module BrandingAttachments
  extend ActiveSupport::Concern

  private

  def attach_branding_logo(record)
    file = params.dig(:branding, :logo_file)
    record.logo_file.attach(file) if file.present?
  end

  def attach_cover_image(record, entitlements:)
    remove_flag = params[:remove_cover].to_s == "1" || params.dig(:match, :remove_cover).to_s == "1"
    if remove_flag
      record.cover_image.purge if record.cover_image.attached?
      record.cover_slate.purge if record.cover_slate.attached?
      return
    end

    file = params.dig(:branding, :cover_image) || params[:cover_image]
    return if file.blank?

    entitlements.assert_can_upload_cover!
    validate_cover_file!(file)
    record.cover_slate.purge if record.cover_slate.attached?
    record.cover_image.attach(file)
  end

  def validate_cover_file!(file)
    allowed_types = Coverable::COVER_IMAGE_TYPES

    # Rileva MIME dal contenuto (magic bytes) ignorando il declared_type del client.
    io = file.respond_to?(:tempfile) ? file.tempfile : file
    io.rewind if io.respond_to?(:rewind)
    detected = Marcel::MimeType.for(io, name: file.respond_to?(:original_filename) ? file.original_filename : nil)
    io.rewind if io.respond_to?(:rewind)

    unless detected.in?(allowed_types)
      raise CoverUploadError, I18n.t("coverable.errors.invalid_type")
    end

    byte_size = file.respond_to?(:size) ? file.size : File.size(file.path)
    if byte_size > Coverable::MAX_COVER_BYTES
      raise CoverUploadError, I18n.t("coverable.errors.too_large")
    end
  end

  class CoverUploadError < StandardError; end

  def enqueue_cover_slate_generation(record)
    GenerateCoverSlateJob.enqueue_for(record) if record.cover_image.attached?
  end

  def normalize_hex_color(value, fallback)
    v = value.to_s.strip
    v = "##{v}" if v.match?(/\A[0-9A-Fa-f]{6}\z/)
    v.match?(Brandable::HEX_COLOR) ? v : fallback
  end
end