/*H*******************************************************
 *  Udp.cpp: Library to send/receive UDP packets.
 * NOTE: UDP is fast, but has some important limitations (thanks to Warren Gray
       for mentioning )
 * 1) UDP does not guarantee the order in which assembled UDP packets are 
	    received. This
 * might not happen often in practice, but in larger network topologies, a UDP
 * packet can be received out of sequence. 
 * 2) UDP does not guard against lost packets - so packets *can* disappear 
        without the sender being
 * aware of it. Again, this may not be a concern in practice on small local 
        networks.
 * For more information, see http://www.cafeaulait.org/course/week12/35.html
 * MIT License:
 * Copyright (c) 2008 Bjoern Hartmann
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 * bjoern@cs.stanford.edu 12/30/2008
 ********************************************************/
#ifndef udp_h
#define udp_h
#include <Stream.h>
#include <IPAddress.h>

class UDP: public Stream 
{
    public:
/*F********************************************************************
*
**********************************************************************/
virtual 
~UDP() 
{};



/*F********************************************************************
* initialize, start listening on specified port. Returns 1 if successful, 
0 if no sockets available to use
**********************************************************************/
virtual uint8_t 
begin( uint16_t ) =0;	
 


/*F********************************************************************
* Finish with UDP socket
**********************************************************************/
virtual void 
stop() =0;

Sending UDP packets



/*F********************************************************************
  Start building up a packet to send to remote host specific in ip and port
Return: 1 if successful, 0 if was a problem with supplied IP address or port
**********************************************************************/
virtual int 
beginPacket( IPAddress ip, uint16_t port ) = 0;



/*F********************************************************************
* Start building up a packet to send to remote host specific in host and port
  Return: 1 if successful, 0 if a problem resolving hostname or port
**********************************************************************/
virtual int 
beginPacket( const char *host, uint16_t port ) =0;



/*F********************************************************************
* Finish off this packet and send it
  Return: 1 if packet was sent successfully, 0 if was an error
**********************************************************************/
virtual int 
endPacket() =0;



/*F********************************************************************
* Write a single byte into packet
**********************************************************************/
virtual size_t 
write( uint8_t ) =0;



/*F********************************************************************
* Write size bytes from buffer into packet
**********************************************************************/
virtual size_t 
write( const uint8_t *buffer, size_t size) =0;



/*F********************************************************************
* Start processing next available incoming packet
  Return: size of packet in bytes, or 0 if no packets are available
**********************************************************************/
virtual int 
parsePacket() =0;



/*F********************************************************************
* Number of bytes remaining in current packet
**********************************************************************/
virtual int 
available() =0;



/*F********************************************************************
* Read a single byte from current packet
**********************************************************************/
virtual int 
read() =0;



/*F********************************************************************
* Read up to len bytes from current packet and place into buffer
Return: number of bytes read, or 0 if none are available
**********************************************************************/
virtual int 
read( unsigned char* buffer, size_t len ) =0;



/*F********************************************************************
* Read up to len characters from current packet and place into buffer
Return: number of characters read, or 0 if none are available
**********************************************************************/
virtual int 
read( char* buffer, size_t len ) =0;



/*F********************************************************************
* Retur: next byte from current packet without moving on to next byte
**********************************************************************/
virtual int 
peek() =0;



/*F********************************************************************
* Finish reading current packet
**********************************************************************/
virtual void 
flush() =0;



/*F********************************************************************
* Return IP address of host who sent current incoming packet
**********************************************************************/
virtual IPAddress 
remoteIP() =0;



/*F********************************************************************
* Return port of host who sent current incoming packet
**********************************************************************/
virtual uint16_t 
remotePort() =0;

    protected:



/*F********************************************************************
*
**********************************************************************/
uint8_t* 
rawIPAddress( IPAddress &addr ) 
{
    return addr.raw_address();
}



/*F********************************************************************
*
**********************************************************************/
const uint8_t* 
rawIPAddress( const IPAddress &addr ) 
{
	return addr.raw_address();
}
};

#endif