module PluginTool

  @@notification_announce_reconnect = false

  def self.start_notifications
    @@notification_queue_name = nil
    Thread.new do
      while true
        begin
          self.do_notifications
        rescue => e
          puts "NOTICE: Lost notification connection, will attempt to reconnect soon."
          @@notification_announce_reconnect = true
          sleep(5)  # throttle errors
        end
      end
    end
  end

  def self.do_notifications
    http = make_http_connection
    puts "NOTICE: Notification connection established." if @@notification_announce_reconnect
    while true
      sleep(0.25) # small throttle of requests
      path = '/api/development_plugin_loader/get_notifications'
      path << "?queue=#{@@notification_queue_name}" if @@notification_queue_name
      request = Net::HTTP::Get.new(path)
      setup_request(request)
      # Server uses long-polling, and will respond after a long timeout, or when a notification
      # has been queued for sending to this process.
      response = http.request(request)
      if response.kind_of?(Net::HTTPOK)
        @@notification_queue_name = response['X-Queue-Name']
        begin
          decode_and_handle_notifications response.body
        rescue
          puts "NOTICE: Error handling notification from server."
        end
      else
        raise "Bad response"
      end
    end
  end
  
  def self.decode_and_handle_notifications(encoded)
    size = encoded.length
    pos = 0
    while pos < (size - 12)
      type = encoded[pos, 4]
      data_size = encoded[pos + 4, 8].to_i(16)
      data = encoded[pos + 12, data_size]
      pos += 12 + data_size
      handle_notification(type, data)
    end
  end
  
  def self.handle_notification(type, data)
    case type
    when 'log '
      # Output from console.log()
      puts "LOG:#{data}"
    else
      puts "WARNING: Unknown notification received from server. Upgrade the plugin tool."
      sleep(5) # throttle problematic responses
    end
  end

end