Prepare for updating accounts in database

lib/model/compose.dart

@@ -142,7 +142,7 @@ String quoteAndReplyPlaceholder(PerAccountStore store, {
   final sender = store.users[message.senderId];
   assert(sender != null);
   final url = narrowLink(store,
-    SendableNarrow.ofMessage(message, selfUserId: store.account.userId),
+    SendableNarrow.ofMessage(message, selfUserId: store.selfUserId),
     nearMessageId: message.id);
   // See note in [quoteAndReply] about asking `mention` to omit the |<id> part.
   return '${mention(sender!, silent: true)} ${inlineLink('said', url)}: ' // TODO(i18n) ?
@@ -164,7 +164,7 @@ String quoteAndReply(PerAccountStore store, {
   final sender = store.users[message.senderId];
   assert(sender != null);
   final url = narrowLink(store,
-    SendableNarrow.ofMessage(message, selfUserId: store.account.userId),
+    SendableNarrow.ofMessage(message, selfUserId: store.selfUserId),
     nearMessageId: message.id);
     // Could ask `mention` to omit the |<id> part unless the mention is ambiguous…
     // but that would mean a linear scan through all users, and the extra noise

lib/model/database.dart

@@ -7,10 +7,25 @@ import 'package:path_provider/path_provider.dart';
 
 part 'database.g.dart';
 
+/// The table of [Account] records in the app's database.
 class Accounts extends Table {
+  /// The ID of this account in the app's local database.
+  ///
+  /// This uniquely identifies the account within this install of the app,
+  /// and never changes for a given account.  It has no meaning to the server,
+  /// though, or anywhere else outside this install of the app.
   Column<int>    get id => integer().autoIncrement()();
 
+  /// The URL of the Zulip realm this account is on.
+  ///
+  /// This corresponds to [GetServerSettingsResult.realmUrl].
+  /// It never changes for a given account.
   Column<String> get realmUrl => text().map(const UriConverter())();
+
+  /// The Zulip user ID of this account.
+  ///
+  /// This is the identifier the server uses for the account.
+  /// It never changes for a given account.
   Column<int>    get userId => integer()();
 
   Column<String> get email => text()();

lib/model/internal_link.dart

@@ -95,23 +95,13 @@ Uri narrowLink(PerAccountStore store, Narrow narrow, {int? nearMessageId}) {
     fragment.write('/near/$nearMessageId');
   }
 
-  return store.account.realmUrl.replace(fragment: fragment.toString());
-}
-
-/// Create a new `Uri` object in relation to a given realmUrl.
-///
-/// Returns `null` if `urlString` could not be parsed as a `Uri`.
-Uri? tryResolveOnRealmUrl(String urlString, Uri realmUrl) {
-  try {
-    return realmUrl.resolve(urlString);
-  } on FormatException {
-    return null;
-  }
+  return store.realmUrl.replace(fragment: fragment.toString());
 }
 
 /// A [Narrow] from a given URL, on `store`'s realm.
 ///
-/// `url` must already be passed through [tryResolveOnRealmUrl].
+/// `url` must already be a result from [PerAccountStore.tryResolveUrl]
+/// on `store`.
 ///
 /// Returns `null` if any of the operator/operand pairs are invalid.
 ///
@@ -124,7 +114,7 @@ Uri? tryResolveOnRealmUrl(String urlString, Uri realmUrl) {
 ///   #narrow/stream/1-announce/stream/1-announce (duplicated operator)
 // TODO(#252): handle all valid narrow links, returning a search narrow
 Narrow? parseInternalLink(Uri url, PerAccountStore store) {
-  if (!_isInternalLink(url, store.account.realmUrl)) return null;
+  if (!_isInternalLink(url, store.realmUrl)) return null;
 
   final (category, segments) = _getCategoryAndSegmentsFromFragment(url.fragment);
   switch (category) {
@@ -197,7 +187,7 @@ Narrow? _interpretNarrowSegments(List<String> segments, PerAccountStore store) {
 
   if (dmElement != null) {
     if (streamElement != null || topicElement != null) return null;
-    return DmNarrow.withUsers(dmElement.operand, selfUserId: store.account.userId);
+    return DmNarrow.withUsers(dmElement.operand, selfUserId: store.selfUserId);
   } else if (streamElement != null) {
     final streamId = streamElement.operand;
     if (topicElement != null) {

lib/model/store.dart

@@ -111,22 +111,19 @@ abstract class GlobalStore extends ChangeNotifier {
     }
 
     // It's up to us.  Start loading.
-    final account = getAccount(accountId);
-    assert(account != null, 'Account not found on global store');
-    future = loadPerAccount(account!);
+    future = loadPerAccount(accountId);
     _perAccountStoresLoading[accountId] = future;
     store = await future;
     _setPerAccount(accountId, store);
     _perAccountStoresLoading.remove(accountId);
     return store;
   }
 
