feat: Extend upload API end point to support external images (#10062)

app/controllers/api/v1/accounts/upload_controller.rb

@@ -1,13 +1,68 @@
 class Api::V1::Accounts::UploadController < Api::V1::Accounts::BaseController
   def create
-    file_blob = ActiveStorage::Blob.create_and_upload!(
-      key: nil,
-      io: params[:attachment].tempfile,
-      filename: params[:attachment].original_filename,
-      content_type: params[:attachment].content_type
-    )
-    file_blob.save!
+    result = if params[:attachment].present?
+               create_from_file
+             elsif params[:external_url].present?
+               create_from_url
+             else
+               render_error('No file or URL provided', :unprocessable_entity)
+             end
 
+    render_success(result) if result.is_a?(ActiveStorage::Blob)
+  end
+
+  private
+
+  def create_from_file
+    attachment = params[:attachment]
+    create_and_save_blob(attachment.tempfile, attachment.original_filename, attachment.content_type)
+  end
+
+  def create_from_url
+    uri = parse_uri(params[:external_url])
+    return if performed?
+
+    fetch_and_process_file_from_uri(uri)
+  end
+
+  def parse_uri(url)
+    uri = URI.parse(url)
+    validate_uri(uri)
+    uri
+  rescue URI::InvalidURIError, SocketError
+    render_error('Invalid URL provided', :unprocessable_entity)
+    nil
+  end
+
+  def validate_uri(uri)
+    raise URI::InvalidURIError unless uri.is_a?(URI::HTTP) || uri.is_a?(URI::HTTPS)
+  end
+
+  def fetch_and_process_file_from_uri(uri)
+    uri.open do |file|
+      create_and_save_blob(file, File.basename(uri.path), file.content_type)
+    end
+  rescue OpenURI::HTTPError => e
+    render_error("Failed to fetch file from URL: #{e.message}", :unprocessable_entity)
+  rescue SocketError
+    render_error('Invalid URL provided', :unprocessable_entity)
+  rescue StandardError
+    render_error('An unexpected error occurred', :internal_server_error)
+  end
+
+  def create_and_save_blob(io, filename, content_type)
+    ActiveStorage::Blob.create_and_upload!(
+      io: io,
+      filename: filename,
+      content_type: content_type
+    )
+  end
+
+  def render_success(file_blob)
     render json: { file_url: url_for(file_blob), blob_key: file_blob.key, blob_id: file_blob.id }
   end
+
+  def render_error(message, status)
+    render json: { error: message }, status: status
+  end
 end