/*
 * TCP protocol
 * Copyright (c) 2002 Fabrice Bellard
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
#include "libavformat/avformat.h"
#include "libavutil/avassert.h"
#include "libavutil/parseutils.h"
#include "libavutil/opt.h"
#include "libavutil/time.h"
#include "libavutil/random_seed.h"

#include "libavformat/internal.h"
#include "libavformat/network.h"
#include "libavformat/os_support.h"
#include "libavformat/url.h"

#include "aml_getaddrinfo.h"
#include "get_config.h"
#if HAVE_POLL_H
#include <poll.h>
#endif
#if HAVE_PTHREADS
#include <pthread.h>
#endif

#include "fftcp.h"
#include "dns_cache.h"
#include "getaddrinfo_nonblock.h"

#include "addrinfo_reorder.h"

typedef struct TCPContext {
    const AVClass *class;
    int fd;
    int listen;
    int open_timeout;
    int rw_timeout;
    int listen_timeout;
    int recv_buffer_size;
    int send_buffer_size;
    int tcp_nodelay;

    int addrinfo_one_by_one;
    int addrinfo_timeout;
    int dns_cache_timeout;

    DNS_seq_mode dns_seq_mode;

    char *ip_char;
} TCPContext;

#define OFFSET(x) offsetof(TCPContext, x)
#define D AV_OPT_FLAG_DECODING_PARAM
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption tcp_options[] = {
    { "listen",          "Listen for incoming connections",  OFFSET(listen),         AV_OPT_TYPE_INT, { .i64 = 0 },     0,       2,       .flags = D|E },
    { "tcp_rw_timeout",     "set timeout (in microseconds) of socket I/O operations", OFFSET(rw_timeout),     AV_OPT_TYPE_INT, { .i64 = 100000 },         -1, INT_MAX, .flags = D|E },
    { "tcp_connect_timeout",  "set connect timeout (in microseconds) of socket", OFFSET(open_timeout),     AV_OPT_TYPE_INT, { .i64 = 1000000 },         -1, INT_MAX, .flags = D|E },
    { "listen_timeout",  "Connection awaiting timeout (in milliseconds)",      OFFSET(listen_timeout), AV_OPT_TYPE_INT, { .i64 = 5000 },         -1, INT_MAX, .flags = D|E },
    { "send_buffer_size", "Socket send buffer size (in bytes)",                OFFSET(send_buffer_size), AV_OPT_TYPE_INT, { .i64 = INT_MAX },         -1, INT_MAX, .flags = D|E },
    { "recv_buffer_size", "Socket receive buffer size (in bytes)",             OFFSET(recv_buffer_size), AV_OPT_TYPE_INT, { .i64 = -1 },         -1, INT_MAX, .flags = D|E },
    { "tcp_nodelay", "Use TCP_NODELAY to disable nagle's algorithm",           OFFSET(tcp_nodelay), AV_OPT_TYPE_BOOL, { .i64 = 0 },             0, 1, .flags = D|E },

    { "addrinfo_one_by_one",  "parse addrinfo one by one in getaddrinfo()",    OFFSET(addrinfo_one_by_one), AV_OPT_TYPE_INT, { .i64 = 0 },         0, INT_MAX, .flags = D|E },
    { "dns_seq_mode",  "the seq to get IP from DNS list",    OFFSET(dns_seq_mode), AV_OPT_TYPE_INT, { .i64 = 0 },         0, INT_MAX, .flags = D|E },
    { "addrinfo_timeout", "set timeout (in microseconds) for getaddrinfo()",   OFFSET(addrinfo_timeout), AV_OPT_TYPE_INT, { .i64 = 5000000 },       -1, INT_MAX, .flags = D|E },
    { "dns_cache_timeout", "dns cache TTL (in second)",   OFFSET(dns_cache_timeout), AV_OPT_TYPE_INT, { .i64 = 50000 },       -1, INT_MAX, .flags = D|E },
    { "tcp_ip_char", "set HTTP proxy to tunnel through", OFFSET(ip_char), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D | E },
    { NULL }
};

static const AVClass tcp_class = {
    .class_name = "tcp",
    .item_name  = av_default_item_name,
    .option     = tcp_options,
    .version    = LIBAVUTIL_VERSION_INT,
};

