class Overlay < ApplicationRecord
  belongs_to :user, optional: true
  has_many :template_overlays, dependent: :destroy
  has_many :server_templates, through: :template_overlays

  validates :name, :overlay_type, :slug, presence: true
  validates :overlay_type, inclusion: { in: %w[system custom] }
  validates :name, uniqueness: { scope: :user_id, message: "must be unique per user" }
  validate :slug_is_single_directory

  before_validation :normalize_slug

  scope :system_overlays, -> { where(overlay_type: "system").where(user_id: nil) }
  scope :custom_overlays, -> { where(overlay_type: "custom") }
  scope :for_user, ->(user) { where("user_id IS NULL OR user_id = ?", user.id) }

  private

  def normalize_slug
    return if slug.blank? && name.blank?

    # Use provided slug or derive from name
    source = slug.presence || name
    self.slug = source.to_s.strip
                      .downcase
                      .gsub(%r{[^\w\-.]}, "_")  # Replace non-word chars (except - and .) with underscore
                      .gsub(%r{_+}, "_")        # Collapse multiple underscores
                      .sub(%r{^_+}, "")         # Strip leading underscores
                      .sub(%r{_+$}, "")         # Strip trailing underscores
  end

  def slug_is_single_directory
    return if slug.blank?

    if slug.match?(%r{[\\/]})
      errors.add(:slug, "must be a single directory name (no slashes)")
    end
  end
end