/**
 * The MIT License (MIT)
 *
 * Copyright (c) 2013-2020 Winlin
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <srs_service_st.hpp>

#include <co_routine.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netdb.h>
#include <unistd.h>
using namespace std;

#include <srs_core_autofree.hpp>
#include <srs_kernel_error.hpp>
#include <srs_kernel_log.hpp>
#include <srs_service_utility.hpp>
#include <srs_kernel_utility.hpp>

// nginx also set to 512
#define SERVER_LISTEN_BACKLOG 512

#ifdef __linux__
#include <sys/epoll.h>

static int set_fd_nonblock(int fd)
{
    int flags;

    flags = fcntl(fd, F_GETFL, 0); 
    flags |= O_NONBLOCK;
    flags |= O_NDELAY;
    int ret = fcntl(fd, F_SETFL, flags);
    return ret;
}

bool srs_st_epoll_is_supported(void)
{
    struct epoll_event ev;
    
    ev.events = EPOLLIN;
    ev.data.ptr = NULL;
    /* Guaranteed to fail */
    epoll_ctl(-1, EPOLL_CTL_ADD, -1, &ev);
    
    return (errno != ENOSYS);
}
#endif

srs_error_t srs_st_init()
{
    return srs_success;
}

void srs_close_stfd(srs_netfd_t& stfd)
{
    ::close(stfd);
}

srs_error_t srs_fd_closeexec(int fd)
{
    int flags = fcntl(fd, F_GETFD);
    flags |= FD_CLOEXEC;
    if (fcntl(fd, F_SETFD, flags) == -1) {
        return srs_error_new(ERROR_SOCKET_SETCLOSEEXEC, "FD_CLOEXEC fd=%v", fd);
    }

    return srs_success;
}

srs_error_t srs_fd_reuseaddr(int fd)
{
    int v = 1;
    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(int)) == -1) {
        return srs_error_new(ERROR_SOCKET_SETREUSEADDR, "SO_REUSEADDR fd=%v", fd);
    }

	return srs_success;
}

srs_error_t srs_fd_reuseport(int fd)
{
#if defined(SO_REUSEPORT)
    int v = 1;
    if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(int)) == -1) {
        #ifdef SRS_AUTO_CROSSBUILD
            srs_warn("SO_REUSEPORT disabled for crossbuild");
            return srs_success;
        #else
            return srs_error_new(ERROR_SOCKET_SETREUSEADDR, "SO_REUSEPORT fd=%v", fd);
        #endif
    }
#else
    #warning "SO_REUSEPORT is not supported by your OS"
    srs_warn("SO_REUSEPORT is not supported util Linux kernel 3.9");
#endif

	return srs_success;
}

srs_error_t srs_fd_keepalive(int fd)
{
#ifdef SO_KEEPALIVE
    int v = 1;
    if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &v, sizeof(int)) == -1) {
        return srs_error_new(ERROR_SOCKET_SETKEEPALIVE, "SO_KEEPALIVE fd=%d", fd);
    }
#endif

	return srs_success;
}

srs_thread_t srs_thread_self()
{
    return (srs_thread_t)co_self();
}

srs_error_t srs_tcp_connect(string server, int port, srs_utime_t tm, srs_netfd_t* pstfd)
{
    srs_utime_t timeout = SRS_UTIME_NO_TIMEOUT;
    if (tm != SRS_UTIME_NO_TIMEOUT) {
        timeout = tm;
    }

    (void)timeout;

    char sport[8];
    snprintf(sport, sizeof(sport), "%d", port);
    
    addrinfo hints;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    
    addrinfo* r  = NULL;
    SrsAutoFree(addrinfo, r);
    if(getaddrinfo(server.c_str(), sport, (const addrinfo*)&hints, &r)) {
        return srs_error_new(ERROR_SYSTEM_IP_INVALID, "get address info");
    }
    
    int sock = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
    if(sock == -1){
        return srs_error_new(ERROR_SOCKET_CREATE, "create socket");
    }

    *pstfd = sock;
    
    // TODO: timeout
    if (connect(sock, r->ai_addr, r->ai_addrlen) == -1) {
        srs_close_stfd(sock);
        return srs_error_new(ERROR_ST_CONNECT, "connect to %s:%d", server.c_str(), port);
    }
    
    return srs_success;
}

srs_error_t do_srs_tcp_listen(int fd, addrinfo* r, srs_netfd_t* pfd)
{
	srs_error_t err = srs_success;

    // Detect alive for TCP connection.
    // @see https://github.com/ossrs/srs/issues/1044
    if ((err = srs_fd_keepalive(fd)) != srs_success) {
        return srs_error_wrap(err, "set keepalive");
    }

    if ((err = srs_fd_closeexec(fd)) != srs_success) {
        return srs_error_wrap(err, "set closeexec");
    }

    if ((err = srs_fd_reuseaddr(fd)) != srs_success) {
        return srs_error_wrap(err, "set reuseaddr");
    }

    if ((err = srs_fd_reuseport(fd)) != srs_success) {
        return srs_error_wrap(err, "set reuseport");
    }

    if (::bind(fd, r->ai_addr, r->ai_addrlen) == -1) {
        return srs_error_new(ERROR_SOCKET_BIND, "bind");
    }

    if (::listen(fd, SERVER_LISTEN_BACKLOG) == -1) {
        return srs_error_new(ERROR_SOCKET_LISTEN, "listen");
    }

    return err;
}

srs_error_t srs_tcp_listen(std::string ip, int port, srs_netfd_t* pfd)
{
	srs_error_t err = srs_success;

