#ifndef SAPROTOCOL_H
#define SAPROTOCOL_H

#include <QtCore/QObject>
#include <QtBluetooth/QBluetoothUuid>

class SAProtocol
{
	Q_GADGET
	Q_ENUMS(Role FrameType ControlFrameType)

public:
	static const QBluetoothUuid dataServiceUuid;
	static const QBluetoothUuid nudgeServiceUuid;

	enum Role {
		ClientRole,
		ServerRole
	};

	static const quint8 currentProtocolVersion = 0;

	static const quint16 defaultSessionId = 0x3FF;
	static const quint16 maxSessionId = 0x3FF;

	static quint16 computeCrc16(const QByteArray &buf);

	static const char peerDescriptionSeparator = ';';

	/** One of the early connection setup messages. Seems to describe each
	 *  other's capabilities and network settings to the remote peer. */
	struct PeerDescription {
		/** No idea: either 5 or 6. Wild guess: 5 is request, 6 is response. */
		quint8 messageType;
		quint16 accessoryProtocolVersion;
		quint16 accessorySoftwareVersion;
		/** Status code. 0 generally means "no error". */
		quint8 status;
		quint8 errorCode; /**< Used when status != 0 and messageType == 6 */

		/* Seemingly network parameters, but I am not sure how the other end
		 * actually handles them. Seem to do nothing. */
		quint32 APDUSize;
		quint16 SSDUSize;
		quint16 sessions; /**< Seemingly maximum number of sessions allowed. */
		quint16 timeout; /**< Looks like a timeout, but no idea what for. */

		/* No idea. */
		quint8 unk_1;
		quint16 unk_2;
		quint8 unk_3;

		/* No one cares about the ones below. Seemingly free-form text. */
		QString product;
		QString manufacturer;
		QString name;
		QString profile;
	};

	static PeerDescription unpackPeerDescription(const QByteArray &data);
	static QByteArray packPeerDescription(const PeerDescription &desc);

	enum SecurityFrameType {
		SecurityAuthenticateRequest = 0x10,
		SecurityAuthenticateResponse = 0x11,
		SecurityAuthenticateConfirm = 0x12
	};

	struct SecurityFrame {
		SecurityFrameType type;
		quint8 authType; // ???
		quint8 version; // Always 0 so far.
		quint8 dataType; // ???
		QByteArray data;
	};

	static SecurityFrame unpackSecurityFrame(const QByteArray &data);
	static QByteArray packSecurityFrame(const SecurityFrame &sframe);

	enum FrameType {
		FrameData = 0,
		FrameControl = 1
	};

	struct Frame {
		quint8 protocolVersion; // Always 0 so far.
		FrameType type;
		quint16 sessionId;
		QByteArray data;
	};

	static Frame unpackFrame(const QByteArray &data);
	static QByteArray packFrame(const Frame& frame);
	static QByteArray packFrame(quint16 sessionId, const QByteArray &data, FrameType type = FrameData);

	enum FragmentStatus {
		FragmentNone = 0,
		FragmentMiddle = 1,
		FragmentLast = 3
	};

	struct DataFrame {
		bool withSeqNum; // (not actually present in frame)
		// The following field is only present if "withSeqNum":
		quint16 seqNum; // Monotonically increasing
		bool withFragStatus; // (not actually present in frame)
		FragmentStatus fragStatus;
		QByteArray data;
	};

	static DataFrame unpackDataFrame(const QByteArray &data, bool withSeqNum, bool withFragStatus);
	static QByteArray packDataFrame(const DataFrame& frame);

	enum ControlFrameType {
		ControlFrameImmediateAck = 0,
		ControlFrameBlockAck = 1,
		ControlFrameNak = 2
	};

	typedef QPair<quint16, quint16> SeqNumRange;

	struct ControlFrame {
		ControlFrameType type;
		QList<SeqNumRange> seqNums; // Used for Naks only
		quint16 seqNum;
	};

	static ControlFrame unpackControlFrame(const QByteArray &data);
	static QByteArray packControlFrame(const ControlFrame& frame);

