powersync prototype (WIP)

Author: Dieterbe

lib/api_client.dart

@@ -0,0 +1,60 @@
+import 'dart:convert';
+import 'package:http/http.dart' as http;
+import 'package:logging/logging.dart';
+
+final log = Logger('powersync-test');
+
+class ApiClient {
+  final String baseUrl;
+
+  ApiClient(this.baseUrl);
+
+  Future<Map<String, dynamic>> authenticate(String username, String password) async {
+    final response = await http.post(
+      Uri.parse('$baseUrl/api/auth/'),
+      headers: {'Content-Type': 'application/json'},
+      body: json.encode({'username': username, 'password': password}),
+    );
+    if (response.statusCode == 200) {
+      return json.decode(response.body);
+    } else {
+      throw Exception('Failed to authenticate');
+    }
+  }
+
+  Future<Map<String, dynamic>> getToken(String userId) async {
+    final response = await http.get(
+      Uri.parse('$baseUrl/api/get_powersync_token/'),
+      headers: {'Content-Type': 'application/json'},
+    );
+    if (response.statusCode == 200) {
+      return json.decode(response.body);
+    } else {
+      throw Exception('Failed to fetch token');
+    }
+  }
+
+  Future<void> upsert(Map<String, dynamic> record) async {
+    await http.put(
+      Uri.parse('$baseUrl/api/upload_data/'),
+      headers: {'Content-Type': 'application/json'},
+      body: json.encode(record),
+    );
+  }
+
+  Future<void> update(Map<String, dynamic> record) async {
+    await http.patch(
+      Uri.parse('$baseUrl/api/upload_data/'),
+      headers: {'Content-Type': 'application/json'},
+      body: json.encode(record),
+    );
+  }
+
+  Future<void> delete(Map<String, dynamic> record) async {
+    await http.delete(
+      Uri.parse('$baseUrl/api/upload_data/'),
+      headers: {'Content-Type': 'application/json'},
+      body: json.encode(record),
+    );
+  }
+}

lib/app_config.dart

@@ -0,0 +1,4 @@
+class AppConfig {
+  static const String djangoUrl = 'http://192.168.2.223:6061';
+  static const String powersyncUrl = 'http://192.168.2.223:8080';
+}

lib/main.dart

@@ -16,6 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:provider/provider.dart';
@@ -52,15 +53,34 @@ import 'package:wger/screens/workout_plans_screen.dart';
 import 'package:wger/theme/theme.dart';
 import 'package:wger/widgets/core/about.dart';
 import 'package:wger/widgets/core/settings.dart';
+import 'package:logging/logging.dart';
 
 import 'providers/auth.dart';
 
 void main() async {
   //zx.setLogEnabled(kDebugMode);
+  Logger.root.level = Level.INFO;
+  Logger.root.onRecord.listen((record) {
+    if (kDebugMode) {
+      print('[${record.loggerName}] ${record.level.name}: ${record.time}: ${record.message}');
+
+      if (record.error != null) {
+        print(record.error);
+      }
+      if (record.stackTrace != null) {
+        print(record.stackTrace);
+      }
+    }
+  });
 
   // Needs to be called before runApp
   WidgetsFlutterBinding.ensureInitialized();
 
+  await openDatabase();
+
+  final loggedIn = await isLoggedIn();
+  print('is logged in $loggedIn');
+
   // Locator to initialize exerciseDB
   await ServiceLocator().configure();
   // Application

lib/models/schema.dart

@@ -0,0 +1,54 @@
+import 'package:powersync/powersync.dart';
+
+const todosTable = 'todos';
+
+// these are the same ones as in postgres, except for 'id'
+Schema schema = const Schema(([
+  Table(todosTable, [
+    Column.text('list_id'),
+    Column.text('created_at'),
+    Column.text('completed_at'),
+    Column.text('description'),
+    Column.integer('completed'),
+    Column.text('created_by'),
+    Column.text('completed_by'),
+  ], indexes: [
+    // Index to allow efficient lookup within a list
+    Index('list', [IndexedColumn('list_id')])
+  ]),
+  Table('lists',
+      [Column.text('created_at'), Column.text('name'), Column.text('owner_id')])
+]));
+
+// post gres columns:
+// todos:
+// id                                   | created_at                    | completed_at | description       | completed | created_by | completed_by | list_id
+// lists:
+// id                                   | created_at                    | name        | owner_id
+
+// diagnostics app:
+/*
+new Schema([
+  new Table({
+    name: 'lists', // same as flutter
+    columns: [
+      new Column({ name: 'created_at', type: ColumnType.TEXT }),
+      new Column({ name: 'name', type: ColumnType.TEXT }),
+      new Column({ name: 'owner_id', type: ColumnType.TEXT })
+    ]
+  }),
+  new Table({
+    name: 'todos', // misses completed_at and completed_by, until these actually get populated with something
+    columns: [
+      new Column({ name: 'created_at', type: ColumnType.TEXT }),
+      new Column({ name: 'description', type: ColumnType.TEXT }),
+      new Column({ name: 'completed', type: ColumnType.INTEGER }),
+      new Column({ name: 'created_by', type: ColumnType.TEXT }),
+      new Column({ name: 'list_id', type: ColumnType.TEXT })
+    ]
+  })
+])
+
+    Column.text('completed_at'),
+    Column.text('completed_by'),
+*/

