.e_id)
                EventRDate.delete(myenv, event.e_id)
                Event.delete(myenv, event.e_id)
                db = myenv.get_db_cnx()
                cursor = db.cursor()
                # TODO: that is hackish. find out how to use trac arg formatting
                # of "select * from foo where bar like 'baz%';"
                like = "delete from wiki where name like 'events/%s/%%'" % int(event.e_id)
                cursor.execute(like)
                db.commit()
                req.session["deleted"] = True
                req.redirect(req.href.event("new"))

            is_valid = True
            event.name = req.args.get("name", None)
            try:
                event.old_time_begin = event.time_begin
                event.time_begin = datetime_parse("%s %s" % (req.args["date_begin"], req.args["time_begin"]), selected_tz)
                print "time_begin", event.time_begin, req.args["time_begin"]
            except Exception:
                add_warning(req, _("Wrong format in 'Date begin'."))
                is_valid = False
            try:
                event.old_time_end = event.time_end
                event.time_end = datetime_parse("%s %s" % (req.args["date_end"], req.args["time_end"]), selected_tz)
                print "time_end", event.time_end, req.args["time_end"]
            except Exception, e:
                add_warning(req, _("Wrong format in 'Date end'."))
                is_valid = False
            try:
                event.location_id = int(req.args["location_id"])
                location = ItemLocation.fetch_one(myenv, event.location_id)
            except Exception, e:
                add_warning(req, _("Could not find location"))
                is_valid = False
            tags = req.args.get("tags", None)
            if tags:
                event.tags = sub("[,;.:]", " ", tags)
            attendees = req.args.get("attendees", None)
            if attendees:
                attendees = sub("[,;.:]", " ", attendees)

            if is_valid:
                if not req.args.has_key("e_id"):
                    req.perm.require("EVENTS_ADD")
                    try:
                        self.__validate_event(event)
                        event.commit()
                    except Exception, e:
                        add_warning(req, str(e))
                        raise
                    event.wikipage = "events/%d" % event.e_id
                    event.update()
                    wikicontent = u" = %s =\n[[EventHeader(%d)]]\n\n%s" % (event.name, event.e_id, self.config.get("event", "wiki_content"))
                    try:
                        gen_wiki_page(myenv, req.authname, event.wikipage, wikicontent, req.remote_addr)
                    except IntegrityError, e:
                        add_warning(req, _("Wikipage already exists."))
                    if req.args.has_key("show_recurrency"):
                        req.redirect(req.href.event("recurrency", event.e_id))
                        req.session["event_added"] = True
                        req.session.save()
                    if req.args.has_key("show_recurrency"):
                        req.session["added"] = True
                        req.session.save()
                    req.redirect(req.href.event("edit", event.e_id))
                else:
                    req.perm.require("EVENTS_MODIFY")
                    try:
                        self.__validate_event(event)
                    except Exception, e:
                        add_warning(req, str(e))
                        raise
                    else:
                        event.time_modified = utc.localize(datetime.utcnow())
                        event.update()
                        req.session["edited"] = True
                        req.session.save()
                    req.redirect(req.href.event("edit", event.e_id))


        return "event_edit.html", {"event" : event,
            "session_tzname" : session_tzname,
            "selected_tz" : selected_tz,
            "default_location" : self.config.getint("location", "default_location"),
            "locations" : ItemLocation.fetch_all(myenv)}, None

    def __display_events(self, req):
        '''process add,change,delete actions'''
        add_stylesheet (req, 'hw/css/event.css')
        if "EVENTS_ADD" in req.perm:
            add_ctxtnav(req, _('Add New Event'), req.href.event("new"))
        add_ctxtnav(req, _('Upcoming Events'), req.href.event("upcoming"))
        if req.args.has_key("e_id"):
            events = [Event.fetch_one(self.env, req.args["e_id"], show_next=True)]
            title = _("Event Details")
        else:
            events = Event.fetch_all_with_rrule(self.env)
            events = sorted(events, key=attrgetter("time_begin"))
            title = _("Event Overview")
        session_tzname, selected_tz = get_tz(req.session.get('tz', self.env.config.get("trac", "default_timezone") or None))
        return "event_list.html", {"events" : events, "title" : title, "session_tzname" : session_tzname, "selected_tz" : selected_tz}, None

