namespace :alchemy do
  namespace :tidy do

    desc "Tidy up Alchemy database."
    task :up do
      Rake::Task['alchemy:tidy:cells'].invoke
      Rake::Task['alchemy:tidy:element_positions'].invoke
    end

    desc "Creates missing cells for pages."
    task :cells => :environment do
      cells = Alchemy::Cell.definitions
      page_layouts = Alchemy::PageLayout.all
      if cells && page_layouts
        Alchemy::Tidy.create_missing_cells(page_layouts, cells)
      else
        puts "No page layouts or cell definitions found."
      end
    end

    desc "Fixes element positions."
    task :element_positions => [:environment] do
      Alchemy::Tidy.update_element_positions
    end

  end
end

module Alchemy
  class Tidy
    extend Shell

    def self.create_missing_cells(page_layouts, cells)
      desc "Create missing cells"
      page_layouts.each do |layout|
        next if layout['cells'].blank?
        cells_for_layout = cells.select { |cell| layout['cells'].include? cell['name'] }
        Alchemy::Page.where(page_layout: layout['name']).each do |page|
          cells_for_layout.each do |cell_for_layout|
            cell = Alchemy::Cell.find_or_initialize_by(name: cell_for_layout['name'], page_id: page.id)
            cell.elements << page.elements.select { |element| cell_for_layout['elements'].include?(element.name) }
            if cell.new_record?
              cell.save
              log "Creating cell #{cell.name} for page #{page.name}"
            else
              log "Cell #{cell.name} for page #{page.name} already present", :skip
            end
          end
        end
      end
    end

    def self.update_element_positions
      desc "Update element positions"
      Alchemy::Page.all.each do |page|
        page.elements.group_by(&:cell_id).each do |cell_id, elements|
          elements.each_with_index do |element, idx|
            position = idx + 1
            if element.position != position
              log "Updating position for element ##{element.id} to #{position}"
              element.update_column(:position, position)
            else
              log "Position for element ##{element.id} is already correct", :skip
            end
          end
        end
      end
    end

    # TODO: implement remove_orphan_cells
    def self.remove_orphan_cells(page_layouts, cells)
      puts "== Remove cell orphans"
      Alchemy::Cell.all.each do |cell|
        if cells.detect { |cell| cell['name'] == cell.name }.nil?
          # move elements to page or into another cell of page
          # remove cell from database
        end
      end
    end

  end
end