package caldav import ( "strings" "time" "github.com/emersion/go-ical" ) // Filter returns the filtered list of calendar objects matching the provided query. // A nil query will return the full list of calendar objects. func Filter(query *CalendarQuery, cos []CalendarObject) ([]CalendarObject, error) { if query == nil { // FIXME: should we always return a copy of the provided slice? return cos, nil } var out []CalendarObject for _, co := range cos { ok, err := Match(query.CompFilter, &co) if err != nil { return nil, err } if !ok { continue } // TODO properties are not currently filtered even if requested out = append(out, co) } return out, nil } // Match reports whether the provided CalendarObject matches the query. func Match(query CompFilter, co *CalendarObject) (matched bool, err error) { if co.Data == nil || co.Data.Component == nil { panic("request to process empty calendar object") } return match(query, co.Data.Component) } func match(filter CompFilter, comp *ical.Component) (bool, error) { if comp.Name != filter.Name { return filter.IsNotDefined, nil } var zeroDate time.Time if filter.Start != zeroDate { match, err := matchCompTimeRange(filter.Start, filter.End, comp) if err != nil { return false, err } if !match { return false, nil } } for _, compFilter := range filter.Comps { match, err := matchCompFilter(compFilter, comp) if err != nil { return false, err } if !match { return false, nil } } for _, propFilter := range filter.Props { match, err := matchPropFilter(propFilter, comp) if err != nil { return false, err } if !match { return false, nil } } return true, nil } func matchCompFilter(filter CompFilter, comp *ical.Component) (bool, error) { var matches []*ical.Component for _, child := range comp.Children { match, err := match(filter, child) if err != nil { return false, err } else if match { matches = append(matches, child) } } if len(matches) == 0 { return filter.IsNotDefined, nil } return true, nil } func matchPropFilter(filter PropFilter, comp *ical.Component) (bool, error) { // TODO: this only matches first field, there can be multiple field := comp.Props.Get(filter.Name) if field == nil { return filter.IsNotDefined, nil } for _, paramFilter := range filter.ParamFilter { if !matchParamFilter(paramFilter, field) { return false, nil } } var zeroDate time.Time if filter.Start != zeroDate { match, err := matchPropTimeRange(filter.Start, filter.End, field) if err != nil { return false, err } if !match { return false, nil } } else if filter.TextMatch != nil { if !matchTextMatch(*filter.TextMatch, field.Value) { return false, nil } return true, nil } // empty prop-filter, property exists return true, nil } func matchCompTimeRange(start, end time.Time, comp *ical.Component) (bool, error) { // See https://datatracker.ietf.org/doc/html/rfc4791#section-9.9 // TODO handle "infinity" values in query // TODO handle recurring events if comp.Name != ical.CompEvent { return false, nil } event := ical.Event{comp} eventStart, err := event.DateTimeStart(start.Location()) if err != nil { return false, err } eventEnd, err := event.DateTimeEnd(end.Location()) if err != nil { return false, err } // Event starts in time range if eventStart.After(start) && eventStart.Before(end) { return true, nil } // Event ends in time range if eventEnd.After(start) && eventEnd.Before(end) { return true, nil } // Event covers entire time range plus some if eventStart.Before(start) && eventEnd.After(end) { return true, nil } return false, nil } func matchPropTimeRange(start, end time.Time, field *ical.Prop) (bool, error) { // See https://datatracker.ietf.org/doc/html/rfc4791#section-9.9 // TODO handle "infinity" values in query ptime, err := field.DateTime(start.Location()) if err != nil { return false, err } if ptime.After(start) && ptime.Before(end) { return true, nil } return false, nil } func matchParamFilter(filter ParamFilter, field *ical.Prop) bool { // TODO there can be multiple values value := field.Params.Get(filter.Name) if value == "" { return filter.IsNotDefined } else if filter.IsNotDefined { return false } if filter.TextMatch != nil { return matchTextMatch(*filter.TextMatch, value) } return true } func matchTextMatch(txt TextMatch, value string) bool { // TODO: handle text-match collation attribute match := strings.Contains(value, txt.Text) if txt.NegateCondition { match = !match } return match }