| 1 | package calendar |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "fmt" |
| 7 | "time" |
| 8 | |
| 9 | "gorm.io/gorm" |
| 10 | ) |
| 11 | |
| 12 | // EnsureDefaultReminder gives a newly created event the person's own |
| 13 | // default warning, using the preference that matches what kind of thing |
| 14 | // it is. |
| 15 | // |
| 16 | // A default rather than nothing, because a reminder somebody has to |
| 17 | // remember to set is a reminder that exists for the events they were |
| 18 | // already thinking about. A note gets none: a birthday does not need a |
| 19 | // ten-minute warning, and the all-day default is the evening before. |
| 20 | func (s *Store) EnsureDefaultReminder(ctx context.Context, p Person, e Event) error { |
| 21 | offset := p.DefaultReminderMin |
| 22 | if e.AllDay { |
| 23 | offset = p.DefaultAllDayMin |
| 24 | } |
| 25 | if offset == 0 { |
| 26 | return nil |
| 27 | } |
| 28 | r := Reminder{ |
| 29 | EventID: e.ID, |
| 30 | PersonID: p.ID, |
| 31 | OffsetMin: offset, |
| 32 | Channel: "email", |
| 33 | CreatedAt: time.Now().UTC(), |
| 34 | } |
| 35 | if err := s.g.WithContext(ctx).Create(&r).Error; err != nil { |
| 36 | return fmt.Errorf("calendar: create reminder: %w", err) |
| 37 | } |
| 38 | return s.RescheduleReminder(ctx, r.ID) |
| 39 | } |
| 40 | |
| 41 | // RemindersFor lists a person's own reminders on an event. Only their |
| 42 | // own: a reminder is a fact about a person, and whether a colleague |
| 43 | // wants a warning is not information the event's page should carry. |
| 44 | func (s *Store) RemindersFor(ctx context.Context, personID, eventID int64) ([]Reminder, error) { |
| 45 | var out []Reminder |
| 46 | err := s.g.WithContext(ctx). |
| 47 | Where("event_id = ? AND person_id = ?", eventID, personID). |
| 48 | Order("offset_min DESC"). |
| 49 | Find(&out).Error |
| 50 | if err != nil { |
| 51 | return nil, fmt.Errorf("calendar: list reminders: %w", err) |
| 52 | } |
| 53 | return out, nil |
| 54 | } |
| 55 | |
| 56 | // AddReminder attaches a warning to an event the person can see. |
| 57 | func (s *Store) AddReminder(ctx context.Context, personID, eventID, offsetMin int64) error { |
| 58 | if _, err := s.Event(ctx, personID, eventID); err != nil { |
| 59 | return err |
| 60 | } |
| 61 | r := Reminder{ |
| 62 | EventID: eventID, |
| 63 | PersonID: personID, |
| 64 | OffsetMin: int(offsetMin), |
| 65 | Channel: "email", |
| 66 | CreatedAt: time.Now().UTC(), |
| 67 | } |
| 68 | if err := s.g.WithContext(ctx).Create(&r).Error; err != nil { |
| 69 | return fmt.Errorf("calendar: add reminder: %w", err) |
| 70 | } |
| 71 | return s.RescheduleReminder(ctx, r.ID) |
| 72 | } |
| 73 | |
| 74 | // RemoveReminder deletes one of the person's own reminders, and the |
| 75 | // queued row with it. |
| 76 | func (s *Store) RemoveReminder(ctx context.Context, personID, reminderID int64) error { |
| 77 | return s.g.WithContext(ctx).Transaction(func(tx *gorm.DB) error { |
| 78 | res := tx.Where("id = ? AND person_id = ?", reminderID, personID).Delete(&Reminder{}) |
| 79 | if res.Error != nil { |
| 80 | return fmt.Errorf("calendar: remove reminder: %w", res.Error) |
| 81 | } |
| 82 | if res.RowsAffected == 0 { |
| 83 | // Somebody else's reminder, or none. Not found, never |
| 84 | // forbidden. |
| 85 | return ErrNotFound |
| 86 | } |
| 87 | return tx.Where("reminder_id = ?", reminderID).Delete(&ReminderQueue{}).Error |
| 88 | }) |
| 89 | } |
| 90 | |
| 91 | // RescheduleReminder recomputes when a rule next fires and writes the |
