//OpenSCADA OPC_UA implementation library file: libOPC_UA.h
/********************************************************************************
 *   Copyright (C) 2009-2024 by Roman Savochenko, <roman@oscada.org>		*
 *										*
 *   Version: 2.2.2								*
 *	* UA::symmetricEncrypt() and UA::symmetricDecrypt() merged		*
 *	  to UA::symmetricCrypt() and switched for using EVP_CipherInit()	*
 *	  and EVP_CipherUpdate() instead AES_cbc_encrypt();			*
 *	* using of RSA_public_encrypt() moved to EVP_PKEY_encrypt()		*
 *	  of RSA_private_decrypt() moved to EVP_PKEY_decrypt() for new versions	*
 *   Version: 2.1.30								*
 *	* NodeId appended for the function operator==() of direct comparing.	*
 *	* The default LifeTimeCounter of the subscriptions set to 2400.		*
 *	* The function XML_N::childClear() appended by a result of returning	*
 *	  the same XML_N object for concatenation.				*
 *	CLIENT:									*
 *	* Client::Subscr::MonitItem is appended as a replace of XML_N		*
 *	  in the monitored items representing.					*
 *	* Values acquisition is unified in their reading in the function	*
 *	  Client::poll() both for the Read and Publish modes.			*
 *	* Appended for the CHUNKS implementation both for requests and responses.
 *	* Completely revised and cleared in the common requesting function	*
 *	  reqService() from doubling the arguments and parameters, appended for	*
 *	  restoring sessions at reconnection the secure channel.		*
 *	* The Read request set to the plain requesting with limition on	CHUNKS.	*
 *	* Client::SClntSess::{sessOpen,lstMessReq} renamed to			*
 *	  {secChnlOpenTm,secLstMessReqTm} and prevented from clearing.		*
 *	* OpcUa_ClntPublishResentCntr is set by default to 2.			*
 *	SERVER:									*
 *	* The session checking of all messages appended of preventing of using	*
 *	  foreign connections with the same secure channel and session.		*
 *	* The Publish processing prevented on processing wrong and foreign	*
 *	  Subscriptions, by checking inPrtId, sesTokId and isSecCnlAct.		*
 *	* Subscriptions processing returned to they processing in a separate	*
 *	  task and the function subScrCycle() for true counting all timeouts,	*
 *	  and processing the periodicity of subscription and publishing returned*
 *	  to the counter also, but the publishing left for processing in	*
 *	  the input channel activity and the function Server::EP::publishCall().*
 *	* Link of the sessions to secure channels switched to single one.	*
 *	* Not final chunk packages switched to send directly, for not append	*
 *	  to single TCP-package.						*
 *	* The secure channels limited in OpcUa_SecCnlLimit(10) and the publishes*
 *	  queue in OpcUa_ServerMaxPublishQueue(10).				*
 *   Version: 2.0.20								*
 *	* Short functions appended for str2int() and str2uint().		*
 *	CLIENT:									*
 *	* The main services processing function protIO() adapted to work	*
 *	  in the asynchronous mode (not requesting).				*
 *	* The "Client" object appended for the functions: poll().		*
 *	* The service requests appended for implementation, include processing	*
 *	  the responses, for: CreateSubscription, DeleteSubscriptions,		*
 *	  CreateMonitoredItems, Publish, Poll.					*
 *	* The message property "timeoutHint" set to 0 for all messages since	*
 *	  the possibility of that triggering for Publish messages.		*
 *	* The client object appended by the common resources lock mtxData.	*
 *	SERVER:									*
 *	* Some fields renamed: publInterv to publInterval,			*
 *	  cntrLifeTime to lifetimeCnt, cntrKeepAlive to maxKeepAliveCnt,	*
 *	  maxNotPerPubl to maxNtfPerPubl, en to publEn, secSize() to secN().	*
 *	* Added EP::sessN(), EP::subscrN() and chnlList().			*
 *	* EP::mtxData lock switched to PTHREAD_MUTEX_RECURSIVE.			*
 *   Version: 1.2.8								*
 *	* Hello/Acknowledge properties set configurable and client's ones	*
 *	  also storing.								*
 *	* New OPCAlloc object is added for mutex handle and its automatic free	*
 *	  for exception. Some locks lost fix.					*
 *	  A copy constructor was added for object NodeId and the strange	*
 *	  problem here closed.							*
 *	  Chunks support was added to server's part.				*
 *	  Publish requests, and messages in general, queuing and next its	*
 *	  processing fixed for secure connections and for Acknowledges		*
 *	  for insecure ones in direct processing.				*
 *   Version: 1.1.7								*
 *	* Packages sequence number managing for server part is fixed by		*
 *	  separating from the value of input packages.				*
 *	* Initial filters support is added into requests			*
 *	  CreateMonitoredItemsRequest and ModifyMonitoredItemsRequest.		*
 *	* Packages sequence number managing for input part also unified		*
 *	  and fixed to prevent the value repeats.				*
 *	* Early Acknowledgements processing in request "Publish" is added.	*
 *	* Adapting to work with UAExpert 1.4.					*
 *   Version: 1.0.4								*
 *	* Initial version control.						*
 *										*
 *   This library is free software; you can redistribute it and/or modify	*
 *   it under the terms of the GNU Lesser General Public License as		*
 *   published by the Free Software Foundation; version 3 of the License.	*
 *										*
 *   This library is distributed in the hope that it will be useful,		*
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of		*
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the		*
 *   GNU Lesser General Public License for more details.			*
 *										*
 *   You should have received a copy of the GNU Lesser General Public License	*
 *   along with this library; if not, write to the				*
 *   Free Software Foundation, Inc.,						*
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.			*
 ********************************************************************************/

