#include <arpa/inet.h>
#include <sys/socket.h>
#include <assert.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if EMSCRIPTEN
#include <emscripten.h>
#endif

int main() {
  struct addrinfo hints;
  struct addrinfo *servinfo;
  struct sockaddr_in *sa4;
  struct sockaddr_in6 *sa6;
  int err;

  // no name or service
  err = getaddrinfo(NULL, NULL, NULL, &servinfo);
  assert(err == EAI_NONAME);

  // invalid socket type
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET;
  hints.ai_socktype = 9999;
  err = getaddrinfo("www.mozilla.org", "80", &hints, &servinfo);
#ifdef __APPLE__
  assert(err == EAI_BADHINTS);
#else
  assert(err == EAI_SOCKTYPE);
#endif

  // invalid family
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_UNIX;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo("www.mozilla.org", "80", &hints, &servinfo);
  assert(err == EAI_FAMILY);

  // invalid service
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo("www.mozilla.org", "foobar", &hints, &servinfo);
#ifdef __APPLE__
  assert(err == EAI_NONAME);
#else
  assert(err == EAI_SERVICE);
#endif

  // test loopback resolution (ipv4)
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo(NULL, "80", &hints, &servinfo);
  assert(!err);
  sa4 = ((struct sockaddr_in*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET);
  assert(servinfo->ai_socktype == SOCK_STREAM);
  assert(*(uint32_t*)&(sa4->sin_addr) == ntohl(INADDR_LOOPBACK));
  assert(sa4->sin_port == ntohs(80));
  freeaddrinfo(servinfo);

  // test loopback resolution (ipv6)
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET6;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo(NULL, "81", &hints, &servinfo);
  assert(!err);
  sa6 = ((struct sockaddr_in6*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET6);
  assert(servinfo->ai_socktype == SOCK_STREAM);
  memcmp(&sa6->sin6_addr, &in6addr_loopback, sizeof(in6addr_loopback));
  assert(sa6->sin6_port == ntohs(81));
  freeaddrinfo(servinfo);

  // test bind preparation
  memset(&hints, 0, sizeof(hints));
  hints.ai_flags = AI_PASSIVE;
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo(NULL, "82", &hints, &servinfo);
  assert(!err);
  sa4 = ((struct sockaddr_in*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET);
  assert(servinfo->ai_socktype == SOCK_STREAM);
  assert(*(uint32_t*)&(sa4->sin_addr) == 0);
  assert(sa4->sin_port == ntohs(82));
  freeaddrinfo(servinfo);

  // test numeric address (ipv4)
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_DGRAM;
  err = getaddrinfo("1.2.3.4", "83", &hints, &servinfo);
  assert(!err);
  sa4 = ((struct sockaddr_in*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET);
  assert(servinfo->ai_socktype == SOCK_DGRAM);
  assert(*(uint32_t*)&(sa4->sin_addr) == 67305985);
  assert(sa4->sin_port == ntohs(83));
  freeaddrinfo(servinfo);

  // test numeric address (ipv4 address specified as ipv6 with AI_V4MAPPED)
  memset(&hints, 0, sizeof(hints));
  hints.ai_flags = AI_V4MAPPED;
  hints.ai_family = AF_INET6;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo("1.2.3.4", "84", &hints, &servinfo);
  assert(!err);
  sa6 = ((struct sockaddr_in6*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET6);
  assert(servinfo->ai_socktype == SOCK_STREAM);
  assert(*((uint32_t*)&(sa6->sin6_addr)+2) == htonl(0xffff));
  assert(*((uint32_t*)&(sa6->sin6_addr)+3) == 67305985);
  assert(sa6->sin6_port == ntohs(84));
  freeaddrinfo(servinfo);

  // test numeric address (ipv4 address specified as ipv6 without AI_V4MAPPED)
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET6;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo("1.2.3.4", "85", &hints, &servinfo);
#ifdef __linux__
  assert(err == -9 /* EAI_ADDRFAMILY */);
#else
  assert(err == EAI_NONAME);
#endif

  // test numeric address (ipv6)
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET6;
  hints.ai_socktype = SOCK_DGRAM;
  err = getaddrinfo("2001:0db8:85a3:0042:1000:8a2e:0370:7334", "86", &hints, &servinfo);
  assert(!err);
  sa6 = ((struct sockaddr_in6*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET6);
  assert(servinfo->ai_socktype == SOCK_DGRAM);
  assert(*((uint32_t*)&(sa6->sin6_addr)+0) == -1207107296);
  assert(*((uint32_t*)&(sa6->sin6_addr)+1) == 1107338117);
  assert(*((uint32_t*)&(sa6->sin6_addr)+2) == 780795920);
  assert(*((uint32_t*)&(sa6->sin6_addr)+3) == 879980547);
  assert(sa6->sin6_port == ntohs(86));
  freeaddrinfo(servinfo);

  // test numeric address (ipv6 address specified as ipv4)
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo("2001:0db8:85a3:0042:1000:8a2e:0370:7334", "87", &hints, &servinfo);
#ifdef __linux__
  assert(err == -9 /* EAI_ADDRFAMILY */);
#else
  assert(err == EAI_NONAME);
#endif

