Migration to Shrine attachment handling

app/uploaders/image_uploader.rb

@@ -0,0 +1,49 @@
+# This is a subclass of Shrine base that will be further configured for it's requirements.
+# This will be included in the model to manage the file.
+
+class ImageUploader < Shrine
+  ALLOWED_TYPES  = %w[image/jpeg image/png image/webp]
+  MAX_SIZE       = 5*1024*1024 # 5 MB
+  MAX_DIMENSIONS = [3000, 3000] # 3000x3000
+
+  plugin :remove_attachment
+  plugin :pretty_location
+  plugin :validation_helpers
+  plugin :store_dimensions, log_subscriber: nil
+  # plugin :derivation_endpoint, prefix: "derivations/image"
+
+  # File validations (requires `validation_helpers` plugin)
+  Attacher.validate do
+    validate_size 0..MAX_SIZE
+
+    if validate_mime_type ALLOWED_TYPES
+      validate_max_dimensions MAX_DIMENSIONS
+    end
+  end
+
+  # Thumbnails processor (requires `derivatives` plugin)
+  Attacher.derivatives do |original|
+    puts "original=#{original}"
+    magick = ImageProcessing::MiniMagick.source(original)
+    {
+      small: magick.resize_to_limit!(160, 120),
+      medium: magick.resize_to_limit!(800, 600),
+      large: magick.composite!('public/logo/watermark.png', gravity: 'east')
+    }
+    # GenerateThumbnail.call(original, width, height) # lib/generate_thumbnail.rb
+
+    # THUMBNAILS.transform_values do |(width, height)|
+    #   GenerateThumbnail.call(original, width, height) # lib/generate_thumbnail.rb
+    # end
+  end
+
+  # Default to dynamic thumbnail URL (requires `default_url` plugin)
+  Attacher.default_url do |derivative: nil, **|
+    file&.derivation_url(:thumbnail, *THUMBNAILS.fetch(derivative)) if derivative
+  end
+
+  # Dynamic thumbnail definition (requires `derivation_endpoint` plugin)
+  # derivation :thumbnail do |file, width, height|
+  #   GenerateThumbnail.call(file, width.to_i, height.to_i) # lib/generate_thumbnail.rb
+  # end
+end