/**
 * @file include/protocol/LowLevel.h
 * @brief Low level DI-Net protocol handling
 * @date April 30, 2015
 * @author R.W.A. van der Heijden
 * @copyright 2015 Dual Inventive Technology Centre B.V.
 *
 * Generic low level DI-Net layer handler, it can handle incoming packets
 * and create them
 */
#ifndef INCLUDE_SERVER_LOWLEVEL_H_
#define INCLUDE_SERVER_LOWLEVEL_H_

#include <memory>
#include <di/Buffer.h>

/**
 * @class LowLevel
 * Low level protocol handling
 */
class LowLevel {
 public:
	struct LowLevelMessage {
		unsigned char type; /**< Message type @ref DinetMessageTypes */
		size_t length; /**< length of unpacked data is stored here */
		Di::Buffer data; /**< Unpacked data is stored here */
	};

	/**
	 * Parse incoming data, this function erases all unwanted data from the
	 * stream, but not buffer the rest elsewhere
	 * @param stream incoming data which must get parsed
	 * @return dinet errno or @ref DinetMessageTypes
	 */
	std::shared_ptr<LowLevelMessage> decode(std::shared_ptr<Di::Buffer> stream);

	/**
	 * Wrap a packet into the generic message format
	 * this functions modifies the packet in place
	 * @param stream incoming data, wrapped in the lowlevel format
	 * @return size of total data in stream
	 */
	static int createMessage(std::shared_ptr<Di::Buffer> stream);
	/**
	 * Wrap a device_uid into a generic handshake
	 * this functions modifies the packet in place
	 * @param device_uid which must be wrapped in a handshake
	 * @return size of total data in stream
	 */
	int createReply(std::shared_ptr<Di::Buffer> obuf, bool positive);
	/**
	 * Fill dinet time string pack
	 * this functions modifies the packet in place
	 * @param time which is filled with getDinetNow
	 * @return size of total data in stream
	 */
	int createTime(std::shared_ptr<Di::Buffer> time);
};

#endif  // INCLUDE_SERVER_LOWLEVEL_H_