module Climatic
  module ConfigLayers

    module ProgramDescriptionHelper

      attr_reader :config_file_base_name, :app_name, :app_version, :app_description

      def add_command_line_section(title='Script specific', &block)
        command_line_layer.add_command_line_section title, &block
      end

      def config_file_base_name=(config_file_base_name)
        return if config_file_base_name.nil?
        @config_file_base_name = config_file_base_name
        rescan_layers
        reload_layers
      end

      def app_name=(app_name)
        return if app_name.nil?
        @app_name = app_name
        command_line_layer.reload
      end

      def app_version=(app_version)
        return if app_version.nil?
        @app_version = app_version
        command_line_layer.reload
      end

      def app_description=(app_description)
        return if app_description.nil?
        @app_description = app_description
        command_line_layer.reload
      end

      def rescan_layers
        layers.values.each do |layer|
          if layer.respond_to? :rescan
            layer.clear
            layer.rescan
          end
        end

      end


      def detailed_layers_info
        info, sep = [], '-' * 80
        info << sep
        layers.values.sort {|a, b| a.priority <=> b.priority}.each do |layer|
          info << layer.name
          if layer.file_name.nil?
            info << 'There is no file attached to this level.'
          else
            info << "Using '#{layer.file_name}' as config file for this layer."
          end
          if layer.empty?
            info << 'There is no data in this layer'
          else
            info << 'This layer contains the following data:'
            info << layer.to_yaml
          end
          info << sep
        end
        info.join "\n"
      end

      def detailed_config_files_info
        merger = SuperStack::Manager.new
        merger.merge_policy = SuperStack::MergePolicies::FullMergePolicy
        layers.values.each do |layer|
          merger << layer.possible_config_files if layer.respond_to? :possible_config_files
        end
        merger[]
      end


      def command_line_help
        command_line_layer.help
      end

      def describes_application(options = {})
        self.app_name = options.fetch(:app_name, nil)
        self.app_version = options.fetch(:app_version, nil)
        self.app_description = options.fetch(:app_description, nil)
        self.config_file_base_name = options.fetch(:config_file_base_name, nil)
      end

    end

  end
end