#ifndef LIBOPC_UA_H
#define LIBOPC_UA_H

#include <stdint.h>

#include <string>
#include <deque>
#include <vector>
#include <map>
#include <algorithm>

using std::string;
using std::deque;
using std::vector;
using std::pair;
using std::map;

namespace OPC
{

//Constants
#define OpcUa_ProtocolVersion		0
#define OpcUa_SecCnlLimit		10
#define OpcUa_SecCnlDefLifeTime		300000
#define OpcUa_ClntPublishResentCntr	2
#define OpcUa_ServerMaxPublishQueue	10

#define OpcUa_NPosID		0xFFFFFFFF

#define NS_OPC_UA		0
#define NS_SERVER		1

//Built-in Data Types
#define OpcUa_Boolean		1
#define OpcUa_SByte		2
#define OpcUa_Byte		3
#define OpcUa_Int16		4
#define OpcUa_UInt16		5
#define OpcUa_Int32		6
#define OpcUa_UInt32		7
#define OpcUa_Int64		8
#define OpcUa_UInt64		9
#define OpcUa_Float		10
#define OpcUa_Double		11
#define OpcUa_String		12
#define OpcUa_DateTime		13
#define OpcUa_Guid		14
#define OpcUa_ByteString	15
#define OpcUa_XmlElement	16
#define OpcUa_NodeId		17
#define OpcUa_ExpandedNodeId	18
#define OpcUa_StatusCode	19
#define OpcUa_QualifiedName	20
#define OpcUa_LocalizedText	21
#define OpcUa_Structure		22
#define OpcUa_DataValue		23
#define OpcUa_BaseDataType	24
#define OpcUa_DiagnosticInfo	25
#define OpcUa_Number		26
#define OpcUa_Integer		27
#define OpcUa_UInteger		28
#define OpcUa_Enumeration	29
#define OpcUa_IntAuto		62	//Expanded by OpenSCADA
#define OpcUa_UIntAuto		63	//Expanded by OpenSCADA
#define OpcUa_VarMask		0x3F
#define OpcUa_ArrayDimension	0x40
#define OpcUa_Array		0x80
#define OpcUa_ServerStatusDataType	862

//Status codes
#define OpcUa_BadUnexpectedError	0x80010000
#define OpcUa_BadCommunicationError	0x80050000
#define OpcUa_BadEncodingError		0x80060000
#define OpcUa_BadDecodingError		0x80070000
#define OpcUa_BadEncodingLimitsExceeded	0x80080000
#define OpcUa_BadTimeout		0x800A0000
#define OpcUa_BadServiceUnsupported	0x800B0000
#define OpcUa_BadNothingToDo		0x800F0000
#define OpcUa_BadTooManyOperations	0x80100000
#define OpcUa_BadUserAccessDenied	0x801F0000
#define OpcUa_BadIdentityTokenInvalid	0x80200000
#define OpcUa_BadIdentityTokenRejected	0x80210000
#define OpcUa_BadSecureChannelIdInvalid	0x80220000
#define OpcUa_BadSessionIdInvalid	0x80250000
#define OpcUa_BadSessionNotActivated	0x80270000
#define OpcUa_BadSubscriptionIdInvalid	0x80280000
#define OpcUa_BadNodeIdInvalid		0x80330000
#define OpcUa_BadNodeIdUnknown		0x80340000
#define OpcUa_BadAttributeIdInvalid	0x80350000
#define OpcUa_BadNotSupported		0x803D0000
#define OpcUa_BadMonitoredItemIdInvalid	0x80420000
#define OpcUa_BadFilterNotAllowed	0x80450000
#define OpcUa_BadContinuationPointInvalid	0x804A0000
#define OpcUa_BadNoContinuationPoints	0x804B0000
#define OpcUa_BadSecurityModeRejected	0x80540000
#define OpcUa_BadSecurityPolicyRejected	0x80550000
#define OpcUa_BadApplicationSignatureInvalid	0x80580000
#define OpcUa_BadBrowseNameInvalid	0x80600000
#define OpcUa_BadNoMatch		0x806F0000
#define OpcUa_BadWriteNotSupported	0x80730000
#define OpcUa_BadTooManySubscriptions	0x80770000
#define OpcUa_BadNoSubscription		0x80790000
#define OpcUa_BadSequenceNumberUnknown	0x807A0000
#define OpcUa_BadMessageNotAvailable	0x807B0000
#define OpcUa_BadTcpMessageTypeInvalid	0x807E0000
#define OpcUa_BadTcpSecureChannelUnknown	0x807F0000
#define OpcUa_BadTcpMessageTooLarge	0x80800000
#define OpcUa_BadTcpEndpointUrlInvalid	0x80830000
#define OpcUa_BadSecureChannelClosed	0x80860000
#define OpcUa_BadSecureChannelTokenUnknown	0x80870000
#define OpcUa_BadInvalidArgument	0x80AB0000
#define OpcUa_BadEndOfStream		0x80B00000
#define OpcUa_BadRequestTooLarge	0x80B80000
#define OpcUa_BadResponseTooLarge	0x80B90000
#define OpcUa_BadProtocolVersionUnsupported	0x80BE0000

//Status codes of values
#define OpcUa_UncertainNoCommunicationLastUsableValue	0x408F0000
#define OpcUa_UncertainLastUsableValue	0x40900000
#define OpcUa_UncertainSubstituteValue	0x40910000
#define OpcUa_UncertainInitialValue	0x40920000
#define OpcUa_UncertainSensorNotAccurate	0x40930000
#define OpcUa_UncertainEngineeringUnitsExceeded	0x40940000
#define OpcUa_UncertainSubNormal	0x40950000