/* return non zero if error */
static int tcp_open(URLContext *h, const char *uri, int flags)
{
    struct addrinfo hints = { 0 }, *ai = NULL, *cur_ai = NULL;
    int port, fd = -1;
    TCPContext *s = h->priv_data;
    const char *p;
    char buf[256];
    int ret = -1;
    char hostname[1024],proto[1024],path[1024];
    char portstr[10];
    char hostname_bak[1024] = {0};
    DnsPrivateEntry *dns_entry = NULL;
    int priority = check_ip_priority();

    if (s->open_timeout < 0) {
        s->open_timeout = 5000000;
    }

    av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
                 &port, path, sizeof(path), uri);
    if (strcmp(proto, "tcp"))
        return AVERROR(EINVAL);
    if (port <= 0 || port >= 65536) {
        av_log(NULL, AV_LOG_ERROR,"Port missing in uri");
        return AVERROR(EINVAL);
    }
    p = strchr(uri, '?');
    if (p) {
        if (av_find_info_tag(buf, sizeof(buf), "listen", p)) {
            char *endptr = NULL;
            s->listen = strtol(buf, &endptr, 10);
            /* assume if no digits were found it is a request to enable it */
            if (buf == endptr)
                s->listen = 1;
        }
        if (av_find_info_tag(buf, sizeof(buf), "timeout", p)) {
            s->rw_timeout = strtol(buf, NULL, 10);
        }
        if (av_find_info_tag(buf, sizeof(buf), "listen_timeout", p)) {
            s->listen_timeout = strtol(buf, NULL, 10);
        }
    }
    if (s->rw_timeout >= 0) {
        //s->open_timeout =
        h->rw_timeout   = s->rw_timeout;
    }
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    snprintf(portstr, sizeof(portstr), "%d", port);
    if (s->listen)
        hints.ai_flags |= AI_PASSIVE;
    else {
        if (priority == DNS_INTE_V4_only)
            hints.ai_family = AF_INET;
        if (priority == DNS_INTE_V6_only)
            hints.ai_family = AF_INET6;
    }

    if (s->dns_cache_timeout > 0) {
        //enable dns cache
        memcpy(hostname_bak, hostname, 1024);
        dns_entry = get_dns_cache_reference(hostname);

        if (dns_entry) {
            av_log(NULL, AV_LOG_VERBOSE,"Hit DNS cache");
            cur_ai = dns_entry->res;
        } else {
#ifdef HAVE_PTHREADS
            ret = tcp_getaddrinfo_nonblock(hostname, portstr, &hints, &ai, s->addrinfo_timeout, &h->interrupt_callback, s->addrinfo_one_by_one);
#else
            if (s->addrinfo_timeout > 0)
                av_log(NULL, AV_LOG_WARNING,"Ignore addrinfo_timeout without pthreads support.");
            if (!hostname[0])
                ret = aml_getaddrinfo(NULL, portstr, &hints, &ai);
            else
                ret = aml_getaddrinfo(hostname, portstr, &hints, &ai);
#endif
            if (ret) {
                av_log(NULL, AV_LOG_ERROR,"Failed to resolve hostname %s: %s:%d",
                       hostname, gai_strerror(ret), ret);
                return AVERROR(EIO);
            }
            ret = addrinfo_reorder(&ai, priority, s->dns_seq_mode);
            if (ret) {
                if (ai) {
                    freeaddrinfo(ai);
                }
                av_log(NULL, AV_LOG_ERROR,"sortaddrinfo err, hostname:%s",
                       hostname);
                return AVERROR(EIO);
            }
            ret = add_dns_cache_entry(hostname, ai, s->dns_cache_timeout, priority, s->dns_seq_mode);
            if (ret) {
                if (ai) {
                    freeaddrinfo(ai);
                }
                av_log(NULL, AV_LOG_ERROR,"add_dns_cache_entry err, hostname:%s: %s",
                       hostname, gai_strerror(ret));
                return AVERROR(EIO);
            }
            ai = NULL;
        }
    } else {
        //disable dns cache
        if (!hostname[0])
            ret = getaddrinfo(NULL, portstr, &hints, &ai);
        else
            ret = getaddrinfo(hostname, portstr, &hints, &ai);
        if (ret) {
            av_log(NULL, AV_LOG_ERROR,"Failed to resolve hostname %s: %s",
                   hostname, gai_strerror(ret));
            return AVERROR(EIO);
        }
        cur_ai = ai;
    }

