webcit/availability.c

   1 /*
   2  * $Id$
   3  *
   4  * Copyright (c) 1996-2010 by the citadel.org team
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21
  22 #include "webcit.h"
  23 #include "webserver.h"
  24 #include "calendar.h"
  25
  26 /*
  27  * Utility function to fetch a VFREEBUSY type of thing for any specified user.
  28  */
  29 icalcomponent *get_freebusy_for_user(char *who) {
  30         long nLines;
  31         char buf[SIZ];
  32         StrBuf *serialized_fb = NewStrBuf();
  33         icalcomponent *fb = NULL;
  34
  35         serv_printf("ICAL freebusy|%s", who);
  36         serv_getln(buf, sizeof buf);
  37         if (buf[0] == '1') {
  38                 read_server_text(serialized_fb, &nLines);
  39         }
  40
  41         if (serialized_fb == NULL) {
  42                 return NULL;
  43         }
  44
  45         fb = icalcomponent_new_from_string(ChrPtr(serialized_fb));
  46         FreeStrBuf(&serialized_fb);
  47         if (fb == NULL) {
  48                 return NULL;
  49         }
  50
  51         return(fb);
  52 }
  53
  54
  55 /*
  56  * Check to see if two events overlap.
  57  * (This function is used in both Citadel and WebCit.  If you change it in
  58  * one place, change it in the other.  We should seriously consider moving
  59  * this function upstream into libical.)
  60  *
  61  * Returns nonzero if they do overlap.
  62  */
  63 int ical_ctdl_is_overlap(
  64                         struct icaltimetype t1start,
  65                         struct icaltimetype t1end,
  66                         struct icaltimetype t2start,
  67                         struct icaltimetype t2end
  68 ) {
  69
  70         if (icaltime_is_null_time(t1start)) return(0);
  71         if (icaltime_is_null_time(t2start)) return(0);
  72
  73         /* if either event lacks end time, assume end = start */
  74         if (icaltime_is_null_time(t1end))
  75                 memcpy(&t1end, &t1start, sizeof(struct icaltimetype));
  76         else {
  77                 if (t1end.is_date && icaltime_compare(t1start, t1end)) {
  78                         /*
  79                          * the end date is non-inclusive so adjust it by one
  80                          * day because our test is inclusive, note that a day is
  81                          * not too much because we are talking about all day
  82                          * events
  83                          * if start = end we assume that nevertheless the whole
  84                          * day is meant
  85                          */
  86                         icaltime_adjust(&t1end, -1, 0, 0, 0);
  87                 }
  88         }
  89
  90         if (icaltime_is_null_time(t2end))
  91                 memcpy(&t2end, &t2start, sizeof(struct icaltimetype));
  92         else {
  93                 if (t2end.is_date && icaltime_compare(t2start, t2end)) {
  94                         icaltime_adjust(&t2end, -1, 0, 0, 0);
  95                 }
  96         }
  97
  98         /* First, check for all-day events */
  99         if (t1start.is_date || t2start.is_date) {
 100                 /* If event 1 ends before event 2 starts, we're in the clear. */
 101                 if (icaltime_compare_date_only(t1end, t2start) < 0) return(0);
 102
 103                 /* If event 2 ends before event 1 starts, we're also ok. */
 104                 if (icaltime_compare_date_only(t2end, t1start) < 0) return(0);
 105
 106                 return(1);
 107         }
 108
 109         /* lprintf (9, "Comparing t1start %d:%d t1end %d:%d t2start %d:%d t2end %d:%d \n",
 110                 t1start.hour, t1start.minute, t1end.hour, t1end.minute,
 111                 t2start.hour, t2start.minute, t2end.hour, t2end.minute);
 112         */
 113
 114         /* Now check for overlaps using date *and* time. */
 115
 116         /* If event 1 ends before event 2 starts, we're in the clear. */
 117         if (icaltime_compare(t1end, t2start) <= 0) return(0);
 118         /* lprintf(9, "first passed\n"); */
 119
 120         /* If event 2 ends before event 1 starts, we're also ok. */
 121         if (icaltime_compare(t2end, t1start) <= 0) return(0);
 122         /* lprintf(9, "second passed\n"); */
 123
 124         /* Otherwise, they overlap. */
 125         return(1);
 126 }
 127
 128
 129
 130 /*
 131  * Back end function for check_attendee_availability()
 132  * This one checks an individual attendee against a supplied
 133  * event start and end time.  All these fields have already been
 134  * broken out.
 135  *
 136  * attendee_string      name of the attendee
 137  * event_start          start time of the event to check
 138  * event_end            end time of the event to check
 139  *
 140  * The result is placed in 'annotation'.
 141  */
 142 void check_individual_attendee(char *attendee_string,
 143                                 struct icaltimetype event_start,
 144                                 struct icaltimetype event_end,
 145                                 char *annotation) {
 146
 147         icalcomponent *fbc = NULL;
 148         icalcomponent *fb = NULL;
 149         icalproperty *thisfb = NULL;
 150         struct icalperiodtype period;
 151
 152         /*
 153          * Set to 'unknown' right from the beginning.  Unless we learn
 154          * something else, that's what we'll go with.
