GlobalSettingsStore, and other refactors

lib/model/database.dart

@@ -9,11 +9,13 @@ import 'settings.dart';
 
 part 'database.g.dart';
 
-/// The table of the user's chosen settings independent of account, on this
-/// client.
+/// The table of one [GlobalSettingsData] record, the user's chosen settings
+/// on this client that are independent of account.
 ///
 /// These apply across all the user's accounts on this client (i.e. on this
 /// install of the app on this device).
+///
+/// This table should always have exactly one row (it's created by a migration).
 @DataClassName('GlobalSettingsData')
 class GlobalSettings extends Table {
   Column<String> get themeSetting => textEnum<ThemeSetting>()
@@ -78,6 +80,8 @@ VersionedSchema _getSchema({
       return Schema3(database: database);
     case 4:
       return Schema4(database: database);
+    case 5:
+      return Schema5(database: database);
     default:
       throw Exception('unknown schema version: $schemaVersion');
   }
@@ -95,12 +99,12 @@ class AppDatabase extends _$AppDatabase {
   //    See ../../README.md#generated-files for more
   //    information on using the build_runner.
   //  * Update [_getSchema] to handle the new schemaVersion.
-  //  * Write a migration in `onUpgrade` below.
+  //  * Write a migration in `_migrationSteps` below.
   //  * Write tests.
   @override
-  int get schemaVersion => 4; // See note.
+  int get schemaVersion => 5; // See note.
 
-  Future<void> _dropAndCreateAll(Migrator m, {
+  static Future<void> _dropAndCreateAll(Migrator m, {
     required int schemaVersion,
   }) async {
     await m.database.transaction(() async {
@@ -125,11 +129,42 @@ class AppDatabase extends _$AppDatabase {
     });
   }
 
+  static final MigrationStepWithVersion _migrationSteps = migrationSteps(
+    from1To2: (m, schema) async {
+      await m.addColumn(schema.accounts, schema.accounts.ackedPushToken);
+    },
+    from2To3: (m, schema) async {
+      await m.createTable(schema.globalSettings);
+    },
+    from3To4: (m, schema) async {
+      await m.addColumn(
+        schema.globalSettings, schema.globalSettings.browserPreference);
+    },
+    from4To5: (m, schema) async {
+      // Corresponds to the `into(globalSettings).insert` in `onCreate`.
+      // This migration ensures there is a row in GlobalSettings.
+      // (If the app already ran at schema 3 or 4, there will be;
+      // if not, there won't be before this point.)
+      await m.database.transaction(() async {
+        final rows = await m.database.select(schema.globalSettings).get();
+        if (rows.isEmpty) {
+          await m.database.into(schema.globalSettings).insert(
+            // No field values; just use the defaults for both fields.
+            // (This is like `GlobalSettingsCompanion.insert()`, but
+            // without dependence on the current schema.)
+            RawValuesInsertable({}));
+        }
+      });
+    },
+  );
+
   @override
   MigrationStrategy get migration {
     return MigrationStrategy(
       onCreate: (Migrator m) async {
         await m.createAll();
+        // Corresponds to `from4to5` above.
+        await into(globalSettings).insert(GlobalSettingsCompanion());
       },
       onUpgrade: (Migrator m, int from, int to) async {
         if (from > to) {
@@ -142,39 +177,13 @@ class AppDatabase extends _$AppDatabase {
         }
         assert(1 <= from && from <= to && to <= schemaVersion);
 
-        await m.runMigrationSteps(from: from, to: to,
-          steps: migrationSteps(
-            from1To2: (m, schema) async {
-              await m.addColumn(schema.accounts, schema.accounts.ackedPushToken);
-            },
-            from2To3: (m, schema) async {
-              await m.createTable(schema.globalSettings);
-            },
-            from3To4: (m, schema) async {
-              await m.addColumn(
-                schema.globalSettings, schema.globalSettings.browserPreference);
-            },
-          ));
+        await m.runMigrationSteps(from: from, to: to, steps: _migrationSteps);
       });
   }
 
-  Future<GlobalSettingsData> ensureGlobalSettings() async {
-    final settings = await select(globalSettings).get();
-    // TODO(db): Enforce the singleton constraint more robustly.
-    if (settings.isNotEmpty) {
-      if (settings.length > 1) {
-        assert(debugLog('Expected one globalSettings, got multiple: $settings'));
-      }
-      return settings.first;
-    }
-
-    final rowsAffected = await into(globalSettings).insert(GlobalSettingsCompanion.insert());
-    assert(rowsAffected == 1);
-    final result = await select(globalSettings).get();
-    if (result.length > 1) {
-      assert(debugLog('Expected one globalSettings, got multiple: $result'));
-    }
-    return result.first;
+  Future<GlobalSettingsData> getGlobalSettings() async {
+    // The migrations ensure there is a row.
+    return await (select(globalSettings)..limit(1)).getSingle();
   }
 