restart:
    if (ai == NULL && dns_entry == NULL)
    {
        dns_entry = get_dns_cache_reference(hostname);
        if (dns_entry) {
            av_log(NULL, AV_LOG_VERBOSE,"Hit DNS cache");
            cur_ai = dns_entry->res;
        } else {
            av_log(NULL, AV_LOG_ERROR,"get_dns_cache_reference err, hostname:%s: %s",
                   hostname, gai_strerror(ret));
            return AVERROR(EAGAIN);
        }
    }
    {
        char cur_serv[96];
        char cur_ip[1024];
        getnameinfo(cur_ai->ai_addr, cur_ai->ai_addrlen, cur_ip, sizeof(cur_ip),
                    cur_serv, sizeof(cur_serv), NI_NUMERICHOST);
        av_log(NULL, AV_LOG_DEBUG,"now to connect hostname = %s, ip = %s, port:%s", hostname_bak , cur_ip, portstr);
    }
#if HAVE_STRUCT_SOCKADDR_IN6
    // workaround for IOS9 getaddrinfo in IPv6 only network use hardcode IPv4 address can not resolve port number.
    if (cur_ai->ai_family == AF_INET6) {
        struct sockaddr_in6 * sockaddr_v6 = (struct sockaddr_in6 *)cur_ai->ai_addr;
        sockaddr_v6->sin6_port = htons(port);
    }
#endif

    if (cur_ai->ai_family == AF_INET) {
        struct sockaddr_in * sockaddr_v4 = (struct sockaddr_in *)cur_ai->ai_addr;
        sockaddr_v4->sin_port = htons(port);
    }

    fd = ff_socket(cur_ai->ai_family,
                   cur_ai->ai_socktype,
                   cur_ai->ai_protocol);
    if (fd < 0) {
        ret = ff_neterrno();
        av_log(NULL, AV_LOG_WARNING,"ff_neterrno:%d, goto fail", ret);
        goto fail;
    }

    /* Set the socket's send or receive buffer sizes, if specified.
       If unspecified or setting fails, system default is used. */
    if (s->recv_buffer_size > 0) {
        setsockopt (fd, SOL_SOCKET, SO_RCVBUF, &s->recv_buffer_size, sizeof (s->recv_buffer_size));
        int optval = 0;
        int optlen = sizeof(optval);
        getsockopt (fd, SOL_SOCKET, SO_RCVBUF, (char*)&optval, &optlen);
        av_log(NULL, AV_LOG_VERBOSE,"this tcp SO_RCVBUF:%d", optval);
    }
    if (s->send_buffer_size > 0) {
        setsockopt (fd, SOL_SOCKET, SO_SNDBUF, &s->send_buffer_size, sizeof (s->send_buffer_size));
    }
    if (s->tcp_nodelay > 0) {
        setsockopt (fd, IPPROTO_TCP, TCP_NODELAY, &s->tcp_nodelay, sizeof (s->tcp_nodelay));
    }