//Requests types
#define OpcUa_ServiceFault			397
#define OpcUa_FindServersRequest		422
#define OpcUa_FindServersResponse		425
#define OpcUa_GetEndpointsRequest		428
#define OpcUa_GetEndpointsResponse		431
#define OpcUa_OpenSecureChannelRequest		446
#define OpcUa_OpenSecureChannelResponse		449
#define OpcUa_CloseSecureChannelRequest		452
#define OpcUa_CreateSessionRequest		461
#define OpcUa_CreateSessionResponse		464
#define OpcUa_ActivateSessionRequest		467
#define OpcUa_ActivateSessionResponse		470
#define OpcUa_CloseSessionRequest		473
#define OpcUa_CloseSessionResponse		476
#define OpcUa_BrowseRequest			527
#define OpcUa_BrowseResponse			530
#define OpcUa_BrowseNextRequest			533
#define OpcUa_BrowseNextResponse		536
#define OpcUa_TranslateBrowsePathsToNodeIdsRequest	554
#define OpcUa_TranslateBrowsePathsToNodeIdsResponse	557
#define OpcUaId_RegisterNodesRequest		560
#define OpcUaId_RegisterNodesResponse		563
#define OpcUaId_UnregisterNodesRequest		566
#define OpcUaId_UnregisterNodesResponse		569
#define OpcUa_ReadRequest			631
#define OpcUa_ReadResponse			634
#define OpcUa_WriteRequest			673
#define OpcUa_WriteResponse			676
#define OpcUa_EventFilterResult			736
#define OpcUa_CreateMonitoredItemsRequest	751
#define OpcUa_CreateMonitoredItemsResponse	754
#define OpcUa_ModifyMonitoredItemsRequest	763
#define OpcUa_ModifyMonitoredItemsResponse	766
#define OpcUa_SetMonitoringModeRequest		769
#define OpcUa_SetMonitoringModeResponse		772
#define OpcUa_DeleteMonitoredItemsRequest	781
#define OpcUa_DeleteMonitoredItemsResponse	784
#define OpcUa_CreateSubscriptionRequest		787
#define OpcUa_CreateSubscriptionResponse	790
#define OpcUa_ModifySubscriptionRequest		793
#define OpcUa_ModifySubscriptionResponse	796
#define OpcUa_SetPublishingModeRequest		799
#define OpcUa_SetPublishingModeResponse		802
#define OpcUa_PublishRequest			826
#define OpcUa_PublishResponse			829
#define OpcUa_RepublishRequest			832
#define OpcUa_RepublishResponse			835
#define OpcUa_TransferSubscriptionsRequest	841
#define OpcUa_TransferSubscriptionsResponse	844
#define OpcUa_DeleteSubscriptionsRequest	847
#define OpcUa_DeleteSubscriptionsResponse	850

//Object Identifiers
#define OpcUa_RootFolder		84
#define OpcUa_ObjectsFolder		85
#define OpcUa_TypesFolder		86
#define OpcUa_ViewsFolder		87
#define OpcUa_ObjectTypesFolder		88
#define OpcUa_VariableTypesFolder	89
#define OpcUa_DataTypesFolder		90
#define OpcUa_ReferenceTypesFolder	91
#define OpcUa_AnonymousIdentityToken	321
#define OpcUa_UserNameIdentityToken	324
#define OpcUa_X509IdentityToken		327
#define OpcUa_LiteralOperand		597
#define OpcUa_EventFilter		727
#define OpcUa_DataChangeNotification	811
#define OpcUa_Server			2253

//ObjectType Identifiers
#define OpcUa_BaseObjectType		58
#define OpcUa_FolderType		61
#define OpcUa_DataTypeSystemType	75
#define OpcUa_DataTypeEncodingType	76
#define OpcUa_ModellingRuleType		77
#define OpcUa_ServerType		2004
#define OpcUa_ServerCapabilitiesType	2013
#define OpcUa_ServerDiagnosticsType	2020
#define OpcUa_SessionsDiagnosticsSummaryType	2026
#define OpcUa_SessionDiagnosticsObjectType	2029
#define OpcUa_VendorServerInfoType	2033
#define OpcUa_ServerRedundancyType	2034
#define OpcUa_TransparentRedundancyType	2036
#define OpcUa_NonTransparentRedundancyType	2039
#define OpcUa_BaseEventType		2041
#define OpcUa_GeneralModelChangeEventType 2133
#define OpcUa_StateType			2307
#define OpcUa_TransitionType		2310

//Variable Identifiers
#define OpcUa_BaseVariableType		62
#define OpcUa_BaseDataVariableType	63
#define OpcUa_PropertyType		68
#define OpcUa_Server_ServerArray	2254
#define OpcUa_Server_NamespaceArray	2255
#define OpcUa_Server_ServerStatus	2256
#define OpcUa_Server_ServerStatus_State	2259
#define OpcUa_Server_ServerCapabilities	2268
#define OpcUa_Server_ServerCapabilities_MinSupportedSampleRate	2272
#define OpcUa_Server_ServerCapabilities_MaxBrowseContinuationPoints	2735
#define OpcUa_Server_ServerCapabilities_MaxQueryContinuationPoints	2736
#define OpcUa_Server_ServerCapabilities_MaxHistoryContinuationPoints	2737
#define OpcUa_Server_Auditing		2994
#define OpcUa_Server_ServerCapabilities_MaxArrayLength	11702
#define OpcUa_Server_ServerCapabilities_MaxStringLength	11703

//ReferenceType Identifiers
#define OpcUa_References		31
#define OpcUa_NonHierarchicalReferences	32
#define OpcUa_HierarchicalReferences	33
#define OpcUa_HasChild			34
#define OpcUa_Organizes			35
#define OpcUa_HasEventSource		36
#define OpcUa_HasModellingRule		37
#define OpcUa_HasEncoding		38
#define OpcUa_HasDescription		39
#define OpcUa_HasTypeDefinition		40
#define OpcUa_GeneratesEvent		41
#define OpcUa_Aggregates		44
#define OpcUa_HasSubtype		45
#define OpcUa_HasProperty		46
#define OpcUa_HasComponent		47
#define OpcUa_HasModelParent		50

