api: Add presences to InitialSnapshot

Author: chrisbobbe

lib/api/model/initial_snapshot.dart

@@ -49,6 +49,11 @@ class InitialSnapshot {
 
   final List<MutedUserItem> mutedUsers;
 
+  // In the modern format because we pass `slim_presence`.
+  // TODO(#1611) stop passing and mentioning the deprecated slim_presence;
+  //   presence_last_update_id will be why we get the modern format.
+  final Map<int, PerUserPresence> presences;
+
   final Map<String, RealmEmojiItem> realmEmoji;
 
   final List<RecentDmConversation> recentPrivateConversations;
@@ -142,6 +147,7 @@ class InitialSnapshot {
     required this.serverTypingStoppedWaitPeriodMilliseconds,
     required this.serverTypingStartedWaitPeriodMilliseconds,
     required this.mutedUsers,
+    required this.presences,
     required this.realmEmoji,
     required this.recentPrivateConversations,
     required this.savedSnippets,

lib/api/model/initial_snapshot.g.dart

@@ -330,6 +330,26 @@ enum UserRole{
   }
 }
 
+/// A value in [InitialSnapshot.presences].
+///
+/// For docs, search for "presences:"
+/// in <https://zulip.com/api/register-queue>.
+@JsonSerializable(fieldRename: FieldRename.snake)
+class PerUserPresence {
+  final int activeTimestamp;
+  final int idleTimestamp;
+
+  PerUserPresence({
+    required this.activeTimestamp,
+    required this.idleTimestamp,
+  });
+
+  factory PerUserPresence.fromJson(Map<String, dynamic> json) =>
+    _$PerUserPresenceFromJson(json);
+
+  Map<String, dynamic> toJson() => _$PerUserPresenceToJson(this);
+}
+
 /// An item in `saved_snippets` from the initial snapshot.
 ///
 /// For docs, search for "saved_snippets:"

lib/api/model/model.dart

@@ -1106,6 +1106,7 @@ InitialSnapshot initialSnapshot({
   int? serverTypingStoppedWaitPeriodMilliseconds,
   int? serverTypingStartedWaitPeriodMilliseconds,
   List<MutedUserItem>? mutedUsers,
+  Map<int, PerUserPresence>? presences,
   Map<String, RealmEmojiItem>? realmEmoji,
   List<RecentDmConversation>? recentPrivateConversations,
   List<SavedSnippet>? savedSnippets,
@@ -1146,6 +1147,7 @@ InitialSnapshot initialSnapshot({
     serverTypingStartedWaitPeriodMilliseconds:
       serverTypingStartedWaitPeriodMilliseconds ?? 10000,
     mutedUsers: mutedUsers ?? [],
+    presences: presences ?? {},
     realmEmoji: realmEmoji ?? {},
     recentPrivateConversations: recentPrivateConversations ?? [],
     savedSnippets: savedSnippets ?? [],