Sequel.extension :migration
module Enginery
  class Migrator
    MigratorInstance = Sequel.migration do
      up do
        <?rb if @create_table ?>
        create_table :#{ @create_table } do
          primary_key :id
          <?rb @create_columns.each do |(n,t)| ?>
          column :#{ n }, #{ t }
          <?rb end ?>
        end
        <?rb elsif @update_table && (@create_columns.any? || @update_columns.any?) ?>
        alter_table :#{ @update_table } do
        <?rb @create_columns.each do |(n,t)| ?>
          add_column :#{ n }, #{ t }
        <?rb end ?>
        <?rb @update_columns.each do |(n,t)| ?>
          set_column_type :#{ n }, #{ t }
        <?rb end ?>
        end
        <?rb end ?>

        <?rb @rename_columns.each do |(n,nn)| ?>
        rename_column :#{ @update_table }, :#{ n }, :#{ nn }
        <?rb end ?>
      end

      down do
        <?rb if @create_table ?>
        drop_table :#{ @create_table }
        <?rb elsif @update_table && (@create_columns.any? || @update_columns.any?) ?>
        alter_table :#{ @update_table } do
        <?rb @create_columns.each do |(n,t)| ?>
          drop_column :#{ n }
        <?rb end ?>
        <?rb if (update_columns = @update_columns.select {|n,t,ct| ct}).any?
        update_columns.each do |(n,t,ct)| ?>
          set_column_type :#{ n }, #{ ct }
        <?rb end
        end ?>
        end
        <?rb end ?>

        <?rb @rename_columns.each do |(n,nn)| ?>
        rename_column :#{ @update_table }, :#{ nn }, :#{ n }
        <?rb end ?>
      end
    end

    # *** do not remove this ***
    MigratorContext = #{@context}
  end
end