/** \file TcpSocket.h
 **	\date  2004-02-13
 **	\author grymse@alhem.net
**/
/*
Copyright (C) 2004-2007  Anders Hedstrom

This library is made available under the terms of the GNU GPL.

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_TcpSocket_H
#define _SOCKETS_TcpSocket_H
#include "sockets-config.h"
#include "StreamSocket.h"
#ifdef HAVE_OPENSSL
#include <openssl/ssl.h>
#include "SSLInitializer.h"
#endif


#define TCP_BUFSIZE_READ 16400
#define TCP_OUTPUT_CAPACITY 1024000


#ifdef SOCKETS_NAMESPACE
namespace SOCKETS_NAMESPACE {
#endif

class SocketAddress;


/** Socket implementation for TCP. 
	\ingroup basic */
class TcpSocket : public StreamSocket
{
	/** \defgroup internal Internal utility */
protected:
	/** Buffer class containing one read/write circular buffer. 
		\ingroup internal */
	class CircularBuffer
	{
	public:
		CircularBuffer(size_t size);
		~CircularBuffer();

		/** append l bytes from p to buffer */
		bool Write(const char *p,size_t l);
		/** copy l bytes from buffer to dest */
		bool Read(char *dest,size_t l);
		/** skip l bytes from buffer */
		bool Remove(size_t l);
		/** read l bytes from buffer, returns as string. */
		std::string ReadString(size_t l);

		/** total buffer length */
		size_t GetLength();
		/** pointer to circular buffer beginning */
		const char *GetStart();
		/** return number of bytes from circular buffer beginning to buffer physical end */
		size_t GetL();
		/** return free space in buffer, number of bytes until buffer overrun */
		size_t Space();

		/** return total number of bytes written to this buffer, ever */
		unsigned long ByteCounter(bool clear = false);

	private:
		CircularBuffer(const CircularBuffer& s) {}
		CircularBuffer& operator=(const CircularBuffer& ) { return *this; }
		char *buf;
		size_t m_max;
		size_t m_q;
		size_t m_b;
		size_t m_t;
		unsigned long m_count;
	};
	/** Output buffer struct.
		\ingroup internal */
	struct OUTPUT {
		OUTPUT() : _b(0), _t(0), _q(0) {}
		OUTPUT(const char *buf, size_t len) : _b(0), _t(len), _q(len) {
			memcpy(_buf, buf, len);
		}
		size_t Space() {
			return TCP_OUTPUT_CAPACITY - _t;
		}
		void Add(const char *buf, size_t len) {
			memcpy(_buf + _t, buf, len);
			_t += len;
			_q += len;
		}
		size_t Remove(size_t len) {
			_b += len;
			_q -= len;
			return _q;
		}
		const char *Buf() {
			return _buf + _b;
		}
		size_t Len() {
			return _q;
		}
		size_t _b;
		size_t _t;
		size_t _q;
		char _buf[TCP_OUTPUT_CAPACITY];
	};
	typedef std::list<OUTPUT *> output_l;

public:
	/** Constructor with standard values on input/output buffers. */
	TcpSocket(ISocketHandler& );
	/** Constructor with custom values for i/o buffer. 
		\param h ISocketHandler reference
		\param isize Input buffer size
		\param osize Output buffer size */
	TcpSocket(ISocketHandler& h,size_t isize,size_t osize);
	~TcpSocket();

	/** Open a connection to a remote server.
	    If you want your socket to connect to a server, 
	    always call Open before Add'ing a socket to the sockethandler.
	    If not, the connection attempt will not be monitored by the
	    socket handler... 
		\param ip IP address
		\param port Port number
		\param skip_socks Do not use socks4 even if configured */
	bool Open(ipaddr_t ip,port_t port,bool skip_socks = false);
#ifdef ENABLE_IPV6
#ifdef IPPROTO_IPV6
	/** Open connection. 
		\param ip Ipv6 address
		\param port Port number
		\param skip_socks Do not use socks4 even if configured */
	bool Open(in6_addr ip,port_t port,bool skip_socks = false);
#endif
#endif
	bool Open(SocketAddress&,bool skip_socks = false);
	bool Open(SocketAddress&,SocketAddress& bind_address,bool skip_socks = false);
	/** Open connection. 
		\param host Hostname
		\param port Port number */
	bool Open(const std::string &host,port_t port);

	/** Connect timeout callback. */
	void OnConnectTimeout();
#ifdef _WIN32
	/** Connection failed reported as exception on win32 */
	void OnException();
#endif

	/** Close file descriptor - internal use only. 
		\sa SetCloseAndDelete */
	int Close();

	/** Send a string. 
		\param s String to send 
		\param f Dummy flags -- not used */
	void Send(const std::string &s,int f = 0);
	/** Send string using printf formatting. */
	void Sendf(const char *format, ...);
	/** Send buffer of bytes.
		\param buf Buffer pointer
		\param len Length of data
		\param f Dummy flags -- not used */
	void SendBuf(const char *buf,size_t len,int f = 0);
	/** This callback is executed after a successful read from the socket.
		\param buf Pointer to the data
		\param len Length of the data */
	virtual void OnRawData(const char *buf,size_t len);

	/** Called when output buffer has been sent.
	    Note: Will only be called IF the output buffer has been used.
	    Send's that was successful without needing the output buffer
	    will not generate a call to this method. */
	virtual void OnWriteComplete();
	/** Number of bytes in input buffer. */
	size_t GetInputLength();
	/** Number of bytes in output buffer. */
	size_t GetOutputLength();