//VariableType Identifiers
#define OpcUa_ServerStatusType		2138

enum SerializerType	{ ST_Binary };
enum SC_ReqTP		{ SC_ISSUE = 0, SC_RENEW = 1 };
enum MessageSecurityMode{ MS_None = 1, MS_Sign, MS_SignAndEncrypt };
enum AuthTp		{ A_Anon = 0, A_UserNm = 1, A_Cert = 2 };
enum NodeClasses	{ NC_Object = 1, NC_Variable = 2, NC_Method = 4, NC_ObjectType = 8, NC_VariableType = 16,
			  NC_ReferenceType = 32, NC_DataType = 64, NC_View = 128 };
enum BrowseDirection	{ BD_FORWARD = 0, BD_INVERSE, BD_BOTH };
enum TimestampsToReturn	{ TS_SOURCE = 0, TS_SERVER, TS_BOTH, TS_NEITHER };
enum Access		{ ACS_Read = 0x01, ACS_Write = 0x02, ACS_HistRead = 0x04, ACS_HistWrite = 0x08, ACS_SemChange = 0x10 };
enum RefDscrResMask	{ RdRm_RefType = 0x01, RdRm_IsForward = 0x02, RdRm_NodeClass = 0x04, RdRm_BrowseName = 0x08,
			  RdRm_DisplayName = 0x10, RdRm_TypeDef = 0x20 };
enum AttrIds		{ Aid_Error = 0, AId_NodeId, AId_NodeClass, AId_BrowseName, AId_DisplayName, AId_Descr, AId_WriteMask,
			  AId_UserWriteMask, AId_IsAbstract, AId_Symmetric, AId_InverseName, AId_ContainsNoLoops, AId_EventNotifier,
			  AId_Value, AId_DataType, AId_ValueRank, AId_ArrayDimensions, AId_AccessLevel, AId_UserAccessLevel,
			  AId_MinimumSamplingInterval, AId_Historizing, AId_Executable, AId_UserExecutable };
enum SubScrSt		{ SS_CUR = 0, SS_CLOSED, SS_CREATING, SS_NORMAL, SS_LATE, SS_KEEPALIVE };
enum MonitoringMode	{ MM_CUR = -1, MM_DISABLED = 0, MM_SAMPLING, MM_REPORTING };

//* External functions                        */
extern int64_t curTime( clockid_t clc = CLOCK_REALTIME );
extern string int2str( int val );
extern int str2int( const string &val );
extern string uint2str( unsigned val );
extern unsigned long str2uint( const string &val );
extern string ll2str( int64_t val );
extern string real2str( double val, int prec = 15, char tp = 'g' );
extern double str2real( const string &val );
extern string strParse( const string &path, int level, const string &sep, int *off = NULL, bool mergeSepSymb = false );
extern string strLine( const string &str, int level, int *off = NULL );
extern string strMess( const char *fmt, ... );

//***********************************************************
//* Automatic POSIX mutex unlock object for OPC		    *
//***********************************************************
class OPCAlloc
{
    public:
    //Methods
    OPCAlloc( pthread_mutex_t &iM, bool ilock = false ) : m(iM), mLock(false)
    { if(ilock) lock(); }
    ~OPCAlloc( )	{ unlock(); }

    int lock( ) {
	if(mLock) return 0;
	int rez = pthread_mutex_lock(&m);
	if(!rez) mLock = true;
	return rez;
    }
    int tryLock( ) {
	if(mLock) return 0;
	int rez = pthread_mutex_trylock(&m);
	if(!rez) mLock = true;
	return rez;
    }
    int unlock( ) {
	if(!mLock) return 0;
	int rez = pthread_mutex_unlock(&m);
	if(!rez) mLock = false;
	return rez;
    }

    private:
    //Attributes
    pthread_mutex_t	&m;
    bool		mLock;
};

//*************************************************
//* OPCError					  *
//*************************************************
class OPCError
{
    public:
    //Methods
    OPCError( const char *fmt, ... );
    OPCError( int cod, const char *fmt, ... );

    //Attributes
    int		cod;
    string	mess;
};

//*************************************************
//* XML_N					  *
//*************************************************
class XML_N
{
    public:
    //Methods
    XML_N( const string &name = "" ) : mName(name), mText(""), mParent(NULL)	{  }
    XML_N( const XML_N &nd );
    ~XML_N( )				{ clear(); }

    XML_N	&operator=( const XML_N &prm );

    string	name( ) const			{ return mName; }
    XML_N*	setName( const string &s )	{ mName = s; return this; }

    string	text( bool childs = false, bool recursive = false ) const;
    XML_N*	setText( const string &s, bool childs = false );

    void	attrList( vector<string> &list ) const;
    XML_N*	attrDel( const string &name );
    void	attrClear( );
    string	attr( const string &name, bool caseSens = true ) const;
    XML_N*	setAttr( const string &name, const string &val );

    XML_N*	clear( );

    bool	childEmpty( ) const	{ return mChildren.empty(); }
    unsigned	childSize( ) const	{ return mChildren.size(); }
    void	childAdd( XML_N *nd );
    XML_N*	childAdd( const string &name = "" );
    int		childIns( unsigned id, XML_N *nd );
    XML_N*	childIns( unsigned id, const string &name = "" );
    void	childDel( const unsigned id );
    void	childDel( XML_N *nd );
    XML_N*	childClear( const string &name = "" );
    XML_N*	childGet( const int, bool noex = false ) const;
    XML_N*	childGet( const string &name, const int numb = 0, bool noex = false ) const;
    XML_N*	childGet( const string &attr, const string &name, bool noex = false ) const;
    XML_N*	getElementBy( const string &attr, const string &val );

