webcit/availability.c

   1 /*
   2  * Copyright (c) 1996-2012 by the citadel.org team
   3  *
   4  * This program is open source software.  You can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License, version 3.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  */
  12
  13
  14 #include "webcit.h"
  15 #include "webserver.h"
  16 #include "calendar.h"
  17
  18 /*
  19  * Utility function to fetch a VFREEBUSY type of thing for any specified user.
  20  */
  21 icalcomponent *get_freebusy_for_user(char *who) {
  22         long nLines;
  23         char buf[SIZ];
  24         StrBuf *serialized_fb = NewStrBuf();
  25         icalcomponent *fb = NULL;
  26
  27         serv_printf("ICAL freebusy|%s", who);
  28         serv_getln(buf, sizeof buf);
  29         if (buf[0] == '1') {
  30                 read_server_text(serialized_fb, &nLines);
  31         }
  32
  33         if (serialized_fb == NULL) {
  34                 return NULL;
  35         }
  36
  37         fb = icalcomponent_new_from_string(ChrPtr(serialized_fb));
  38         FreeStrBuf(&serialized_fb);
  39         if (fb == NULL) {
  40                 return NULL;
  41         }
  42
  43         return(fb);
  44 }
  45
  46
  47 /*
  48  * Check to see if two events overlap.
  49  * (This function is used in both Citadel and WebCit.  If you change it in
  50  * one place, change it in the other.  We should seriously consider moving
  51  * this function upstream into libical.)
  52  *
  53  * Returns nonzero if they do overlap.
  54  */
  55 int ical_ctdl_is_overlap(
  56                         struct icaltimetype t1start,
  57                         struct icaltimetype t1end,
  58                         struct icaltimetype t2start,
  59                         struct icaltimetype t2end
  60 ) {
  61
  62         if (icaltime_is_null_time(t1start)) return(0);
  63         if (icaltime_is_null_time(t2start)) return(0);
  64
  65         /* if either event lacks end time, assume end = start */
  66         if (icaltime_is_null_time(t1end))
  67                 memcpy(&t1end, &t1start, sizeof(struct icaltimetype));
  68         else {
  69                 if (t1end.is_date && icaltime_compare(t1start, t1end)) {
  70                         /*
  71                          * the end date is non-inclusive so adjust it by one
  72                          * day because our test is inclusive, note that a day is
  73                          * not too much because we are talking about all day
  74                          * events
  75                          * if start = end we assume that nevertheless the whole
  76                          * day is meant
  77                          */
  78                         icaltime_adjust(&t1end, -1, 0, 0, 0);
  79                 }
  80         }
  81
  82         if (icaltime_is_null_time(t2end))
  83                 memcpy(&t2end, &t2start, sizeof(struct icaltimetype));
  84         else {
  85                 if (t2end.is_date && icaltime_compare(t2start, t2end)) {
  86                         icaltime_adjust(&t2end, -1, 0, 0, 0);
  87                 }
  88         }
  89
  90         /* First, check for all-day events */
  91         if (t1start.is_date || t2start.is_date) {
  92                 /* If event 1 ends before event 2 starts, we're in the clear. */
  93                 if (icaltime_compare_date_only(t1end, t2start) < 0) return(0);
  94
  95                 /* If event 2 ends before event 1 starts, we're also ok. */
  96                 if (icaltime_compare_date_only(t2end, t1start) < 0) return(0);
  97
  98                 return(1);
  99         }
 100
 101         /* syslog(LOG_DEBUG, "Comparing t1start %d:%d t1end %d:%d t2start %d:%d t2end %d:%d \n",
 102                 t1start.hour, t1start.minute, t1end.hour, t1end.minute,
 103                 t2start.hour, t2start.minute, t2end.hour, t2end.minute);
 104         */
 105
 106         /* Now check for overlaps using date *and* time. */
 107
 108         /* If event 1 ends before event 2 starts, we're in the clear. */
 109         if (icaltime_compare(t1end, t2start) <= 0) return(0);
 110         /* syslog(LOG_DEBUG, "first passed\n"); */
 111
 112         /* If event 2 ends before event 1 starts, we're also ok. */
 113         if (icaltime_compare(t2end, t1start) <= 0) return(0);
 114         /* syslog(LOG_DEBUG, "second passed\n"); */
 115
 116         /* Otherwise, they overlap. */
 117         return(1);
 118 }
 119
 120
 121
 122 /*
 123  * Back end function for check_attendee_availability()
 124  * This one checks an individual attendee against a supplied
 125  * event start and end time.  All these fields have already been
 126  * broken out.
 127  *
 128  * attendee_string      name of the attendee
 129  * event_start          start time of the event to check
 130  * event_end            end time of the event to check
 131  *
 132  * The result is placed in 'annotation'.
 133  */
 134 void check_individual_attendee(char *attendee_string,
 135                                 struct icaltimetype event_start,
 136                                 struct icaltimetype event_end,
 137                                 char *annotation) {
 138
 139         icalcomponent *fbc = NULL;
 140         icalcomponent *fb = NULL;
 141         icalproperty *thisfb = NULL;
 142         struct icalperiodtype period;
 143
 144         /*
 145          * Set to 'unknown' right from the beginning.  Unless we learn
 146          * something else, that's what we'll go with.
