import 'dart:io';
import 'package:google_mlkit_text_recognition/google_mlkit_text_recognition.dart';
import 'package:image_picker/image_picker.dart';

class OcrResult {
  final double? amount;
  final String? rawText;
  
  OcrResult({this.amount, this.rawText});
}

class OcrService {
  final ImagePicker _picker = ImagePicker();
  
  Future<OcrResult?> scanReceiptFromCamera() async {
    final XFile? image = await _picker.pickImage(source: ImageSource.camera);
    if (image == null) return null;
    return await _processImage(File(image.path));
  }

  Future<OcrResult?> scanReceiptFromGallery() async {
    final XFile? image = await _picker.pickImage(source: ImageSource.gallery);
    if (image == null) return null;
    return await _processImage(File(image.path));
  }
  
  Future<OcrResult> _processImage(File file) async {
    final inputImage = InputImage.fromFile(file);
    final textRecognizer = TextRecognizer(script: TextRecognitionScript.latin);
    
    try {
      final RecognizedText recognizedText = await textRecognizer.processImage(inputImage);
      String text = recognizedText.text;
      
      // Simple regex to find a monetary amount (e.g., $145.50 or 145.50)
      final RegExp amountRegex = RegExp(r'\$?\d+\.\d{2}');
      final Iterable<Match> matches = amountRegex.allMatches(text);
      
      double? maxAmount;
      for (final Match m in matches) {
        final matchText = m.group(0)?.replaceAll('\$', '');
        if (matchText != null) {
          final amount = double.tryParse(matchText);
          if (amount != null) {
            if (maxAmount == null || amount > maxAmount) {
              maxAmount = amount; // Usually the total is the largest amount
            }
          }
        }
      }

      return OcrResult(
        amount: maxAmount,
        rawText: text,
      );
    } finally {
      textRecognizer.close();
    }
  }
}