    XML_N*	parent( )		{ return mParent; }
    XML_N*	root( );

    private:
    //Attributes
    string	mName;
    string	mText;
    vector<XML_N*>			mChildren;
    vector<pair<string,string> >	mAttr;
    XML_N	*mParent;
};

//*************************************************
//* NodeId object				  *
//*************************************************
class NodeId
{
    public:
    //Data
    enum Type	{ Numeric, String, Guid, Opaque };

    //Methods
    NodeId( ) : mNs(0), mTp(Numeric), numb(0)	{ }
    NodeId( uint32_t n, uint16_t ns = 0 );
    NodeId( const string &str, uint16_t ns = 0, Type tp = String );
    NodeId( const NodeId &node ){ operator=(node); }
    ~NodeId( );

    bool operator==( const NodeId &node );
    NodeId &operator=( const NodeId &node );

    Type type( ) const		{ return mTp; }
    bool isNull( ) const	{ return (mTp == Numeric && numb == 0); }

    uint16_t ns( ) const	{ return mNs; }
    uint32_t numbVal( ) const;
    string strVal( ) const;

    void setNs( uint16_t ns )	{ mNs = ns; }
    void setNumbVal( uint32_t n );
    void setStrVal( const string &str, Type tp = String );

    static NodeId fromAddr( const string &strAddr, bool strictStr = false, int *off = NULL );
    string toAddr( ) const;

    private:
    //Attributes
    uint16_t	mNs;
    Type	mTp;
    uint32_t	numb;
    string	str;
};

//*************************************************
//* Protocol OPC UA				  *
//*************************************************
class UA
{
    public:
    //Data
    class SecuritySetting
    {
	public:
	SecuritySetting( const string &plc, int8_t mMode ) : policy(plc), messageMode((MessageSecurityMode)mMode) { }
	SecuritySetting( ) : policy("None"), messageMode(MS_None)	{ }

	string		policy;
	MessageSecurityMode	messageMode;
    };

    //Methods
    UA( );
    ~UA( );

    virtual string langCodeSYS( )	{ return "en"; }
    virtual void debugMess( const string &mess ) { }

    // Generic constants
    virtual uint32_t rcvBufSz( )	{ return 0x10000; }	//Great for 8192
    virtual uint32_t sndBufSz( )	{ return 0x10000; }	//Great for 8192
    virtual uint32_t msgMaxSz( )	{ return 0x1000000; }	//Unlimited by default
    virtual uint32_t chunkMaxCnt( )	{ return 5000; }	//Unlimited by default

    // Protocol's data processing
    //----------------------------------------------------
    static string iErr( const string &buf, int &off );
    static const char *iVal( const string &buf, int &off, char vSz );
    static int64_t iN( const string &rb, int &off, char vSz );
    static uint64_t iNu( const string &rb, int &off, char vSz );
    static double iR( const string &rb, int &off, char vSz = 4 );
    static string iS( const string &buf, int &off );
    static string iSl( const string &buf, int &off, string *locale = NULL );
    static string iSqlf( const string &buf, int &off, uint16_t *nsIdx = NULL );
    static int64_t iTm( const string &buf, int &off );
    static NodeId iNodeId( const string &buf, int &off );
    static string iVariant( const string &buf, int &off, uint8_t *tp = NULL );
    static void iDataValue( const string &buf, int &off, XML_N &nVal );

    static void oN( string &buf, int64_t val, char sz, int off = -1 );
    static void oNu( string &buf, uint64_t val, char sz, int off = -1 );
    static void oR( string &buf, double val, char sz = 4 );
    static void oS( string &buf, const string &val, int off = -1 );
    static void oSl( string &buf, const string &val, const string &locale = "" );
    static void oSqlf( string &buf, const string &val, uint16_t nsIdx = 0 );
    static void oTm( string &buf, int64_t val );
    static void oNodeId( string &buf, const NodeId &val );
    static void oRef( string &buf, uint32_t resMask, const NodeId &nodeId, const NodeId &refTypeId,
		      bool isForward, const string &name, uint32_t nodeClass, const NodeId &typeDef );
    void oDataValue( string &buf, uint8_t eMsk, const string &vl, uint8_t vEMsk = 0, int64_t srcTmStmp = 0 );

    static string randBytes( int num );
    static string certPEM2DER( const string &certPem );
    static string certDER2PEM( const string &certDer );
    static string certThumbprint( const string &certPem );
    static string asymmetricEncrypt( const string &mess, const string &certPem, const string &secPolicy );
    static string asymmetricDecrypt( const string &mess, const string &pvKeyPem, const string &secPolicy );
    static bool asymmetricVerify( const string &mess, const string &sign, const string &certPem );
    static string asymmetricSign( const string &mess, const string &pvPem );
    static int asymmetricKeyLength( const string &keyCertPem );
    static string deriveKey( const string &secret, const string &seed, int keyLen );
    static string symmetricCrypt( const string &mess, const string &keySet, const string &secPolicy, bool encrypt );
    static string symmetricSign( const string &mess, const string &keySet, const string &secPolicy );
};

//*************************************************
//* Protocol OPC UA client part			  *
//*************************************************
class Client: public UA
{
    public:
    //Data
    //* Subscription object by monitoreditems set
    class Subscr
    {
	public:
	//Data
	//* Monitored item
	class MonitItem
	{
	    public:
	    //Methods
	    MonitItem( NodeId ind, uint32_t iaid, MonitoringMode imd = MM_REPORTING ) :
		md(imd), nd(ind), aid(iaid), smplItv(0), qSz(1), active(false)	{ }

