/* ------------------main_srv.c ---------------------------
 * server using TCP protocol
 *
 * simple error handling
 */

int solution[4] = {1, 3, 5, 2};
int sol_used[6] = {1, 1, 1, 0, 1, 0};

#include <stdlib.h>
#include <stdio.h>
#include "inet.h"
#include "sign.h"

int guess(int guess, int socket) {
   int i, z;
   int numbers[4], used[6];
   int black = 0, white = 0;
   char res[MAXLINE];
   for (i = 0; i < 6; i++) used[i] = 0;
   if ((guess < 1234) || (guess > 6543))
      return(send(socket, "Bad input\r\n", 11, 0));
   for (i = 0; i < 4; i++) {
      z = guess % 10;
      if (!z || (z > 6))
	 return(send(socket, "Bad numbers\r\n", 13, 0));
      if (used[z - 1]) 
	 return(send(socket, "Digits must be unique\r\n", 23, 0));
      numbers[i] = z;
      used[z - 1] = 1;
      guess /= 10;
   }
   for (i = 0; i < 4; i++) {
      if (numbers[i] == solution[i]) 
	 black++;
      else
	 if (sol_used[numbers[i] -1]) white++;
   }
   sprintf(res, "Your guess: %d black and %d white.\r\n", black, white);
   return send(socket, res, strlen(res), 0);
   /* error = send(newsockfd, res, strlen(res), 0); */
}

int main() {
   int sockfd,newsockfd,clilen,childpid, n;
   struct sockaddr_in cli_addr, serv_addr;
   char recvline[MAXLINE];

   if( (ignoresig(SIGCHLD) == SIG_ERR) ) {
       perror("Signal");
       exit(1);
   }
   /*
    * open a TCP socket - Internet stream socket
    */
   if ( (sockfd = socket(AF_INET, SOCK_STREAM,0)) < 0) {
      perror("server: can't open stream socket");
      exit(1);
   }

   /*
    * bind our local address so that the client can send us
    */
   /*bzero((char *) &serv_addr, sizeof(serv_addr));*/
   memset((char *) &serv_addr, 0, sizeof(serv_addr));
   serv_addr.sin_family = AF_INET;

   serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
   /* INADR_ANY: tells the system that we'll accept a connection
    * on any Internet interface on the system, if it is multihomed
    * Address to accept any incoming messages (-> in.h).
    * INADDR_ANY is defined as ((unsigned long int) 0x00000000)
    */

   serv_addr.sin_port = htons(SERV_TCP_PORT);

   if ( bind(sockfd, (struct sockaddr *)&serv_addr, 
         sizeof(serv_addr)) < 0) {
      perror("server: can't bind local address");
      exit(1);
   }
   listen(sockfd,5);
   while(1) {
      /*
       * wait for a connection from a client process
       * - concurrent server -
       */
      clilen=sizeof(cli_addr);
      newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen); 
      if (newsockfd < 0 ) {
         if (errno == EINTR) continue; /*try again*/
         perror("server: accept error");
         exit(1);
      }
      if ( (childpid = fork()) < 0) {
         perror("server: fork error");
         close(sockfd);
         close(newsockfd);
         exit(1);
      } 
      else if (childpid == 0) {
	 int running = 1, error = 0;
	 char rec[MAXLINE];
         close(sockfd);
	 do {
	    if ((n=recv(newsockfd, recvline, MAXLINE, 0)) < 0) exit(2);
	    strncpy(rec, recvline, n);
	    rec[n] = '\0';
	    printf("Got: %d chars: %s", n, rec);
	    if (strstr(rec, "quit")) {
	       close(newsockfd);
	       exit(3);
	    }
	    error = guess(atoi(rec), newsockfd);
	    /* if ((input = atoi(rec)) == 0) {
	       error = send(newsockfd, "Not a number\r\n", 14, 0);
	       printf("Null\n");
	    } else {
	       printf("Nr: %d\n", input);
	       sprintf(res, "Your guess: %d\r\n", input);
	       error = send(newsockfd, res, strlen(res), 0);
	    }
	    */
	    /* if( send(newsockfd,rec,n,0) < n) exit(4); */
	 } while (running & (error >= 0));
         close(newsockfd);
         exit(0);
      }

      close(newsockfd); /*parent*/
   }
}