/*
SYNOPSIS:    servidorPrecio <puerto TCP de escucha Actualizador> <puerto TCP escucha caja>
*/

#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

void reusePort(int sock);  

int main(int argc,  char *argv[]) {
  fd_set readfds, readfdsCopy;
  int n;
  int actSock=0, cajaSock=0;
  struct addrinfo hints, *result, *rp;
  int as, cs;
  struct sockaddr_storage from_addr;
  socklen_t from_addr_len;
  char precio[50];

  memset(&hints, 0, sizeof(hints));

  hints.ai_family = AF_INET; //IPv4
  hints.ai_socktype = SOCK_STREAM; //TCP
  hints.ai_flags = AI_PASSIVE; //For wildcard IP address

  if ((getaddrinfo(NULL, argv[1], &hints, &result)) != 0)   {
    fprintf(stderr, "getaddrinfo error\n");
    exit(EXIT_FAILURE);
  }

  for (rp = result; rp != NULL; rp = rp -> ai_next)  {
    as = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
    reusePort(as);
    if (as == -1) continue;
    if (bind(as, rp -> ai_addr, rp -> ai_addrlen) == 0)  break; //Success
    close(as);        
  }
  memset(&hints, 0, sizeof(hints));

  hints.ai_family = AF_INET; //IPv4
  hints.ai_socktype = SOCK_STREAM; //TCP
  hints.ai_flags = AI_PASSIVE; //For wildcard IP address

  if ((getaddrinfo(NULL, argv[2], &hints, &result)) != 0)   {
    fprintf(stderr, "getaddrinfo error\n");
    exit(EXIT_FAILURE);
  }

  for (rp = result; rp != NULL; rp = rp -> ai_next)  {
    cs = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
    reusePort(cs);
    if (cs == -1)  continue;
    if (bind(cs, rp -> ai_addr, rp -> ai_addrlen) == 0) break; //Success
    close(cs);        
  }
  freeaddrinfo(result); //No longer needed
  listen(as,4);
  listen(cs,4);
  from_addr_len = sizeof(from_addr);
  FD_ZERO(&readfdsCopy);
  FD_SET(as,&readfdsCopy);
  FD_SET(cs,&readfdsCopy);
  
  for(;;){
    memcpy(&readfds, &readfdsCopy, sizeof(fd_set));
    n = select(FD_SETSIZE, &readfds, (fd_set *) 0, (fd_set *) 0, NULL);
    if (n > 0) {
      if (FD_ISSET(as, &readfds)) {
        printf("Accepting an Actualizador...\n");
        actSock = accept(as, (struct sockaddr *) &from_addr, &from_addr_len);
        FD_SET(actSock, &readfdsCopy);
      }
      if (FD_ISSET(cs, &readfds)) {
        printf("Accepting a Caja...\n");
        cajaSock = accept(cs, (struct sockaddr *) &from_addr, &from_addr_len);
        write(cajaSock, precio, strlen(precio));
      }
      if (FD_ISSET(actSock, &readfds)) {
        if ((n=read(actSock, precio, sizeof(precio)))>0) {
          precio[n]='\0';
          if (cajaSock > 0) write(cajaSock, precio, strlen(precio));
          printf("precio: %s", precio);
        } else {
          close(actSock);
          FD_CLR(actSock, &readfdsCopy);
        }
      if (FD_ISSET(cajaSock, &readfds))
        if ((n=read(cajaSock, precio, sizeof(precio)))<=0) {
          close(cajaSock);
          FD_CLR(cajaSock, &readfdsCopy);
        }
      }
    }
  }
}
void reusePort(int s) {
  int one=1;
  if ( setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *) &one,sizeof(one)) == -1 ) {
    printf("error in setsockopt,SO_REUSEPORT \n");
    exit(-1);
  }
}