/** 
 @file  unix.c
 @brief ENet Unix system specific functions
*/
#ifndef _WIN32

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <arpa/inet.h>
#include <netinet/tcp.h>
#include <netdb.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <time.h>

#define ENET_BUILDING_LIB 1
#include "enet/enet.h"

#ifdef __APPLE__
#ifdef HAS_POLL
#undef HAS_POLL
#endif
#ifndef HAS_FCNTL
#define HAS_FCNTL 1
#endif
#ifndef HAS_INET_PTON
#define HAS_INET_PTON 1
#endif
#ifndef HAS_INET_NTOP
#define HAS_INET_NTOP 1
#endif
#ifndef HAS_MSGHDR_FLAGS
#define HAS_MSGHDR_FLAGS 1
#endif
#ifndef HAS_SOCKLEN_T
#define HAS_SOCKLEN_T 1
#endif
#endif

#ifdef HAS_FCNTL
#include <fcntl.h>
#endif

#ifdef HAS_POLL
#include <sys/poll.h>
#endif

#ifndef HAS_SOCKLEN_T
typedef int socklen_t;
#endif

#ifndef MSG_NOSIGNAL
#define MSG_NOSIGNAL 0
#endif

static enet_uint32 timeBase = 0;

#ifdef ENABLE_IPV6
extern void stkInitialize(void);
extern int isIPv6Socket(void);
extern void getIPV6FromMappedAddress(const ENetAddress* ea, struct sockaddr_in6* in6);
extern void getMappedFromIPV6(const struct sockaddr_in6* in6, ENetAddress* ea);
#endif

int
enet_initialize (void)
{
#ifdef ENABLE_IPV6
    stkInitialize();
#endif
    return 0;
}

void
enet_deinitialize (void)
{
}

enet_uint32
enet_host_random_seed (void)
{
    return (enet_uint32) time (NULL);
}

enet_uint32
enet_time_get (void)
{
    struct timeval timeVal;

    gettimeofday (& timeVal, NULL);

    return timeVal.tv_sec * 1000 + timeVal.tv_usec / 1000 - timeBase;
}

void
enet_time_set (enet_uint32 newTimeBase)
{
    struct timeval timeVal;

    gettimeofday (& timeVal, NULL);
    
    timeBase = timeVal.tv_sec * 1000 + timeVal.tv_usec / 1000 - newTimeBase;
}

int
enet_address_set_host (ENetAddress * address, const char * name)
{
    struct hostent * hostEntry = NULL;
#ifdef HAS_GETHOSTBYNAME_R
    struct hostent hostData;
    char buffer [2048];
    int errnum;

#if defined(linux) || defined(__linux) || defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__GNU__)
    gethostbyname_r (name, & hostData, buffer, sizeof (buffer), & hostEntry, & errnum);
#else
    hostEntry = gethostbyname_r (name, & hostData, buffer, sizeof (buffer), & errnum);
#endif
#else
    hostEntry = gethostbyname (name);
#endif

    if (hostEntry == NULL ||
        hostEntry -> h_addrtype != AF_INET)
    {
#ifdef HAS_INET_PTON
        if (! inet_pton (AF_INET, name, & address -> host))
#else
        if (! inet_aton (name, (struct in_addr *) & address -> host))
#endif
            return -1;
        return 0;
    }

    address -> host = * (enet_uint32 *) hostEntry -> h_addr_list [0];

    return 0;
}

int
enet_address_get_host_ip (const ENetAddress * address, char * name, size_t nameLength)
{
#ifdef HAS_INET_NTOP
    if (inet_ntop (AF_INET, & address -> host, name, nameLength) == NULL)
#else
    char * addr = inet_ntoa (* (struct in_addr *) & address -> host);
    if (addr != NULL)
    {
        size_t addrLen = strlen(addr);
        if (addrLen >= nameLength)
          return -1;
        memcpy (name, addr, addrLen + 1);
    } 
    else
#endif
        return -1;
    return 0;
}

int
enet_address_get_host (const ENetAddress * address, char * name, size_t nameLength)
{
    struct in_addr in;
    struct hostent * hostEntry = NULL;
#ifdef HAS_GETHOSTBYADDR_R
    struct hostent hostData;
    char buffer [2048];
    int errnum;

    in.s_addr = address -> host;

