redesigned payment page + a lot of fixes

frontend/pshared/lib/provider/payment/updates.dart

@@ -0,0 +1,96 @@
+import 'package:flutter/foundation.dart';
+
+import 'package:pshared/models/payment/payment.dart';
+import 'package:pshared/provider/payment/multiple/provider.dart';
+import 'package:pshared/provider/payment/payments.dart';
+import 'package:pshared/provider/payment/provider.dart';
+
+
+class PaymentsUpdatesProvider extends ChangeNotifier {
+  PaymentsProvider? _payments;
+  PaymentProvider? _paymentProvider;
+  MultiPaymentProvider? _multiPaymentProvider;
+  Set<String> _knownKeys = {};
+
+  void update({
+    required PaymentsProvider paymentsProvider,
+    required PaymentProvider paymentProvider,
+    required MultiPaymentProvider multiPaymentProvider,
+  }) {
+    if (!identical(_payments, paymentsProvider)) {
+      _payments = paymentsProvider;
+      _syncKnownKeys();
+    }
+    if (!identical(_paymentProvider, paymentProvider)) {
+      _paymentProvider?.removeListener(_onSinglePaymentChanged);
+      _paymentProvider = paymentProvider;
+      _paymentProvider?.addListener(_onSinglePaymentChanged);
+    }
+    if (!identical(_multiPaymentProvider, multiPaymentProvider)) {
+      _multiPaymentProvider?.removeListener(_onMultiPaymentChanged);
+      _multiPaymentProvider = multiPaymentProvider;
+      _multiPaymentProvider?.addListener(_onMultiPaymentChanged);
+    }
+    _syncKnownKeys();
+  }
+
+  void _syncKnownKeys() {
+    _knownKeys = {
+      for (final payment in _payments?.payments ?? const <Payment>[])
+        ..._keyFor(payment),
+    };
+  }
+
+  void _onSinglePaymentChanged() {
+    final payment = _paymentProvider?.payment;
+    if (payment == null) return;
+    final key = _key(payment);
+    if (key != null && _knownKeys.contains(key)) return;
+    _merge([payment]);
+  }
+
+  void _onMultiPaymentChanged() {
+    final payments = _multiPaymentProvider?.payments ?? const <Payment>[];
+    if (payments.isEmpty) return;
+    final incoming = <Payment>[];
+    for (final payment in payments) {
+      final key = _key(payment);
+      if (key == null || !_knownKeys.contains(key)) {
+        incoming.add(payment);
+      }
+    }
+    if (incoming.isEmpty) return;
+    _merge(incoming);
+  }
+
+  void _merge(List<Payment> incoming) {
+    if (incoming.isEmpty) return;
+    _payments?.mergePayments(incoming);
+    for (final payment in incoming) {
+      final key = _key(payment);
+      if (key != null) {
+        _knownKeys.add(key);
+      }
+    }
+  }
+
+  String? _key(Payment payment) {
+    final ref = payment.paymentRef?.trim();
+    if (ref != null && ref.isNotEmpty) return ref;
+    final idempotency = payment.idempotencyKey?.trim();
+    if (idempotency != null && idempotency.isNotEmpty) return idempotency;
+    return null;
+  }
+
+  Iterable<String> _keyFor(Payment payment) sync* {
+    final key = _key(payment);
+    if (key != null) yield key;
+  }
+
+  @override
+  void dispose() {
+    _paymentProvider?.removeListener(_onSinglePaymentChanged);
+    _multiPaymentProvider?.removeListener(_onMultiPaymentChanged);
+    super.dispose();
+  }
+}