MatchedScoreV2 constructor

Implementation

MatchedScoreV2(
  final Product product,
  final ProductPreferencesManager productPreferencesManager,
) : barcode = product.barcode! {
  _score = 0;
  _debug = '';

  final List<AttributeGroup>? attributeGroups = product.attributeGroups;
  if (attributeGroups == null) {
    // the product does not have the attribute_groups field
    _status = MatchedProductStatusV2.UNKNOWN_MATCH;
    _debug = 'no attribute_groups';
    return;
  }

  int sumOfFactors = 0;
  int sumOfFactorsForUnknownAttributes = 0;
  bool mayNotMatch = false;
  bool doesNotMatch = false;
  bool isUnknown = false;

  for (final AttributeGroup group in attributeGroups) {
    if (group.attributes == null) {
      continue;
    }
    for (final Attribute attribute in group.attributes!) {
      final String attributeId = attribute.id!;
      final double match = attribute.match ?? 0;
      final String importanceId = productPreferencesManager
          .getImportanceIdForAttributeId(attributeId);

      if (importanceId == PreferenceImportance.ID_NOT_IMPORTANT) {
        // Ignore attribute
        _debug += '$attributeId $importanceId\n';
        continue;
      }

      final int factor = _preferencesFactors[importanceId]!;
      sumOfFactors += factor;

      if (attribute.status == Attribute.STATUS_UNKNOWN) {
        sumOfFactorsForUnknownAttributes += factor;
        if (importanceId == PreferenceImportance.ID_MANDATORY) {
          isUnknown = true;
        }
      } else {
        _score += match * factor;
        _debug += '$attributeId $importanceId - match: $match\n';

        if (importanceId == PreferenceImportance.ID_MANDATORY) {
          if (match <= 10) {
            // Mandatory attribute with a very bad score (e.g. contains an allergen) -> status: does not match
            doesNotMatch = true;
          }
          // Mandatory attribute with a bad score (e.g. may contain traces of an allergen) -> status: may not match
          else if (match <= 50) {
            mayNotMatch = true;
          }
        }
      }
    }
  }

  // Normalize the score from 0 to 100
  if (sumOfFactors == 0) {
    _score = 0;
  } else {
    _score /= sumOfFactors;
  }

  // If one of the attributes does not match, the product does not match
  if (doesNotMatch) {
    // Set score to 0 for products that do not match
    _score = 0;
    _status = MatchedProductStatusV2.DOES_NOT_MATCH;
  } else if (mayNotMatch) {
    _status = MatchedProductStatusV2.MAY_NOT_MATCH;
  } else if (isUnknown) {
    _status = MatchedProductStatusV2.UNKNOWN_MATCH;
  }
  // If too many attributes are unknown, set an unknown match
  else if (sumOfFactorsForUnknownAttributes >= sumOfFactors / 2) {
    _status = MatchedProductStatusV2.UNKNOWN_MATCH;
  }
  // If the product matches, check how well it matches user preferences
  else if (score >= 75) {
    _status = MatchedProductStatusV2.VERY_GOOD_MATCH;
  } else if (score >= 50) {
    _status = MatchedProductStatusV2.GOOD_MATCH;
  } else {
    _status = MatchedProductStatusV2.POOR_MATCH;
  }
}