#
# Author:: Christine Draper (<christine_draper@thirdwaveinsights.com>)
# Copyright:: Copyright (c) 2015 ThirdWave Insights LLC
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

#
# The converter class converts data in a given format into "topo" format data
#

class Chef
  module Topo
    # Base converter
    class Converter
      # rubocop:disable Style/ClassVars
      # Converters for each format
      @@converter_classes = {}

      def self.register_converter(format, class_name)
        @@converter_classes[format] = class_name
      end

      # Get the right converter for the input format
      def self.converter(format)
        converter_class = @@converter_classes[format]
        converter_class = load_converter(format) unless converter_class

        Object.const_get(converter_class).new(format)
      end

      def self.load_converter(format)
        require "chef/topo/converter/#{format}"
        @@converter_classes[format]
      rescue LoadError
        STDERR.puts("#{format} is not a known format for the topology file")
        exit(1)
      end

      def self.convert(format, data)
        converter = self.converter(format)
        converter.convert(data)
      end

      attr_accessor :input

      def initialize(format, data = nil)
        @format = format
        @input = data
        @output = { 'nodes' => [] }
      end

      # Other format converters should override the following methods
      register_converter('default', name)
      register_converter('topo', name)

      def convert(data = nil)
        @input = data if data
        @output = @input
        @output
      end
    end
  end
end