module Daengine
  class TaxonomyProcessor

    @@last_read_time = 2.days.ago

    def self.is_windows?
      processor, platform, *rest = RUBY_PLATFORM.split("-")
      platform =~ /mswin/ || platform =~ /mingw/
    end

    def self.process_taxonomy_file
      file = Daengine.config[:taxonomy_xml_filepath]
      raise "ERROR: TaxonomyProcessor: Invalid taxonomy_xml_filepath provided. Unable to read from #{file}" unless File::exist?(file)
      time = self.read_last_process_time
      if not time.blank?
        @@last_read_time = time
      end
      Daengine.log("TaxonomyProcessor: Last process time was #{@@last_read_time}", "info")
      if (File.mtime(file) > @@last_read_time)
        Daengine.log("TaxonomyProcessor: Processing file #{file} --- #{File.mtime(file)}", "info")
        open_file = File.open(file, 'rb')
        Daengine::TaxonomyParser.parse_taxonomy_file(open_file)
        Daengine.log("TaxonomyProcessor: Finished processing #{file}", "info")
        @@last_read_time = File.mtime(file) + 1.second
        self.save_last_read_time
        Daengine.log("TaxonomyProcessor: Last process time set to #{@@last_read_time}", "info")
      else
        Daengine.log("TaxonomyProcessor: No updates to taxonomy since last process task.", "info")
      end
    end

    def self.save_last_read_time
      begin
        target = Daengine.config[:taxonomyengine_yml_file]
        content = "last_read_time: #{@@last_read_time}"
        File.open(target, "w+") do |f|
          f.write(content)
        end
      rescue Exception => e
        puts e
        Daengine.log("ERROR: TaxonomyProcessor: Failed to write to #{target}.", "error")
      end
    end

    def self.read_last_process_time
      time = ""
      begin
        target = Daengine.config[:taxonomyengine_yml_file]
        property = YAML.load_file(target)
        time = property['last_read_time']
      rescue Exception => e
        puts e
        Daengine.log("ERROR: TaxonomyProcessor: Failed to read from #{target}", "error")
      end
      time
    end

  end
end