fix: Make transactions atomic / AutoLogout

2026-08-03 02:22:26 +02:00
parent 6060ca2713
commit 0997d110d4
14 changed files with 604 additions and 285 deletions
@@ -8,6 +8,7 @@ import '../models/closed_tab_item.dart';
 import '../models/payment_method.dart';
 import '../models/product.dart';
 import '../models/tab_item.dart';
+import 'product_service.dart';

 abstract class BarTabService {
  Future<List<BarTab>> getOpenTabs();
@@ -19,18 +20,19 @@ abstract class BarTabService {
  Future<void> addProductToTab({
    required String tabId,
    required Product product,
-    Future<void> Function()? stockAdjustment,
  });

-  Future<void> updateTabItemQuantity({
+  Future<int> adjustTabItemQuantity({
    required String tabItemId,
-    required int quantity,
-    Future<void> Function()? stockAdjustment,
+    required int delta,
  });

  /// Archives the tab's current items into history and clears them.
  /// The tab itself stays open under the same customer name.
-  Future<void> closeTab(String tabId, {PaymentMethod paymentMethod = PaymentMethod.cash});
+  Future<void> closeTab(
+    String tabId, {
+    PaymentMethod paymentMethod = PaymentMethod.cash,
+  });

  Future<List<ClosedTab>> getClosedTabs();

@@ -94,6 +96,54 @@ class DriftBarTabService implements BarTabService {
    return rows.map(_mapItemRow).toList();
  }

+  Future<void> _decreaseProductStock(String productId, int amount) async {
+    if (amount <= 0) {
+      throw ArgumentError.value(amount, 'amount', 'Must be greater than zero');
+    }
+
+    final updatedRows = await database.customUpdate(
+      'UPDATE products '
+      'SET stock_quantity = stock_quantity - ? '
+      'WHERE id = ? AND stock_quantity >= ?',
+      variables: [
+        Variable.withInt(amount),
+        Variable.withString(productId),
+        Variable.withInt(amount),
+      ],
+      updates: {database.products},
+    );
+
+    if (updatedRows == 1) return;
+
+    final product = await (database.select(
+      database.products,
+    )..where((row) => row.id.equals(productId))).getSingleOrNull();
+
+    if (product == null) {
+      throw Exception('Product not found');
+    }
+
+    throw const InsufficientStockException();
+  }
+
+  Future<void> _increaseProductStock(String productId, int amount) async {
+    if (amount <= 0) {
+      throw ArgumentError.value(amount, 'amount', 'Must be greater than zero');
+    }
+
+    final updatedRows = await database.customUpdate(
+      'UPDATE products '
+      'SET stock_quantity = stock_quantity + ? '
+      'WHERE id = ?',
+      variables: [Variable.withInt(amount), Variable.withString(productId)],
+      updates: {database.products},
+    );
+
+    if (updatedRows == 1) return;
+
+    throw Exception('Product not found');
+  }
+
  @override
  Future<List<BarTab>> getOpenTabs() async {
    final query = database.select(database.barTabs)
@@ -157,9 +207,10 @@ class DriftBarTabService implements BarTabService {
  Future<void> addProductToTab({
    required String tabId,
    required Product product,
-    Future<void> Function()? stockAdjustment,
  }) async {
    await database.transaction(() async {
+      await _decreaseProductStock(product.id, 1);
+
      final existingItemQuery = database.select(database.tabItems)
        ..where(
          (item) =>
@@ -176,10 +227,6 @@ class DriftBarTabService implements BarTabService {
          TabItemsCompanion(quantity: Value(existingItem.quantity + 1)),
        );

-        if (stockAdjustment != null) {
-          await stockAdjustment();
-        }
-
        return;
      }

@@ -196,46 +243,60 @@ class DriftBarTabService implements BarTabService {
              createdAt: DateTime.now(),
            ),
          );
-
-      if (stockAdjustment != null) {
-        await stockAdjustment();
-      }
    });
  }

  @override
-  Future<void> updateTabItemQuantity({
+  Future<int> adjustTabItemQuantity({
    required String tabItemId,
-    required int quantity,
-    Future<void> Function()? stockAdjustment,
+    required int delta,
  }) async {
-    await database.transaction(() async {
-      if (quantity <= 0) {
-        final deleteQuery = database.delete(database.tabItems)
-          ..where((item) => item.id.equals(tabItemId));
+    return database.transaction(() async {
+      final item = await (database.select(
+        database.tabItems,
+      )..where((row) => row.id.equals(tabItemId))).getSingleOrNull();

