From 07b1df336961f5c55b0fa11787f14997d4536070 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lukas=20M=C3=BCllner?= <derkauzigekoala@gmail.com>
Date: Thu, 5 Mar 2026 08:37:13 +0100
Subject: [PATCH] perf: reduce scanner OCR workload

---
 lib/scanner_screen.dart | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/lib/scanner_screen.dart b/lib/scanner_screen.dart
index be7c858..ada97ec 100644
--- a/lib/scanner_screen.dart
+++ b/lib/scanner_screen.dart
@@ -31,6 +31,11 @@ class ScannerScreen extends StatefulWidget {
 }
 
 class _ScannerScreenState extends State<ScannerScreen> {
+  static const _autoScanTickInterval = Duration(milliseconds: 700);
+  static const _scanCooldownSuccess = Duration(milliseconds: 1500);
+  static const _scanCooldownNoMatch = Duration(milliseconds: 2200);
+  static const _scanCooldownError = Duration(milliseconds: 2600);
+
   CameraController? _cameraController;
   late final TextRecognizer _textRecognizer;
   bool _isBusy = false;
@@ -42,6 +47,7 @@ class _ScannerScreenState extends State<ScannerScreen> {
   String? _activeCollectionId;
   bool _autoScanEnabled = false;
   Timer? _autoScanTimer;
+  DateTime _nextScanAllowedAt = DateTime.fromMillisecondsSinceEpoch(0);
 
   @override
   void initState() {
@@ -76,7 +82,7 @@ class _ScannerScreenState extends State<ScannerScreen> {
 
     _cameraController = CameraController(
       backCamera,
-      ResolutionPreset.high,
+      ResolutionPreset.medium,
       enableAudio: false,
     );
 
@@ -88,8 +94,9 @@ class _ScannerScreenState extends State<ScannerScreen> {
 
   void _startAutoScanLoop() {
     _autoScanTimer?.cancel();
-    _autoScanTimer = Timer.periodic(const Duration(milliseconds: 1400), (_) {
+    _autoScanTimer = Timer.periodic(_autoScanTickInterval, (_) {
       if (!_autoScanEnabled || _isBusy || !_cameraReady || !mounted) return;
+      if (DateTime.now().isBefore(_nextScanAllowedAt)) return;
       _captureAndScan();
     });
   }
@@ -105,6 +112,7 @@ class _ScannerScreenState extends State<ScannerScreen> {
   /// Capture a photo, run OCR, and look for a Hot Wheels ID.
   Future<void> _captureAndScan() async {
     if (_isBusy || _cameraController == null || !_cameraController!.value.isInitialized) return;
+    if (_cameraController!.value.isTakingPicture) return;
 
     setState(() {
       _isBusy = true;
@@ -131,11 +139,13 @@ class _ScannerScreenState extends State<ScannerScreen> {
       if (!mounted) return;
 
       if (found != null) {
+        _nextScanAllowedAt = DateTime.now().add(_scanCooldownSuccess);
         setState(() => _lastDetected = found);
         if (widget.onDetected != null) {
           await _submitDetected(found);
         }
       } else {
+        _nextScanAllowedAt = DateTime.now().add(_scanCooldownNoMatch);
         setState(() {
           _scanAccepted = false;
           _scanNotFound = true;
@@ -143,6 +153,7 @@ class _ScannerScreenState extends State<ScannerScreen> {
         });
       }
     } catch (e) {
+      _nextScanAllowedAt = DateTime.now().add(_scanCooldownError);
       if (!mounted) return;
       ScaffoldMessenger.of(context).showSnackBar(
         SnackBar(content: Text('Scan error: $e'), backgroundColor: Colors.red),