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(Handler, CommonEvent): 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_for_update(self.user) 107 try: 108 offers = self.store.get_freebusy_offers(self.user) 109 110 # Check the periods against any scheduled events and against 111 # any outstanding offers. 112 113 scheduled = self.can_schedule(freebusy, periods) 114 scheduled = scheduled and self.can_schedule(offers, periods) 115 116 # Where the corrected object can be scheduled, issue a counter 117 # request. 118 119 if scheduled and corrected: 120 method = "COUNTER" 121 122 # Find the next available slot if the event cannot be scheduled. 123 124 #elif not scheduled and len(periods) == 1: 125 126 # # Find a free period, update the object with the details. 127 128 # duration = periods[0].get_duration() 129 # free = invert_freebusy(freebusy) 130 131 # for found in periods_from(free, periods[0]): 132 # # NOTE: Correct the found period first. 133 # if found.get_duration() >= duration 134 # scheduled = True 135 # method = "COUNTER" 136 # # NOTE: Set the period using the original duration. 137 # break 138 139 # Update the participation of the resource in the object. 140 141 attendee_attr = self.update_participation(self.obj, 142 scheduled and "ACCEPTED" or "DECLINED") 143 144 # Update free/busy information. 145 146 if method == "REPLY": 147 self.update_event_in_freebusy(for_organiser=False) 148 self.remove_event_from_freebusy_offers() 149 150 # For countered proposals, record the offer in the resource's 151 # free/busy collection. 152 153 elif method == "COUNTER": 154 self.update_event_in_freebusy_offers() 155 156 finally: 157 self.store.release_freebusy(self.user) 158 159 # Set the complete event or an additional occurrence. 160 161 event = self.obj.to_node() 162 self.store.set_event(self.user, self.uid, self.recurrenceid, event) 163 164 # Remove additional recurrences if handling a complete event. 165 166 if not self.recurrenceid: 167 self.store.remove_recurrences(self.user, self.uid) 168 169 # Make a version of the object with just this attendee, update the 170 # DTSTAMP in the response, and return the object for sending. 171 172 self.obj["ATTENDEE"] = [(self.user, attendee_attr)] 173 self.update_dtstamp() 174 self.add_result(method, map(get_address, self.obj.get_values("ORGANIZER")), to_part(method, [self.obj.to_node()])) 175 176 def _cancel_for_attendee(self): 177 178 """ 179 Cancel for the current user their attendance of the event described by 180 the current object. 181 """ 182 183 # Update free/busy information. 184 185 self.remove_event_from_freebusy() 186 187 # Update the stored event and cancel it. 188 189 self.store.set_event(self.user, self.uid, self.recurrenceid, self.obj.to_node()) 190 self.store.cancel_event(self.user, self.uid, self.recurrenceid) 191 192 def _revoke_for_attendee(self): 193 194 "Revoke any counter-proposal recorded as a free/busy offer." 195 196 self.remove_event_from_freebusy_offers() 197 198 class Event(ResourceHandler): 199 200 "An event handler." 201 202 def add(self): 203 204 "Add a new occurrence to an existing event." 205 206 self._record_and_respond(self._add_for_attendee) 207 208 def cancel(self): 209 210 "Cancel attendance for attendees." 211 212 self._record_and_respond(self._cancel_for_attendee) 213 214 def counter(self): 215 216 "Since this handler does not send requests, it will not handle replies." 217 218 pass 219 220 def declinecounter(self): 221 222 "Revoke any counter-proposal." 223 224 self._record_and_respond(self._revoke_for_attendee) 225 226 def publish(self): 227 228 """ 229 Resources only consider events sent as requests, not generally published 230 events. 231 """ 232 233 pass 234 235 def refresh(self): 236 237 """ 238 Refresh messages are typically sent to event organisers, but resources 239 do not act as organisers themselves. 240 """ 241 242 pass 243 244 def reply(self): 245 246 "Since this handler does not send requests, it will not handle replies." 247 248 pass 249 250 def request(self): 251 252 """ 253 Respond to a request by preparing a reply containing accept/decline 254 information for the recipient. 255 256 No support for countering requests is implemented. 257 """ 258 259 self._record_and_respond(self._schedule_for_attendee) 260 261 class Freebusy(Handler, CommonFreebusy): 262 263 "A free/busy handler." 264 265 def publish(self): 266 267 "Resources ignore generally published free/busy information." 268 269 pass 270 271 def reply(self): 272 273 "Since this handler does not send requests, it will not handle replies." 274 275 pass 276 277 # request provided by CommonFreeBusy.request 278 279 # Handler registry. 280 281 handlers = [ 282 ("VFREEBUSY", Freebusy), 283 ("VEVENT", Event), 284 ] 285 286 # vim: tabstop=4 expandtab shiftwidth=4