mqtt5/include/async_mqtt5/error.hpp

//
// Copyright (c) 2023-2024 Ivica Siladic, Bruno Iljazovic, Korina Simicevic
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef ASYNC_MQTT5_ERROR_HPP
#define ASYNC_MQTT5_ERROR_HPP

#include <cstdint>
#include <ostream>
#include <string>

#include <boost/asio/error.hpp>

namespace async_mqtt5 {

/**
 * \brief A representation of Disconnect Reason Code.
 *
 * \details Represents all Reason Codes that the Client can send to the Server
 * in the \__DISCONNECT\__ packet as the reason for the disconnection.
 */
enum class disconnect_rc_e : uint8_t {
	/** Close the connection normally. Do not send the Will Message. */
	normal_disconnection = 0x00,

	/** The Client wishes to disconnect but requires that
	 the Server also publishes its Will Message. */
	disconnect_with_will_message = 0x04
};

namespace detail {

enum class disconnect_rc_e : uint8_t {
	normal_disconnection = 0x00,
	disconnect_with_will_message = 0x04,

	unspecified_error = 0x80,
	malformed_packet = 0x81,
	protocol_error = 0x82,
	implementation_specific_error = 0x83,
	topic_name_invalid = 0x90,
	receive_maximum_exceeded = 0x93,
	topic_alias_invalid = 0x94,
	packet_too_large = 0x95,
	message_rate_too_high = 0x96,
	quota_exceeded = 0x97,
	administrative_action = 0x98,
	payload_format_invalid = 0x99
};

}


namespace client {
/**
 * \brief Defines error codes related to MQTT client.
 *
 * \details Encapsulates errors that occur on the client side.
 */
enum class error : int {
	/** The packet is malformed */
	malformed_packet = 100,

	/** The packet has exceeded the Maximum Packet Size the Server is willing to accept */
	packet_too_large,

	/** The Client's session does not exist or it has expired */
	session_expired,

	/** There are no more available Packet Identifiers to use */
	pid_overrun,

	/** The Topic is invalid and does not conform to the specification */
	invalid_topic,

	// publish
	/** The Server does not support the specified \ref qos_e */
	qos_not_supported,

	/** The Server does not support retained messages */
	retain_not_available,

	/** The Client attempted to send a Topic Alias that is greater than Topic Alias Maximum */
	topic_alias_maximum_reached,

	// subscribe
	/** The Server does not support Wildcard Subscriptions */
	wildcard_subscription_not_available,

	/** The Server does not support this Subscription Identifier */
	subscription_identifier_not_available,

	/** The Server does not support Shared Subscriptions */
	shared_subscription_not_available
};


inline std::string client_error_to_string(error err) {
	switch (err) {
		case error::malformed_packet:
			return "The packet is malformed";
		case error::packet_too_large:
			return "The packet has exceeded the Maximum Packet Size "
				"the Server is willing to accept";
		case error::session_expired:
			return "The Client's session does not exist or it has expired";
		case error::pid_overrun:
			return "There are no more available Packet Identifiers to use";
		case error::invalid_topic:
			return "The Topic is invalid and "
				"does not conform to the specification";
		case error::qos_not_supported:
			return "The Server does not support the specified QoS";
		case error::retain_not_available:
			return "The Server does not support retained messages";
		case error::topic_alias_maximum_reached:
			return "The Client attempted to send a Topic Alias "
				"that is greater than Topic Alias Maximum";
		case error::wildcard_subscription_not_available:
			return "The Server does not support Wildcard Subscriptions";
		case error::subscription_identifier_not_available:
			return "The Server does not support this Subscription Identifier";
		case error::shared_subscription_not_available:
			return "The Server does not support Shared Subscriptions";
		default:
			return "Unknown client error";
	}
}

struct client_ec_category : public boost::system::error_category {
	const char* name() const noexcept override { return "mqtt_client_error"; }
	std::string message(int ev) const noexcept override {
		return client_error_to_string(static_cast<error>(ev));
	}
};

/// Returns the error category associated with \ref client::error.
inline const client_ec_category& get_error_code_category() {
	static client_ec_category cat;
	return cat;
}

/// Creates an \ref error_code from a \ref client::error.
inline boost::system::error_code make_error_code(error r) {
	return { static_cast<int>(r), get_error_code_category() };
}

inline std::ostream& operator<<(std::ostream& os, const error& err) {
	os << get_error_code_category().name() << ":" << static_cast<int>(err);
	return os;
}

} // end namespace client

} // end namespace async_mqtt5

namespace boost::system {

template <>
struct is_error_code_enum <async_mqtt5::client::error> : std::true_type {};

} // end namespace boost::system


#endif // !ASYNC_MQTT5_ERROR_HPP