module Aigu
  class Merger
    def initialize(opts = {})
      @output_file = opts[:'output-file']
      @input_directory = opts[:'input-directory']
    end

    def process!
      puts "Generating flat Accent JSON file `#{@output_file}` merging json files in `#{@input_directory}` directory"

      puts '---'

      build_output
      write_json_file

      puts '---'
      puts 'Done'
    end

  protected

    def build_output
      @output = {}

      pattern = File.join(@input_directory, '*.json')
      Dir[pattern].each do |filepath|
        puts "Processing #{filepath}"

        file_name =  filepath.rpartition(File::SEPARATOR).last.split('.', 2).first
        prefix = file_name == 'default' ? '' : "@#{file_name.upcase}@__"

        json = JSON.parse(File.read(filepath))
        json.each_pair do |key, value|
          @output[prefix + key] = value
        end
      end

      @output
    end

    def write_json_file
      file_path = @output_file
      puts "Generating #{file_path}"
      FileUtils.mkdir_p(File.dirname(file_path))

      File.open(file_path, 'w+') do |file|
        file << JSON.pretty_generate(JSON.parse(@output.to_json))
      end
    end
  end
end