renuo/i18n-docs

module I18nDocs
  class TranslationFileExport
    attr_accessor :translations

    def initialize(source_dir, source_file, output_dir, locales)
      @source_dir = source_dir
      @source_file = source_file

      @output_file = File.join(output_dir, source_file.gsub('.yml', '.csv'))
      @locales = locales.map(&:to_s)

      @translations = {}
    end

    def export
      load_translations
      write_to_csv
    end

    def write_to_csv
      main_locale = @locales.include?('en') ? 'en' : @locales.first

      puts "    #{@source_file}: write CSV to '#{@output_file}' \n\n"

      CSV.open(@output_file, 'wb') do |csv|
        csv << (['key'] + @locales)

        @translations[main_locale].keys.each do |key|
          values = @locales.map do |locale|
            @translations[locale][key]
          end
          csv << values.unshift(key)
        end
      end
    end

    def load_translations
      @locales.each do |locale|
        translation_hash = load_language(locale)
        @translations[locale] = flatten_translations_hash(translation_hash)
      end
    end

    def load_language(locale)
      puts "    #{@source_file}: load translations for '#{locale}'"

      input_file = File.join(@source_dir, locale, @source_file)
      translations = {}
      translations = YAML.load_file(input_file) if File.exist?(input_file)
      translations[locale]
    end

    def flatten_translations_hash(translations, parent_key = [])
      flat_hash = {}

      translations.each do |key, t|
        current_key = parent_key.dup << key
        if t.is_a?(Hash)
          # descend
          flat_hash.merge!(flatten_translations_hash(t, current_key))
        else
          # leaf -> store as value for key
          flat_hash[current_key.join('.')] = t
        end
      end
      flat_hash
    end
  end
end