class ImportDatabase
  attr_accessor :src_prefix
  attr_accessor :map
  attr_accessor :tables
  
  def logger
    RAILS_DEFAULT_LOGGER
  end
  
  def mapped_from(table, value)
    logger.warn  "NOT FOUND #{table}, #{value}, #{value.class}" unless @map[table][value] 
    @map[table][value]
  end
  
  def import_table(table, options = {})
    logger.info "Import: #{table}"
    table_options = (@tables[table] || {}).merge(options[:table] || {})
    model = table_options[:model]
    model.destroy_all if (options[:destroy_all])    
    sql ="SELECT * FROM #{@src_prefix}#{table_options[:src]}"
    sql << " WHERE #{table_options[:conditions]}" if table_options[:conditions]
    ActiveRecord::Base.connection.select_all(sql).each do |src_record|
      begin
        table_options[:before_row_import].call(src_record) if table_options[:before_row_import]
        dest_record = model.new
        table_options[:attributes].each do |key, value|
          dest_value = case value
            when Symbol
              src_record[value.to_s]
            when Proc
              value.call(src_record)
            else
              value
          end
          dest_record.send("#{key}=", dest_value)
      end
      dest_record.save!
      logger.info "Imported from #{table} #{src_record["id"]} to #{dest_record.id}"
      (@map[table] ||= {})[src_record["id"]] = dest_record.id
      rescue 
        logger.warn "Not imported: #{table_options[:src]}:#{src_record["id"]} because #{$!}"
      end
    end
  end

  
end