A whole lot of stuff

lib/screens/report_screen.dart

@@ -7,10 +7,12 @@ import 'package:provider/provider.dart';
 import 'package:url_launcher/url_launcher.dart';
 
 import '../services/app_state.dart';
+import '../services/estimated_refund.dart';
 import '../services/fuel_report.dart';
 import '../services/fuel_report_images.dart';
 import '../services/fuel_report_pdf.dart';
 import '../services/onboarding_keys.dart';
+import 'faq_screen.dart';
 
 /// Missouri's Motor Fuel Refund Claim form isn't something this app can
 /// file for the user — it's a state form, submitted to the state — so the
@@ -51,13 +53,26 @@ class _ReportScreenState extends State<ReportScreen> with AutomaticKeepAliveClie
   @override
   bool get wantKeepAlive => true;
 
+  @override
+  void initState() {
+    super.initState();
+    final (start, end) = defaultReportDateRange(DateTime.now());
+    _startDate = start;
+    _endDate = end;
+  }
+
   Future<void> _pickDate({required bool isStart}) async {
     final now = DateTime.now();
+    // The default range's end can fall in the future (it covers the
+    // fuel-tax-refund period currently underway, per defaultReportDateRange)
+    // — showDatePicker asserts initialDate <= lastDate, so lastDate has to
+    // stretch to cover it too, not just "today".
+    final lastDate = _endDate != null && _endDate!.isAfter(now) ? _endDate! : now;
     final picked = await showDatePicker(
       context: context,
       initialDate: (isStart ? _startDate : _endDate) ?? now,
       firstDate: DateTime(2000),
-      lastDate: now,
+      lastDate: lastDate,
     );
     if (picked == null) return;
     setState(() {
@@ -118,6 +133,22 @@ class _ReportScreenState extends State<ReportScreen> with AutomaticKeepAliveClie
     }
   }
 
+  Future<void> _preview(FuelReport report) async {
+    setState(() => _busy = true);
+    Uint8List bytes;
+    try {
+      bytes = await _buildPdfBytes(report);
+    } finally {
+      if (mounted) setState(() => _busy = false);
+    }
+    if (!mounted) return;
+    await Navigator.of(context).push(
+      MaterialPageRoute(
+        builder: (_) => _ReportPreviewScreen(bytes: bytes, fileName: fuelReportFileName(report)),
+      ),
+    );
+  }
+
   Future<void> _openRefundFormLink() async {
     final launched = await launchUrl(_refundFormUrl, mode: LaunchMode.externalApplication);
     if (!launched && mounted) {
@@ -161,7 +192,10 @@ class _ReportScreenState extends State<ReportScreen> with AutomaticKeepAliveClie
           );
 
     return Scaffold(
-      appBar: AppBar(title: const Text('Fuel Report')),
+      appBar: AppBar(
+        title: const Text('Fuel Report'),
+        actions: const [FaqActionButton()],
+      ),
       body: ListView(
         padding: const EdgeInsets.all(16),
         children: [
@@ -233,6 +267,7 @@ class _ReportScreenState extends State<ReportScreen> with AutomaticKeepAliveClie
               _VehicleSelectionCard(
                 row: row,
                 selected: _selectedVehicleIds.contains(row.vehicle.id),
+                showEstimatedRefund: appState.showEstimatedFuelRefund,
                 onTap: () => setState(() {
                   if (_selectedVehicleIds.contains(row.vehicle.id)) {
                     _selectedVehicleIds.remove(row.vehicle.id);
@@ -252,7 +287,9 @@ class _ReportScreenState extends State<ReportScreen> with AutomaticKeepAliveClie
                 title: const Text('Total', style: TextStyle(fontWeight: FontWeight.bold)),
                 trailing: Text(
                   '${report.totalGallons.toStringAsFixed(3)} gal · '
-                  '${NumberFormat.simpleCurrency().format(report.totalCost)}',
+                  '${NumberFormat.simpleCurrency().format(report.totalCost)}'
+                  '${appState.showEstimatedFuelRefund ? ' · Est. '
+                      '${NumberFormat.simpleCurrency().format(estimatedFuelRefund(report.totalGallons))}' : ''}',
                   style: const TextStyle(fontWeight: FontWeight.bold),
                 ),
               ),
@@ -260,6 +297,14 @@ class _ReportScreenState extends State<ReportScreen> with AutomaticKeepAliveClie
               Row(
                 key: OnboardingKeys.reportShareAndPrintRow,
                 children: [
+                  Expanded(
+                    child: OutlinedButton.icon(
+                      onPressed: _busy ? null : () => _preview(report),
+                      icon: const Icon(Icons.visibility_outlined),
+                      label: const Text('Preview'),
+                    ),
+                  ),
+                  const SizedBox(width: 12),
                   Expanded(
                     child: FilledButton.icon(
                       onPressed: _busy ? null : () => _share(report),
@@ -334,9 +379,15 @@ class _ReportScreenState extends State<ReportScreen> with AutomaticKeepAliveClie
 class _VehicleSelectionCard extends StatelessWidget {
   final VehicleReportRow row;
   final bool selected;
+  final bool showEstimatedRefund;
   final VoidCallback onTap;
 
-  const _VehicleSelectionCard({required this.row, required this.selected, required this.onTap});
+  const _VehicleSelectionCard({
+    required this.row,
+    required this.selected,
+    required this.showEstimatedRefund,
+    required this.onTap,
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -379,6 +430,13 @@ class _VehicleSelectionCard extends StatelessWidget {
                     NumberFormat.simpleCurrency().format(row.totalCost),
                     style: TextStyle(color: foreground),
                   ),
+                  if (showEstimatedRefund) ...[
+                    const SizedBox(height: 2),
+                    Text(
+                      'Est. ${NumberFormat.simpleCurrency().format(estimatedFuelRefund(row.totalGallons))}',
+                      style: TextStyle(color: foregroundVariant, fontSize: 12),
+                    ),
+                  ],
                 ],
               ),
             ],
@@ -388,3 +446,31 @@ class _VehicleSelectionCard extends StatelessWidget {
     );
   }
 }
+
+/// Shows the already-built report PDF in-app, with [PdfPreview]'s own
+/// built-in Share/Print actions — so Preview isn't a dead end, the same
+/// two actions available back on [ReportScreen] are still reachable from
+/// here without backing out first. The report's format is fixed
+/// ([buildFuelReportPdf] always renders US Letter), so the page
+/// format/orientation controls [PdfPreview] would otherwise offer are
+/// turned off since they wouldn't actually change anything.
+class _ReportPreviewScreen extends StatelessWidget {
+  final Uint8List bytes;
+  final String fileName;
+
+  const _ReportPreviewScreen({required this.bytes, required this.fileName});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text('Report Preview')),
+      body: PdfPreview(
+        build: (format) async => bytes,
+        pdfFileName: fileName,
+        canChangePageFormat: false,
+        canChangeOrientation: false,
+        canDebug: false,
+      ),
+    );
+  }
+}