-  Future<void> _reloadPerAccount(Account account) async {
-    assert(identical(_accounts[account.id], account));
-    assert(_perAccountStores.containsKey(account.id));
-    assert(!_perAccountStoresLoading.containsKey(account.id));
-    final store = await loadPerAccount(account);
-    _setPerAccount(account.id, store);
+  Future<void> _reloadPerAccount(int accountId) async {
+    assert(_perAccountStores.containsKey(accountId));
+    assert(!_perAccountStoresLoading.containsKey(accountId));
+    final store = await loadPerAccount(accountId);
+    _setPerAccount(accountId, store);
   }
 
   void _setPerAccount(int accountId, PerAccountStore store) {
@@ -141,7 +138,7 @@ abstract class GlobalStore extends ChangeNotifier {
   /// This method should be called only by the implementation of [perAccount].
   /// Other callers interested in per-account data should use [perAccount]
   /// and/or [perAccountSync].
-  Future<PerAccountStore> loadPerAccount(Account account);
+  Future<PerAccountStore> loadPerAccount(int accountId);
 
   // Just the Iterables, not the actual Map, to avoid clients mutating the map.
   // Mutations should go through the setters/mutators below.
@@ -191,76 +188,106 @@ class PerAccountStore extends ChangeNotifier with StreamStore {
   /// but it may have already been used for other requests.
   factory PerAccountStore.fromInitialSnapshot({
     required GlobalStore globalStore,
-    required Account account,
+    required int accountId,
     ApiConnection? connection,
     required InitialSnapshot initialSnapshot,
   }) {
+    final account = globalStore.getAccount(accountId)!;
     connection ??= globalStore.apiConnectionFromAccount(account);
     final streams = StreamStoreImpl(initialSnapshot: initialSnapshot);
     return PerAccountStore._(
       globalStore: globalStore,
-      account: account,
       connection: connection,
+      realmUrl: account.realmUrl,
       zulipVersion: initialSnapshot.zulipVersion,
       maxFileUploadSizeMib: initialSnapshot.maxFileUploadSizeMib,
       realmDefaultExternalAccounts: initialSnapshot.realmDefaultExternalAccounts,
       realmEmoji: initialSnapshot.realmEmoji,
       customProfileFields: _sortCustomProfileFields(initialSnapshot.customProfileFields),
+      accountId: accountId,
+      selfUserId: account.userId,
       userSettings: initialSnapshot.userSettings,
-      unreads: Unreads(
-        initial: initialSnapshot.unreadMsgs,
-        selfUserId: account.userId,
-        streamStore: streams,
-      ),
       users: Map.fromEntries(
         initialSnapshot.realmUsers
         .followedBy(initialSnapshot.realmNonActiveUsers)
         .followedBy(initialSnapshot.crossRealmBots)
         .map((user) => MapEntry(user.userId, user))),
       streams: streams,
+      unreads: Unreads(
+        initial: initialSnapshot.unreadMsgs,
+        selfUserId: account.userId,
+        streamStore: streams,
+      ),
       recentDmConversationsView: RecentDmConversationsView(
         initial: initialSnapshot.recentPrivateConversations, selfUserId: account.userId),
     );
   }
 
   PerAccountStore._({
     required GlobalStore globalStore,
-    required this.account,
     required this.connection,
+    required this.realmUrl,
     required this.zulipVersion,
     required this.maxFileUploadSizeMib,
     required this.realmDefaultExternalAccounts,
     required this.realmEmoji,
     required this.customProfileFields,
+    required this.accountId,
+    required this.selfUserId,
     required this.userSettings,
-    required this.unreads,
     required this.users,
     required streams,
+    required this.unreads,
     required this.recentDmConversationsView,
-  }) : _globalStore = globalStore,
+  }) : assert(selfUserId == globalStore.getAccount(accountId)!.userId),
+       assert(realmUrl == globalStore.getAccount(accountId)!.realmUrl),
+       assert(realmUrl == connection.realmUrl),
+       _globalStore = globalStore,
        _streams = streams;
 
-  final GlobalStore _globalStore;
+  ////////////////////////////////////////////////////////////////
+  // Data.
 
-  final Account account;
-  final ApiConnection connection; // TODO(#135): update zulipFeatureLevel with events
+  ////////////////////////////////
+  // Where data comes from in the first place.
 
-  // TODO(#135): Keep all this data updated by handling Zulip events from the server.
+  final GlobalStore _globalStore;
+  final ApiConnection connection; // TODO(#135): update zulipFeatureLevel with events
 
+  ////////////////////////////////
   // Data attached to the realm or the server.
+
+  /// Always equal to `account.realmUrl` and `connection.realmUrl`.
+  final Uri realmUrl;
+
+  /// Resolve [reference] as a URL relative to [realmUrl].
+  ///
+  /// This returns null if [reference] fails to parse as a URL.
+  Uri? tryResolveUrl(String reference) => _tryResolveUrl(realmUrl, reference);
+
   final String zulipVersion; // TODO get from account; update there on initial snapshot
   final int maxFileUploadSizeMib; // No event for this.
   final Map<String, RealmDefaultExternalAccount> realmDefaultExternalAccounts;
   Map<String, RealmEmojiItem> realmEmoji;
   List<CustomProfileField> customProfileFields;
 
+  ////////////////////////////////
   // Data attached to the self-account on the realm.
+
+  final int accountId;
+  Account get account => _globalStore.getAccount(accountId)!;
+
+  /// Always equal to `account.userId`.
+  final int selfUserId;
+
   final UserSettings? userSettings; // TODO(server-5)
-  final Unreads unreads;
 
+  ////////////////////////////////
   // Users and data about them.
+
   final Map<int, User> users;
 
+  ////////////////////////////////
   // Streams, topics, and stuff about them.
 
