+// Recursive function to apply CalDAV FILTERS to a calendar item.
+// Returns zero if the calendar item was disqualified by a filter, nonzero if the calendar item still qualifies.
+int caldav_apply_filters(void *cal, Array *filters, int apply_at_level) {
+
+ int f = 0; // filter number iterator
+ int qual = 1; // 0 for disqualify, 1 for qualify
+ int previous_level = -1;
+ int disregard_further_comp_filters = 0;
+
+ while ( (f<array_len(filters)) && (qual) ) {
+
+ // Tokenize the filter (a future performance hack would be to pre-tokenize instead of storing delimited strings)
+ char this_filter[SIZ];
+ safestrncpy(this_filter, array_get_element_at(filters, f), sizeof(this_filter));
+ char *t[10] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL } ;
+ char *ft = this_filter;
+ int num_tokens = 0;
+ while ( (t[num_tokens]=strtok_r(ft, "|", &ft)) && (num_tokens<10) ) {
+ ++num_tokens;
+ }
+ int this_rule_level = atoi(t[0]);
+ syslog(LOG_DEBUG, "caldav_apply_filters() filter=%d, level=%d, <%s>", f, this_rule_level, array_get_element_at(filters, f) );
+
+ // Handle the individual filters defined in RFC4791 9.7.1 through 9.7.5
+
+ if (apply_at_level < previous_level) {
+ syslog(LOG_DEBUG, "caldav: walking back down");
+ return(qual);
+ }
+
+ else if (this_rule_level != apply_at_level) {
+ syslog(LOG_DEBUG, "caldav: apply_at_level=%d, this_rule_level=%d, skipping this rule", apply_at_level, this_rule_level);
+ }
+
+ else if ( (!strcasecmp(t[1], "comp-filter"))
+ && (!disregard_further_comp_filters)
+ ) { // RFC4791 9.7.1 - filter by component
+ syslog(LOG_DEBUG, "component filter at level %d", this_rule_level);
+
+ // Root element is NOT a component, but the root filter is "comp-filter" -- reject!
+ if ( (!icalcomponent_isa_component(cal)) && (this_rule_level == 0) ) {
+ syslog(LOG_DEBUG, "caldav: root element is not a component, rejecting");
+ return(0);
+ }
+
+ // Current element is a component and the filter is "comp-filter" -- see if it matches the requested type
+ if ( (icalcomponent_isa_component(cal))
+ && (!strcasecmp(t[2], "name"))
+ ) {
+ if (icalcomponent_isa(cal) == icalcomponent_string_to_kind(t[3]) ) {
+ syslog(LOG_DEBUG, "caldav: component at level %d is <%s>, looking for <%s>, recursing...",
+ apply_at_level,
+ icalcomponent_kind_to_string(icalcomponent_isa(cal)), t[3]
+ );
+
+ // We have a match. Drill down into the subcomponents.
+
+ icalcomponent *c = NULL;
+ int number_of_subcomponents = 0;
+ int number_of_matches = 0;
+ for ( c = icalcomponent_get_first_component(cal, ICAL_ANY_COMPONENT);
+ (c != 0);
+ c = icalcomponent_get_next_component(cal, ICAL_ANY_COMPONENT)
+ ) {
+ ++number_of_subcomponents;
+ if (caldav_apply_filters(c, filters, apply_at_level+1)) {
+ syslog(LOG_DEBUG, "Subcomponent %d might match", number_of_subcomponents);
+ ++number_of_matches;
+ }
+ }
+ if (number_of_matches > 0) { // something matched
+ qual = 1;
+ disregard_further_comp_filters = 1;
+
+ }
+ else if (number_of_subcomponents > 0) { // nothing matched
+ return(0); // but only fail if there *were* subcomponents.
+ }
+
+ }
+ else {
+ syslog(LOG_DEBUG, "caldav: component at level %d is <%s>, looking for <%s>, rejecting",
+ apply_at_level,
+ icalcomponent_kind_to_string(icalcomponent_isa(cal)),
+ t[3]
+ );
+ return(0);
+ }
+ }
+
+ }
+
+ else if (!strcasecmp(t[1], "prop-filter")) { // RFC4791 9.7.2 - filter by property
+ syslog(LOG_DEBUG, "property filter at level %d FIXME not implemented yet", this_rule_level);
+ }
+
+ else if (!strcasecmp(t[1], "param-filter")) { // RFC4791 9.7.3 - filter by parameter
+ syslog(LOG_DEBUG, "parameter filter at level %d FIXME not implemented yet", this_rule_level);
+ }
+
+ else if (!strcasecmp(t[1], "is-not-defined")) { // RFC4791 9.7.4
+ syslog(LOG_DEBUG, "is-not-defined filter at level %d FIXME not implemented yet", this_rule_level);
+ }
+
+ else if (!strcasecmp(t[1], "text-match")) { // RFC4791 9.7.5
+ syslog(LOG_DEBUG, "text match filter at level %d FIXME not implemented yet", this_rule_level);
+ }
+
+ else if (!strcasecmp(t[1], "time-range")) {
+ syslog(LOG_DEBUG, "time range filter at level %d FIXME not implemented yet", this_rule_level);
+ }
+
+ ++f;
+ }
+
+ syslog(LOG_DEBUG, "caldav: we reached the end of level %d , returning %d", apply_at_level, qual);
+ return(qual);
+}
+
+