    def __display_upcoming_events(self, req):
        if req.args.get("format") == 'ical':
            events = Event.fetch_as_ical(self.env)
            Mimeview(self.env).send_converted(req, 'tracrendezvous.Event', events, "ical", _("CTDO: Upcoming Events"))

        add_stylesheet (req, 'hw/css/event.css')
        if req.locale is not None:
            add_script(req, 'parent/tracrendezvous/%s.js' % req.locale)
        if "EVENTS_ADD" in req.perm:
            add_ctxtnav(req, _('Add New Event'), req.href.event("new"))
        add_ctxtnav(req, _('Events Overview'), req.href.event())
        for conversion in Mimeview(self.env).get_supported_conversions("tracrendezvous.Event"):
            conversion_href = req.href.event("upcoming", format=conversion[0])
            add_link(req, 'alternate', conversion_href, conversion[1], conversion[3], conversion[0])
        session_tzname, selected_tz = get_tz(req.session.get('tz', self.env.config.get("trac", "default_timezone") or None))

        n = datetime.now(utc)
        n = n.replace(hour=0, minute=0, second=0, microsecond=0)
        end = n + timedelta(183)
        end = end.replace(hour=23, minute=0, second=59, microsecond=999)
        table, headers = self.__get_upcoming_table(n, end)

        return "events.html", {"table" : table, "headers" : headers, "session_tzname" : session_tzname, "format" : "%a, %d.%m.%Y", "selected_tz" : selected_tz, "title" : _("Upcoming Events for"),  "title2" : "%s - %s" % (n.strftime('%A, %d.%m.%Y %H:%M'), end.strftime('%A, %d.%m.%Y %H:%M')), "now" : n, "end" : end}, None

    def __display_events_by_day(self, req):
        add_stylesheet (req, 'hw/css/event.css')
        add_ctxtnav(req, _('Back to Upcoming Events'), req.href.event("upcoming"))
        session_tzname, selected_tz = get_tz(req.session.get('tz', self.env.config.get("trac", "default_timezone") or None))
        # do datetime calc only in utc !!!
        n = title = req.args["arg_date"]
        n = datetime(n.year, n.month, n.day, tzinfo=utc)
        #n = local_to_utc(n, selected_tz)
        e = n + timedelta(1)
        if "EVENTS_ADD" in req.perm:
            add_ctxtnav(req, _('Add New Event'), req.href.event("new", title.strftime("%Y-%m-%d")))
        table, headers = self.__get_day_table(n, e)
        return "event_details.html", {"table" : table, "headers" : headers, "format" : "%H:%M", "session_tzname" : session_tzname, "selected_tz" : selected_tz, "title" : _("Details of %s") % (title.strftime('%A, %d.%m.%Y'),), "now" : n, "end" : e}, None

    def __export_upcoming_events_rss(self, req, foo):
        now = datetime.now(utc)
        now.replace(hour=0,second=0,microsecond=0)
        end = now + timedelta(183)
        end.replace(hour=23,second=59,microsecond=999)
        events = Event.fetch_all(self.env)
        data = {"events" : sorted(events, key=attrgetter("time_begin")), "today" : datetime.now(utc)}
        output = Chrome(self.env).render_template(req, 'upcoming_events.rss', data,
                                                  'application/rss+xml')
        return output, 'application/rss+xml'

