/// Metadata for a motorcycle photograph or reference image
class MotorcycleImageReference {
  final String? assetPath;
  final String? networkUrl;
  final String? localFilePath;
  final String caption;
  final String attribution;
  final bool isPhoto;

  const MotorcycleImageReference({
    this.assetPath,
    this.networkUrl,
    this.localFilePath,
    required this.caption,
    this.attribution = 'Technical Reference',
    this.isPhoto = false,
  });

  bool get hasImage => assetPath != null || networkUrl != null || localFilePath != null;
}

/// Metadata descriptor for registered motorcycle reference images
class MotorcycleImageDescriptor {
  final String make;
  final String model;
  final int? exactYear;
  final int? minYear;
  final int? maxYear;
  final List<String> modelAliases;
  final String assetPath;
  final String caption;
  final String attribution;
  final bool isPhoto;

  const MotorcycleImageDescriptor({
    required this.make,
    required this.model,
    this.exactYear,
    this.minYear,
    this.maxYear,
    this.modelAliases = const [],
    required this.assetPath,
    required this.caption,
    this.attribution = 'Factory Technical Reference',
    this.isPhoto = true,
  });

  /// Normalizes vehicle names for invariant comparison
  static String normalize(String input) {
    return input.toLowerCase().replaceAll(RegExp(r'[^a-z0-9]'), '');
  }

  /// Evaluates whether this descriptor matches the specified make, model, and year
  bool matches(String targetMake, String targetModel, int? targetYear) {
    final normTargetMake = normalize(targetMake);
    final normMake = normalize(make);
    if (normMake != normTargetMake) return false;

    final normTargetModel = normalize(targetModel);
    final normModel = normalize(model);
    final isModelMatch = normModel == normTargetModel ||
        modelAliases.any((alias) => normalize(alias) == normTargetModel);

    if (!isModelMatch) return false;

    // Exact year check
    if (exactYear != null) {
      return targetYear == exactYear;
    }

    // Generation / Year range check
    if (minYear != null || maxYear != null) {
      if (targetYear == null) return false;
      if (minYear != null && targetYear < minYear!) return false;
      if (maxYear != null && targetYear > maxYear!) return false;
      return true;
    }

    return true;
  }

  MotorcycleImageReference toReference() {
    return MotorcycleImageReference(
      assetPath: assetPath,
      caption: caption,
      attribution: attribution,
      isPhoto: isPhoto,
    );
  }
}

/// Central extensible repository providing authentic motorcycle reference images
class MotorcycleImageService {
  static const MotorcycleImageService _instance = MotorcycleImageService._internal();
  factory MotorcycleImageService() => _instance;
  const MotorcycleImageService._internal();

  /// List of verified physical photographic assets bundled in the APK
  static const List<String> bundledPhotographicAssets = [
    'assets/images/motorcycles/yamaha_yzf_r6_2001.png',
  ];

  /// Default registry of curated motorcycle reference descriptors
  static final List<MotorcycleImageDescriptor> _defaultDescriptors = [
    // Tier 1 & 2: 1st Gen Yamaha YZF-R6 (1999-2002 5EB) including 2001 field test vehicle
    const MotorcycleImageDescriptor(
      make: 'Yamaha',
      model: 'YZF-R6',
      minYear: 1999,
      maxYear: 2002,
      modelAliases: ['R6', 'YZFR6', 'YZF R6'],
      assetPath: 'assets/images/motorcycles/yamaha_yzf_r6_2001.png',
      caption: '2001 Yamaha YZF-R6 (5EB)',
      attribution: 'Factory Supersport Reference',
      isPhoto: true,
    ),
  ];

  static final List<MotorcycleImageDescriptor> _customDescriptors = [];

  /// Registers a custom image descriptor (for extensions/plugins/tests)
  static void registerDescriptor(MotorcycleImageDescriptor descriptor) {
    _customDescriptors.add(descriptor);
  }

  /// Clears custom descriptors (resets to default registry)
  static void resetRegistry() {
    _customDescriptors.clear();
  }

  /// Returns all active descriptors in evaluation order (custom first, then defaults)
  List<MotorcycleImageDescriptor> get allDescriptors => [
        ..._customDescriptors,
        ..._defaultDescriptors,
      ];

  /// Resolves the best available photographic image or reference for a motorcycle
  ///
  /// Matching Hierarchy:
  /// 1. Exact Year Match (Make + Model + Exact Year)
  /// 2. Generation / Year-Range Match (Make + Model + Generation Range)
  /// 3. Make + Model Match (Ageless / General Model Reference)
  /// 4. Dynamic Technical Schematic Fallback (Accurate make/model/year vector card)
  MotorcycleImageReference getReferenceImage({
    required String? make,
    required String? model,
    int? year,
  }) {
    if (make == null || model == null || make.trim().isEmpty || model.trim().isEmpty) {
      return const MotorcycleImageReference(
        caption: 'Motorcycle Technical Reference',
        attribution: 'Schematic Vector',
        isPhoto: false,
      );
    }

    final descriptors = allDescriptors;

    // Tier 1: Exact Year Match
    if (year != null) {
      for (final desc in descriptors) {
        if (desc.exactYear != null && desc.matches(make, model, year)) {
          return desc.toReference();
        }
      }
    }

    // Tier 2: Generation / Year-Range Match (e.g. 1999-2002 1st Gen R6)
    if (year != null) {
      for (final desc in descriptors) {
        if ((desc.minYear != null || desc.maxYear != null) && desc.matches(make, model, year)) {
          return desc.toReference();
        }
      }
    }

    // Tier 3: Make + Model Match (Ageless / General Model Reference)
    for (final desc in descriptors) {
      if (desc.exactYear == null && desc.minYear == null && desc.maxYear == null && desc.matches(make, model, year)) {
        return desc.toReference();
      }
    }

    // Tier 4: Graceful Technical Schematic Fallback
    final yearPrefix = year != null && year > 1900 ? '$year ' : '';
    final formattedCaption = '$yearPrefix${make.trim()} ${model.trim()}'.trim();
    return MotorcycleImageReference(
      caption: formattedCaption,
      attribution: 'Technical Schematic',
      isPhoto: false,
    );
  }

  /// Checks whether a genuine photographic asset is registered and available for a given vehicle
  bool hasPhotographicAsset({
    required String? make,
    required String? model,
    int? year,
  }) {
    final ref = getReferenceImage(make: make, model: model, year: year);
    return ref.isPhoto && ref.assetPath != null;
  }
}