| package calendar |
| |
| import ( |
| "context" |
| "fmt" |
| "io" |
| "net/http" |
| "sort" |
| "strings" |
| "time" |
| _ "time/tzdata" |
| |
| ics "github.com/arran4/golang-ical" |
| "github.com/golang/glog" |
| rrule "github.com/teambition/rrule-go" |
| ) |
| |
| const ( |
| // EventsURL is the calendar from which we load public Hackerspace events. |
| EventsURL = "https://owncloud.hackerspace.pl/remote.php/dav/public-calendars/g8toktZrA9fyAHNi/?export" |
| ) |
| |
| // eventsBySooner sorts upcoming events so the one that happens the soonest |
| // will be first in the list. |
| type eventBySooner []*UpcomingEvent |
| |
| func (e eventBySooner) Len() int { return len(e) } |
| func (e eventBySooner) Swap(i, j int) { e[i], e[j] = e[j], e[i] } |
| func (e eventBySooner) Less(i, j int) bool { |
| a, b := e[i], e[j] |
| if a.Start.Time == b.Start.Time { |
| if a.End.Time == b.End.Time { |
| return a.UID < b.UID |
| } |
| return a.End.Time.Before(b.End.Time) |
| } |
| return a.Start.Time.Before(b.Start.Time) |
| } |
| |
| // parseUpcomingEvents generates a list of upcoming events from an open ICS/iCal file. |
| func parseUpcomingEvents(now time.Time, data io.Reader) ([]*UpcomingEvent, error) { |
| cal, err := ics.ParseCalendar(data) |
| if err != nil { |
| return nil, fmt.Errorf("ParseCalendar(%q): %w", err) |
| } |
| |
| var out []*UpcomingEvent |
| for _, event := range cal.Events() { |
| uidProp := event.GetProperty(ics.ComponentPropertyUniqueId) |
| if uidProp == nil || uidProp.Value == "" { |
| glog.Errorf("Event with no UID, ignoring: %+v", event) |
| continue |
| } |
| uid := uidProp.Value |
| |
| summaryProp := event.GetProperty(ics.ComponentPropertySummary) |
| if summaryProp == nil || summaryProp.Value == "" { |
| glog.Errorf("Event %s has no summary, ignoring", uid) |
| } |
| summary := summaryProp.Value |
| |
| var description string |
| descriptionProp := event.GetProperty(ics.ComponentPropertyDescription) |
| if descriptionProp != nil && descriptionProp.Value != "" { |
| // The ICS/iCal description has escaped newlines. Undo that. |
| description = strings.ReplaceAll(descriptionProp.Value, `\n`, "\n") |
| } |
| |
| status := event.GetProperty(ics.ComponentPropertyStatus) |
| tentative := false |
| if status != nil { |
| if status.Value == string(ics.ObjectStatusCancelled) { |
| // NextCloud only has CONFIRMED, CANCELELD and TENTATIVE for |
| // events. We drop everything CANCELELD and keep things that are |
| // TENTATIVE. |
| continue |
| } |
| if status.Value == string(ics.ObjectStatusTentative) { |
| tentative = true |
| } |
| } |
| |
| start, err := parseICSTime(event.GetProperty(ics.ComponentPropertyDtStart)) |
| if err != nil { |
| glog.Errorf("Event %s has unparseable DTSTART, ignoring: %v", uid, err) |
| continue |
| } |
| end, err := parseICSTime(event.GetProperty(ics.ComponentPropertyDtEnd)) |
| if err != nil { |
| glog.Errorf("Event %s has unparseable DTEND, ignoring: %v", uid, err) |
| continue |
| } |
| |
| if (start.WholeDay && !end.WholeDay) || (!start.WholeDay && end.WholeDay) { |
| glog.Errorf("Event %s has whole-day inconsistencies, start: %s, end: %s, ignoring", uid, start, end) |
| } |
| |
| rruleS := event.GetProperty(ics.ComponentPropertyRrule) |
| if rruleS != nil { |
| rrule, err := rrule.StrToRRule(rruleS.Value) |
| if err != nil { |
| glog.Errorf("Event %s has unparseable RRULE, ignoring: %v", uid, err) |
| continue |
| } |
| rrule.DTStart(start.Time) |
| |
| duration := end.Time.Sub(start.Time) |
| if start.WholeDay { |
| duration = time.Hour * 24 |
| } |
| |
| next := rrule.After(now, true) |
| if next.IsZero() { |
| continue |
| } |
| u := &UpcomingEvent{ |
| UID: uid, |
| Summary: summary, |
| Description: description, |
| Start: &EventTime{ |
| Time: next, |
| WholeDay: start.WholeDay, |
| }, |
| End: &EventTime{ |
| Time: next.Add(duration), |
| WholeDay: start.WholeDay, |
| }, |
| Tentative: tentative, |
| } |
| out = append(out, u) |
| continue |
| } |
| |
| u := &UpcomingEvent{ |
| UID: uid, |
| Summary: summary, |
| Description: description, |
| Start: start, |
| End: end, |
| Tentative: tentative, |
| } |
| if u.Elapsed(now) { |
| continue |
| } |
| |
| out = append(out, u) |
| } |
| sort.Sort(eventBySooner(out)) |
| return out, nil |
| } |
| |
| // GetUpcomingEvents returns all public Hackerspace events that are upcoming |
| // relative to the given time 'now' as per the Warsaw Hackerspace public |
| // calender (from owncloud.hackerspace.pl). |
| func GetUpcomingEvents(ctx context.Context, now time.Time) ([]*UpcomingEvent, error) { |
| r, err := http.NewRequestWithContext(ctx, "GET", EventsURL, nil) |
| if err != nil { |
| return nil, fmt.Errorf("NewRequest(%q): %w", EventsURL, err) |
| } |
| res, err := http.DefaultClient.Do(r) |
| if err != nil { |
| return nil, fmt.Errorf("Do(%q): %w", EventsURL, err) |
| } |
| defer res.Body.Close() |
| return parseUpcomingEvents(now, res.Body) |
| } |