#ifndef STOPANDWAIT_H
#define STOPANDWAIT_H

#include	<cnet.h>

typedef enum    { DATA, ACK }   FrameKind;

typedef struct
{
    FrameKind	kind;      	      /* only ever DATA or ACK */
    int			messageLength;    /* the length of the message portion only */
    int			checksum;  	      /* checksum of the whole frame */
    int			sequenceNumber;   /* only ever 0 or 1 */
    char		message[MAX_MESSAGE_SIZE];
} Frame;

#define FRAME_HEADER_SIZE  (sizeof(FrameKind) + 3*sizeof(int))
#define FRAME_SIZE(f)      (FRAME_HEADER_SIZE + f.messageLength * sizeof(char))


static void on_physical_ready( CnetEvent ev, CnetTimer ts, CnetData data );
static void on_application_ready( CnetEvent ev, CnetTimer ts, CnetData data );
static void on_timer_expired( CnetEvent ev, CnetTimer ts, CnetData data );
static void transmit_frame( char *message, int messageLength, FrameKind kind, int sequenceNumber );

#endif