	/* Default session messages */

	enum DefaultSessionMessageType {
		ServiceConnectionRequest = 1,
		ServiceConnectionResponse = 2,
		ServiceTerminationRequest = 3,
		ServiceTerminationResponse = 4
	};

	/** The following settings map 1:1 to contents in service.xml files (thank god).
	 *  That does not mean I understand what they do, specially the QoS part. */

	struct ServiceConnectionRequestSession {
		quint16 sessionId;
		quint16 channelId;
		quint8 qosType;
		quint8 qosDataRate;
		quint8 qosPriority;
		quint8 payloadType;
	};

	struct ServiceConnectionRequestFrame {
		quint8 messageType;
		quint16 acceptorId;
		quint16 initiatorId;
		QString profile;
		QList<ServiceConnectionRequestSession> sessions;
	};

	static ServiceConnectionRequestFrame unpackServiceConnectionRequestFrame(const QByteArray &data);
	static QByteArray packServiceConnectionRequestFrame(const ServiceConnectionRequestFrame &frame);

	struct ServiceConnectionResponseFrame {
		quint8 messageType;
		quint16 acceptorId;
		quint16 initiatorId;
		QString profile;
		quint8 statusCode;
		QList<quint16> sessions;
	};

	static ServiceConnectionResponseFrame unpackServiceConnectionResponseFrame(const QByteArray &data);
	static QByteArray packServiceConnectionResponseFrame(const ServiceConnectionResponseFrame &frame);

	struct ServiceTerminationRequestFrame {
		quint8 messageType;
		quint16 acceptorId;
		quint16 initiatorId;
		QString profile;
	};

	static ServiceTerminationRequestFrame unpackServiceTerminationRequestFrame(const QByteArray &data);
	static QByteArray packServiceTerminationRequestFrame(const ServiceTerminationRequestFrame &frame);

	struct ServiceTerminationResponseFrame {
		quint8 messageType;
		quint16 acceptorId;
		quint16 initiatorId;
		QString profile;
		quint8 statusCode;
	};

	static ServiceTerminationResponseFrame unpackServiceTerminationResponseFrame(const QByteArray &data);
	static QByteArray packServiceTerminationResponseFrame(const ServiceTerminationResponseFrame &frame);

	/* Capability discovery messages */

	static const QLatin1String capabilityDiscoveryProfile;
	static const quint16 capabilityDiscoveryChannel = 255;
	static const quint16 capabilityDiscoveryAgentId = 0xFFFF;

	enum CapabilityDiscoveryMessageType {
		CapabilityDiscoveryMessageTypeQuery = 1,
		CapabilityDiscoveryMessageTypeResponse = 2
	};

	struct CapabilityDiscoveryQuery {
		CapabilityDiscoveryMessageType messageType;
		quint8 queryType;
		quint32 checksum;
		QList<QString> records;
	};

	static CapabilityDiscoveryQuery unpackCapabilityDiscoveryQuery(const QByteArray &data);
	static QByteArray packCapabilityDiscoveryQuery(const CapabilityDiscoveryQuery &msg);

	struct CapabilityDiscoveryService {
		quint16 componentId;
		quint16 aspVersion;
		quint8 role;
		quint16 connTimeout;
		QString profile;
	};

	struct CapabilityDiscoveryProvider {
		quint16 uuid;
		QString name;
		QList<CapabilityDiscoveryService> services;
	};

	struct CapabilityDiscoveryResponse {
		CapabilityDiscoveryMessageType messageType;
		quint8 queryType;
		quint32 checksum;
		QList<CapabilityDiscoveryProvider> providers;
	};

	static CapabilityDiscoveryResponse unpackCapabilityDiscoveryResponse(const QByteArray &data);
	static QByteArray packCapabilityDiscoveryResponse(const CapabilityDiscoveryResponse &msg);

private:
	Q_DISABLE_COPY(SAProtocol)
	SAProtocol();
};

#endif // SAPROTOCOL_H