webcit/availability.c

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