/** \file SocketHandler.h
 **	\date  2004-02-13
 **	\author grymse@alhem.net
**/
/*
Copyright (C) 2004-2011  Anders Hedstrom

This library is made available under the terms of the GNU GPL, with
the additional exemption that compiling, linking, and/or using OpenSSL 
is allowed.

If you would like to use this library in a closed-source application,
a separate license agreement is available. For information about 
the closed-source license agreement for the C++ sockets library,
please visit http://www.alhem.net/Sockets/license.html and/or
email license@alhem.net.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/
#ifndef _SOCKETS_SocketHandler_H
#define _SOCKETS_SocketHandler_H

#include "sockets-config.h"
#include <map>
#include <list>

#include "socket_include.h"
#include "ISocketHandler.h"

#ifdef SOCKETS_NAMESPACE
namespace Sockets {
#endif


class Socket;
#ifdef ENABLE_RESOLVER
class ResolvServer;
#endif
class IMutex;
class SocketHandlerThread;
class UdpSocket;

/** Socket container class, event generator. 
	\ingroup basic */
class SocketHandler : public ISocketHandler
{
protected:
	/** Map type for holding file descriptors/socket object pointers. */
	typedef std::map<SOCKET,Socket *> socket_m;

public:
	/** SocketHandler constructor.
		\param log Optional log class pointer */
	SocketHandler(StdLog *log = NULL);

	/** SocketHandler threadsafe constructor.
		\param mutex Externally declared mutex variable
		\param log Optional log class pointer */
	SocketHandler(IMutex& mutex,StdLog *log = NULL);

	SocketHandler(IMutex&, ISocketHandler& parent, StdLog * = NULL);

	~SocketHandler();

	virtual ISocketHandler *Create(StdLog * = NULL);
	virtual ISocketHandler *Create(IMutex&, ISocketHandler&, StdLog * = NULL);

	virtual bool ParentHandlerIsValid();

	virtual ISocketHandler& ParentHandler();

	virtual ISocketHandler& GetRandomHandler();

	virtual ISocketHandler& GetEffectiveHandler();

	virtual void SetNumberOfThreads(size_t n);
	virtual bool IsThreaded();

	virtual void EnableRelease();
	virtual void Release();

	/** Get mutex reference for threadsafe operations. */
	IMutex& GetMutex() const;

	/** Register StdLog object for error callback. 
		\param log Pointer to log class */
	void RegStdLog(StdLog *log);

	/** Log error to log class for print out / storage. */
	void LogError(Socket *p,const std::string& user_text,int err,const std::string& sys_err,loglevel_t t = LOG_LEVEL_WARNING);

	/** Add socket instance to socket map. Removal is always automatic. */
	void Add(Socket *);

	/** Set read/write/exception file descriptor sets (fd_set). */
	void ISocketHandler_Add(Socket *,bool bRead,bool bWrite);
	void ISocketHandler_Mod(Socket *,bool bRead,bool bWrite);
	void ISocketHandler_Del(Socket *);

	/** Wait for events, generate callbacks. */
	int Select(long sec,long usec);

	/** This method will not return until an event has been detected. */
	int Select();

	/** Wait for events, generate callbacks. */
	int Select(struct timeval *tsel);

	/** Check that a socket really is handled by this socket handler. */
	bool Valid(Socket *);
	bool Valid(socketuid_t);

	/** Return number of sockets handled by this handler.  */
	size_t GetCount();
	size_t MaxCount() { return FD_SETSIZE; }

	/** Override and return false to deny all incoming connections. 
		\param p ListenSocket class pointer (use GetPort to identify which one) */
	bool OkToAccept(Socket *p);

	/** Use with care, always lock with h.GetMutex() if multithreaded */
	const std::map<SOCKET, Socket *>& AllSockets() { return m_sockets; }

	size_t MaxTcpLineSize() { return TCP_LINE_SIZE; }

	void SetCallOnConnect(bool = true);
	void SetDetach(bool = true);
	void SetTimeout(bool = true);
	void SetRetry(bool = true);
	void SetClose(bool = true);

private:
	static FILE *m_event_file;
	static unsigned long m_event_counter;

public:
	// Connection pool
#ifdef ENABLE_POOL
	/** Find available open connection (used by connection pool). */
	ISocketHandler::PoolSocket *FindConnection(int type,const std::string& protocol,SocketAddress&);
	/** Enable connection pool (by default disabled). */
	void EnablePool(bool x = true);
	/** Check pool status. 
		\return true if connection pool is enabled */
	bool PoolEnabled();
#endif // ENABLE_POOL