| 92 | // single pending queue row for it. |
| 93 | // |
| 94 | // One row per rule, always — never one per occurrence. A daily standup |
| 95 | // that repeats forever has exactly one queued row at any moment, and |
| 96 | // firing it computes the next. Materialising a series' reminders is how |
| 97 | // a queue becomes unbounded. |
| 98 | func (s *Store) RescheduleReminder(ctx context.Context, reminderID int64) error { |
| 99 | return s.rescheduleAfter(ctx, reminderID, 0) |
| 100 | } |
| 101 | |
| 102 | // rescheduleAfter queues the first occurrence starting strictly after |
| 103 | // `after`, or after now when `after` is zero. |
| 104 | func (s *Store) rescheduleAfter(ctx context.Context, reminderID, after int64) error { |
| 105 | return s.rescheduleAfterTx(s.g.WithContext(ctx), reminderID, after) |
| 106 | } |
| 107 | |
| 108 | // rescheduleAfterTx is rescheduleAfter on a caller's transaction, so a |
| 109 | // reschedule of a booked meeting can rebuild its reminder rows in the |
| 110 | // SAME transaction as the move (booking spec B24): a crash between the |
| 111 | // two would otherwise leave a row that sends a reminder for a time the |
| 112 | // meeting no longer has. |
| 113 | // |
| 114 | // Any rewrite of a queue row clears its claim and its retry: whoever |
| 115 | // held it was announcing a time that is gone, and must find zero rows |
| 116 | // when they try to complete. |
| 117 | func (s *Store) rescheduleAfterTx(tx *gorm.DB, reminderID, after int64) error { |
| 118 | var rem Reminder |
| 119 | if err := tx.First(&rem, reminderID).Error; err != nil { |
| 120 | if errors.Is(err, gorm.ErrRecordNotFound) { |
| 121 | return nil |
| 122 | } |
| 123 | return fmt.Errorf("calendar: read reminder: %w", err) |
| 124 | } |
| 125 | var e Event |
| 126 | if err := tx.Where("id = ? AND deleted_at IS NULL AND status <> ?", rem.EventID, StatusCancelled). |
| 127 | First(&e).Error; err != nil { |
| 128 | if errors.Is(err, gorm.ErrRecordNotFound) { |
| 129 | // The event is gone, or cancelled; so is any reason to |
| 130 | // warn about it. |
| 131 | return tx.Where("reminder_id = ?", reminderID).Delete(&ReminderQueue{}).Error |
| 132 | } |
| 133 | return fmt.Errorf("calendar: read event for reminder: %w", err) |
| 134 | } |
| 135 | |
| 136 | // The floor for the search: whichever is later of "now" and the |
| 137 | // occurrence just fired. Zero means nothing has fired, so now. |
| 138 | floor := time.Now().Unix() |
| 139 | if after > floor { |
| 140 | floor = after |
| 141 | } |
| 142 | occStart, occLocal, ok := s.nextOccurrenceAfter(e, floor, rem.OffsetMin) |
| 143 | if !ok { |
| 144 | // Nothing left to warn about: a finished series, or a single |
| 145 | // event already past. Drop the queue row rather than leave a |
| 146 | // due time in the past that every drain re-examines. |
| 147 | return tx.Where("reminder_id = ?", reminderID).Delete(&ReminderQueue{}).Error |
| 148 | } |
| 149 | |
| 150 | q := ReminderQueue{ |
| 151 | ReminderID: reminderID, |
| 152 | OccurrenceKey: fmt.Sprintf("%d/%s", e.ID, occLocal), |
| 153 | DueAt: occStart - int64(rem.OffsetMin)*60, |
| 154 | } |
| 155 | // Upsert on the unique reminder_id, so rescheduling is idempotent |
| 156 | // and two callers cannot leave two pending rows for one rule. |
| 157 | err := tx. |
| 158 | Where(ReminderQueue{ReminderID: reminderID}). |
| 159 | Assign(map[string]any{ |
| 160 | "occurrence_key": q.OccurrenceKey, |
| 161 | "due_at": q.DueAt, |
| 162 | "claimed_at": nil, |
