require 'lib/string_helper'
require 'db/mongo/models/stack_template/stack_template_factory'

module Devops
  module StackTemplatePresets
    class Base

      def id
        StringHelper.underscore_class(self.class)
      end

      def to_hash
        {id: id, template_preset_body: template_preset_body}
      end

      def build_template_from_preset(provider, stack_template_id, template_attrs)
        stack_template_attrs = {
          id: stack_template_id,
          provider: provider,
          template_body: serialize(actual_template_hash(template_preset_hash, template_attrs))
        }
        template_model = Model::StackTemplateFactory.create(provider, stack_template_attrs)
      end

      def template_preset_body
        @template_preset_body ||= begin
          file_name = File.join("lib/stack_template_presets/#{id}.#{template_file_extension}")
          File.read(file_name)
        end
      end


      private

      def template_preset_hash
        unserialize(template_preset_body)
      end

      def actual_template_hash(template_preset_hash, params)

      end

      # some templates may be YAML files
      def template_file_extension
        serialization_strategy.to_s
      end

      # some templates may be YAML files
      def serialize(hash)
        case serialization_strategy
        when :json
          hash.to_json
        else
          raise
        end
      end

      def unserialize(text)
        case serialization_strategy
        when :json
          JSON.parse(text)
        else
          raise
        end
      end

      def serialization_strategy
        :json
      end

    end
  end
end