valid base64 rails

# frozen_string_literal: true

module Imageable
  extend ActiveSupport::Concern

  included do
    before_save :upload_image
  end

  def img_attribute
    self.class.reflect_on_all_attachments
        .filter{ |association| association.instance_of? ActiveStorage::Reflection::HasOneAttachedReflection }
        .map(&:name).join.to_sym
  end

  def img_attribute_size
    self.class::SIZE_IMG
  end

  def img_attribute_content
    send("#{img_attribute}_content")
  end

  def klass_name
    self.class.model_name.singular
  end

  def valid_image_format
    acceptable_types = %w[image/jpeg image/png]
    unless acceptable_types.include?(content_type_upload)
      errors.add(img_attribute, I18n.t('record.errors.wrong_content_type_img'))
      return false
    end
    true
  end

  def valid_image_size
    if send(img_attribute).blob.byte_size > img_attribute_size
      errors.add(img_attribute, I18n.t('record.errors.wrong_size_img', size_img: img_attribute))
      return false
    end
    true
  end

  def check_if_file_exist
    unless decode64_img
      errors.add(img_attribute, I18n.t('record.errors.file_not_exist'))
      raise ActiveRecord::Rollback
    end
    true
  end

  def acceptable_image
    return unless send(img_attribute).attached?

    if valid_image_format && valid_image_size
      true
    else
      send(img_attribute).purge
      raise ActiveRecord::Rollback
    end
  end

  def upload_image
    return unless img_attribute_content.present? && content_type.present? && check_if_file_exist

    blob = ActiveStorage::Blob.create_after_upload!(
      io: decode64_img,
      content_type: content_type,
      filename: "#{klass_name}-#{SecureRandom.hex(7)}.#{file_extension}"
    )
    new_record? ? send(img_attribute).attach(blob) : send("#{img_attribute}=", blob)
    acceptable_image
  end

  def extract_base64
    img_attribute_content.sub(/^data:.*,/, '')
  end

  def decode64_img
    file = Base64.decode64(extract_base64)
    File.open(file) if File.exist?(file)
  end

  def file_extension
    content_type.try(:split, '/')[1]
  end

  def content_type_upload
    Rack::Mime.mime_type(File.extname(decode64_img))
  end
end