 147          */
 148         strcpy(annotation, _("availability unknown"));
 149
 150         fbc = get_freebusy_for_user(attendee_string);
 151         if (fbc == NULL) {
 152                 return;
 153         }
 154
 155         /*
 156          * Make sure we're looking at a VFREEBUSY by itself.  What we're probably
 157          * looking at initially is a VFREEBUSY encapsulated in a VCALENDAR.
 158          */
 159         if (icalcomponent_isa(fbc) == ICAL_VCALENDAR_COMPONENT) {
 160                 fb = icalcomponent_get_first_component(fbc, ICAL_VFREEBUSY_COMPONENT);
 161         }
 162         else if (icalcomponent_isa(fbc) == ICAL_VFREEBUSY_COMPONENT) {
 163                 fb = fbc;
 164         }
 165
 166         /* Iterate through all FREEBUSY's looking for conflicts. */
 167         if (fb != NULL) {
 168
 169                 strcpy(annotation, _("free"));
 170
 171                 for (thisfb = icalcomponent_get_first_property(fb, ICAL_FREEBUSY_PROPERTY);
 172                     thisfb != NULL;
 173                     thisfb = icalcomponent_get_next_property(fb, ICAL_FREEBUSY_PROPERTY) ) {
 174
 175                         /** Do the check */
 176                         period = icalproperty_get_freebusy(thisfb);
 177                         if (ical_ctdl_is_overlap(period.start, period.end,
 178                            event_start, event_end)) {
 179                                 strcpy(annotation, _("BUSY"));
 180                         }
 181
 182                 }
 183         }
 184
 185         icalcomponent_free(fbc);
 186 }
 187
 188
 189
 190
 191 /*
 192  * Check the availability of all attendees for an event (when possible)
 193  * and annotate accordingly.
 194  *
 195  * vevent       the event which should be compared with attendees calendar
 196  */
 197 void check_attendee_availability(icalcomponent *vevent) {
 198         icalproperty *attendee = NULL;
 199         icalproperty *dtstart_p = NULL;
 200         icalproperty *dtend_p = NULL;
 201         struct icaltimetype dtstart_t;
 202         struct icaltimetype dtend_t;
 203         char attendee_string[SIZ];
 204         char annotated_attendee_string[SIZ];
 205         char annotation[SIZ];
 206         const char *ch;
 207
 208         if (vevent == NULL) {
 209                 return;
 210         }
 211
 212         /*
 213          * If we're looking at a fully encapsulated VCALENDAR
 214          * rather than a VEVENT component, attempt to use the first
 215          * relevant VEVENT subcomponent.  If there is none, the
 216          * NULL returned by icalcomponent_get_first_component() will
 217          * tell the next iteration of this function to create a
 218          * new one.
 219          */
 220         if (icalcomponent_isa(vevent) == ICAL_VCALENDAR_COMPONENT) {
 221                 check_attendee_availability(
 222                         icalcomponent_get_first_component(
 223                                 vevent, ICAL_VEVENT_COMPONENT
 224                         )
 225                 );
 226                 return;
 227         }
 228
 229         ical_dezonify(vevent);          /**< Convert everything to UTC */
 230
 231         /*
 232          * Learn the start and end times.
 233          */
 234         dtstart_p = icalcomponent_get_first_property(vevent, ICAL_DTSTART_PROPERTY);
 235         if (dtstart_p != NULL) dtstart_t = icalproperty_get_dtstart(dtstart_p);
 236
 237         dtend_p = icalcomponent_get_first_property(vevent, ICAL_DTEND_PROPERTY);
 238         if (dtend_p != NULL) dtend_t = icalproperty_get_dtend(dtend_p);
 239
 240         /*
 241          * Iterate through attendees.
 242          */
 243         for (attendee = icalcomponent_get_first_property(vevent, ICAL_ATTENDEE_PROPERTY);
 244             attendee != NULL;
 245             attendee = icalcomponent_get_next_property(vevent, ICAL_ATTENDEE_PROPERTY)) {
 246                 ch = icalproperty_get_attendee(attendee);
 247                 if ((ch != NULL) && !strncasecmp(ch, "MAILTO:", 7)) {
 248
 249                         /** screen name or email address */
 250                         safestrncpy(attendee_string, ch + 7, sizeof(attendee_string));
 251                         striplt(attendee_string);
 252
 253                         check_individual_attendee(attendee_string,
 254                                                 dtstart_t, dtend_t,
 255                                                 annotation);
 256
 257                         /** Replace the attendee name with an annotated one. */
 258                         snprintf(annotated_attendee_string, sizeof annotated_attendee_string,
 259                                 "MAILTO:%s (%s)", attendee_string, annotation);
 260                         icalproperty_set_attendee(attendee, annotated_attendee_string);
 261
 262                 }
 263         }
 264
 265 }
 266