	    //Attributes
	    MonitoringMode md;		//Monitoring mode
	    NodeId	nd;		//Target node: <EMPTY>-free monitored item
	    uint32_t	aid;		//Attribute ID of the node

	    double	smplItv;	//Sample interval
	    uint32_t	qSz;		//Queue size

	    bool	active;		//Active item
	    uint32_t	st;		//Status

	    XML_N	val;		//Value: the attribute "nodata" presence means the data missing;
	};

	//Methods
	Subscr( Client *iclnt, double ipublInterval = 1e3 ) :
	    publEn(true), publInterval(ipublInterval), subScrId(0), lifetimeCnt(2400),
	    maxKeepAliveCnt(10), maxNtfPerPubl(65536), pr(0), lstPublTm(0),
	    clnt(iclnt)	{ }

	bool isActivated( )	{ return subScrId; }
	void activate( bool vl, bool onlyLocally = false );

	int monitoredItemAdd( const NodeId &nd, AttrIds aId = AId_Value, MonitoringMode mMode = MM_REPORTING );
	void monitoredItemDel( int32_t mItId, bool localDeactivation = false, bool onlyNoData = false );

	//Attributes
	bool	publEn;		//Enable publishing
	double	publInterval;	//Publish interval, milliseconds
	uint32_t subScrId,	//Subscription identifier: <ZERO>-inactive object
		lifetimeCnt,	//Counter, at which and in the absence of notifications, the client deletes this object
		maxKeepAliveCnt,//Counter for which you need to send an empty publication response
		maxNtfPerPubl;	//Maximum notifications per single Publish response
	uint8_t	pr;		//Priority

	vector<MonitItem> mItems; //The monitored items
	vector<uint32_t> mSeqToAcq; //Register of the sequences of the Publish responses need to be acknowledged in a near Publish request;
	int64_t	lstPublTm;	//Last publication response time

	Client *clnt;		//Direct link to the Client object
    };

    class SClntSess
    {
	public:
	//Methods
	SClntSess( ) : secChnlOpenTm(0), secLstMessReqTm(0)	{ clearSess(); clearSecCnl(true); }

	void clearSecCnl( bool inclEP = false ) {
	    servRcvBufSz = servSndBufSz = servMsgMaxSz = servChunkMaxCnt = 0;

	    servCert = clKey = servKey = "";
	    secPolicy = "None"; secMessMode = MS_None;
	    secChnl = secToken = reqHndl = 0;
	    secChnlChanged = false;
	    sqNumb = 33;
	    sqReqId = 1;
	    secLifeTime = 0;
	    //secChnlOpenTm = secLstMessReqTm = 0;

	    if(inclEP) { endPoint = ""; endPointDscr.clear(); }
	}
	void clearSess( bool inclSubscr = true ) {
	    sesId = authTkId = servNonce = "";
	    sesLifeTime = 1.2e6;

	    //Clear subscriptions
	    for(unsigned iSubscr = 0; inclSubscr && iSubscr < mSubScr.size(); ++iSubscr)
		mSubScr[iSubscr].activate(false, true);
	}

	uint32_t	servRcvBufSz,		//Buffer size of the server receiver
			servSndBufSz,		//Buffer size of the server transmitter
			servMsgMaxSz,		//Maximum message size of the server
			servChunkMaxCnt;	//Maximum chunks number of the server
	string		endPoint;		//End Point
	XML_N		endPointDscr;		//End Point description
	uint32_t	secChnl, secToken;	//Security channel index and token
	int		secLifeTime;		//Secure channel lifetime
	bool		secChnlChanged;		//The flag of the secure channel changing for reconnection or reactivation of the session
	uint32_t	sqNumb, sqReqId, reqHndl;	//The sequence number, the sequence number of request and the request handler
	string		secPolicy;		//Security policy
	char		secMessMode;		//Message security mode
	int64_t		secChnlOpenTm, secLstMessReqTm;	//Time of opening/renewing the secure channel and the last message request
	string		sesId, authTkId;	//Session identifier and token of authentication
	double		sesLifeTime;		//Session lifetime
	string		servCert, servNonce, servKey;	//Server certificate, "nonce" and symmetric key
	string		clKey;			//Client symmetric key

	vector<Subscr>	mSubScr;		//Subscriptions list
	vector<int32_t> mPublSeqs;		//Publish packages registration
    };

    //Methods
    Client( );
    ~Client( );

    // Main variables
    virtual string applicationUri( ) = 0;
    virtual string productUri( ) = 0;
    virtual string applicationName( ) = 0;
    virtual string sessionName( ) = 0;
    virtual string endPoint( ) = 0;
    virtual string secPolicy( ) = 0;
    virtual int secMessMode( ) = 0;
    virtual string cert( ) = 0;
    virtual string pvKey( ) = 0;
    virtual string authData( ) = 0;	//Empty			- anonymous
					//{User}\n{Password}	- by user and password
    virtual uint8_t publishReqsPool( )	{ return 2; }	//Pool of the publish requests for the server

    virtual string poll( bool byRead = false );		//To call in some cycle for processing the subscriptions
							//  and user code in it reimplementation
							//<byRead> is designed for direct reading the registered monitored items
							//  by the "Read" function

    // External imlementations
    virtual int messIO( const char *oBuf, int oLen, char *iBuf = NULL, int iLen = 0, int time = 0 ) = 0;

    // Main call methods
    //  Connection state check and/or establist by <est> > 0 or it close by == 0.
    virtual bool connect( int8_t est = -1 )	{ return false; }
    virtual void protIO( XML_N &io );
    virtual void reqService( XML_N &io );

    //Attributes
    SClntSess		sess;		//Assigned session

    protected:
    //Attributes
    pthread_mutex_t	mtxData;
};

