class Admin::PagesController < Admin::ResourceController
  before_action :initialize_meta_rows_and_buttons, only: %i[new edit create update]
  before_action :count_deleted_pages, only: [:destroy]
  rescue_from ActiveRecord::RecordInvalid, with: :validation_error

  class PreviewStop < ActiveRecord::Rollback
    def message
      'Changes not saved!'
    end
  end

  create_responses do |r|
    r.plural.js do
      @level = params[:level].to_i
      @index = params[:index].to_i
      @rendered_html = ''
      @template_name = 'index'
      self.models = Page.find(params[:page_id]).children.all
      response.headers['Content-Type'] = 'text/html;charset=utf-8'
      render action: 'children.html.haml', layout: false
    end
  end

  def index
    @homepage = Page.find_by_parent_id(nil)
    response_for :plural
  end

  def new
    @page = self.model = model_class.new_with_defaults(trusty_config)
    assign_page_attributes
    response_for :new
  end

  def preview
    render_preview
  rescue PreviewStop => e
    render text: e.message unless @performed_render
  end

  def save_table_position
    new_position = params[:new_position]
    Page.save_order(new_position)
    head :ok
  end

  private

  def validation_error(e)
    flash[:error] = e.message
    render :new
  end

  def assign_page_attributes
    if params[:page_id].blank?
      model.slug = '/'
    end
    model.parent_id = params[:page_id]
  end

  def model_class
    if Page.descendants.any? { |d| d.to_s == params[:page_class] }
      verify_page_class(params[:page_class])
    elsif params[:page_id]
      Page.find(params[:page_id]).children
    else
      Page
    end
  end

  def render_preview
    params.permit!
    Page.transaction do
      page_class = Page.descendants.include?(model_class) ? model_class : Page
      if request.referer =~ %r{/admin/pages/(\d+)/edit}
        page = Page.find($1).becomes(page_class)
        layout_id = page.layout_id
        page.update(params[:page])
        page.published_at ||= Time.now
      else
        page = page_class.new(params[:page])
        page.published_at = page.updated_at = page.created_at = Time.now
        page.parent = Page.find($1) if request.referer =~ %r{/admin/pages/(\d+)/children/new}
      end
      page.pagination_parameters = pagination_parameters
      process_with_exception(page)
    end
  end

  def process_with_exception(page)
    page.process(request, response)
    @performed_render = true
    render template: 'site/show_page', layout: false
    raise PreviewStop
  end

  def count_deleted_pages
    @count = model.children.count + 1
  end

  def initialize_meta_rows_and_buttons
    @buttons_partials ||= []
    @meta ||= []
    @meta << { field: 'slug', type: 'text_field', args: [{ class: 'textbox' }] }
    @meta << { field: 'breadcrumb', type: 'text_field', args: [{ class: 'textbox' }] }
  end

  def verify_page_class(page_class)
    if page_class.constantize.ancestors.include?(Page)
      page_class.constantize
    else
      raise "I'm not allowed to constantize #{page_class}!"
    end
  end
end