#if defined(linux) || defined(__linux) || defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__GNU__)
    gethostbyaddr_r ((char *) & in, sizeof (struct in_addr), AF_INET, & hostData, buffer, sizeof (buffer), & hostEntry, & errnum);
#else
    hostEntry = gethostbyaddr_r ((char *) & in, sizeof (struct in_addr), AF_INET, & hostData, buffer, sizeof (buffer), & errnum);
#endif
#else
    in.s_addr = address -> host;

    hostEntry = gethostbyaddr ((char *) & in, sizeof (struct in_addr), AF_INET);
#endif

    if (hostEntry == NULL)
      return enet_address_get_host_ip (address, name, nameLength);
    else
    {
       size_t hostLen = strlen (hostEntry -> h_name);
       if (hostLen >= nameLength)
         return -1;
       memcpy (name, hostEntry -> h_name, hostLen + 1);
    }

    return 0;
}

int
enet_socket_bind (ENetSocket socket, const ENetAddress * address)
{
#ifdef ENABLE_IPV6
    // In STK we only bind port and listen to any address
    if (isIPv6Socket())
    {
        struct sockaddr_in6 sin;
        memset (&sin, 0, sizeof (struct sockaddr_in6));
        sin.sin6_family = AF_INET6;
        sin.sin6_addr = in6addr_any;
        sin.sin6_port = ENET_HOST_TO_NET_16 (address -> port);
        return bind (socket, (struct sockaddr *) & sin,
                     sizeof (struct sockaddr_in6));
    }
    else
#endif
    {
        struct sockaddr_in sin;

        memset (& sin, 0, sizeof (struct sockaddr_in));

        sin.sin_family = AF_INET;

        if (address != NULL)
        {
           sin.sin_port = ENET_HOST_TO_NET_16 (address -> port);
           sin.sin_addr.s_addr = address -> host;
        }
        else
        {
           sin.sin_port = 0;
           sin.sin_addr.s_addr = INADDR_ANY;
        }

        return bind (socket,
                     (struct sockaddr *) & sin,
                     sizeof (struct sockaddr_in));
    }
}

int
enet_socket_get_address (ENetSocket socket, ENetAddress * address)
{
    struct sockaddr_in sin;
    socklen_t sinLength = sizeof (struct sockaddr_in);

    if (getsockname (socket, (struct sockaddr *) & sin, & sinLength) == -1)
      return -1;

    address -> host = (enet_uint32) sin.sin_addr.s_addr;
    address -> port = ENET_NET_TO_HOST_16 (sin.sin_port);

    return 0;
}

int 
enet_socket_listen (ENetSocket socket, int backlog)
{
    return listen (socket, backlog < 0 ? SOMAXCONN : backlog);
}

ENetSocket
enet_socket_create (ENetSocketType type)
{
#ifdef ENABLE_IPV6
    int af_family = isIPv6Socket() == 1 ? PF_INET6 : PF_INET;
#else
    int af_family = PF_INET;
#endif
    int socket_fd = socket (af_family, type == ENET_SOCKET_TYPE_DATAGRAM ? SOCK_DGRAM : SOCK_STREAM, 0);
#ifdef ENABLE_IPV6
    if (isIPv6Socket() && socket_fd != -1)
    {
        int no = 0;
        // Allow IPv6 socket listen to IPv4 connection (as long as the host has IPv4 address)
        int ret = setsockopt(socket_fd, IPPROTO_IPV6, IPV6_V6ONLY, (void*)&no, sizeof(no));
        if (ret != 0)
        {
            close(socket_fd);
            return -1;
        }
    }
#endif
    return socket_fd;
}

int
enet_socket_set_option (ENetSocket socket, ENetSocketOption option, int value)
{
    int result = -1;
    switch (option)
    {
        case ENET_SOCKOPT_NONBLOCK:
#ifdef HAS_FCNTL
            result = fcntl (socket, F_SETFL, O_NONBLOCK | fcntl (socket, F_GETFL));
#else
            result = ioctl (socket, FIONBIO, & value);
#endif
            break;

        case ENET_SOCKOPT_BROADCAST:
            result = setsockopt (socket, SOL_SOCKET, SO_BROADCAST, (char *) & value, sizeof (int));
            break;

        case ENET_SOCKOPT_REUSEADDR:
            result = setsockopt (socket, SOL_SOCKET, SO_REUSEADDR, (char *) & value, sizeof (int));
            break;

        case ENET_SOCKOPT_RCVBUF:
            result = setsockopt (socket, SOL_SOCKET, SO_RCVBUF, (char *) & value, sizeof (int));
            break;

