activestorage rename already uploaded files (Rails rename activestorage) Local and AWS storage support

remote_file_renamer.rb

# frozen_string_literal: true

module Storage
  class RemoteFileRenamer < ApplicationService
    attr_reader :file_blob, :new_name, :file

    # @param file [ActiveStorage::File]
    # @param new_name [String]
    # @param variation [Symbol] Sample: :thumbnail
    def initialize(file, new_name, variation = nil)
      @file = file
      @file_blob = variation ? find_variation_blob(file, variation) : file.blob
      @new_name = new_name
    end

    def call
      log('file-blob not found', mode: :error) && return unless file_blob

      file_blob.service.name == :amazon ? rename_aws_file : rename_local_file
      file_blob.update!(key: new_name, filename: new_name)
      file.reload
    end

    private

    def rename_aws_file
      obj = file_blob.service.send(:object_for, file_blob.key)
      obj.move_to(bucket: obj.bucket.name, key: new_name)
    end

    def rename_local_file
      old_path = file_blob.service.path_for(file_blob.key)
      new_path = file_blob.service.path_for(new_name)
      Dir.exist?(File.dirname(new_path)) || FileUtils.mkdir_p(File.dirname(new_path))
      FileUtils.mv(old_path, new_path) if File.exist?(old_path)
    end

    def find_variation_blob(file, variation)
      variant = file.variant(variation)
      variant.process unless variant.processed?
      variant.image
    end
  end
end

user.rb

# frozen_string_literal: true

class User < ApplicationRecord
  has_one_attached :photo do |attachable|
    attachable.variant :thumb, resize_to_fill: [100, nil]
  end

  after_create_commit :rename_remote_photo, prepend: true, on: :create, if: :file_blob
  after_update_commit :rename_remote_photo, prepend: true, if: -> { saved_changes_to_name? && photo.blob }
  
  def remote_photo_filename
    "#{name}#{File.extname(photo.blob.filename.to_s)}"
  end
  
  def remote_thumb_filename
    "#{name}-thumb#{File.extname(photo.blob.filename.to_s)}"
  end

  private
  
  def rename_remote_photo
    new_name = remote_photo_filename
    RemoteFileRenamer.new(file, new_name).call
    rename_thumbnail
  end

  def rename_thumbnail
    new_name = remote_thumb_filename
    RemoteFileRenamer.new(file, new_name, :thumb).call
  end
end

Thinking to make it part of activestorage-delayed gem by default.