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

#include <nanomsg/nn.h>
#include <nanomsg/survey.h>

#define SERVER "server"
#define CLIENT "client"
#define DATE   "DATE"

void
fatal(const char *func)
{
  fprintf(stderr, "%s: %s\n", func, nn_strerror(nn_errno()));
  exit(1);
}

char *
date(void)
{
  time_t now = time(&now);
  struct tm *info = localtime(&now);
  char *text = asctime(info);
  text[strlen(text) - 1] = '\0'; // remove '\n'
  return (text);
}

int
server(const char *url)
{
  int sock;

  if ((sock = nn_socket (AF_SP, NN_SURVEYOR)) < 0)
  {
    fatal("nn_socket");
  }
  if (nn_bind(sock, url)  < 0)
  {
    fatal("nn_bind");
  }
  for (;;)
  {
    printf("SERVER: SENDING DATE SURVEY REQUEST\n");
    int bytes = nn_send(sock, DATE, strlen(DATE) + 1, 0);
    if (bytes < 0)
    {
      fatal("nn_send");
    }

    for (;;)
    {
      char *buf = NULL;
      int bytes = nn_recv(sock, &buf, NN_MSG, 0);
      if (bytes < 0)
      {
        if (nn_errno() == ETIMEDOUT)
        {
          break;
        }
        fatal("nn_recv");
      }
      printf("SERVER: RECEIVED \"%s\" SURVEY RESPONSE\n", buf);
      nn_freemsg(buf);
    }

    printf("SERVER: SURVEY COMPLETE\n");
    sleep(1); // Start another survey in a second
  }
}

int
client(const char *url, const char *name)
{
  int sock;

  if ((sock = nn_socket(AF_SP, NN_RESPONDENT)) < 0)
  {
    fatal("nn_socket");
  }
  if (nn_connect (sock, url) < 0)
  {
    fatal("nn_connect");
  }
  for (;;)
  {
    char *buf = NULL;
    int bytes = nn_recv(sock, &buf, NN_MSG, 0);
    if (bytes >= 0)
    {
      printf("CLIENT (%s): RECEIVED \"%s\" SURVEY REQUEST\n", name, buf);
      nn_freemsg(buf);
      char *d = date();
      int sz_d = strlen(d) + 1; // '\0' too
      printf("CLIENT (%s): SENDING DATE SURVEY RESPONSE\n", name);
      if (nn_send(sock, d, sz_d, 0) < 0)
      {
        fatal("nn_send");
      }
    }
  }
}

int
main(const int argc, const char **argv)
{
  if ((argc >= 2) && (strcmp(SERVER, argv[1]) == 0))
    return (server(argv[2]));

  if ((argc >= 3) && (strcmp(CLIENT, argv[1]) == 0))
    return (client(argv[2], argv[3]));

  fprintf(stderr, "Usage: survey %s|%s <URL> <ARG> ...\n",
          SERVER, CLIENT);
  return 1;
}