webcit/availability.c

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