require_dependency 'landable/has_assets'

module Landable
  class PageRevision < ActiveRecord::Base
    include Landable::Engine.routes.url_helpers
    include Landable::HasAssets
    include Landable::TableName

    class << self
      attr_accessor :ignored_page_attributes
    end
    @ignored_page_attributes = %w(page_id imported_at created_at deleted_at updated_at published_revision_id is_publishable updated_by_author_id lock_version audit_flags page_name)

    belongs_to :author
    belongs_to :page, inverse_of: :revisions

    after_commit :add_screenshot!, on: :create

    def page_id=(id)
      # set the value
      self[:page_id] = id

      # copy grab attributes from the page
      self.title          = page.title
      self.body           = page.body
      self.head_content   = page.head_content
      self.path           = page.path
      self.status_code    = page.status_code
      self.category_id    = page.category_id
      self.theme_id       = page.theme_id
      self.meta_tags      = page.meta_tags
      self.redirect_url   = page.redirect_url
      self.abstract       = page.abstract
      self.hero_asset_id  = page.hero_asset_id
    end

    def snapshot
      Page.new(title: title,
               meta_tags: page.meta_tags,
               head_content: page.head_content,
               body: body,
               path: path,
               redirect_url: redirect_url,
               status_code: status_code,
               theme_id: theme_id,
               category_id: category_id,
               abstract: abstract,
               hero_asset_id: hero_asset_id)
    end

    def publish!
      update_attribute :is_published, true
    end

    def unpublish!
      update_attribute :is_published, false
    end

    def republish!(options)
      unpublish!
      PageRevision.create!(page_id: page_id,
                           title: title,
                           meta_tags: page.meta_tags,
                           head_content: page.head_content,
                           body: body,
                           path: path,
                           redirect_url: redirect_url,
                           status_code: status_code,
                           theme_id: theme_id,
                           category_id: category_id,
                           abstract: abstract,
                           hero_asset_id: hero_asset_id,
                           notes: "Publishing update for template #{options[:template]}: #{options[:notes]}",
                           is_minor: options[:is_minor],
                           author_id: options[:author_id],
                           is_published: true)
    end

    def preview_url
      public_preview_page_revision_url(self, host: Landable.configuration.public_host)
    rescue ArgumentError
      Rails.logger.warn "Failed to generate preview url for page revision #{id} - missing Landable.configuration.public_host"
      nil
    end

    def preview_path
      public_preview_page_revision_path(self)
    end

    mount_uploader :screenshot, Landable::AssetUploader

    def screenshot_url
      screenshot.try(:url)
    end

    def add_screenshot!
      return nil if preview_url.blank?

      unless Landable.configuration.screenshots_enabled
        Rails.logger.info "Screenshots disabled; skipping for #{path}"
        return
      end

      attempts_left = 3

      begin
        attempts_left -= 1

        self.screenshot = ScreenshotService.capture(preview_url)

        # we've got a trigger preventing updates to other columns, so! muck
        # about under the hood to commit the asset, and explicitly only update
        # this column.
        store_screenshot!
        write_screenshot_identifier
        update_column :screenshot, self[:screenshot]

      rescue ScreenshotService::Error => error
        Rails.logger.warn "Failed to generate screenshot (#{attempts_left} attempt(s) left) for #{path}: #{error.inspect}"

        retry if attempts_left > 0
      end
    end
  end
end