    if (s->listen == 2) {
        // multi-client
        if ((ret = ff_listen(fd, cur_ai->ai_addr, cur_ai->ai_addrlen)) < 0)
        {
            av_log(NULL, AV_LOG_WARNING,"ff_listen:%d, goto fail1", ret);
            goto fail1;
        }
    } else if (s->listen == 1) {
        // single client
        if ((ret = ff_listen_bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen, s->listen_timeout, h)) < 0)
        {
            av_log(NULL, AV_LOG_WARNING,"ff_listen_bind:%d, goto fail1", ret);
            goto fail1;
        }
        // Socket descriptor already closed here. Safe to overwrite to client one.
        fd = ret;
    } else {
        if ((ret = ff_listen_connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen,
                                     s->open_timeout / 1000, h, !!cur_ai->ai_next)) < 0) {

            if (ret == AVERROR_EXIT)
            {
                av_log(NULL, AV_LOG_WARNING,"ff_listen_connect:%d, goto fail1", ret);
                goto fail1;
            }
            else
            {
                av_log(NULL, AV_LOG_WARNING,"ff_listen_connect:%d, goto fail", ret);
                goto fail;
            }
        }
    }

    h->is_streamed = 1;
    s->fd = fd;

    {
        char cur_serv[96];
        char cur_ip[1024];

        getnameinfo(cur_ai->ai_addr, cur_ai->ai_addrlen, cur_ip, sizeof(cur_ip),
                    cur_serv, sizeof(cur_serv), NI_NUMERICHOST);
        av_log(NULL, AV_LOG_VERBOSE,"connect successful hostname = %s, ip = %s", hostname_bak , cur_ip);
        //add_IP_cache(fd, cur_ip);
        s->ip_char = av_mallocz(strlen(cur_ip)+1);
        strcpy(s->ip_char, cur_ip);
    }
    if (dns_entry) {
        release_DnsPriEntry(&dns_entry);
    }
    if (ai) {
        freeaddrinfo(ai);
    }
    return 0;
fail:
    if (fd >= 0)
    {
        closesocket(fd);
        fd = -1;
    }
    if (ai) {
        if (cur_ai->ai_next) {
            /* Retry with the next sockaddr */
            cur_ai = cur_ai->ai_next;
            av_freep(&s->ip_char);
            //remove_IP_cache(s->fd);
            ret = 0;
            av_log(NULL, AV_LOG_WARNING,"fail, goto restart");
            goto restart;
        } else {
            av_log(NULL, AV_LOG_WARNING,"fail, goto fail1");
            goto fail1;
        }
    } else {
        if (dns_entry->res == NULL) {
            av_log(NULL, AV_LOG_WARNING,"fail, dns_entry->res == NULL, goto fail1");
            goto fail1;
        }

        char cur_serv[96];
        char cur_ip[1024];
        getnameinfo(cur_ai->ai_addr, cur_ai->ai_addrlen, cur_ip, sizeof(cur_ip),
                    cur_serv, sizeof(cur_serv), NI_NUMERICHOST);
        int ret_set_dns = set_dns_IP_failed(hostname_bak, cur_ip);
        if (ret_set_dns < 0)
        {
            if (ret_set_dns == -2)
            {
                av_log(NULL, AV_LOG_WARNING,"tcp open net down, hostname:%s, IP:%s", hostname_bak, cur_ip);
                goto fail2;
            } else {
                av_log(NULL, AV_LOG_WARNING,"DNS Cache fail! return, hostname:%s, IP:%s, ret:%d", hostname_bak, cur_ip, ret_set_dns);
                goto fail1;
            }
        }
        av_log(NULL, AV_LOG_WARNING,"DNS Cache fail! restart now, hostname:%s, IP:%s", hostname_bak, cur_ip);
        release_DnsPriEntry(&dns_entry);
        goto restart;
    }
    av_log(NULL, AV_LOG_WARNING,"goto fail1");
    goto fail1;
fail2:
    if (dns_entry) {
        av_log(NULL, AV_LOG_ERROR,"Hit dns cache but net down");
        release_DnsPriEntry(&dns_entry);
        dns_entry = NULL;
    }
fail1:
    av_freep(&s->ip_char);
    //remove_IP_cache(s->fd);
    if (fd >= 0)
    {
        closesocket(fd);
        fd = -1;
    }

