completed velocity integration

lib/screens/poll/poll_screen.dart

@@ -1,13 +1,16 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:provider/provider.dart';
-import 'package:qpay/models/responsive_policy.dart';
 import 'package:qpay/screens/gateway/gateway_controller.dart';
 import 'package:qpay/screens/transaction_controller.dart';
-import 'package:skeletonizer/skeletonizer.dart';
+import 'package:qpay/widgets/step_loading_widget.dart';
+import 'package:web/web.dart' as web;
 
 class PollScreen extends StatefulWidget {
-  const PollScreen({super.key});
+  final String? transactionId;
+
+  const PollScreen({super.key, this.transactionId});
 
   @override
   State<PollScreen> createState() => _PollScreenState();
@@ -17,8 +20,6 @@ class _PollScreenState extends State<PollScreen> {
   late GatewayController controller;
   late TransactionController transactionController;
 
-  bool integrating = false;
-
   @override
   void initState() {
     super.initState();
@@ -28,21 +29,35 @@ class _PollScreenState extends State<PollScreen> {
       listen: false,
     );
 
-    controller.pollTransaction(transactionController.model.confirmationData['id']);
+    _startPolling();
   }
 
-  void _showErrorSnackBar(String? message) {
-    WidgetsBinding.instance.addPostFrameCallback((_) {
-      ScaffoldMessenger.of(context).showSnackBar(
-        SnackBar(
-          content: Text(message.toString()),
-          behavior: SnackBarBehavior.floating,
-          backgroundColor: Colors.deepOrange,
-        ),
-      );
-    });
-  }
+  void _startPolling() {
+    // Priority 1: transaction ID passed via route param (/poll/:id)
+    String? transactionId = widget.transactionId;
 
+    // Priority 2: localStorage (for when gateway redirect causes page reload
+    // and the route param path is not available due to hub redirect override)
+    if (transactionId == null && kIsWeb) {
+      transactionId = web.window.localStorage.getItem('pendingTransactionId');
+      web.window.localStorage.removeItem('pendingTransactionId');
+    }
+
+    // Priority 3: in-memory confirmation data (normal SPA navigation)
+    if (transactionId == null) {
+      try {
+        transactionId =
+            transactionController.model.confirmationData['id'] as String?;
+      } catch (_) {
+        // confirmationData is late and may not be initialized
+        // after a page reload -- ignore
+      }
+    }
+
+    if (transactionId != null && transactionId.isNotEmpty) {
+      controller.pollTransaction(transactionId);
+    }
+  }
 
   @override
   void dispose() {
@@ -55,6 +70,10 @@ class _PollScreenState extends State<PollScreen> {
     return Scaffold(
       appBar: AppBar(
         title: const Text('Completing your transaction'),
+        leading: IconButton(
+          icon: const Icon(Icons.arrow_back),
+          onPressed: () => context.go('/'),
+        ),
       ),
       body: ListenableBuilder(
         listenable: controller,
@@ -65,60 +84,19 @@ class _PollScreenState extends State<PollScreen> {
             });
           }
 
-          return Container(
-            padding: EdgeInsets.all(50),
-            child: Center(
-              child: LayoutBuilder(
-                  builder: (context, constraints) {
-                    return SizedBox(
-                      width: double.parse(constraints.maxWidth > ResponsivePolicy.md ?
-                      ResponsivePolicy.md.toString() :
-                      constraints.maxWidth.toString()),
-                      child: Column(
-                        mainAxisAlignment: MainAxisAlignment.center,
-                        crossAxisAlignment: CrossAxisAlignment.center,
-                        children: [
-                          SizedBox(height: 75),
-
-                          Column(
-                            children: [
-                              Text(
-                                'We\'re checking with our gateway if your transaction was successful. This won\'t take long',
-                                style: TextStyle(fontSize: 20),
-                                textAlign: TextAlign.center,
-                              ),
-                              SizedBox(height: 50,),
-                              Image.asset('assets/velocity-animation.gif', width: 150),
-                              SizedBox(height: 50),
-                              if(controller.model.status == 'FAILED')
-                                Column(
-                                  children: [
-                                    Text(
-                                      'We failed to check your transaction status',
-                                      style: TextStyle(fontSize: 20),
-                                      textAlign: TextAlign.center,
-                                    ),
-                                    SizedBox(height: 20,),
-                                    Skeletonizer(
-                                      enabled: controller.model.isLoading,
-                                      child: OutlinedButton(
-                                        child: Text('Retry'),
-                                        onPressed: () {
-                                          controller.model.isCancelled = false;
-                                          controller.pollTransaction(transactionController.model.confirmationData['id']);
-                                        },
-                                      ),
-                                    ),
-                                  ],
-                                ),
-                            ],
-                          ),
-                        ],
-                      ),
-                    );
-                  }
-              ),
-            ),
+          return StepLoadingWidget(
+            currentStep: 1,
+            title: 'Verifying Payment',
+            subtitle:
+                'We\'re checking with our gateway if your transaction was '
+                'successful. This won\'t take long.',
+            status: controller.model.status,
+            isLoading: controller.model.isLoading,
+            errorMessage: 'We failed to check your transaction status',
+            onRetry: () {
+              controller.model.isCancelled = false;
+              _startPolling();
+            },
           );
         },
       ),