        case ENET_SOCKOPT_SNDBUF:
            result = setsockopt (socket, SOL_SOCKET, SO_SNDBUF, (char *) & value, sizeof (int));
            break;

        case ENET_SOCKOPT_RCVTIMEO:
        {
            struct timeval timeVal;
            timeVal.tv_sec = value / 1000;
            timeVal.tv_usec = (value % 1000) * 1000;
            result = setsockopt (socket, SOL_SOCKET, SO_RCVTIMEO, (char *) & timeVal, sizeof (struct timeval));
            break;
        }

        case ENET_SOCKOPT_SNDTIMEO:
        {
            struct timeval timeVal;
            timeVal.tv_sec = value / 1000;
            timeVal.tv_usec = (value % 1000) * 1000;
            result = setsockopt (socket, SOL_SOCKET, SO_SNDTIMEO, (char *) & timeVal, sizeof (struct timeval));
            break;
        }

        case ENET_SOCKOPT_NODELAY:
            result = setsockopt (socket, IPPROTO_TCP, TCP_NODELAY, (char *) & value, sizeof (int));
            break;

        default:
            break;
    }
    return result == -1 ? -1 : 0;
}

int
enet_socket_get_option (ENetSocket socket, ENetSocketOption option, int * value)
{
    int result = -1;
    socklen_t len;
    switch (option)
    {
        case ENET_SOCKOPT_ERROR:
            len = sizeof (int);
            result = getsockopt (socket, SOL_SOCKET, SO_ERROR, value, & len);
            break;

        default:
            break;
    }
    return result == -1 ? -1 : 0;
}

int
enet_socket_connect (ENetSocket socket, const ENetAddress * address)
{
    struct sockaddr_in sin;
    int result;

    memset (& sin, 0, sizeof (struct sockaddr_in));

    sin.sin_family = AF_INET;
    sin.sin_port = ENET_HOST_TO_NET_16 (address -> port);
    sin.sin_addr.s_addr = address -> host;

    result = connect (socket, (struct sockaddr *) & sin, sizeof (struct sockaddr_in));
    if (result == -1 && errno == EINPROGRESS)
      return 0;

    return result;
}

ENetSocket
enet_socket_accept (ENetSocket socket, ENetAddress * address)
{
    int result;
    struct sockaddr_in sin;
    socklen_t sinLength = sizeof (struct sockaddr_in);

    result = accept (socket, 
                     address != NULL ? (struct sockaddr *) & sin : NULL, 
                     address != NULL ? & sinLength : NULL);
    
    if (result == -1)
      return ENET_SOCKET_NULL;

    if (address != NULL)
    {
        address -> host = (enet_uint32) sin.sin_addr.s_addr;
        address -> port = ENET_NET_TO_HOST_16 (sin.sin_port);
    }

    return result;
} 
    
int
enet_socket_shutdown (ENetSocket socket, ENetSocketShutdown how)
{
    return shutdown (socket, (int) how);
}

void
enet_socket_destroy (ENetSocket socket)
{
    if (socket != -1)
      close (socket);
}

int
enet_socket_send (ENetSocket socket,
                  const ENetAddress * address,
                  const ENetBuffer * buffers,
                  size_t bufferCount)
{
    struct msghdr msgHdr;
    struct sockaddr_in sin;
#ifdef ENABLE_IPV6
    struct sockaddr_in6 sin6;
#endif
    int sentLength;

    memset (& msgHdr, 0, sizeof (struct msghdr));

    if (address != NULL)
    {
#ifdef ENABLE_IPV6
        if (isIPv6Socket())
        {
            getIPV6FromMappedAddress(address, &sin6);
            msgHdr.msg_name = & sin6;
            msgHdr.msg_namelen = sizeof (struct sockaddr_in6);
        }
        else
#endif
        {
            memset (& sin, 0, sizeof (struct sockaddr_in));

            sin.sin_family = AF_INET;
            sin.sin_port = ENET_HOST_TO_NET_16 (address -> port);
            sin.sin_addr.s_addr = address -> host;

            msgHdr.msg_name = & sin;
            msgHdr.msg_namelen = sizeof (struct sockaddr_in);
        }
    }

    msgHdr.msg_iov = (struct iovec *) buffers;
    msgHdr.msg_iovlen = bufferCount;

    sentLength = sendmsg (socket, & msgHdr, MSG_NOSIGNAL);
    
    if (sentLength == -1)
    {
       if (errno == EWOULDBLOCK)
         return 0;

