#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#define PORT 8080
#define MAX 80
void transfer(int sock){
struct timeval tv;
tv.tv_sec = 1;
tv.tv_usec = 0;
setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (const char*)&tv, sizeof tv);
      printf("Send\tFrame status\tACK status");
        int *n,i=0,j,o,k=0;
        n=&i;
       for(j=0;j<10;j++){
         o=i;
        TES:
        k++;
          i=j%2;
         

          write(sock,n,sizeof(i));
          printf("\n%d\t Frame no:%d\t",j,i);
          if(k==3){
          printf("ACK missing");
          goto TES;
          continue;
          }
          if(read(sock,n,sizeof(i))){
          if(i==o){
            printf("Frame missing");
            goto TES;
          }
          else
             printf("ACK no:%d",i);
             
          }
         
         
      }
        
}

int main(int argc, char const* argv[])
{
	int server_fd, new_socket;
	struct sockaddr_in address;
	int opt = 1,n;
	int addrlen = sizeof(address);

	

	// Creating socket file descriptor
	if ((server_fd = socket(AF_INET, SOCK_STREAM, 0))
		== 0) {
		perror("socket failed");
		exit(EXIT_FAILURE);
	}

	// Forcefully attaching socket to the port 8080
	if (setsockopt(server_fd, SOL_SOCKET,
				SO_REUSEADDR | SO_REUSEPORT, &opt,
				sizeof(opt))) {
		perror("setsockopt");
		exit(EXIT_FAILURE);
	}
	address.sin_family = AF_INET;
	address.sin_addr.s_addr = INADDR_ANY;
	address.sin_port = htons(PORT);

	// Forcefully attaching socket to the port 8080
	if (bind(server_fd, (struct sockaddr*)&address,
			sizeof(address))
		< 0) {
		perror("bind failed");
		exit(EXIT_FAILURE);
	}
	if (listen(server_fd, 3) < 0) {
		perror("listen");
		exit(EXIT_FAILURE);
	}
	if ((new_socket
		= accept(server_fd, (struct sockaddr*)&address,
				(socklen_t*)&addrlen))
		< 0) {
		perror("accept");
		exit(EXIT_FAILURE);
	}
	
	transfer(new_socket);
// closing the connected socket
	close(new_socket);
// closing the listening socket
	shutdown(server_fd, SHUT_RDWR);
	return 0;
}