@namespace("gregor.1")
@go_field_suffix("_")
protocol common {

  record TimeOrOffset {
    Time time;
    DurationMsec offset;
  }

  record Metadata {
    UID uid;
    MsgID msgID;
    Time ctime;
    DeviceID deviceID;
    int inBandMsgType;
  }

  record InBandMessage {
    union { null, StateUpdateMessage } stateUpdate;
    union { null, StateSyncMessage} stateSync;
  }

  record State {
    array<ItemAndMetadata> items;
  }

  record StateUpdateMessage {
    Metadata md;
    union { null, Item } creation;
    union { null, Dismissal } dismissal;
  }

  record StateSyncMessage {
    Metadata md;
  }

  record MsgRange {
    TimeOrOffset endTime;
    Category category;
    array<MsgID> skipMsgIDs;
  }

  record Dismissal {
    array<MsgID> msgIDs;
    array<MsgRange> ranges;
  }

  record Item {
    Category category;
    TimeOrOffset dtime;
    array<TimeOrOffset> remindTimes;
    Body body;
  }

  record ItemAndMetadata {
    union { null, Metadata } md;
    union { null, Item } item;
  }

  record Reminder {
    ItemAndMetadata item;
    int seqno;
    Time remindTime;
  }

  record ReminderID {
    UID uid;
    MsgID msgID;
    int seqno;
  }

  record OutOfBandMessage {
    UID uid;
    System system;
    Body body;
  }

  record ReminderSet {
    array<Reminder> reminders;
    boolean moreRemindersReady;
  }

  record Message {
    union { null, OutOfBandMessage } oobm;
    union { null, InBandMessage } ibm;
  }

  @typedef("int64") @lint("ignore") record DurationMsec {}
  @typedef("int64") @lint("ignore") record DurationSec {}
  @typedef("string") record Category {}
  @typedef("string") record System {}
  @typedef("bytes") record UID {}
  @typedef("bytes") record MsgID {}
  @typedef("bytes") record DeviceID {}
  @typedef("bytes") record Body {}
  @typedef("long") record Time {} // ms since epoch
  @typedef("string") record SessionID {}
  @typedef("string") record SessionToken {}
}