    def __export_upcoming_events_ical(self, req, events):
        data = {"stamp" : datetime.now(utc).strftime("%Y%m%dT%H%M%SZ"),
            "events" : sorted(events, key=attrgetter("time_begin")),
            "today" : datetime.now(utc),
            "calname" : self.env.config.get("events", "upcoming_name"),
            "caldesc" : self.env.config.get("events", "upcoming_desc")}
        ch = Chrome(self.env)
        ds = ch.get_all_templates_dirs()
        data = ch.populate_data(req, data)
        templates = TemplateLoader(ds, auto_reload=self.env.config.getbool('trac', 'auto_reload'), variable_lookup='lenient')
        template = templates.load("ical.txt", cls=NewTextTemplate)
        try:
            stream = template.generate(**data)
            output = stream.render()
            return output, 'text/calendar'
        except Exception, e:
            # give some hints when hitting a Genshi unicode error
            if isinstance(e, UnicodeError):
                pos = self._stream_location(stream)
                if pos:
                    location = "'%s', line %s, char %s" % pos
                else:
                    location = _("(unknown template location)")
                raise TracError(_("Genshi %(error)s error while rendering "
                                  "template %(location)s",
                                  error=e.__class__.__name__,
                                  location=location))
            raise

    def __validate_event(self, event):
        if not event.name:
            raise TypeError(_("EventValidationError: Title is empty"))
        if event.time_end <= event.time_begin:
            raise TypeError(_("EventValidationError: end time before or equal begin time"))

    def __get_upcoming_table(self, timerange_begin, timerange_end):
        # ongoing events goes in here referenced by column index
        res = Event.fetch_by_period_dict(self.env, timerange_begin, timerange_end)
        ongoing = {} # column index -> event
        table = []
        timerange_begin = timerange_begin.date()
        timerange_end = timerange_end.date()
        dt = timedelta(1)
        column_count = 0
        def get_next(d):
            count = 1
            while 1:
                if not d.has_key(count):
                    return count
                count += 1
        while timerange_begin < timerange_end:
            row = {0 : timerange_begin}
            done = []
            for key,event in ongoing.iteritems():
                if event.time_end.date() < timerange_begin:
                    done.append(key)
            for i in done:
                del ongoing[i]
            for key in ongoing.iterkeys():
                row[key] = False
            events = res[timerange_begin]
            for event in events:
                dt2 = event.time_end - event.time_begin
                dt2_days = dt2.days + 1
                if dt2.seconds > 43200:
                    dt2_days += 1
                slot = get_next(ongoing)
                event.rowspan = dt2_days
                ongoing[slot] = event
                row[slot] = [event,]
            column_count = max(column_count, len(ongoing))
            table.append(row)
            timerange_begin += dt
        table2 = []
        mbase = [True for x in xrange(column_count+1)]
        for row in table:
            myrow = mbase[:]
            for key,value in row.iteritems():
                myrow[key] = value
            table2.append(myrow)
        mbase = ["" for x in xrange(column_count+1)]
        mbase[0] = _("date")
        return table2, mbase

    def __create_wiki_page(self, req):
        '''Programatically create a new wiki page tailored to a given occurence of an event
         - one date of a recurrence set.
        '''

        req.perm.require("WIKI_CREATE")
        dt = req.args["arg_date"]
        e_id = req.args["e_id"]
        wikipage = "events/%d/%s" % (e_id, dt.strftime("%Y-%m-%d"))
        event = Event.fetch_one(self.env, e_id)
        wikicontent = u" = %s =\n[[EventHeader(%d)]]\n\n%s" % (event.name, event.e_id, self.env.config.get("event", "wiki_content", ""))
        try:
            gen_wiki_page(self.env, req.authname, wikipage, wikicontent, req.remote_addr)
        except IntegrityError, e:
            pass
        req.redirect(req.href.wiki(wikipage))

    def __get_day_table(self, timerange_begin, timerange_end, dt=timedelta(0, 1800)):
        ''' Calculates and arranges events during a day period which can be defined
        by start datetime 'timerange_begin' and end datetime 'timerange_end'.
        The resolution of the "table" prepared for html or other UIs can be
        controlled by timedelta 'dt'.
        The first column contains the time slots, additional columns contain
        destinct locations.
        It returns a row list of cells.'''

        class UList(list):
            def ___init__(self):
                list.__init__(self)
                self.rowspan = None
        events = Event.fetch_by_period_list(self.env, timerange_begin, timerange_end)
        if not events:
            return None, None
        timerange_begin = min(events, key=lambda x:x.time_begin).time_begin
        timerange_end = max(events, key=lambda x:x.time_end).time_end