-        await deleteQuery.go();
+      if (item == null || delta == 0) return 0;

-        if (stockAdjustment != null) {
-          await stockAdjustment();
+      final requestedQuantity = item.quantity + delta;
+      final actualDelta = requestedQuantity <= 0 ? -item.quantity : delta;
+
+      if (actualDelta > 0) {
+        await _decreaseProductStock(item.productId, actualDelta);
+      } else {
+        await _increaseProductStock(item.productId, -actualDelta);
+      }
+
+      if (requestedQuantity <= 0) {
+        final deletedRows = await (database.delete(
+          database.tabItems,
+        )..where((row) => row.id.equals(tabItemId))).go();
+
+        if (deletedRows != 1) {
+          throw StateError('Tab item was changed before it could be deleted');
        }
+      } else {
+        final updatedRows =
+            await (database.update(database.tabItems)
+                  ..where((row) => row.id.equals(tabItemId)))
+                .write(TabItemsCompanion(quantity: Value(requestedQuantity)));

-        return;
+        if (updatedRows != 1) {
+          throw StateError(
+            'Tab item was changed before its quantity was updated',
+          );
+        }
      }

-      final updateQuery = database.update(database.tabItems)
-        ..where((item) => item.id.equals(tabItemId));
-
-      await updateQuery.write(TabItemsCompanion(quantity: Value(quantity)));
-
-      if (stockAdjustment != null) {
-        await stockAdjustment();
-      }
+      return actualDelta;
    });
  }

  @override
-  Future<void> closeTab(String tabId, {PaymentMethod paymentMethod = PaymentMethod.cash}) async {
+  Future<void> closeTab(
+    String tabId, {
+    PaymentMethod paymentMethod = PaymentMethod.cash,
+  }) async {
    await database.transaction(() async {
      final tabQuery = database.select(database.barTabs)
        ..where((tab) => tab.id.equals(tabId));
@@ -307,8 +368,7 @@ class DriftBarTabService implements BarTabService {
      ..limit(limit, offset: offset);

    if (customerName != null && customerName.isNotEmpty) {
-      query = query
-        ..where((tab) => tab.customerName.equals(customerName));
+      query = query..where((tab) => tab.customerName.equals(customerName));
    }

    final closedTabRows = await query.get();
@@ -355,10 +415,6 @@ class DriftBarTabService implements BarTabService {
  @override
  Future<List<String>> getDistinctCustomerNames() async {
    final rows = await database.select(database.closedTabs).get();
-    return rows
-        .map((row) => row.customerName)
-        .toSet()
-        .toList()
-      ..sort();
+    return rows.map((row) => row.customerName).toSet().toList()..sort();
  }
 }
@@ -130,31 +130,48 @@ class DriftProductService implements ProductService {

  @override
  Future<void> decreaseStock(String productId, int amount) async {
-    final product = await getProductById(productId);
+    _validateStockAmount(amount);

-    if (product == null) {
-      throw Exception('Product not found');
-    }
-
-    if (product.stockQuantity < amount) {
-      throw const InsufficientStockException();
-    }
-
-    await updateProduct(
-      product.copyWith(stockQuantity: product.stockQuantity - amount),
+    final updatedRows = await database.customUpdate(
+      'UPDATE products '
+      'SET stock_quantity = stock_quantity - ? '
+      'WHERE id = ? AND stock_quantity >= ?',
+      variables: [
+        Variable.withInt(amount),
+        Variable.withString(productId),
+        Variable.withInt(amount),
+      ],
+      updates: {database.products},
    );
+
+    if (updatedRows == 1) return;
+
+    final product = await getProductById(productId);
+    if (product == null) throw Exception('Product not found');
+
+    throw const InsufficientStockException();
  }

  @override
  Future<void> increaseStock(String productId, int amount) async {
-    final product = await getProductById(productId);
+    _validateStockAmount(amount);

-    if (product == null) {
-      throw Exception('Product not found');
-    }
-
-    await updateProduct(
-      product.copyWith(stockQuantity: product.stockQuantity + amount),
+    final updatedRows = await database.customUpdate(
+      'UPDATE products '
+      'SET stock_quantity = stock_quantity + ? '
+      'WHERE id = ?',
+      variables: [Variable.withInt(amount), Variable.withString(productId)],
+      updates: {database.products},
    );
+
+    if (updatedRows == 1) return;
+
+    throw Exception('Product not found');
+  }
+
+  void _validateStockAmount(int amount) {
+    if (amount <= 0) {
+      throw ArgumentError.value(amount, 'amount', 'Must be greater than zero');
+    }
  }
 }