module DragOrder
  module Controllers
    module Admin
      module PagesController
            
        def self.included(base)
          base.class_eval do
            
            helper_method :order_dragger
            
            def move_to
              @page = Page.find(params[:id])
              @old_parent = @page.parent
              @current_position = params[:pos].to_i
              
              ensure_no_nil_position_values
              
              remove_page_from_old_position unless copying?
              
              @target = Page.find(params[:rel])
              
              make_room_for_page if @current_position != 2
              
              if copying?
                @orig_parts = @page.parts
                @page = @page.clone
              end
              
              @target.reload
              
              put_page
              
              solve_slug_conflicts if copying? || new_parent_different?
              
              @page.save!
              
              create_copy_of_parts if copying?
              
              clear_cache
              redirect_back_or_to_admin_pages_page
            end
          
          private
            def order_dragger
              %{<img src="/images/admin/extensions/drag_order/handle.png" alt ="Drag this icon to move the page" />}
            end
            
            def copying?
              params[:copy].to_i > 0
            end
            
            def ensure_no_nil_position_values
              if @page.newly_created_siblings?
                i = 1
                @page.siblings_and_self.each do |p|
                  p.position = i
                  p.save
                  i += 1
                end
                @page.reload
              end
            end
            
            def remove_page_from_old_position
              @page.following_siblings.each do |sibling|
                sibling.position -= 1
                sibling.save!
              end
            end
            
            def put_page
              if @current_position != 2
                @page.parent = @target.parent
                @page.position = @target.position.to_i + (@current_position == 1 ? 1 : -1)
              else
                @page.parent = @target
                @page.position = 1
              end
            end
            
            def make_room_for_page
              new_siblings = Page.children_of_after_position(@target.parent_id, @target.position + @current_position)
              new_siblings.each do |sibling|
                if sibling != @page || copying?
                  sibling.position += 1
                  sibling.save!
                end
              end
            end
            
            def new_parent_different?
              # @page.parent.changed? always gives false...
              @page.parent != @old_parent
            end
            
            def solve_slug_conflicts
              check_slug = @page.slug.sub(/-copy-?[0-9]*$/, "")
              count = 0
              parent_id = @current_position == 2 ? @target.id : @target.parent.id
              duplicates = Page.children_of_with_slug_like(parent_id, check_slug )
              duplicates.each do |d|
                m = d.slug.match("^#{check_slug}(-copy-?([0-9]*))?$")
                if !m.nil?
                  if !(m[2].nil? || m[2] == "")
                    nc = m[2].to_i + 1
                  elsif m[1]
                    nc = 2
                  else
                    nc = 1
                  end
                  count = nc if nc > count
                end
              end
              if count > 0
                # Remove old copy counters
                re = / - COPY ?[0-9]*$/
                @page.title.sub! re, ""
                @page.breadcrumb.sub! re, ""
                # Add new copy counters
                @page.slug = check_slug + "-copy" + (count > 1 ? "-" + count.to_s : "")
                @page.title += " - COPY" + (count > 1 ? " " + count.to_s : "")
                @page.breadcrumb += " - COPY" + (count > 1 ? " " + count.to_s : "")
              end
            end
            
            def create_copy_of_parts
              @orig_parts.each do |op|
                @page.parts.create({
                  :name => op.name,
                  :filter_id => op.filter_id,
                  :content => op.content
                })
              end
            end
            
            def redirect_back_or_to_admin_pages_page
              redirect_to(:back) rescue redirect_to(admin_page_url)
            end
            
            def clear_cache
              if defined? ResponseCache == 'constant'
                ResponseCache.instance.clear
              else
                Radiant::Cache.clear
              end
            end
            
          end
        end
        
      end
    end
  end
end