  // test non-numeric host with AI_NUMERICHOST
  memset(&hints, 0, sizeof(hints));
  hints.ai_flags = AI_NUMERICHOST;
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo("www.mozilla.org", "88", &hints, &servinfo);
  assert(err == EAI_NONAME);

  // test non-numeric host with AF_INET
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo("www.mozilla.org", "89", &hints, &servinfo);
  assert(!err);
  sa4 = ((struct sockaddr_in*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET);
  assert(servinfo->ai_socktype == SOCK_STREAM);
  assert(sa4->sin_port == ntohs(89));
  freeaddrinfo(servinfo);

  // test non-numeric host with AF_INET6
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = AF_INET6;
  hints.ai_socktype = SOCK_STREAM;
  err = getaddrinfo("www.mozilla.org", "90", &hints, &servinfo);
  assert(!err);
  sa6 = ((struct sockaddr_in6*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET6);
  assert(servinfo->ai_socktype == SOCK_STREAM);
  assert(*((uint32_t*)&(sa6->sin6_addr)+0) != 0 ||
         *((uint32_t*)&(sa6->sin6_addr)+1) != 0 ||
         *((uint32_t*)&(sa6->sin6_addr)+2) != 0 ||
         *((uint32_t*)&(sa6->sin6_addr)+3) != 0);
  assert(sa6->sin6_port == ntohs(90));
  freeaddrinfo(servinfo);

  // test with NULL hints
  // Specifying hints as NULL is equivalent to setting ai_socktype and ai_protocol to 0;
  // ai_family to AF_UNSPEC; and ai_flags to (AI_V4MAPPED | AI_ADDRCONFIG)
  // N.B. with NULL hints getaddrinfo should really be passing back multiple addrinfo structures in a
  // linked list with next values given in ai_next. The current implementation doesn't do that yet but the
  // following tests have assert(servinfo->ai_next == NULL) so that they will fail when multiple values do
  // eventually get implemented, so we know to improve the tests then to cope with multiple values.

  // test numeric host
  err = getaddrinfo("1.2.3.4", "85", NULL, &servinfo);
  assert(!err);
  sa4 = ((struct sockaddr_in*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET);
  assert(servinfo->ai_socktype == SOCK_STREAM);
  assert(servinfo->ai_protocol == IPPROTO_TCP);
  assert(sa4->sin_port == ntohs(85));
  assert(servinfo->ai_next == NULL);
  freeaddrinfo(servinfo);

  // test non-numeric host
  err = getaddrinfo("www.mozilla.org", "89", NULL, &servinfo);
  assert(!err);
  sa4 = ((struct sockaddr_in*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET);
  assert(servinfo->ai_socktype == SOCK_STREAM);
  assert(servinfo->ai_protocol == IPPROTO_TCP);
  assert(sa4->sin_port == ntohs(89));
  assert(servinfo->ai_next == NULL);
  freeaddrinfo(servinfo);

  // test loopback resolution
  err = getaddrinfo(NULL, "80", NULL, &servinfo);
  assert(!err);
  sa4 = ((struct sockaddr_in*)servinfo->ai_addr);
  assert(servinfo->ai_family == AF_INET);
  assert(servinfo->ai_socktype == SOCK_STREAM);
  assert(servinfo->ai_protocol == IPPROTO_TCP);
  assert(sa4->sin_port == ntohs(80));
  assert(servinfo->ai_next == NULL);
  freeaddrinfo(servinfo);

  // test gai_strerror
  assert(strncmp(gai_strerror(0), "Success", 256) == 0);
  assert(strncmp(gai_strerror(EAI_BADFLAGS), "Invalid value for 'ai_flags' field", 256) == 0);
  assert(strncmp(gai_strerror(EAI_NONAME), "NAME or SERVICE is unknown", 256) == 0);
  assert(strncmp(gai_strerror(EAI_AGAIN), "Temporary failure in name resolution", 256) == 0);
  assert(strncmp(gai_strerror(EAI_FAIL), "Non-recoverable failure in name res", 256) == 0);
  assert(strncmp(gai_strerror(EAI_FAMILY), "'ai_family' not supported", 256) == 0);
  assert(strncmp(gai_strerror(EAI_SOCKTYPE), "'ai_socktype' not supported", 256) == 0);
  assert(strncmp(gai_strerror(EAI_SERVICE), "SERVICE not supported for 'ai_socktype'", 256) == 0);
  assert(strncmp(gai_strerror(EAI_MEMORY), "Memory allocation failure", 256) == 0);
  assert(strncmp(gai_strerror(EAI_SYSTEM), "System error returned in 'errno'", 256) == 0);
  assert(strncmp(gai_strerror(EAI_OVERFLOW), "Argument buffer overflow", 256) == 0);
  assert(strncmp(gai_strerror(-5), "Unknown error", 256) == 0);
  assert(strncmp(gai_strerror(-9), "Unknown error", 256) == 0);
  assert(strncmp(gai_strerror(-13), "Unknown error", 256) == 0);
  assert(strncmp(gai_strerror(-100), "Unknown error", 256) == 0);

  puts("success");

  return EXIT_SUCCESS;
}