lib/models/todo_item.dart

@@ -0,0 +1,48 @@
+import '../powersync.dart';
+import 'package:powersync/sqlite3.dart' as sqlite;
+
+/// TodoItem represents a result row of a query on "todos".
+///
+/// This class is immutable - methods on this class do not modify the instance
+/// directly. Instead, watch or re-query the data to get the updated item.
+/// confirm how the watch works. this seems like a weird pattern
+class TodoItem {
+  final String id;
+  final String description;
+  final String? photoId;
+  final bool completed;
+
+  TodoItem(
+      {required this.id,
+      required this.description,
+      required this.completed,
+      required this.photoId});
+
+  factory TodoItem.fromRow(sqlite.Row row) {
+    return TodoItem(
+        id: row['id'],
+        description: row['description'],
+        photoId: row['photo_id'],
+        completed: row['completed'] == 1);
+  }
+
+  Future<void> toggle() async {
+    if (completed) {
+      await db.execute(
+          'UPDATE $todosTable SET completed = FALSE, completed_by = NULL, completed_at = NULL WHERE id = ?',
+          [id]);
+    } else {
+      await db.execute(
+          'UPDATE $todosTable SET completed = TRUE, completed_by = ?, completed_at = datetime() WHERE id = ?',
+          [await getUserId(), id]);
+    }
+  }
+
+  Future<void> delete() async {
+    await db.execute('DELETE FROM $todosTable WHERE id = ?', [id]);
+  }
+
+  static Future<void> addPhoto(String photoId, String id) async {
+    await db.execute('UPDATE $todosTable SET photo_id = ? WHERE id = ?', [photoId, id]);
+  }
+}

lib/models/todo_list.dart

@@ -0,0 +1,103 @@
+import 'package:powersync/sqlite3.dart' as sqlite;
+
+import './todo_item.dart';
+import '../powersync.dart';
+
+/// TodoList represents a result row of a query on "lists".
+///
+/// This class is immutable - methods on this class do not modify the instance
+/// directly. Instead, watch or re-query the data to get the updated list.
+class TodoList {
+  /// List id (UUID).
+  final String id;
+
+  /// Descriptive name.
+  final String name;
+
+  /// Number of completed todos in this list.
+  final int? completedCount;
+
+  /// Number of pending todos in this list.
+  final int? pendingCount;
+
+  TodoList(
+      {required this.id,
+      required this.name,
+      this.completedCount,
+      this.pendingCount});
+
+  factory TodoList.fromRow(sqlite.Row row) {
+    return TodoList(
+        id: row['id'],
+        name: row['name'],
+        completedCount: row['completed_count'],
+        pendingCount: row['pending_count']);
+  }
+
+  /// Watch all lists.
+  static Stream<List<TodoList>> watchLists() {
+    // This query is automatically re-run when data in "lists" or "todos" is modified.
+    return db
+        .watch('SELECT * FROM lists ORDER BY created_at, id')
+        .map((results) {
+      return results.map(TodoList.fromRow).toList(growable: false);
+    });
+  }
+
+  /// Watch all lists, with [completedCount] and [pendingCount] populated.
+  static Stream<List<TodoList>> watchListsWithStats() {
+    // This query is automatically re-run when data in "lists" or "todos" is modified.
+    return db.watch('''
+      SELECT
+        *,
+        (SELECT count() FROM todos WHERE list_id = lists.id AND completed = TRUE) as completed_count,
+        (SELECT count() FROM todos WHERE list_id = lists.id AND completed = FALSE) as pending_count
+      FROM lists
+      ORDER BY created_at
+    ''').map((results) {
+      return results.map(TodoList.fromRow).toList(growable: false);
+    });
+  }
+
+  /// Create a new list
+  static Future<TodoList> create(String name) async {
+    final results = await db.execute('''
+      INSERT INTO
+        lists(id, created_at, name, owner_id)
+        VALUES(uuid(), datetime(), ?, ?)
+      RETURNING *
+      ''', [name, await getUserId()]);
+    return TodoList.fromRow(results.first);
+  }
+
+  /// Watch items within this list.
+  Stream<List<TodoItem>> watchItems() {
+    return db.watch(
+        'SELECT * FROM todos WHERE list_id = ? ORDER BY created_at DESC, id',
+        parameters: [id]).map((event) {
+      return event.map(TodoItem.fromRow).toList(growable: false);
+    });
+  }
+
+  /// Delete this list.
+  Future<void> delete() async {
+    await db.execute('DELETE FROM lists WHERE id = ?', [id]);
+  }
+
+  /// Find list item.
+  static Future<TodoList> find(id) async {
+    final results = await db.get('SELECT * FROM lists WHERE id = ?', [id]);
+    return TodoList.fromRow(results);
+  }
+
+  /// Add a new todo item to this list.
+  Future<TodoItem> add(String description) async {
+    final results = await db.execute('''
+      INSERT INTO
+        todos(id, created_at, completed, list_id, description, created_by)
+        VALUES(uuid(), datetime(), FALSE, ?, ?, ?)
+      RETURNING *
+    ''', [id, description, await getUserId()]);
+    return TodoItem.fromRow(results.first);
+  }
+}