//*************************************************
//* Protocol OPC UA server part			  *
//*************************************************
class Server: public UA
{
    public:
	//Data
	//* Security Channel
	class SecCnl
	{
	    public:
	    //Methods
	    SecCnl( const string &ep, uint32_t tokenId, int32_t lifeTm, const string &clCert,
		const string &secPolicy, char secMessMode, const string &clAddr, uint32_t secN );
	    SecCnl( );

	    //Attributes
	    string	endPoint;
	    string	secPolicy;
	    char	secMessMode;
	    int64_t	tCreate;
	    int32_t	tLife;
	    uint32_t	tokenId, tokenIdPrev;
	    string	clCert, clAddr, clKey;
	    string	servKey;
	    uint32_t	servSeqN, clSeqN/*, startClSeqN*/, reqId;
	    // Chunks accumulation
	    int		chCnt;	//Negative for error chunks sequence
	    string	chB;
	};
	//* Session
	class EP;
	class Sess
	{
	    public:
	    //Data
	    //* Connection point for Browse and BrowseNext services
	    class ContPoint
	    {
		public:
		//Methods
		ContPoint( ) : brDir(0), refPerN(100), nClassMask(0), resMask(0) { }
		ContPoint( const string &i_brNode, const string &i_lstNode,
			uint32_t i_brDir, uint32_t i_refPerN, const string &i_refTypeId, uint32_t i_nClassMask, uint32_t i_resMask ) :
		    brDir(i_brDir), refPerN(i_refPerN), nClassMask(i_nClassMask), resMask(i_resMask), brNode(i_brNode), lstNode(i_lstNode),
		    refTypeId(i_refTypeId) { }

		bool empty( ) const	{ return brNode.empty(); }

		//Attributes
		uint32_t brDir,		//Browse direction
			refPerN,	//References per node
			nClassMask,	//Node class mask
			resMask;	//Result mask
		string	brNode, lstNode,
			refTypeId;	//Reference type id
	    };

	    //Methods
	    Sess( const string &name, double tInact );
	    Sess( );

	    bool isSecCnlActive( EP *ep );

	    //Attributes
	    string	name, inPrtId;
			//idPolicyId, user;
	    uint32_t	secCnl;
	    double	tInact;
	    int64_t	tAccess;
	    string	servNonce;

	    map<string, ContPoint> cntPnts;	//>> Continuation points

	    // Subscription
	    deque<string>	publishReqs;	//Publish requests queue
	};

	//* Subscription object by monitoreditems set
	class Subscr
	{
	    public:
	    //Data
	    //* Monitored item
	    class MonitItem
	    {
		public:
		//Data
		//* Value
		class Val
		{
		    public:
		    Val( ) : tm(0), st(OpcUa_UncertainNoCommunicationLastUsableValue) { }
		    Val( const string &ivl, int64_t itm, uint32_t ist = 0 ) : vl(ivl), tm(itm), st(ist) { }

		    string	vl;
		    int64_t	tm;
		    uint32_t	st;
		};

		//Methods
		MonitItem( ) : md(MM_DISABLED), aid(0), tmToRet(TS_SOURCE), smplItv(1000), qSz(OpcUa_NPosID),
		    dO(false), cH(0), vTp(0), dtTm(0)	{ }

		//Attributes
		MonitoringMode	md;		//Monitoring mode
		NodeId		nd;		//Target node
		uint32_t	aid;		//The node's attribute ID
		TimestampsToReturn tmToRet;	//Timestamps to return
		double		smplItv;	//Sample interval
		uint32_t	qSz;		//Queue size
		bool		dO;		//Discard oldest
		uint32_t	cH;		//Client handle
		XML_N		fltr;		//Filters

		int		vTp;		//Values type
		int64_t		dtTm;		//Last value time
		deque<Val>	vQueue;		//Values queue
	    };

	    //Methods
	    Subscr( ) : st(SS_CLOSED), sess(-1), publEn(false), toInit(true), publInterval(100), seqN(1), pubCntr(0), pubCntr_(0),
		lifetimeCnt(2400), wLT(0), maxKeepAliveCnt(50), wKA(0), maxNtfPerPubl(0), pr(0)	{ }

	    Subscr copy( bool noWorkData = true );
	    SubScrSt setState( SubScrSt st = SS_CUR );

	    //Attributes
	    SubScrSt	st;			//Subscription status
	    int		sess;			//Session of the subscription
	    bool	publEn,			//Enabling the publication
			toInit;			//Flag of the subscription initiation - sending of the first-empty package of the publication response
	    double	publInterval;		//Publish interval, milliseconds
	    uint32_t	seqN,			//Sequence number for responses, rolls over 1, no increment for KeepAlive messages
			pubCntr, pubCntr_,	//Publish counter
			lifetimeCnt, wLT,	//Counter after that missing the client notifications will be removed from the object
			maxKeepAliveCnt, wKA,	//Counter after that need to send empty publish response and
						//send StatusChangeNotification with Bad_Timeout
			maxNtfPerPubl;		//Maximum number of the notifications at one response of the publishing
	    uint8_t	pr;			//Priority
	    vector<MonitItem> mItems;
	    deque<string> retrQueue;		//Retransmission queue; used by Republish request;
						//cleared to deep by KeepAlive! or by field Acknowledgements sets
	};

	//* End Point
	class EP
	{
	    friend class Server;
	    public:
	    //Methods
	    EP( Server *serv );
	    ~EP( );

	    virtual string id( ) = 0;
	    virtual string url( ) = 0;
	    virtual string cert( ) = 0;
	    virtual string pvKey( ) = 0;
	    virtual double subscrProcPer( ) = 0;	//Generic minimum cycle period of publishes and the data processing