   @override
@@ -278,7 +305,10 @@ class PerAccountStore extends ChangeNotifier with StreamStore {
   @visibleForTesting
   StreamStoreImpl get debugStreamStore => _streams;
 
-  // TODO lots more data.  When adding, be sure to update handleEvent too.
+  ////////////////////////////////
+  // Messages, and summaries of messages.
+
+  final Unreads unreads;
 
   final RecentDmConversationsView recentDmConversationsView;
 
@@ -294,8 +324,14 @@ class PerAccountStore extends ChangeNotifier with StreamStore {
     assert(removed);
   }
 
+  ////////////////////////////////
+  // Other digests of data.
+
   final AutocompleteViewManager autocompleteViewManager = AutocompleteViewManager();
 
+  // End of data.
+  ////////////////////////////////////////////////////////////////
+
   /// Called when the app is reassembled during debugging, e.g. for hot reload.
   ///
   /// This will redo from scratch any computations we can, such as parsing
@@ -464,6 +500,16 @@ class PerAccountStore extends ChangeNotifier with StreamStore {
 }
 
 const _apiSendMessage = sendMessage; // Bit ugly; for alternatives, see: https://chat.zulip.org/#narrow/stream/243-mobile-team/topic/flutter.3A.20PerAccountStore.20methods/near/1545809
+const _tryResolveUrl = tryResolveUrl;
+
+/// Like [Uri.resolve], but on failure return null instead of throwing.
+Uri? tryResolveUrl(Uri baseUrl, String reference) {
+  try {
+    return baseUrl.resolve(reference);
+  } on FormatException {
+    return null;
+  }
+}
 
 /// A [GlobalStore] that uses a live server and live, persistent local database.
 ///
@@ -517,8 +563,8 @@ class LiveGlobalStore extends GlobalStore {
   final AppDatabase _db;
 
   @override
-  Future<PerAccountStore> loadPerAccount(Account account) async {
-    final updateMachine = await UpdateMachine.load(this, account);
+  Future<PerAccountStore> loadPerAccount(int accountId) async {
+    final updateMachine = await UpdateMachine.load(this, accountId);
     return updateMachine.store;
   }
 
@@ -554,7 +600,8 @@ class UpdateMachine {
   /// Load the user's data from the server, and start an event queue going.
   ///
   /// In the future this might load an old snapshot from local storage first.
-  static Future<UpdateMachine> load(GlobalStore globalStore, Account account) async {
+  static Future<UpdateMachine> load(GlobalStore globalStore, int accountId) async {
+    final account = globalStore.getAccount(accountId)!;
     // TODO test UpdateMachine.load, now that it uses [GlobalStore.apiConnection]
     final connection = globalStore.apiConnectionFromAccount(account);
 
@@ -566,7 +613,7 @@ class UpdateMachine {
 
     final store = PerAccountStore.fromInitialSnapshot(
       globalStore: globalStore,
-      account: account,
+      accountId: accountId,
       connection: connection,
       initialSnapshot: initialSnapshot,
     );
@@ -624,7 +671,7 @@ class UpdateMachine {
         switch (e) {
           case ZulipApiException(code: 'BAD_EVENT_QUEUE_ID'):
             assert(debugLog('Lost event queue for $store.  Replacing…'));
-            await store._globalStore._reloadPerAccount(store.account);
+            await store._globalStore._reloadPerAccount(store.accountId);
             dispose();
             debugLog('… Event queue replaced.');
             return;

lib/widgets/action_sheet.dart

@@ -26,12 +26,11 @@ void showMessageActionSheet({required BuildContext context, required Message mes
   // any message list, so that's fine.
   final isComposeBoxOffered = MessageListPage.composeBoxControllerOf(context) != null;
 
-  final selfUserId = store.account.userId;
   final hasThumbsUpReactionVote = message.reactions
     ?.aggregated.any((reactionWithVotes) =>
       reactionWithVotes.reactionType == ReactionType.unicodeEmoji
       && reactionWithVotes.emojiCode == '1f44d'
-      && reactionWithVotes.userIds.contains(selfUserId))
+      && reactionWithVotes.userIds.contains(store.selfUserId))
     ?? false;
 
   showDraggableScrollableModalBottomSheet(

lib/widgets/app.dart

@@ -265,7 +265,7 @@ class HomePage extends StatelessWidget {
               const SizedBox(height: 12),
               Text.rich(TextSpan(
                 text: 'Connected to: ',
-                children: [bold(store.account.realmUrl.toString())])),
+                children: [bold(store.realmUrl.toString())])),
               Text.rich(TextSpan(
                 text: 'Zulip server version: ',
                 children: [bold(store.zulipVersion)])),