set up Drift database with local data models

lib/core/database/app_database.dart

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+import 'dart:io';
+import 'package:drift/drift.dart';
+import 'package:drift/native.dart';
+import 'package:path/path.dart' as p;
+import 'package:path_provider/path_provider.dart';
+import 'package:zplit/core/database/daos/balances_dao.dart';
+
+import 'package:zplit/core/database/daos/groups_dao.dart';
+import 'package:zplit/core/database/daos/transactions_dao.dart';
+import 'package:zplit/core/database/daos/users_dao.dart';
+
+import 'package:zplit/core/database/tables/groups_table.dart';
+
+import 'tables/users_table.dart';
+import 'tables/transactions_table.dart';
+import 'tables/balances_table.dart';
+
+import 'package:uuid/uuid.dart';
+
+part 'app_database.g.dart';
+
+const _uuid = Uuid();
+
+@DriftDatabase(
+  tables: [UsersTable, TransactionsTable, BalancesTable, GroupsTable],
+  daos: [TransactionsDao, GroupsDao, UsersDao, BalancesDao],
+)
+class AppDatabase extends _$AppDatabase {
+  AppDatabase() : super(_openConnection());
+  AppDatabase.forTesting(QueryExecutor executor) : super(executor);
+
+  @override
+  int get schemaVersion => 1;
+  @override
+  MigrationStrategy get migration => MigrationStrategy(
+    beforeOpen: (details) async {
+      await customStatement('PRAGMA foreign_keys = ON;');
+    },
+  );
+}
+
+LazyDatabase _openConnection() {
+  return LazyDatabase(() async {
+    final dir = await getApplicationDocumentsDirectory();
+    final file = File(p.join(dir.path, 'zplit.sqlite'));
+    return NativeDatabase.createInBackground(file);
+  });
+}

lib/core/database/daos/balances_dao.dart

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+import 'package:drift/drift.dart';
+import 'package:zplit/core/database/tables/balances_table.dart';
+import 'package:zplit/core/database/app_database.dart';
+
+part 'balances_dao.g.dart';
+
+@DriftAccessor(tables: [BalancesTable])
+class BalancesDao extends DatabaseAccessor<AppDatabase>
+    with _$BalancesDaoMixin {
+  BalancesDao(super.db);
+
+  Future<List<BalancesTableData>> getAll() {
+    return select(balancesTable).get();
+  }
+
+  Future<BalancesTableData?> getByPublicKey(String userPublicKey) {
+    final query = select(balancesTable);
+    query.where((t) => t.userPublicKey.equals(userPublicKey));
+    return query.getSingleOrNull();
+  }
+
+  // we can just use upsert for update and insert
+  Future<void> upsert(BalancesTableCompanion balance) {
+    return into(balancesTable).insertOnConflictUpdate(balance);
+  }
+
+  Future<int> deleteBalances(String userPublicKey) {
+    final query = delete(balancesTable);
+    query.where((t) => t.userPublicKey.equals(userPublicKey));
+    return query.go();
+  }
+}

lib/core/database/daos/groups_dao.dart

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+import 'package:drift/drift.dart';
+import 'package:zplit/core/database/tables/groups_table.dart';
+import 'package:zplit/core/database/app_database.dart';
+
+part 'groups_dao.g.dart';
+
+@DriftAccessor(tables: [GroupsTable])
+class GroupsDao extends DatabaseAccessor<AppDatabase> with _$GroupsDaoMixin {
+  GroupsDao(super.db);
+
+  Future<List<GroupsTableData>> getAll() {
+    return select(groupsTable).get();
+  }
+
+  Future<GroupsTableData?> getById(String id) {
+    final query = select(groupsTable);
+    query.where((t) => t.id.equals(id));
+    return query.getSingleOrNull();
+  }
+
+  Future<void> upsert(GroupsTableCompanion group) {
+    return into(groupsTable).insertOnConflictUpdate(group);
+  }
+
+  Future<int> deletegroup(String id) {
+    final query = delete(groupsTable);
+    query.where((t) => t.id.equals(id));
+    return query.go();
+  }
+}