        # now we calcutate the value of previous "slot" beginning as datetime to beautify
        # the slot time beginnings. Try to uncomment the next few lines and reload to see
        # what happens to the table without;-)
        dts = dt.days * 86400 + dt.seconds
        tbs = ((timerange_begin.hour*3600+timerange_begin.minute*60)/dts)*dts
        minutes, seconds = divmod(tbs, 60)
        hours, minutes = divmod(minutes, 60)
        timerange_begin = timerange_begin.replace(hour=hours, minute=minutes)
        #timerange_end += dt # we want one slot after the last event ends

        column_count = 1 # column 0 is always timerange_begin
        locmap = dict() # location_id -> column index
        ongoing = dict() # column index of actual used column -> eventlist
        locs = dict() # column index -> location name
        slotcount = 0
        table = []
        done = []
        while timerange_begin < timerange_end:
            row = {0 : timerange_begin}
            for k,e in done:
                events.remove(e)
            done = []
            slot_end = timerange_begin + dt
            for event in events:
                if event.time_begin >= timerange_begin and event.time_begin < slot_end:
                    if not locmap.has_key(event.location_id):
                        index = column_count
                        column_count += 1
                        locmap[event.location_id] = index
                        locs[event.location_id] = event.location.name
                    else:
                        index = locmap[event.location_id]
                    if not hasattr(event, "rowspan_begin"):
                        # event starts in that timeslot
                        event.rowspan_begin = slotcount
                        if not row.has_key(index):
                            row[index] = UList()
                        if ongoing.has_key(index):
                            ongoing[index][0]+=1
                            refc, event_list = ongoing[index]
                        else:
                            event_list = row[index]
                            ongoing[index] = [1, event_list]
                        event_list.append(event)
                if event.time_end <= slot_end:
                    # event ends
                    index = locmap[event.location_id]
                    done.append((locmap[event.location_id], event))
                    event.rowspan_end = slotcount+1
                    refc, el = ongoing[index]
                    if refc<=1:
                        del ongoing[index]
                    else:
                        refc-=1
                        ongoing[index] = [refc, el]
                if hasattr(event, "rowspan_begin") and event.time_begin < timerange_begin and event.time_end > timerange_begin:
                    # marking cell as occupied due to longer lasting event than time slot length
                    index = locmap[event.location_id]
                    row[index] = False
            table.append(row)
            timerange_begin += dt
            slotcount += 1
        final_table = []
        header = [True for x in xrange(column_count)]
        for row in table:
            trow = header[:]
            for index, item in row.iteritems():
                trow[index] = item
                if item and isinstance(item, UList):
                    rowspan_begin = min(item, key=lambda x:x.rowspan_begin).rowspan_begin
                    rowspan_end = max(item, key=lambda x:x.rowspan_end).rowspan_end
                    item.rowspan = rowspan_end - rowspan_begin
            final_table.append(trow)
        for location_id, index in locmap.iteritems():
            header[index] = locs[location_id]
        header[0] = _("Start")
        return final_table, header

    def _format_event_link(self, formatter, ns, target, label, fullmatch=None):
        link, params, fragment = formatter.split_link(target)
        r = Ranges(link)
        if len(r) == 1:
            num = r.a
            validate_id(num)
            cursor = formatter.db.cursor()
            cursor.execute("SELECT name,time_begin,time_end "
                            "FROM events WHERE e_id=%s", (num,))
            session_tzname, selected_tz = get_tz(formatter.req.session.get("tz", self.env.config.get("trac", "default_timezone") or None))
            for name, time_begin, time_end in cursor:
                time_begin = utc.localize(datetime.utcfromtimestamp(time_begin)).astimezone(selected_tz)
                time_end = utc.localize(datetime.datetime.utcfromtimestamp(time_end)).astimezone(selected_tz)
                title = "%s (%s - %s %s)" % (name,
                    time_begin.strftime('%d.%m.%Y %H:%M'),
                    time_end.strftime('%d.%m.%Y %H:%M'), time_begin.tzinfo.tzname(None))
                if label == link:
                    label = title
                href = formatter.href.event(num)
                return tag.a(label, title=title, href=href)
        return tag.a(label, class_='missing event')