#include "barev_net.h"

#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/select.h>
#include <arpa/inet.h>
#include <netinet/in.h>

int barev_net_set_nonblocking(int fd) {
  int flags;
  flags = fcntl(fd, F_GETFL, 0);
  if (flags < 0) return 0;
  if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0) return 0;
  return 1;
}

int barev_net_listen_v6(unsigned short port) {
  int fd;
  int on;
  struct sockaddr_in6 sa;

  fd = socket(AF_INET6, SOCK_STREAM, 0);
  if (fd < 0) return -1;

  on = 1;
  setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));

  memset(&sa, 0, sizeof(sa));
  sa.sin6_family = AF_INET6;
  sa.sin6_port = htons(port);
  sa.sin6_addr = in6addr_any;

  if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) < 0) { close(fd); return -1; }
  if (listen(fd, 16) < 0) { close(fd); return -1; }
  if (!barev_net_set_nonblocking(fd)) { close(fd); return -1; }
  return fd;
}

int barev_net_accept_v6(int listen_fd, char *addr_out, size_t addr_out_n, unsigned short *port_out) {
  int fd;
  struct sockaddr_in6 sa;
  socklen_t sl;
  const char *r;

  sl = (socklen_t)sizeof(sa);
  memset(&sa, 0, sizeof(sa));
  fd = accept(listen_fd, (struct sockaddr *)&sa, &sl);
  if (fd < 0) return -1;

  if (addr_out && addr_out_n > 0) {
    r = inet_ntop(AF_INET6, &sa.sin6_addr, addr_out, (socklen_t)addr_out_n);
    if (!r) addr_out[0] = '\0';
  }
  if (port_out) *port_out = ntohs(sa.sin6_port);
  barev_net_set_nonblocking(fd);
  return fd;
}

int barev_net_connect_v6(const char *ipv6, unsigned short port) {
  int fd;
  int rc;
  struct sockaddr_in6 sa;

  fd = socket(AF_INET6, SOCK_STREAM, 0);
  if (fd < 0) return -1;
  if (!barev_net_set_nonblocking(fd)) { close(fd); return -1; }

  memset(&sa, 0, sizeof(sa));
  sa.sin6_family = AF_INET6;
  sa.sin6_port = htons(port);
  if (inet_pton(AF_INET6, ipv6, &sa.sin6_addr) != 1) { close(fd); return -1; }

  rc = connect(fd, (struct sockaddr *)&sa, sizeof(sa));
  if (rc == 0) return fd;
  if (rc < 0 && (errno == EINPROGRESS || errno == EWOULDBLOCK)) return fd;
  close(fd);
  return -1;
}

int barev_net_is_readable(int fd, int timeout_ms) {
  fd_set rfds;
  struct timeval tv;
  int rc;

  FD_ZERO(&rfds);
  FD_SET(fd, &rfds);
  tv.tv_sec = timeout_ms / 1000;
  tv.tv_usec = (timeout_ms % 1000) * 1000;
  rc = select(fd + 1, &rfds, 0, 0, &tv);
  if (rc <= 0) return 0;
  return FD_ISSET(fd, &rfds) ? 1 : 0;
}

int barev_net_send_all(int fd, const char *buf, size_t n) {
  ssize_t w;
  size_t done;
  done = 0;
  while (done < n) {
    w = send(fd, buf + done, n - done, 0);
    if (w > 0) {
      done += (size_t)w;
      continue;
    }
    if (w < 0 && (errno == EINTR)) continue;
    if (w < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) break;
    return -1;
  }
  return (int)done;
}

int barev_net_recv_some(int fd, char *buf, size_t n) {
  ssize_t r;
  r = recv(fd, buf, n, 0);
  if (r > 0) return (int)r;
  if (r == 0) return 0;
  if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) return -2;
  return -1;
}

void barev_net_close(int fd) {
  if (fd >= 0) close(fd);
}