Apply a diet on uploaded images

app/contexts/uploads.rb

@@ -14,11 +14,33 @@ def initialize(data_uri)
 
   def call
     data_uri_parts = data_uri.match(REGEXP) || {}
-    ext = ((data_uri_parts[:type] || '').match(EXT) || {})[:ext] || '.png'
     {
-      io: StringIO.new(Base64.decode64(data_uri_parts[:content] || '')),
-      content_type: data_uri_parts[:type],
-      filename: "#{SecureRandom.uuid}.#{ext}"
+      io: diet(Base64.decode64(data_uri_parts[:content] || '')),
+      content_type: 'image/jpeg',
+      filename: "#{SecureRandom.uuid}.jpg"
     }
   end
+
+  private
+
+  def diet(content)
+    return StringIO.new('') if content.empty?
+
+    original = Tempfile.new('mersea.uploaded', binmode: true)
+    original << content
+    original.close
+
+    processed = ImageProcessing::MiniMagick
+    .source(original.path)
+    .resize_to_limit(1920, 1080)
+    .quality(90)
+    .convert("jpg")
+    .call(save: true)
+
+    StringIO.new(processed.read)
+  ensure
+    original&.unlink
+    processed&.close
+    processed&.unlink
+  end
 end

lib/tasks/diet_photo.rake

@@ -0,0 +1,22 @@
+namespace :storage do
+  desc 'Diet all images'
+  task diet: :environment do
+    ActiveStorage::Attachment.find_each.each do |attachment|
+      next if attachment.name != "photo"
+      puts "Attachement #{attachment.id}"
+
+      path = ActiveStorage::Blob.service.send(:path_for, attachment.key)
+      puts "     path: #{path}"
+      puts "     size: #{File.size(path)}"
+
+      ImageProcessing::MiniMagick
+        .source(path)
+        .resize_to_limit(1920, 1080)
+        .quality(90)
+        .convert("jpg")
+        .call(save: true, destination: path)
+
+      puts "  newsize: #{File.size(path)}"
+    end
+  end
+end