/**
 * Copyright © 2014-2015 VideoLabs SAS
 *
 * Author: Jonathan Calmels <jbjcalmels@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <assert.h>
#include <errno.h>
#include <string.h>

#include "compat.h"
#include "utils.h"

#if defined (__unix__) || defined (__APPLE__)
struct timeval os_deadline = {
        .tv_sec = 0,
        .tv_usec = 100000,
};
#endif // __unix__ || (__APPLE__)

#if defined (_WIN32)
uint32_t os_deadline = 1000;
#include <winapifamily.h>
#endif // _WIN32

int
os_strerror(int errnum, char *buf, size_t buflen)
{
        int r = 0;
        if (buflen == 0)
            return -1;

        buf[0] = '\0';

        switch (errnum) {
#if defined (_WIN32)
                case MDNS_NETERR:
                        errno = WSAGetLastError();
                        // fallthrough
                case MDNS_STDERR:
                {
                        wchar_t* wbuff = malloc(sizeof(*wbuff) * buflen);
                        if (wbuff == NULL)
                            return (-1);
                        DWORD nbChar = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM,
                                           NULL, errno, 0, wbuff, buflen, NULL);
                        if (!nbChar)
                        {
                                snprintf(buf, buflen, "Error %d\n", errno);
                                r = -1;
                        }
                        else
                                nbChar = WideCharToMultiByte(CP_UTF8, 0, wbuff, nbChar,
                                           buf, buflen, NULL, NULL);
                        free(wbuff);
                        break;
                }
#if WINAPI_FAMILY_PARTITION (WINAPI_PARTITION_DESKTOP) || _WIN32_WINNT >= 0x0A00
                case MDNS_LKPERR:
                {
                        // Win32 gai_strerror returns a static buffer, but as a non-const char*
                        WCHAR *s = gai_strerror(errno);
                        if (!WideCharToMultiByte(CP_UTF8, 0, s, -1, buf, buflen, NULL, NULL))
                                return (-1);
                        break;
                }
#endif
#else
                case MDNS_STDERR:
                case MDNS_NETERR:
                        if (strerror_r(errno, buf, buflen) != 0)
                                return (-1);
                        break;

                case MDNS_LKPERR: {
                        const char *s;
                        s = gai_strerror(errno);
                        if ( s == NULL )
                            return (-1);
                        strncpy(buf, s, buflen);
                        buf[buflen - 1] = '\0';
                        break;
                }
#endif
                default:
                        r = -1;
        }
        return (r);
}

int
os_mcast_join(sock_t s, const struct sockaddr_storage *ss, uint32_t intf_idx,
              const struct sockaddr_storage* intf_addr)
{
#ifdef MCAST_JOIN_GROUP
        (void)intf_addr;
        struct group_req mgroup;

        memset(&mgroup, 0, sizeof(mgroup));
        mgroup.gr_interface = intf_idx;
        memcpy(&mgroup.gr_group, ss, ss_len(ss));
        if (setsockopt(s, ss_level(ss), MCAST_JOIN_GROUP,
            (const void *) &mgroup, sizeof(mgroup)) < 0)
                return (-1);
#else
        union {
                struct sockaddr_storage ss;
                struct sockaddr_in      sin;
                struct sockaddr_in6     sin6;
        } u;

        memcpy(&u, ss, sizeof(*ss));
        switch (ss_family(ss)) {
                case AF_INET: {
                        struct ip_mreq mreq;
                        const struct sockaddr_in* sin = (const struct sockaddr_in*)intf_addr;

                        memcpy(&mreq.imr_multiaddr.s_addr, &u.sin.sin_addr, sizeof(struct in_addr));
                        memcpy(&mreq.imr_interface, &sin->sin_addr, sizeof(sin->sin_addr));
                        if (setsockopt(s, ss_level(ss), IP_ADD_MEMBERSHIP,
                            (const void *) &mreq, sizeof(mreq)) < 0)
                                return (-1);
                        break;
                }
                case AF_INET6: {
                        struct ipv6_mreq mreq6;

                        memcpy(&mreq6.ipv6mr_multiaddr, &u.sin6.sin6_addr, sizeof(struct in6_addr));
                        memcpy(&mreq6.ipv6mr_interface, &intf_idx, sizeof(intf_idx));
                        if (setsockopt(s, ss_level(ss), IPV6_JOIN_GROUP,
                            (const void *) &mreq6, sizeof(mreq6)) < 0)
                                return (-1);
                        break;
                }
                default:
                        assert(1);
        }
#endif
        return (0);
}