 155          */
 156         strcpy(annotation, _("availability unknown"));
 157
 158         fbc = get_freebusy_for_user(attendee_string);
 159         if (fbc == NULL) {
 160                 return;
 161         }
 162
 163         /*
 164          * Make sure we're looking at a VFREEBUSY by itself.  What we're probably
 165          * looking at initially is a VFREEBUSY encapsulated in a VCALENDAR.
 166          */
 167         if (icalcomponent_isa(fbc) == ICAL_VCALENDAR_COMPONENT) {
 168                 fb = icalcomponent_get_first_component(fbc, ICAL_VFREEBUSY_COMPONENT);
 169         }
 170         else if (icalcomponent_isa(fbc) == ICAL_VFREEBUSY_COMPONENT) {
 171                 fb = fbc;
 172         }
 173
 174         /* Iterate through all FREEBUSY's looking for conflicts. */
 175         if (fb != NULL) {
 176
 177                 strcpy(annotation, _("free"));
 178
 179                 for (thisfb = icalcomponent_get_first_property(fb, ICAL_FREEBUSY_PROPERTY);
 180                     thisfb != NULL;
 181                     thisfb = icalcomponent_get_next_property(fb, ICAL_FREEBUSY_PROPERTY) ) {
 182
 183                         /** Do the check */
 184                         period = icalproperty_get_freebusy(thisfb);
 185                         if (ical_ctdl_is_overlap(period.start, period.end,
 186                            event_start, event_end)) {
 187                                 strcpy(annotation, _("BUSY"));
 188                         }
 189
 190                 }
 191         }
 192
 193         icalcomponent_free(fbc);
 194 }
 195
 196
 197
 198
 199 /*
 200  * Check the availability of all attendees for an event (when possible)
 201  * and annotate accordingly.
 202  *
 203  * vevent       the event which should be compared with attendees calendar
 204  */
 205 void check_attendee_availability(icalcomponent *vevent) {
 206         icalproperty *attendee = NULL;
 207         icalproperty *dtstart_p = NULL;
 208         icalproperty *dtend_p = NULL;
 209         struct icaltimetype dtstart_t;
 210         struct icaltimetype dtend_t;
 211         char attendee_string[SIZ];
 212         char annotated_attendee_string[SIZ];
 213         char annotation[SIZ];
 214
 215         if (vevent == NULL) {
 216                 return;
 217         }
 218
 219         /*
 220          * If we're looking at a fully encapsulated VCALENDAR
 221          * rather than a VEVENT component, attempt to use the first
 222          * relevant VEVENT subcomponent.  If there is none, the
 223          * NULL returned by icalcomponent_get_first_component() will
 224          * tell the next iteration of this function to create a
 225          * new one.
 226          */
 227         if (icalcomponent_isa(vevent) == ICAL_VCALENDAR_COMPONENT) {
 228                 check_attendee_availability(
 229                         icalcomponent_get_first_component(
 230                                 vevent, ICAL_VEVENT_COMPONENT
 231                         )
 232                 );
 233                 return;
 234         }
 235
 236         ical_dezonify(vevent);          /**< Convert everything to UTC */
 237
 238         /*
 239          * Learn the start and end times.
 240          */
 241         dtstart_p = icalcomponent_get_first_property(vevent, ICAL_DTSTART_PROPERTY);
 242         if (dtstart_p != NULL) dtstart_t = icalproperty_get_dtstart(dtstart_p);
 243
 244         dtend_p = icalcomponent_get_first_property(vevent, ICAL_DTEND_PROPERTY);
 245         if (dtend_p != NULL) dtend_t = icalproperty_get_dtend(dtend_p);
 246
 247         /*
 248          * Iterate through attendees.
 249          */
 250         for (attendee = icalcomponent_get_first_property(vevent, ICAL_ATTENDEE_PROPERTY);
 251             attendee != NULL;
 252             attendee = icalcomponent_get_next_property(vevent, ICAL_ATTENDEE_PROPERTY)) {
 253
 254                 strcpy(attendee_string, icalproperty_get_attendee(attendee));
 255                 if (!strncasecmp(attendee_string, "MAILTO:", 7)) {
 256
 257                         /** screen name or email address */
 258                         strcpy(attendee_string, &attendee_string[7]);
 259                         striplt(attendee_string);
 260
 261                         check_individual_attendee(attendee_string,
 262                                                 dtstart_t, dtend_t,
 263                                                 annotation);
 264
 265                         /** Replace the attendee name with an annotated one. */
 266                         snprintf(annotated_attendee_string, sizeof annotated_attendee_string,
 267                                 "MAILTO:%s (%s)", attendee_string, annotation);
 268                         icalproperty_set_attendee(attendee, annotated_attendee_string);
 269
 270                 }
 271         }
 272
 273 }
 274