	    // Limits
	    virtual uint32_t limSubScr( )	{ return 10; }
	    virtual uint32_t limMonitItms( )	{ return 1000; }
	    virtual uint32_t limRetrQueueTm( )	{ return 0; }	//Time limit (seconds) for retransmission queue

	    bool enableStat( ) const		{ return mEn; }

	    virtual void setEnable( bool vl );
	    virtual void setPublish( const string &inPrtId )	{ }	//Start a publish task or input request's poll of subScrCycle()
	    void subScrCycle( unsigned cntr );				//Subscriptions processing cycle
	    void publishCall( string *answ = NULL, const string &inPrtId = "" );

	    // Security policies
	    unsigned secN( )	{ return mSec.size(); }
	    string secPolicy( int sec );
	    MessageSecurityMode secMessageMode( int sec );

	    // Sessions
	    unsigned sessN( )	{ return mSess.size(); }
	    int sessCreate( const string &name, double tInact );
	    void sessServNonceSet( int sid, const string &servNonce );
	    virtual uint32_t sessActivate( int sid, uint32_t secCnl, bool check = false,
		const string &inPrtId = "", const XML_N &identTkn = XML_N() );
	    void sessClose( int sid, bool delSubscr = true );
	    Sess sessGet( int sid );
	    //  Continuation points by Browse and BrowseNext
	    Sess::ContPoint sessCpGet( int sid, const string &cpId );
	    void sessCpSet( int sid, const string &cpId, const Sess::ContPoint &cp = Sess::ContPoint() );	//Empty "cp" remove "cpId"
	    //  Subsciption
	    unsigned subscrN( )	{ return mSubScr.size(); }
	    uint32_t subscrSet( uint32_t ssId, SubScrSt st, bool en = false, int sess = -1,	// "sId" = 0 for new create
		double publInterval = 0, uint32_t lifetimeCnt = 0, uint32_t maxKeepAliveCnt = 0,
		uint32_t maxNotePerPubl = OpcUa_NPosID, int pr = -1 );
	    Subscr subscrGet( uint32_t ssId, bool noWorkData = true );
	    //  Monitored items
	    uint32_t mItSet( uint32_t ssId, uint32_t mItId, MonitoringMode md = MM_CUR,	// "mItId" = 0 for new create
		const NodeId &nd = NodeId(), uint32_t aid = OpcUa_NPosID, TimestampsToReturn tmToRet = TimestampsToReturn(-1),
		double smplItv = -2, uint32_t qSz = OpcUa_NPosID, int8_t dO = -1, uint32_t cH = OpcUa_NPosID, XML_N *fltr = NULL );
	    Subscr::MonitItem mItGet( uint32_t ssId, uint32_t mItId );

	    virtual uint32_t reqData( int reqTp, XML_N &req );

	    //Attributes
	    Server		*serv;

	    protected:
	    //Methods
	    XML_N *nodeReg( const NodeId &parent, const NodeId &ndId, const string &name,
		int ndClass, const NodeId &refTypeId, const NodeId &typeDef = 0 );
	    Sess *sessGet_( int sid );	//Unresourced

	    //Attributes
	    char		mEn;

	    uint64_t		cntReq;

	    vector<SecuritySetting>	mSec;
	    vector<Sess>	mSess;
	    vector<Subscr>	mSubScr;	//Subscriptions list

	    XML_N		objTree;
	    map<string, XML_N*>	ndMap;
	    pthread_mutex_t	mtxData;
	};

	//Methods
	Server( );
	~Server( );

	// Generic variables
	virtual bool debug( )	{ return false; }

	virtual string applicationUri( ) = 0;
	virtual string productUri( ) = 0;
	virtual string applicationName( ) = 0;

	virtual uint32_t clientRcvBufSz( const string &inPrtId ) = 0;
	virtual uint32_t clientSndBufSz( const string &inPrtId ) = 0;
	virtual uint32_t clientMsgMaxSz( const string &inPrtId ) = 0;
	virtual uint32_t clientChunkMaxCnt( const string &inPrtId ) = 0;

	virtual void discoveryUrls( vector<string> &ls ) = 0;
	virtual bool inReq( string &request, const string &inPrtId, string *answ = NULL );
	virtual int writeToClient( const string &threadId, const string &data ) = 0;
	virtual string clientAddr( const string &threadId ) = 0;

	virtual void clientRcvBufSzSet( const string &inPrtId, uint32_t vl ) = 0;
	virtual void clientSndBufSzSet( const string &inPrtId, uint32_t vl ) = 0;
	virtual void clientMsgMaxSzSet( const string &inPrtId, uint32_t vl ) = 0;
	virtual void clientChunkMaxCntSet( const string &inPrtId, uint32_t vl ) = 0;

	// Channel manipulation functions
	void chnlList( vector<uint32_t> &chnls );
	int chnlSet( int cid, const string &ep, int32_t lifeTm = 0,
	    const string& clCert = "", const string &secPolicy = "None", char secMessMode = 1,
	    const string &clAddr = "", uint32_t seqN = 1 );
	void chnlClose( int cid );
	SecCnl chnlGet( int cid );
	SecCnl &chnlGet_( int cid )	{ return mSecCnl[cid]; }	//Unsafe direct link. Use "mtxData" to manage!
	void chnlSecSet( int cid, const string &servKey, const string &clKey );

	static string mkError( uint32_t errId, const string &err = "" );

    protected:
	//Methods
	// Request to EndPoints
	virtual void epEnList( vector<string> &ls ) = 0;
	virtual EP *epEnAt( const string &ep ) = 0;

	//Attributed
	pthread_mutex_t		mtxData;

    private:
	//Attributes
	map<uint32_t, SecCnl>	mSecCnl;
	uint32_t		mSecCnlIdLast;
};

} //End namespace OPC_UA

#endif //LIBOPC_UA