1 #!/usr/bin/env python 2 3 """ 4 Handlers for a resource. 5 6 Copyright (C) 2014, 2015 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free Software 10 Foundation; either version 3 of the License, or (at your option) any later 11 version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 details. 17 18 You should have received a copy of the GNU General Public License along with 19 this program. If not, see <http://www.gnu.org/licenses/>. 20 """ 21 22 from imiptools.data import get_address, to_part 23 from imiptools.dates import ValidityError 24 from imiptools.handlers import Handler 25 from imiptools.handlers.common import CommonFreebusy, CommonEvent 26 27 class ResourceHandler(CommonEvent, Handler): 28 29 "Handling mechanisms specific to resources." 30 31 def _record_and_respond(self, handle_for_attendee): 32 33 """ 34 Record details from the incoming message, using the given 35 'handle_for_attendee' callable to process any valid message 36 appropriately. 37 """ 38 39 oa = self.require_organiser_and_attendees() 40 if not oa: 41 return None 42 43 organiser_item, attendees = oa 44 45 # Process for the current user, a resource as attendee. 46 47 if not self.have_new_object() or not self.is_attendee(self.user): 48 return None 49 50 # Collect response objects produced when handling the request. 51 52 handle_for_attendee() 53 54 def _add_for_attendee(self): 55 56 """ 57 Attempt to add a recurrence to an existing object for the current user. 58 This does not request a response concerning participation, apparently. 59 """ 60 61 # Ignore unknown objects. 62 # NOTE: We could issue a REFRESH to get such objects. 63 64 if not self.get_stored_object_version(): 65 return 66 67 # Record the event as a recurrence of the parent object. 68 69 self.update_recurrenceid() 70 event = self.obj.to_node() 71 self.store.set_event(self.user, self.uid, self.recurrenceid, event) 72 73 # Update free/busy information. 74 75 self.update_event_in_freebusy(for_organiser=False) 76 77 def _schedule_for_attendee(self): 78 79 "Attempt to schedule the current object for the current user." 80 81 method = "REPLY" 82 attendee_attr = self.obj.get_value_map("ATTENDEE")[self.user] 83 84 # Check any constraints on the request. 85 86 try: 87 corrected = self.correct_object() 88 89 # Refuse to schedule obviously invalid requests. 90 91 except ValidityError: 92 attendee_attr = self.update_participation(self.obj, "DECLINED") 93 94 # With a valid request, determine whether the event can be scheduled. 95 96 else: 97 # Interpretation of periods can depend on the time zone. 98 99 tzid = self.get_tzid() 100 101 # If newer than any old version, discard old details from the 102 # free/busy record and check for suitability. 103 104 periods = self.obj.get_periods(tzid, self.get_window_end()) 105 106 freebusy = self.store.get_freebusy(self.user) 107 offers = self.store.get_freebusy_offers(self.user) 108 109 # Check the periods against any scheduled events and against 110 # any outstanding offers. 111 112 scheduled = self.can_schedule(freebusy, periods) 113 scheduled = scheduled and self.can_schedule(offers, periods) 114 115 # Where the corrected object can be scheduled, issue a counter 116 # request. 117 118 if scheduled and corrected: 119 method = "COUNTER" 120 121 # Find the next available slot if the event cannot be scheduled. 122 123 #elif not scheduled and len(periods) == 1: 124 125 # # Find a free period, update the object with the details. 126 127 # duration = periods[0].get_duration() 128 # free = invert_freebusy(freebusy) 129 130 # for found in periods_from(free, periods[0]): 131 # # NOTE: Correct the found period first. 132 # if found.get_duration() >= duration 133 # scheduled = True 134 # method = "COUNTER" 135 # # NOTE: Set the period using the original duration. 136 # break 137 138 # Update the participation of the resource in the object. 139 140 attendee_attr = self.update_participation(self.obj, 141 scheduled and "ACCEPTED" or "DECLINED") 142 143 # Update free/busy information. 144 145 if method == "REPLY": 146 self.update_event_in_freebusy(for_organiser=False) 147 self.remove_event_from_freebusy_offers() 148 149 # For countered proposals, record the offer in the resource's 150 # free/busy collection. 151 152 elif method == "COUNTER": 153 self.update_event_in_freebusy_offers() 154 155 # Set the complete event or an additional occurrence. 156 157 if method == "REPLY": 158 event = self.obj.to_node() 159 self.store.set_event(self.user, self.uid, self.recurrenceid, event) 160 161 # Remove additional recurrences if handling a complete event. 162 163 if not self.recurrenceid: 164 self.store.remove_recurrences(self.user, self.uid) 165 166 # Make a version of the object with just this attendee, update the 167 # DTSTAMP in the response, and return the object for sending. 168 169 self.obj["ATTENDEE"] = [(self.user, attendee_attr)] 170 self.update_dtstamp() 171 self.add_result(method, map(get_address, self.obj.get_values("ORGANIZER")), to_part(method, [self.obj.to_node()])) 172 173 def _cancel_for_attendee(self): 174 175 """ 176 Cancel for the current user their attendance of the event described by 177 the current object. 178 """ 179 180 # Update free/busy information. 181 182 self.remove_event_from_freebusy() 183 184 # Update the stored event and cancel it. 185 186 self.store.set_event(self.user, self.uid, self.recurrenceid, self.obj.to_node()) 187 self.store.cancel_event(self.user, self.uid, self.recurrenceid) 188 189 def _revoke_for_attendee(self): 190 191 "Revoke any counter-proposal recorded as a free/busy offer." 192 193 self.remove_event_from_freebusy_offers() 194 195 class Event(ResourceHandler): 196 197 "An event handler." 198 199 def add(self): 200 201 "Add a new occurrence to an existing event." 202 203 self._record_and_respond(self._add_for_attendee) 204 205 def cancel(self): 206 207 "Cancel attendance for attendees." 208 209 self._record_and_respond(self._cancel_for_attendee) 210 211 def counter(self): 212 213 "Since this handler does not send requests, it will not handle replies." 214 215 pass 216 217 def declinecounter(self): 218 219 "Revoke any counter-proposal." 220 221 self._record_and_respond(self._revoke_for_attendee) 222 223 def publish(self): 224 225 """ 226 Resources only consider events sent as requests, not generally published 227 events. 228 """ 229 230 pass 231 232 def refresh(self): 233 234 """ 235 Refresh messages are typically sent to event organisers, but resources 236 do not act as organisers themselves. 237 """ 238 239 pass 240 241 def reply(self): 242 243 "Since this handler does not send requests, it will not handle replies." 244 245 pass 246 247 def request(self): 248 249 """ 250 Respond to a request by preparing a reply containing accept/decline 251 information for the recipient. 252 253 No support for countering requests is implemented. 254 """ 255 256 self._record_and_respond(self._schedule_for_attendee) 257 258 class Freebusy(CommonFreebusy, Handler): 259 260 "A free/busy handler." 261 262 def publish(self): 263 264 "Resources ignore generally published free/busy information." 265 266 pass 267 268 def reply(self): 269 270 "Since this handler does not send requests, it will not handle replies." 271 272 pass 273 274 # request provided by CommonFreeBusy.request 275 276 # Handler registry. 277 278 handlers = [ 279 ("VFREEBUSY", Freebusy), 280 ("VEVENT", Event), 281 ] 282 283 # vim: tabstop=4 expandtab shiftwidth=4