lib/core/database/daos/transactions_dao.dart

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+import 'package:drift/drift.dart';
+import 'package:zplit/core/database/tables/transactions_table.dart';
+import 'package:zplit/core/database/app_database.dart';
+
+part 'transactions_dao.g.dart';
+
+@DriftAccessor(tables: [TransactionsTable])
+class TransactionsDao extends DatabaseAccessor<AppDatabase>
+    with _$TransactionsDaoMixin {
+  TransactionsDao(super.db);
+
+  Future<List<TransactionsTableData>> getAll() {
+    return select(transactionsTable).get();
+  }
+
+  Future<TransactionsTableData?> getById(String id) {
+    final query = select(transactionsTable);
+    query.where((t) => t.id.equals(id));
+    return query.getSingleOrNull();
+  }
+
+  Future<int> insert(TransactionsTableCompanion transaction) {
+    return into(transactionsTable).insert(transaction);
+  }
+}

lib/core/database/daos/users_dao.dart

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+import 'package:drift/drift.dart';
+import 'package:zplit/core/database/tables/users_table.dart';
+import 'package:zplit/core/database/app_database.dart';
+
+part 'users_dao.g.dart';
+
+@DriftAccessor(tables: [UsersTable])
+class UsersDao extends DatabaseAccessor<AppDatabase> with _$UsersDaoMixin {
+  UsersDao(super.db);
+
+  Future<List<UsersTableData>> getAll() {
+    return select(usersTable).get();
+  }
+
+  Future<UsersTableData?> getByPublicKey(String publicKey) {
+    final query = select(usersTable);
+    query.where((t) => t.publicKey.equals(publicKey));
+    return query.getSingleOrNull();
+  }
+
+  Future<void> upsert(UsersTableCompanion user) {
+    return into(usersTable).insertOnConflictUpdate(user);
+  }
+
+  Future<int> deleteUser(String publicKey) {
+    final query = delete(usersTable);
+    query.where((t) => t.publicKey.equals(publicKey));
+    return query.go();
+  }
+}

lib/core/database/tables/balances_table.dart

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+import 'package:drift/drift.dart';
+import 'package:zplit/core/database/tables/users_table.dart';
+
+class BalancesTable extends Table {
+  TextColumn get userPublicKey => text().references(UsersTable, #publicKey)();
+  IntColumn get netAmount => integer()();
+  TextColumn get signed => text().nullable()();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+
+  @override
+  String get tableName => 'balances';
+
+  @override
+  Set<Column> get primaryKey => {userPublicKey};
+}

lib/core/database/tables/groups_table.dart

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+import 'package:drift/drift.dart';
+import 'package:uuid/uuid.dart';
+
+const _uuid = Uuid();
+
+class GroupsTable extends Table {
+  TextColumn get id => text().clientDefault(() => _uuid.v4())();
+  TextColumn get name => text()();
+  // storing member public keys as a set (comma separated string)
+  TextColumn get users => text().withDefault(const Constant(''))();
+  TextColumn get description => text().nullable()();
+
+  @override
+  String get tableName => 'groups';
+
+  @override
+  Set<Column> get primaryKey => {id};
+}

lib/core/database/tables/transactions_table.dart

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+import 'package:drift/drift.dart';
+import 'package:zplit/core/database/tables/users_table.dart';
+
+enum TransactionStatus { unsigned, partiallySigned, signed }
+
+class TransactionsTable extends Table {
+  TextColumn get id => text()();
+  TextColumn get fromUserPublicKey =>
+      text().references(UsersTable, #publicKey)();
+  TextColumn get toUserPublicKey => text().references(UsersTable, #publicKey)();
+  Int64Column get amount => int64()();
+  TextColumn get description => text().nullable()();
+  TextColumn get tag => text().nullable()();
+  TextColumn get status => textEnum<TransactionStatus>()();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
+  TextColumn get senderSignature => text().nullable()();
+  TextColumn get receiverSignature => text().nullable()();
+
+  @override
+  String get tableName => 'transactions';
+
+  @override
+  Set<Column> get primaryKey => {id};
+}

lib/core/database/tables/users_table.dart

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+import 'package:drift/drift.dart';
+
+class UsersTable extends Table {
+  TextColumn get publicKey => text()();
+  TextColumn get displayName => text()();
+  TextColumn get cryptoAddress => text().nullable()();
+  TextColumn get profilePicture => text().nullable()();
+
+  @override
+  String get tableName => 'users';
+
+  @override
+  Set<Column> get primaryKey => {publicKey};
+}