| 163 | "claim_id": nil, |
| 164 | "retry_at": nil, |
| 165 | "fired_at": nil, |
| 166 | "attempts": 0, |
| 167 | "late_by_sec": 0, |
| 168 | }). |
| 169 | FirstOrCreate(&q).Error |
| 170 | if err != nil { |
| 171 | return fmt.Errorf("calendar: queue reminder: %w", err) |
| 172 | } |
| 173 | return nil |
| 174 | } |
| 175 | |
| 176 | // ExcludeOccurrence deletes one occurrence of a series by adding an |
| 177 | // EXDATE, and reschedules any reminder that pointed at it. |
| 178 | func (s *Store) ExcludeOccurrence(ctx context.Context, personID, eventID int64, local string) error { |
| 179 | e, err := s.Event(ctx, personID, eventID) |
| 180 | if err != nil { |
| 181 | return err |
| 182 | } |
| 183 | if !e.Writable() { |
| 184 | return ErrReadOnly |
| 185 | } |
| 186 | set := exdateSet(e.Exdates) |
| 187 | if set[local] { |
| 188 | return nil |
| 189 | } |
| 190 | next := e.Exdates |
| 191 | if next != "" { |
| 192 | next += "," |
| 193 | } |
| 194 | next += local |
| 195 | if err := s.g.WithContext(ctx).Model(&Event{}).Where("id = ?", eventID). |
| 196 | Updates(map[string]any{"exdates": next, "updated_at": time.Now().UTC()}).Error; err != nil { |
| 197 | return fmt.Errorf("calendar: exclude occurrence: %w", err) |
| 198 | } |
| 199 | return s.rescheduleAllFor(ctx, eventID) |
| 200 | } |
| 201 | |
| 202 | // rescheduleAllFor recomputes every reminder on an event, after the |
| 203 | // event's own times or rule changed. |
| 204 | func (s *Store) rescheduleAllFor(ctx context.Context, eventID int64) error { |
| 205 | return s.rescheduleAllForTx(s.g.WithContext(ctx), eventID) |
| 206 | } |
| 207 | |
| 208 | // rescheduleAllForTx enumerates the event's reminder RULES — not its |
| 209 | // queue rows, because a reminder that already fired has none — and |
| 210 | // upserts one queue row per rule from the event's current times |
| 211 | // (booking spec B26). |
| 212 | func (s *Store) rescheduleAllForTx(tx *gorm.DB, eventID int64) error { |
| 213 | var ids []int64 |
| 214 | if err := tx.Model(&Reminder{}). |
| 215 | Where("event_id = ?", eventID).Pluck("id", &ids).Error; err != nil { |
| 216 | return fmt.Errorf("calendar: list reminders to reschedule: %w", err) |
| 217 | } |
| 218 | for _, id := range ids { |
| 219 | if err := s.rescheduleAfterTx(tx, id, 0); err != nil { |
| 220 | return err |
| 221 | } |
| 222 | } |
| 223 | return nil |
| 224 | } |
| 225 | |
| 226 | // CountOccurrences reports how many times a series happens, for the |
| 227 | // delete confirmation — "All 52 of them" is a warning that a bare |
| 228 | // "Delete all" is not. |
| 229 | // |
| 230 | // forever is true for a series with no end, where no count exists and |
| 231 | // the confirmation says so instead of inventing a number. |
| 232 | func (s *Store) CountOccurrences(e EventView) (int, bool) { |
| 233 | if e.RRule == "" { |
| 234 | return 1, false |
| 235 | } |
| 236 | rule, err := ParseRule(e.RRule) |
| 237 | if err != nil { |
| 238 | return 0, true |
| 239 | } |
| 240 | if rule.Count > 0 { |
| 241 | return rule.Count, false |
| 242 | } |
| 243 | if !rule.HasUntil { |
| 244 | return 0, true |
| 245 | } |
| 246 | occs := Expand(e.StartLocal, e.EndLocal, e.TZ, e.AllDay, rule, e.Exdates, |
| 247 | e.StartUTC-1, untilBound(rule)) |
| 248 | return len(occs), false |
| 249 | } |
| 250 | |
| 251 | func untilBound(r Rule) int64 { |
| 252 | if r.HasUntil { |
| 253 | return r.Until.Unix() + 24*3600 |
| 254 | } |
| 255 | return time.Now().AddDate(2, 0, 0).Unix() |
| 256 | } |
| 257 | |
amadan