       return -1;
    }

    return sentLength;
}

int
enet_socket_receive (ENetSocket socket,
                     ENetAddress * address,
                     ENetBuffer * buffers,
                     size_t bufferCount)
{
    struct msghdr msgHdr;
    struct sockaddr_in sin;
#ifdef ENABLE_IPV6
    struct sockaddr_in6 sin6;
#endif
    int recvLength;

    memset (& msgHdr, 0, sizeof (struct msghdr));

    if (address != NULL)
    {
#ifdef ENABLE_IPV6
        if (isIPv6Socket())
        {
            msgHdr.msg_name = & sin6;
            msgHdr.msg_namelen = sizeof (struct sockaddr_in6);
        }
        else
#endif
        {
            msgHdr.msg_name = & sin;
            msgHdr.msg_namelen = sizeof (struct sockaddr_in);
        }
    }

    msgHdr.msg_iov = (struct iovec *) buffers;
    msgHdr.msg_iovlen = bufferCount;

    recvLength = recvmsg (socket, & msgHdr, MSG_NOSIGNAL);

    if (recvLength == -1)
    {
       if (errno == EWOULDBLOCK)
         return 0;

       return -1;
    }

#ifdef HAS_MSGHDR_FLAGS
    if (msgHdr.msg_flags & MSG_TRUNC)
      return -1;
#endif

    if (address != NULL)
    {
#ifdef ENABLE_IPV6
        if (isIPv6Socket())
        {
            getMappedFromIPV6(&sin6, address);
        }
        else
#endif
        {
            address -> host = (enet_uint32) sin.sin_addr.s_addr;
            address -> port = ENET_NET_TO_HOST_16 (sin.sin_port);
        }
    }

    return recvLength;
}

int
enet_socketset_select (ENetSocket maxSocket, ENetSocketSet * readSet, ENetSocketSet * writeSet, enet_uint32 timeout)
{
    struct timeval timeVal;

    timeVal.tv_sec = timeout / 1000;
    timeVal.tv_usec = (timeout % 1000) * 1000;

    return select (maxSocket + 1, readSet, writeSet, NULL, & timeVal);
}

int
enet_socket_wait (ENetSocket socket, enet_uint32 * condition, enet_uint32 timeout)
{
#ifdef HAS_POLL
    struct pollfd pollSocket;
    int pollCount;
    
    pollSocket.fd = socket;
    pollSocket.events = 0;

    if (* condition & ENET_SOCKET_WAIT_SEND)
      pollSocket.events |= POLLOUT;

    if (* condition & ENET_SOCKET_WAIT_RECEIVE)
      pollSocket.events |= POLLIN;

    pollCount = poll (& pollSocket, 1, timeout);

    if (pollCount < 0)
    {
        if (errno == EINTR && * condition & ENET_SOCKET_WAIT_INTERRUPT)
        {
            * condition = ENET_SOCKET_WAIT_INTERRUPT;

            return 0;
        }

        return -1;
    }

    * condition = ENET_SOCKET_WAIT_NONE;

    if (pollCount == 0)
      return 0;

    if (pollSocket.revents & POLLOUT)
      * condition |= ENET_SOCKET_WAIT_SEND;
    
    if (pollSocket.revents & POLLIN)
      * condition |= ENET_SOCKET_WAIT_RECEIVE;

    return 0;
#else
    fd_set readSet, writeSet;
    struct timeval timeVal;
    int selectCount;

    timeVal.tv_sec = timeout / 1000;
    timeVal.tv_usec = (timeout % 1000) * 1000;

    FD_ZERO (& readSet);
    FD_ZERO (& writeSet);

    if (* condition & ENET_SOCKET_WAIT_SEND)
      FD_SET (socket, & writeSet);

    if (* condition & ENET_SOCKET_WAIT_RECEIVE)
      FD_SET (socket, & readSet);

    selectCount = select (socket + 1, & readSet, & writeSet, NULL, & timeVal);

    if (selectCount < 0)
    {
        if (errno == EINTR && * condition & ENET_SOCKET_WAIT_INTERRUPT)
        {
            * condition = ENET_SOCKET_WAIT_INTERRUPT;

            return 0;
        }
      
        return -1;
    }

    * condition = ENET_SOCKET_WAIT_NONE;

    if (selectCount == 0)
      return 0;

    if (FD_ISSET (socket, & writeSet))
      * condition |= ENET_SOCKET_WAIT_SEND;

    if (FD_ISSET (socket, & readSet))
      * condition |= ENET_SOCKET_WAIT_RECEIVE;

    return 0;
#endif
}

#endif