retail/lib/core/config/image_cache_config.dart

/// Performance-optimized image cache configuration
///
/// This configuration provides:
/// - Memory cache limits to prevent OOM errors
/// - Disk cache management for offline support
/// - Optimized image sizing for different use cases
/// - Efficient cache eviction policies

import 'package:flutter_cache_manager/flutter_cache_manager.dart';

/// Custom cache manager for product images with performance optimizations
class ProductImageCacheManager extends CacheManager {
  static const key = 'product_image_cache';

  static ProductImageCacheManager? _instance;

  factory ProductImageCacheManager() {
    _instance ??= ProductImageCacheManager._();
    return _instance!;
  }

  ProductImageCacheManager._() : super(
    Config(
      key,
      // Cache for 30 days
      stalePeriod: const Duration(days: 30),
      // Max 200 cached images
      maxNrOfCacheObjects: 200,
      // Clean cache when app starts
      repo: JsonCacheInfoRepository(databaseName: key),
      fileService: HttpFileService(),
    ),
  );
}

/// Custom cache manager for category images (smaller cache)
class CategoryImageCacheManager extends CacheManager {
  static const key = 'category_image_cache';

  static CategoryImageCacheManager? _instance;

  factory CategoryImageCacheManager() {
    _instance ??= CategoryImageCacheManager._();
    return _instance!;
  }

  CategoryImageCacheManager._() : super(
    Config(
      key,
      // Cache for 60 days (categories change less frequently)
      stalePeriod: const Duration(days: 60),
      // Max 50 cached category images
      maxNrOfCacheObjects: 50,
      repo: JsonCacheInfoRepository(databaseName: key),
      fileService: HttpFileService(),
    ),
  );
}

/// Image size configurations for different use cases
class ImageSizeConfig {
  // Grid thumbnail sizes (small for memory efficiency)
  static const int gridThumbnailWidth = 300;
  static const int gridThumbnailHeight = 300;

  // List item sizes (medium)
  static const int listItemWidth = 400;
  static const int listItemHeight = 400;

  // Detail view sizes (larger but still optimized)
  static const int detailWidth = 800;
  static const int detailHeight = 800;

  // Cart item thumbnail (very small)
  static const int cartThumbnailWidth = 200;
  static const int cartThumbnailHeight = 200;

  // Category card sizes
  static const int categoryCardWidth = 250;
  static const int categoryCardHeight = 250;
}

/// Memory cache configuration
class MemoryCacheConfig {
  // Maximum memory cache size (in MB)
  static const int maxMemoryCacheMB = 50;

  // Maximum number of cached images in memory
  static const int maxMemoryCacheCount = 100;

  // Memory cache for grid items (smaller)
  static const int gridMemoryCacheMB = 30;

  // Preload cache size
  static const int preloadCacheCount = 20;
}

/// Disk cache configuration
class DiskCacheConfig {
  // Maximum disk cache size (in MB)
  static const int maxDiskCacheMB = 200;

  // Cache expiration durations
  static const Duration productImageCacheDuration = Duration(days: 30);
  static const Duration categoryImageCacheDuration = Duration(days: 60);

  // Cache cleanup threshold (cleanup when this % is reached)
  static const double cleanupThreshold = 0.9; // 90%
}

/// Image loading optimization helpers
class ImageOptimization {
  /// Get optimal image dimensions based on screen size
  static ImageDimensions getOptimalDimensions({
    required double screenWidth,
    required ImageContext context,
  }) {
    switch (context) {
      case ImageContext.gridThumbnail:
        return ImageDimensions(
          width: ImageSizeConfig.gridThumbnailWidth,
          height: ImageSizeConfig.gridThumbnailHeight,
        );
      case ImageContext.listItem:
        return ImageDimensions(
          width: ImageSizeConfig.listItemWidth,
          height: ImageSizeConfig.listItemHeight,
        );
      case ImageContext.detail:
        return ImageDimensions(
          width: ImageSizeConfig.detailWidth,
          height: ImageSizeConfig.detailHeight,
        );
      case ImageContext.cartThumbnail:
        return ImageDimensions(
          width: ImageSizeConfig.cartThumbnailWidth,
          height: ImageSizeConfig.cartThumbnailHeight,
        );
      case ImageContext.categoryCard:
        return ImageDimensions(
          width: ImageSizeConfig.categoryCardWidth,
          height: ImageSizeConfig.categoryCardHeight,
        );
    }
  }

  /// Clear all image caches
  static Future<void> clearAllCaches() async {
    await ProductImageCacheManager().emptyCache();
    await CategoryImageCacheManager().emptyCache();
  }

  /// Clear expired cache entries
  static Future<void> clearExpiredCache() async {
    // Cache managers automatically handle this
  }

  /// Get total cache size
  static Future<int> getTotalCacheSize() async {
    // This would require implementing cache size calculation
    return 0;
  }
}

enum ImageContext {
  gridThumbnail,
  listItem,
  detail,
  cartThumbnail,
  categoryCard,
}

class ImageDimensions {
  final int width;
  final int height;

  const ImageDimensions({
    required this.width,
    required this.height,
  });
}