    if (dns_entry) {
        av_log(NULL, AV_LOG_ERROR,"Hit dns cache but connect fail hostname = %s", hostname);
        release_DnsPriEntry(&dns_entry);
        if (ret != AVERROR_EXIT)
            remove_dns_cache_entry(hostname_bak);
    }
    if (ai) {
        freeaddrinfo(ai);
    }
    return ret;
}

static int tcp_accept(URLContext *s, URLContext **c)
{
    TCPContext *sc = s->priv_data;
    TCPContext *cc;
    int ret;
    av_assert0(sc->listen);
    if ((ret = ffurl_alloc(c, s->filename, s->flags, &s->interrupt_callback)) < 0)
        return ret;
    cc = (*c)->priv_data;
    ret = ff_accept(sc->fd, sc->listen_timeout, s);
    if (ret < 0)
        return ret;
    cc->fd = ret;
    return 0;
}

static int tcp_read(URLContext *h, uint8_t *buf, int size)
{
    TCPContext *s = h->priv_data;
    int ret;

    if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
        ret = ff_network_wait_fd_timeout(s->fd, 0, h->rw_timeout, &h->interrupt_callback);
        if (ret)
            return ret;
    }
    ret = recv(s->fd, buf, size, 0);
    if (ret == 0)
        return AVERROR_EOF;
    return ret < 0 ? ff_neterrno() : ret;
}

static int tcp_write(URLContext *h, const uint8_t *buf, int size)
{
    TCPContext *s = h->priv_data;
    int ret;

    if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
        ret = ff_network_wait_fd_timeout(s->fd, 1, h->rw_timeout, &h->interrupt_callback);
        if (ret)
            return ret;
    }
    ret = send(s->fd, buf, size, MSG_NOSIGNAL);
    return ret < 0 ? ff_neterrno() : ret;
}

static int tcp_shutdown(URLContext *h, int flags)
{
    TCPContext *s = h->priv_data;
    int how;

    if (flags & AVIO_FLAG_WRITE && flags & AVIO_FLAG_READ) {
        how = SHUT_RDWR;
    } else if (flags & AVIO_FLAG_WRITE) {
        how = SHUT_WR;
    } else {
        how = SHUT_RD;
    }

    return shutdown(s->fd, how);
}

static int tcp_close(URLContext *h)
{
    TCPContext *s = h->priv_data;
    av_freep(&s->ip_char);
    //remove_IP_cache(s->fd);
    closesocket(s->fd);
    return 0;
}

static int tcp_get_file_handle(URLContext *h)
{
    TCPContext *s = h->priv_data;
    return s->fd;
}

static int tcp_get_window_size(URLContext *h)
{
    TCPContext *s = h->priv_data;
    int avail;
    socklen_t avail_len = sizeof(avail);

#if HAVE_WINSOCK2_H
    /* SO_RCVBUF with winsock only reports the actual TCP window size when
    auto-tuning has been disabled via setting SO_RCVBUF */
    if (s->recv_buffer_size < 0) {
        return AVERROR(ENOSYS);
    }
#endif

    if (getsockopt(s->fd, SOL_SOCKET, SO_RCVBUF, &avail, &avail_len)) {
        return ff_neterrno();
    }
    return avail;
}

/*aml_tcp_protocol*/
const URLProtocol ff_tcp_protocol = {
    .name                = "tcp",
    .url_open            = tcp_open,
    .url_accept          = tcp_accept,
    .url_read            = tcp_read,
    .url_write           = tcp_write,
    .url_close           = tcp_close,
    .url_get_file_handle = tcp_get_file_handle,
    .url_get_short_seek  = tcp_get_window_size,
    .url_shutdown        = tcp_shutdown,
    .priv_data_size      = sizeof(TCPContext),
    .flags               = URL_PROTOCOL_FLAG_NETWORK,
    .priv_data_class     = &tcp_class,
};