   Future<int> createAccount(AccountsCompanion values) async {

lib/model/schema_versions.g.dart

@@ -241,10 +241,56 @@ i1.GeneratedColumn<String> _column_10(String aliasedName) =>
       true,
       type: i1.DriftSqlType.string,
     );
+
+final class Schema5 extends i0.VersionedSchema {
+  Schema5({required super.database}) : super(version: 5);
+  @override
+  late final List<i1.DatabaseSchemaEntity> entities = [
+    globalSettings,
+    accounts,
+  ];
+  late final Shape2 globalSettings = Shape2(
+    source: i0.VersionedTable(
+      entityName: 'global_settings',
+      withoutRowId: false,
+      isStrict: false,
+      tableConstraints: [],
+      columns: [_column_9, _column_10],
+      attachedDatabase: database,
+    ),
+    alias: null,
+  );
+  late final Shape0 accounts = Shape0(
+    source: i0.VersionedTable(
+      entityName: 'accounts',
+      withoutRowId: false,
+      isStrict: false,
+      tableConstraints: [
+        'UNIQUE(realm_url, user_id)',
+        'UNIQUE(realm_url, email)',
+      ],
+      columns: [
+        _column_0,
+        _column_1,
+        _column_2,
+        _column_3,
+        _column_4,
+        _column_5,
+        _column_6,
+        _column_7,
+        _column_8,
+      ],
+      attachedDatabase: database,
+    ),
+    alias: null,
+  );
+}
+
 i0.MigrationStepWithVersion migrationSteps({
   required Future<void> Function(i1.Migrator m, Schema2 schema) from1To2,
   required Future<void> Function(i1.Migrator m, Schema3 schema) from2To3,
   required Future<void> Function(i1.Migrator m, Schema4 schema) from3To4,
+  required Future<void> Function(i1.Migrator m, Schema5 schema) from4To5,
 }) {
   return (currentVersion, database) async {
     switch (currentVersion) {
@@ -263,6 +309,11 @@ i0.MigrationStepWithVersion migrationSteps({
         final migrator = i1.Migrator(database, schema);
         await from3To4(migrator, schema);
         return 4;
+      case 4:
+        final schema = Schema5(database: database);
+        final migrator = i1.Migrator(database, schema);
+        await from4To5(migrator, schema);
+        return 5;
       default:
         throw ArgumentError.value('Unknown migration from $currentVersion');
     }
@@ -273,10 +324,12 @@ i1.OnUpgrade stepByStep({
   required Future<void> Function(i1.Migrator m, Schema2 schema) from1To2,
   required Future<void> Function(i1.Migrator m, Schema3 schema) from2To3,
   required Future<void> Function(i1.Migrator m, Schema4 schema) from3To4,
+  required Future<void> Function(i1.Migrator m, Schema5 schema) from4To5,
 }) => i0.VersionedSchema.stepByStepHelper(
   step: migrationSteps(
     from1To2: from1To2,
     from2To3: from2To3,
     from3To4: from3To4,
+    from4To5: from4To5,
   ),
 );

lib/model/settings.dart

@@ -3,6 +3,7 @@ import 'package:flutter/foundation.dart';
 import '../generated/l10n/zulip_localizations.dart';
 import 'binding.dart';
 import 'database.dart';
+import 'store.dart';
 
 /// The user's choice of visual theme for the app.
 ///
@@ -44,7 +45,39 @@ enum BrowserPreference {
   external,
 }
 
-extension GlobalSettingsHelpers on GlobalSettingsData {
+/// Store for the user's account-independent settings.
+///
+/// From UI code, use [GlobalStoreWidget.settingsOf] to get hold of
+/// an appropriate instance of this class.
+class GlobalSettingsStore extends ChangeNotifier {
+  GlobalSettingsStore({
+    required GlobalStoreBackend backend,
+    required GlobalSettingsData data,
+  }) : _backend = backend, _data = data;
+
+  final GlobalStoreBackend _backend;
+
+  /// A cache of the [GlobalSettingsData] singleton in the underlying data store.
+  GlobalSettingsData _data;
+
+  /// The user's choice of [ThemeSetting];
+  /// null means the device-level choice of theme.
+  ///
+  /// See also [setThemeSetting].
+  ThemeSetting? get themeSetting => _data.themeSetting;
+
+  /// The user's choice of [BrowserPreference];
+  /// null means use our default choice.
+  ///
+  /// Consider using [effectiveBrowserPreference] or [getUrlLaunchMode].
+  ///
+  /// See also [setBrowserPreference].
+  BrowserPreference? get browserPreference => _data.browserPreference;
+
+  /// The value of [BrowserPreference] to use:
+  /// the user's choice [browserPreference] if any, else our default.
+  ///
+  /// See also [getUrlLaunchMode].
   BrowserPreference get effectiveBrowserPreference {
     if (browserPreference != null) return browserPreference!;
     return switch (defaultTargetPlatform) {
@@ -61,6 +94,8 @@ extension GlobalSettingsHelpers on GlobalSettingsData {
     };
   }
 
+  /// The launch mode to use with `url_launcher`,
+  /// based on the user's choice in [browserPreference].
   UrlLaunchMode getUrlLaunchMode(Uri url) {
     switch (effectiveBrowserPreference) {
       case BrowserPreference.inApp:
@@ -78,4 +113,20 @@ extension GlobalSettingsHelpers on GlobalSettingsData {
         return UrlLaunchMode.externalApplication;
     }
   }
+
+  Future<void> _update(GlobalSettingsCompanion data) async {
+    await _backend.doUpdateGlobalSettings(data);
+    _data = _data.copyWithCompanion(data);
+    notifyListeners();
+  }
+
+  /// Set [themeSetting], persistently for future runs of the app.
+  Future<void> setThemeSetting(ThemeSetting? value) async {
+    await _update(GlobalSettingsCompanion(themeSetting: Value(value)));
+  }
+
+  /// Set [browserPreference], persistently for future runs of the app.
+  Future<void> setBrowserPreference(BrowserPreference? value) async {
+    await _update(GlobalSettingsCompanion(browserPreference: Value(value)));
+  }
 }