	// Socks4
#ifdef ENABLE_SOCKS4
	/** Set socks4 server ip that all new tcp sockets should use. */
	void SetSocks4Host(ipaddr_t);
	/** Set socks4 server hostname that all new tcp sockets should use. */
	void SetSocks4Host(const std::string& );
	/** Set socks4 server port number that all new tcp sockets should use. */
	void SetSocks4Port(port_t);
	/** Set optional socks4 userid. */
	void SetSocks4Userid(const std::string& );
	/** If connection to socks4 server fails, immediately try direct connection to final host. */
	void SetSocks4TryDirect(bool x = true);
	/** Get socks4 server ip. 
		\return socks4 server ip */
	ipaddr_t GetSocks4Host();
	/** Get socks4 port number.
		\return socks4 port number */
	port_t GetSocks4Port();
	/** Get socks4 userid (optional).
		\return socks4 userid */
	const std::string& GetSocks4Userid();
	/** Check status of socks4 try direct flag.
		\return true if direct connection should be tried if connection to socks4 server fails */
	bool Socks4TryDirect();
#endif // ENABLE_SOCKS4

	// DNS resolve server
#ifdef ENABLE_RESOLVER
	/** Enable asynchronous DNS. 
		\param port Listen port of asynchronous dns server */
	void EnableResolver(port_t port = 16667);
	/** Check resolver status.
		\return true if resolver is enabled */
	bool ResolverEnabled();
	/** Queue a dns request.
		\param host Hostname to be resolved
		\param port Port number will be echoed in Socket::OnResolved callback */
	int Resolve(Socket *,const std::string& host,port_t port);
#ifdef ENABLE_IPV6
	int Resolve6(Socket *,const std::string& host,port_t port);
#endif
	/** Do a reverse dns lookup. */
	int Resolve(Socket *,ipaddr_t a);
#ifdef ENABLE_IPV6
	int Resolve(Socket *,in6_addr& a);
#endif
	/** Get listen port of asynchronous dns server. */
	port_t GetResolverPort();
	/** Resolver thread ready for queries. */
	bool ResolverReady();
	/** Returns true if the socket is waiting for a resolve event. */
	bool Resolving(Socket *);
#endif // ENABLE_RESOLVER

#ifdef ENABLE_DETACH
	/** Indicates that the handler runs under SocketThread. */
	void SetSlave(bool x = true);
	/** Indicates that the handler runs under SocketThread. */
	bool IsSlave();
#endif

protected:
	socket_m m_sockets; ///< Active sockets map
	std::list<Socket *> m_add; ///< Sockets to be added to sockets map
	std::list<Socket *> m_delete; ///< Sockets to be deleted (failed when Add)

protected:
	/** Actual call to select() */
	int ISocketHandler_Select(struct timeval *);
	/** Remove socket from socket map, used by Socket class. */
	void Remove(Socket *);
	/** Schedule socket for deletion */
	void DeleteSocket(Socket *);
	void AddIncoming();
	void CheckErasedSockets();
	void CheckCallOnConnect();
	void CheckDetach();
	void CheckTimeout(time_t);
	void CheckRetry();
	void CheckClose();
	//
	StdLog *m_stdlog; ///< Registered log class, or NULL
	IMutex& m_mutex; ///< Thread safety mutex
	bool m_b_use_mutex; ///< Mutex correctly initialized
	ISocketHandler& m_parent;
	bool m_b_parent_is_valid;

private:
	void RebuildFdset();
	void Set(Socket *,bool,bool);
	//
	std::list<SocketHandlerThread *> m_threads;
	UdpSocket *m_release;
	//
	SOCKET m_maxsock; ///< Highest file descriptor + 1 in active sockets list
	fd_set m_rfds; ///< file descriptor set monitored for read events
	fd_set m_wfds; ///< file descriptor set monitored for write events
	fd_set m_efds; ///< file descriptor set monitored for exceptions
	time_t m_tlast; ///< timeout control

	// state lists
	std::list<socketuid_t> m_fds_erase; ///< File descriptors that are to be erased from m_sockets

	bool m_b_check_callonconnect;
	bool m_b_check_detach;
	bool m_b_check_timeout;
	bool m_b_check_retry;
	bool m_b_check_close;

#ifdef ENABLE_SOCKS4
	ipaddr_t m_socks4_host; ///< Socks4 server host ip
	port_t m_socks4_port; ///< Socks4 server port number
	std::string m_socks4_userid; ///< Socks4 userid
	bool m_bTryDirect; ///< Try direct connection if socks4 server fails
#endif
#ifdef ENABLE_RESOLVER
	int m_resolv_id; ///< Resolver id counter
	ResolvServer *m_resolver; ///< Resolver thread pointer
	port_t m_resolver_port; ///< Resolver listen port
	std::map<socketuid_t, bool> m_resolve_q; ///< resolve queue
#endif
#ifdef ENABLE_POOL
	bool m_b_enable_pool; ///< Connection pool enabled if true
#endif
#ifdef ENABLE_DETACH
	bool m_slave; ///< Indicates that this is a ISocketHandler run in SocketThread
#endif
};


#ifdef SOCKETS_NAMESPACE
}
#endif

#endif // _SOCKETS_SocketHandler_H