	/** Callback fires when a socket in line protocol has read one full line. 
		\param line Line read */
	void OnLine(const std::string& line);
	/** Get counter of number of bytes received. */
	uint64_t GetBytesReceived(bool clear = false);
	/** Get counter of number of bytes sent. */
	uint64_t GetBytesSent(bool clear = false);

	/** Socks4 specific callback. */
	void OnSocks4Connect();
	/** Socks4 specific callback. */
	void OnSocks4ConnectFailed();
	/** Socks4 specific callback.
		\return 'need_more' */
	bool OnSocks4Read();

#ifdef ENABLE_RESOLVER
	/** Callback executed when resolver thread has finished a resolve request. */
	void OnResolved(int id,ipaddr_t a,port_t port);
#ifdef ENABLE_IPV6
	void OnResolved(int id,in6_addr& a,port_t port);
#endif
#endif
#ifdef HAVE_OPENSSL
	/** Callback for 'New' ssl support - replaces SSLSocket. Internal use. */
	void OnSSLConnect();
	/** Callback for 'New' ssl support - replaces SSLSocket. Internal use. */
	void OnSSLAccept();
	/** This method must be implemented to initialize 
		the ssl context for an outgoing connection. */
	virtual void InitSSLClient();
	/** This method must be implemented to initialize 
		the ssl context for an incoming connection. */
	virtual void InitSSLServer();
#endif

#ifdef ENABLE_RECONNECT
	/** Flag that says a broken connection will try to reconnect. */
	void SetReconnect(bool = true);
	/** Check reconnect on lost connection flag status. */
	bool Reconnect();
	/** Flag to determine if a reconnect is in progress. */
	void SetIsReconnect(bool x = true);
	/** Socket is reconnecting. */
	bool IsReconnect();
#endif

	void DisableInputBuffer(bool = true);

	void OnOptions(int,int,int,SOCKET);

	void SetLineProtocol(bool = true);

	// TCP options
	bool SetTcpNodelay(bool = true);

	virtual int Protocol();

	/** Trigger limit for callback OnTransferLimit. */
	void SetTransferLimit(size_t sz);
	/** This callback fires when the output buffer drops below the value
	    set by SetTransferLimit. Default: 0 (disabled). */
	virtual void OnTransferLimit();

protected:
	TcpSocket(const TcpSocket& );
	void OnRead();
	void OnRead( char *buf, size_t n );
	void OnWrite();
#ifdef HAVE_OPENSSL
	/** SSL; Initialize ssl context for a client socket. 
		\param meth_in SSL method */
	void InitializeContext(const std::string& context, SSL_METHOD *meth_in = NULL);
	/** SSL; Initialize ssl context for a server socket. 
		\param keyfile Combined private key/certificate file 
		\param password Password for private key 
		\param meth_in SSL method */
	void InitializeContext(const std::string& context, const std::string& keyfile, const std::string& password, SSL_METHOD *meth_in = NULL);
	/** SSL; Initialize ssl context for a server socket. 
		\param certfile Separate certificate file
		\param keyfile Combined private key/certificate file 
		\param password Password for private key 
		\param meth_in SSL method */
	void InitializeContext(const std::string& context, const std::string& certfile, const std::string& keyfile, const std::string& password, SSL_METHOD *meth_in = NULL);
	/** SSL; Password callback method. */
static	int SSL_password_cb(char *buf,int num,int rwflag,void *userdata);
	/** SSL; Get pointer to ssl context structure. */
	virtual SSL_CTX *GetSslContext();
	/** SSL; Get pointer to ssl structure. */
	virtual SSL *GetSsl();
	/** ssl; still negotiating connection. */
	bool SSLNegotiate();
	/** SSL; Get ssl password. */
	const std::string& GetPassword();
#endif

	CircularBuffer ibuf; ///< Circular input buffer

private:
	TcpSocket& operator=(const TcpSocket& ) { return *this; }

	/** the actual send() */
	int TryWrite(const char *buf, size_t len);
	/** add data to output buffer top */
	void Buffer(const char *buf, size_t len);

	//
	bool m_b_input_buffer_disabled;
	uint64_t m_bytes_sent;
	uint64_t m_bytes_received;
	bool m_skip_c; ///< Skip second char of CRLF or LFCR sequence in OnRead
	char m_c; ///< First char in CRLF or LFCR sequence
	std::string m_line; ///< Current line in line protocol mode
#ifdef SOCKETS_DYNAMIC_TEMP
	char *m_buf; ///< temporary read buffer
#endif
	output_l m_obuf; ///< output buffer
	OUTPUT *m_obuf_top; ///< output buffer on top
	size_t m_transfer_limit;
	size_t m_output_length;

#ifdef HAVE_OPENSSL
static	SSLInitializer m_ssl_init;
	SSL_CTX *m_ssl_ctx; ///< ssl context
	SSL *m_ssl; ///< ssl 'socket'
	BIO *m_sbio; ///< ssl bio
	std::string m_password; ///< ssl password
#endif

#ifdef ENABLE_SOCKS4
	int m_socks4_state; ///< socks4 support
	char m_socks4_vn; ///< socks4 support, temporary variable
	char m_socks4_cd; ///< socks4 support, temporary variable
	unsigned short m_socks4_dstport; ///< socks4 support
	unsigned long m_socks4_dstip; ///< socks4 support
#endif

#ifdef ENABLE_RESOLVER
	int m_resolver_id; ///< Resolver id (if any) for current Open call
#endif

#ifdef ENABLE_RECONNECT
	bool m_b_reconnect; ///< Reconnect on lost connection flag
	bool m_b_is_reconnect; ///< Trying to reconnect
#endif

};


#ifdef SOCKETS_NAMESPACE
}
#endif

#endif // _SOCKETS_TcpSocket_H