/*Compilar - gcc clienteudp.c -o clienteudp
  Executar - ./clienteudp 127.0.0.1 mensagem
*/

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h> /* memset() */
#include <sys/time.h> /* select() */
#include <iostream>


#define REMOTE_SERVER_PORT 1500
#define MAX_MSG 100
#define LOCAL_SERVER_PORT 1200

using namespace std;

void cliente(int argc, char *argv[]) {

  int sd, rc, i;
  struct sockaddr_in cliAddr, remoteServAddr;
  struct hostent *h;

  /* get server IP address (no check if input is IP address or DNS name */
  h = gethostbyname(argv[1]);
  if(h==NULL) {
    printf("%s: unknown host '%s' \n", argv[0], argv[1]);
    return;
  }

  printf("%s: sending data to '%s' (IP : %s) \n", argv[0], h->h_name,

  inet_ntoa(*(struct in_addr *)h->h_addr_list[0]));

  remoteServAddr.sin_family = h->h_addrtype;

  memcpy((char *) &remoteServAddr.sin_addr.s_addr,

  h->h_addr_list[0], h->h_length);

  remoteServAddr.sin_port = htons(REMOTE_SERVER_PORT);

  /* socket creation */
  sd = socket(AF_INET,SOCK_DGRAM,0);
  if(sd<0) {
    printf("%s: cannot open socket \n",argv[0]);
    return;
  }

  /* bind any port */
  cliAddr.sin_family = AF_INET;
  cliAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  cliAddr.sin_port = htons(0);

  rc = bind(sd, (struct sockaddr *) &cliAddr, sizeof(cliAddr));
  if(rc<0) {
    printf("%s: cannot bind port\n", argv[0]);
    return;
  }

  char mensagem[50];
  /* send data */
  for(;;) {
    cin >> mensagem;
    rc = sendto(sd, mensagem, strlen(mensagem)+1, 0,
        (struct sockaddr *) &remoteServAddr,
        sizeof(remoteServAddr));

    if(rc<0) {
      printf("%s: cannot send data %d \n",argv[0],i-1);
      close(sd);
      return;
    }
  }
  return;

}

void servidor(int argc, char *argv[]) {

  int sd, rc, n;
  socklen_t cliLen;
  struct sockaddr_in cliAddr, servAddr;
  char msg[MAX_MSG];

  /* socket creation */
  sd=socket(AF_INET, SOCK_DGRAM, 0);
  if(sd<0) {
    printf("%s: cannot open socket \n",argv[0]);
    return;
  }

  /* bind local server port */
  servAddr.sin_family = AF_INET;
  servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  servAddr.sin_port = htons(LOCAL_SERVER_PORT);
  rc = bind (sd, (struct sockaddr *) &servAddr,sizeof(servAddr));
  if(rc<0) {
    printf("%s: cannot bind port number %d \n",
     argv[0], LOCAL_SERVER_PORT);
    return;
  }

  printf("%s: waiting for data on port UDP %u\n",
     argv[0],LOCAL_SERVER_PORT);

  /* server infinite loop */
  while(1) {

    /* init buffer */
    memset(msg,0x0,MAX_MSG);


    /* receive message */
    cliLen = sizeof(cliAddr);
    n = recvfrom(sd, msg, MAX_MSG, 0,
     (struct sockaddr *) &cliAddr, &cliLen);

    if(n<0) {
      printf("%s: cannot receive data \n",argv[0]);
      continue;
    }

    /* print received message */
    printf("Mensagem de Usuário 2: %s \n",msg);

  }

  return;
}

int main(int argc, char *argv[]){
  printf("Uso do programa: A todo momento, mensagens do outro usuário\n+estarão disponíveis na UI. Envie sua mensagem a qualquer \n+momento. ");
   pid_t childPID;
  int var_lcl = 0;
  childPID = fork();
  if(childPID >= 0){
    if(childPID == 0){
      cliente(argc,argv);
    }else{
      servidor(argc,argv);
    }
  }else{
    printf("\n Fork failed, quitting...\n");
    return 1;
  }
  return 0;
}