/************************************************************************/
/*		Include Section						*/
/************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <sys/time.h>
/************************************************************************/
/*		Variables declaration Section				*/
/************************************************************************/
#define MAX_SAMPL 256

static time_t starttime;
/************************************************************************/
/*				Code Section				*/
/************************************************************************/

static int moxaconnect(char *ipaddr, unsigned short port)
{
    int sockfd;
    int error;
    int flag = 1;
    struct sockaddr_in addr_dest;

    addr_dest.sin_family = AF_INET;
    addr_dest.sin_addr.s_addr = inet_addr(ipaddr);
    addr_dest.sin_port = htons(port);

    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd<0) {
	return(-2);
    }

    error = connect(sockfd, (struct sockaddr *)&addr_dest, sizeof(addr_dest));
    if (error) {
	close(sockfd);
	return(error);
    }
    error = setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int));
    if (error) {
	close(sockfd);
	return error;
    }
    return sockfd;
}

static void get_usec_now(unsigned int *usec)
{
    struct timeval tv;
    gettimeofday(&tv, NULL);

    tv.tv_sec -= starttime;
    *usec=(tv.tv_sec*1000000) + tv.tv_usec;
}

int main(int argc, char **argv)
{
    int sock, error, i;
    unsigned char val = 'a';
    unsigned char bytein;
    unsigned int cur_diff;
    unsigned int sent_usec;
    unsigned int recv_usec;
    unsigned int min_diff = 0xffffffff;
    unsigned int max_diff = 0;
    unsigned int sum_diff = 0;
    struct timeval tv;

    if (argc<3) {
	printf("Usage: %s <moxa ip address> <port>\n", argv[0]);
	return -1;
    }
    sock=moxaconnect(argv[1], atoi(argv[2]));
    if (sock<0) {
	printf("Error %d opening socket\n", sock);
	return (sock);
    }

    gettimeofday(&tv, NULL);
    starttime = tv.tv_sec;

    printf("Start sending and receving %d bytes - All times in microseconds\n", MAX_SAMPL);

    for(i=0; i<MAX_SAMPL; i++) {
	error = send(sock, &val, 1, 0);
	get_usec_now(&sent_usec);
	if (error != 1)
	    printf("Error %d writing on socket %d\n", error, sock);


	error = read(sock, &bytein, 1);
	get_usec_now(&recv_usec);
	if (error != 1)
	    printf("Error %d reading on socket %d\n", error, sock);

	cur_diff = recv_usec - sent_usec;
	max_diff = (cur_diff > max_diff) ? cur_diff : max_diff;
	min_diff = (cur_diff < min_diff) ? cur_diff : min_diff;
	sum_diff += cur_diff;

	printf("%3d> SEND: %d\tRECV: %d\tDIFF: %d\tMIN: %d\tMAX: %d\tAVG: %d\n",
		i+1, sent_usec, recv_usec, cur_diff, min_diff, max_diff, ((sum_diff)/(i+1)));
    }

    error = shutdown(sock, SHUT_RDWR);
    return error;
}