class Page < ApplicationRecord
  include ActsAsTree

  belongs_to :user, foreign_key: 'updated_by'

  acts_as_versioned version_column: :lock_version
  self.non_versioned_columns += %w[permalink created_at title]

  acts_as_tree order: 'title'

  attr_accessor :old_title # Save title to create redirect page when editing title

  validates_presence_of :title, :body
  validates_uniqueness_of :permalink, :title

  before_validation :set_permalink, on: :create
  before_validation :update_permalink, on: :update
  after_update :create_redirect

  scope :non_redirected, -> { where(redirect: nil) }
  scope :no_parent, -> { where(parent_id: nil) }

  def self.permalink(title)
    title.gsub(%r{[/.,;@\s]}, '_').gsub(/["']/, '')
  end

  def homepage?
    permalink == 'Home'
  end

  def self.dashboard
    where(permalink: 'Dashboard').first
  end

  def self.public_front_page
    where(permalink: 'Public_frontpage').first
  end

  def self.welcome_mail
    where(permalink: 'Welcome_mail').first
  end

  def set_permalink
    return if title.blank?

    self.permalink = Page.count == 0 ? 'Home' : Page.permalink(title)
  end

  def diff
    current = versions.latest
    old = versions.where(['page_id = ? and lock_version < ?', current.page_id,
                          current.lock_version]).order('lock_version DESC').first

    if old
      o = ''
      Diffy::Diff.new(old.body, current.body).each do |line|
        case line
        when /^\+/ then o += "#{line.chomp}<br />" unless line.chomp == '+'
        when /^-/ then o += "#{line.chomp}<br />" unless line.chomp == '-'
        end
      end
      o
    else
      current.body
    end
  end

  protected

  def update_permalink
    return unless changed.include?('title')

    set_permalink
    self.old_title = changes['title'].first # Save title for creating redirect
  end

  def create_redirect
    return if old_title.blank?

    Page.create redirect: id,
                title: old_title,
                body: I18n.t('model.page.redirect', title: title),
                permalink: Page.permalink(old_title),
                updated_by: updated_by
  end
end