webcit/availability.c

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