import 'package:flutter_test/flutter_test.dart';
import 'package:groci/models/ocr_element.dart';
import 'package:groci/services/receipt_parse_config.dart';
import 'package:groci/services/receipt_parser.dart';
import 'package:groci/services/receipt_row_builder.dart';
import 'package:groci/services/receipt_spatial_parser.dart';

/// Synthetic two-column receipt layout (800×1200 image).
///
/// Y increases downward; name column ~left 40–420, price column ~right 620–760.
const _imageWidth = 800.0;
const _imageHeight = 1200.0;
const _nameLeft = 40.0;
const _priceLeft = 620.0;
const _rowHeight = 24.0;
const _rowGap = 8.0;

OcrElement _word(String text, double row, {bool price = false}) {
  final y = row * (_rowHeight + _rowGap) + 100;
  final left = price ? _priceLeft : _nameLeft;
  final width = text.length * 10.0 + 20;
  return OcrElement(
    text: text,
    left: left,
    top: y,
    right: left + width,
    bottom: y + _rowHeight,
  );
}

OcrDocument _document(List<OcrElement> elements, {String? flattened}) {
  return OcrDocument(
    elements: elements,
    imageWidth: _imageWidth,
    imageHeight: _imageHeight,
    flattenedText: flattened ?? elements.map((e) => e.text).join('\n'),
  );
}

void main() {
  setUpAll(() async {
    await ReceiptParser.loadConfig();
  });

  group('ReceiptRowBuilder', () {
    test('clusters name and price on the same row by Y position', () {
      final rows = ReceiptRowBuilder(receiptParseConfig).buildRows(
        _document([
          _word('MILK', 0),
          _word('1,50', 0, price: true),
        ]),
      );

      expect(rows, hasLength(1));
      expect(rows.single.kind.name, 'item');
      expect(rows.single.nameText, 'MILK');
      expect(rows.single.price, 1.50);
    });

    test('classifies pure quantity row before item logic', () {
      final rows = ReceiptRowBuilder(receiptParseConfig).buildRows(
        _document([
          _word('2', 0),
          _word('X', 0),
          _word('2,99', 0, price: true),
        ], flattened: '2 X 2,99'),
      );

      expect(rows, hasLength(1));
      expect(rows.single.kind.name, 'quantityModifier');
      expect(rows.single.quantity, 2);
      expect(rows.single.unitPrice, 2.99);
    });

    test('treats row without price-column token as name-only', () {
      final rows = ReceiptRowBuilder(receiptParseConfig).buildRows(
        _document([_word('BROCCOLI', 0)]),
      );

      expect(rows.single.kind.name, 'nameOnly');
      expect(rows.single.nameText, 'BROCCOLI');
    });
  });

  group('ReceiptSpatialParser lookahead', () {
    test('merges Jumbo-style name row with following quantity modifier', () {
      final result = ReceiptSpatialParser.parse(
        _document([
          _word('AARDBEIEN', 0),
          _word('2', 1),
          _word('X', 1),
          _word('3,99', 1, price: true),
          _word('Totaal', 2),
          _word('7,98', 2, price: true),
        ]),
      );

      expect(result.items, hasLength(1));
      expect(result.items.single.name, 'AARDBEIEN');
      expect(result.items.single.quantity, 2);
      expect(result.items.single.unitPrice, 3.99);
      expect(result.items.single.price, 7.98);
      expect(result.items.single.sourceBounds, isNotNull);
    });

    test('overrides inline price when quantity modifier follows (Kruidvat)', () {
      final result = ReceiptSpatialParser.parse(
        _document([
          _word('ZEEPTABLET', 0),
          _word('NEUTRAL', 0),
          _word('7,98', 0, price: true),
          _word('2', 1),
          _word('X', 1),
          _word('3,99', 1, price: true),
        ]),
      );

      expect(result.items, hasLength(1));
      expect(result.items.single.quantity, 2);
      expect(result.items.single.unitPrice, 3.99);
      expect(result.items.single.price, 7.98);
    });

    test('flags name-only row without following modifier for manual review', () {
      final result = ReceiptSpatialParser.parse(
        _document([
          _word('MILK', 0),
          _word('BREAD', 1),
          _word('2,00', 1, price: true),
        ]),
      );

      expect(result.items, hasLength(2));
      expect(result.items[0].name, 'MILK');
      expect(result.items[0].needsManualReview, isTrue);
      expect(result.items[1].name, 'BREAD');
      expect(result.items[1].price, 2.00);
    });

    test('parses two side-by-side items without cross-assigning prices', () {
      final result = ReceiptSpatialParser.parse(
        _document([
          _word('MILK', 0),
          _word('1,50', 0, price: true),
          _word('BREAD', 1),
          _word('2,00', 1, price: true),
          _word('Totaal', 2),
          _word('3,50', 2, price: true),
        ]),
      );

      expect(result.items.map((i) => i.name), ['MILK', 'BREAD']);
      expect(result.items.map((i) => i.price), [1.50, 2.00]);
      expect(result.validationPassed, isTrue);
    });

    test('fails validation when printed item count does not match', () {
      final result = ReceiptSpatialParser.parse(
        _document([
          _word('MILK', 0),
          _word('1,50', 0, price: true),
          _word('Aantal', 1),
          _word('Artikel:', 1),
          _word('3', 1, price: true),
        ]),
      );

      expect(result.expectedItemCount, 3);
      expect(result.validationPassed, isFalse);
    });
  });
}