A whole bunch of changes

lib/widgets/receipt_capture.dart

@@ -0,0 +1,115 @@
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:image_picker/image_picker.dart';
+import 'package:provider/provider.dart';
+
+import '../screens/confirm_fuel_entry_screen.dart';
+import '../services/app_state.dart';
+import '../services/ocr_service.dart';
+import '../services/receipt_parser.dart';
+import 'image_source_sheet.dart';
+
+/// Long edge and JPEG quality a receipt photo is downscaled to unless
+/// "keep max quality" is on — a receipt is a photo of small printed text,
+/// not something that benefits from a multi-megapixel original, and this
+/// keeps typical files in the low hundreds of KB instead of several MB.
+const receiptImageMaxDimension = 1600.0;
+const receiptImageQuality = 70;
+
+/// Shared by [VehicleDetailScreen]'s "Log Fuel Receipt" button and the
+/// Receipts tab's "+" action: pick a photo, OCR it, and — unless the
+/// receipt looks like it's from outside Missouri, in which case the user
+/// gets a chance to back out first — hand off to [ConfirmFuelEntryScreen]
+/// for [vehicleId].
+Future<void> captureReceiptForVehicle(BuildContext context, String vehicleId) async {
+  final source = await chooseImageSource(context, heading: 'Receipt From');
+  if (source == null || !context.mounted) return;
+
+  final keepMaxQuality = context.read<AppState>().keepMaxQualityReceiptPhotos;
+  final picker = ImagePicker();
+  XFile? photo;
+  try {
+    photo = await picker.pickImage(
+      source: source,
+      imageQuality: keepMaxQuality ? null : receiptImageQuality,
+      maxWidth: keepMaxQuality ? null : receiptImageMaxDimension,
+      maxHeight: keepMaxQuality ? null : receiptImageMaxDimension,
+    );
+  } catch (e) {
+    if (context.mounted) {
+      final sourceLabel = source == ImageSource.camera ? 'camera' : 'photo library';
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text('Could not open $sourceLabel: $e')),
+      );
+    }
+    return;
+  }
+  if (photo == null) return;
+
+  final imageFile = File(photo.path);
+
+  if (!context.mounted) return;
+  showDialog(
+    context: context,
+    barrierDismissible: false,
+    builder: (_) => const Center(child: CircularProgressIndicator()),
+  );
+
+  final ocrService = OcrService();
+  String recognizedText = '';
+  try {
+    recognizedText = await ocrService.recognizeText(imageFile);
+  } catch (_) {
+    recognizedText = '';
+  } finally {
+    ocrService.dispose();
+  }
+
+  final parsed = ReceiptParser.parse(recognizedText);
+
+  if (!context.mounted) return;
+  Navigator.of(context).pop(); // close the OCR loading spinner
+
+  final state = parsed.state;
+  if (state != null && state != 'MO') {
+    final proceed = await _confirmNonMissouriPurchase(context, state);
+    if (!proceed || !context.mounted) return;
+  }
+
+  if (context.mounted) {
+    Navigator.of(context).push(
+      MaterialPageRoute(
+        builder: (_) => ConfirmFuelEntryScreen(
+          vehicleId: vehicleId,
+          imageFile: imageFile,
+          parsed: parsed,
+        ),
+      ),
+    );
+  }
+}
+
+/// Missouri's fuel tax refund only applies to fuel bought in Missouri —
+/// warn if the receipt's address is somewhere else, and let the user
+/// decide whether to log it anyway (e.g. it might still be worth tracking
+/// for other reasons even if it won't qualify for a refund).
+Future<bool> _confirmNonMissouriPurchase(BuildContext context, String stateCode) async {
+  final stateName = usStateNames[stateCode] ?? stateCode;
+  final proceed = await showDialog<bool>(
+    context: context,
+    builder: (context) => AlertDialog(
+      title: const Text('Non-Missouri Purchase'),
+      content: Text(
+        'This receipt looks like it\'s from a gas station in $stateName. '
+        'The Missouri fuel tax refund only applies to fuel purchased in '
+        'Missouri.\n\nDo you still want to add this entry?',
+      ),
+      actions: [
+        TextButton(onPressed: () => Navigator.of(context).pop(false), child: const Text('No')),
+        FilledButton(onPressed: () => Navigator.of(context).pop(true), child: const Text('Yes')),
+      ],
+    ),
+  );
+  return proceed ?? false;
+}