renuo/i18n-docs

module I18nDocs
  class MissingKeysFinder
    def initialize(backend)
      @backend = backend
      load_config
      load_translations
    end

    # Returns an array with all keys from all locales
    def all_keys
      I18n.backend.send(:translations).collect do |_check_locale, translations|
        collect_keys([], translations).sort
      end.flatten.uniq
    end

    def find_missing_keys
      output_available_locales
      output_unique_key_stats(all_keys)

      missing_keys = {}
      all_keys.each do |key|
        I18n.available_locales.each do |locale|
          skip = false
          ls = locale.to_s
          unless @yaml[ls].nil?
            @yaml[ls].each do |re|
              if key.match(re)
                skip = true
                break
              end
            end
          end

          if !key_exists?(key, locale) && skip == false
            if missing_keys[key]
              missing_keys[key] << locale
            else
              missing_keys[key] = [locale]
            end
          end
        end
      end

      output_missing_keys(missing_keys)
      missing_keys
    end

    # rubocop:disable Metrics/LineLength
    def output_available_locales
      puts "#{I18n.available_locales.size} #{I18n.available_locales.size == 1 ? 'locale' : 'locales'} available: #{I18n.available_locales.join(', ')}"
    end

    def output_missing_keys(missing_keys)
      if missing_keys.any?
        puts "#{missing_keys.size} #{missing_keys.size == 1 ? 'key is missing' : 'keys are missing'} from one or more locales:"
        missing_keys.keys.sort.each do |key|
          puts "'#{key}': Missing from #{missing_keys[key].collect(&:inspect).join(', ')}"
        end
        puts "\nERROR: #{missing_keys.size} #{missing_keys.size == 1 ? 'key is missing' : 'keys are missing'} from one or more locales."
      else
        puts 'No keys are missing'
      end
    end
    # rubocop:enable Metrics/LineLength

    def output_unique_key_stats(keys)
      number_of_keys = keys.size
      puts "#{number_of_keys} #{number_of_keys == 1 ? 'unique key' : 'unique keys'} found."
    end

    def collect_keys(scope, translations)
      full_keys = []
      translations.to_a.each do |key, translation|
        new_scope = scope.dup << key
        if translation.is_a?(Hash)
          full_keys += collect_keys(new_scope, translation)
        else
          full_keys << new_scope.join('.')
        end
      end
      full_keys
    end

    # Returns true if key exists in the given locale
    def key_exists?(key, locale)
      I18n.locale = locale
      I18n.translate(key, raise: true)
      return true
    rescue I18n::MissingInterpolationArgument
      return true
    rescue I18n::MissingTranslationData
      return false
    end

    def load_translations
      # Make sure we’ve loaded the translations
      I18n.backend.send(:init_translations)
    end

    def load_config
      @yaml = {}
      begin
        @yaml = YAML.load_file(File.join(Rails.root, 'config', 'ignore_missing_i18n_keys.yml'))
      rescue
        STDERR.puts 'No ignore_missing_keys.yml config file.'
      end
    end
  end
end