    char sport[8];
    snprintf(sport, sizeof(sport), "%d", port);

    addrinfo hints;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family   = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_flags    = AI_NUMERICHOST;

    addrinfo* r = NULL;
    SrsAutoFree(addrinfo, r);
    if(getaddrinfo(ip.c_str(), sport, (const addrinfo*)&hints, &r)) {
        return srs_error_new(ERROR_SYSTEM_IP_INVALID, "getaddrinfo hints=(%d,%d,%d)",
            hints.ai_family, hints.ai_socktype, hints.ai_flags);
    }

    int fd = 0;
    if ((fd = socket(r->ai_family, r->ai_socktype, r->ai_protocol)) == -1) {
        return srs_error_new(ERROR_SOCKET_CREATE, "socket domain=%d, type=%d, protocol=%d",
            r->ai_family, r->ai_socktype, r->ai_protocol);
    }

    set_fd_nonblock(fd);

    if ((err = do_srs_tcp_listen(fd, r, pfd)) != srs_success) {
        ::close(fd);
        return srs_error_wrap(err, "fd=%d", fd);
    }

    *pfd = fd;

    return err;
}

srs_error_t do_srs_udp_listen(int fd, addrinfo* r, srs_netfd_t* pfd)
{
	srs_error_t err = srs_success;

    if ((err = srs_fd_closeexec(fd)) != srs_success) {
        return srs_error_wrap(err, "set closeexec");
    }

    if ((err = srs_fd_reuseaddr(fd)) != srs_success) {
        return srs_error_wrap(err, "set reuseaddr");
    }

    if ((err = srs_fd_reuseport(fd)) != srs_success) {
        return srs_error_wrap(err, "set reuseport");
    }

    if (bind(fd, r->ai_addr, r->ai_addrlen) == -1) {
        return srs_error_new(ERROR_SOCKET_BIND, "bind");
    }

    return err;
}

srs_error_t srs_udp_listen(std::string ip, int port, srs_netfd_t* pfd)
{
	srs_error_t err = srs_success;

    char sport[8];
    snprintf(sport, sizeof(sport), "%d", port);

    addrinfo hints;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family   = AF_UNSPEC;
    hints.ai_socktype = SOCK_DGRAM;
    hints.ai_flags    = AI_NUMERICHOST;

    addrinfo* r  = NULL;
    SrsAutoFree(addrinfo, r);
    if(getaddrinfo(ip.c_str(), sport, (const addrinfo*)&hints, &r)) {
        return srs_error_new(ERROR_SYSTEM_IP_INVALID, "getaddrinfo hints=(%d,%d,%d)",
            hints.ai_family, hints.ai_socktype, hints.ai_flags);
    }

	int fd = 0;
    if ((fd = socket(r->ai_family, r->ai_socktype, r->ai_protocol)) == -1) {
        return srs_error_new(ERROR_SOCKET_CREATE, "socket domain=%d, type=%d, protocol=%d",
            r->ai_family, r->ai_socktype, r->ai_protocol);
    }

    if ((err = do_srs_udp_listen(fd, r, pfd)) != srs_success) {
        ::close(fd);
        return srs_error_wrap(err, "fd=%d", fd);
    }

    return err;
}

srs_cond_t srs_cond_new()
{
    return (srs_cond_t)co_cond_alloc();
}

int srs_cond_destroy(srs_cond_t cond)
{
    return co_cond_free((stCoCond_t*)cond);
}

int srs_cond_wait(srs_cond_t cond)
{
    return co_cond_timedwait((stCoCond_t*)cond, -1);
}

int srs_cond_timedwait(srs_cond_t cond, srs_utime_t timeout)
{
    return co_cond_timedwait((stCoCond_t*)cond, timeout);
}

int srs_cond_signal(srs_cond_t cond)
{
    return co_cond_signal((stCoCond_t*)cond);
}

srs_mutex_t srs_mutex_new()
{
    return NULL;
}

int srs_mutex_destroy(srs_mutex_t mutex)
{
    return 0;
}

int srs_mutex_lock(srs_mutex_t mutex)
{
    return 0;
}

int srs_mutex_unlock(srs_mutex_t mutex)
{
    return 0;
}

int srs_netfd_fileno(srs_netfd_t stfd)
{
    return stfd;
}

int srs_usleep(srs_utime_t usecs)
{
    // XXX: libco has no API like co_sleep, use co_cond_timedwait instead
    stCoCond_t* cond = co_cond_alloc();
    co_cond_timedwait(cond, usecs/1000.0);

    return 0;
}

srs_netfd_t srs_netfd_open_socket(int osfd)
{
    set_fd_nonblock(osfd);
    return osfd;
}

srs_netfd_t srs_netfd_open(int osfd)
{
    set_fd_nonblock(osfd);
    return osfd;
}

int srs_recvfrom(srs_netfd_t stfd, void *buf, int len, struct sockaddr *from, int *fromlen, srs_utime_t timeout)
{
    // TODO: timeout
    return recvfrom(stfd, buf, len, 0, from, (socklen_t*)fromlen);
}

srs_netfd_t srs_accept(srs_netfd_t stfd, struct sockaddr *addr, int *addrlen, srs_utime_t timeout)
{
	struct pollfd pf = { 0 };
    pf.fd = stfd;
    pf.events = (POLLIN | POLLERR | POLLHUP);

    srs_utime_t atm = timeout;
    if (atm != SRS_UTIME_NO_TIMEOUT)
        atm /= 1000;

    int client_fd;
    while ((client_fd = accept(stfd, addr, (socklen_t*)addrlen)) < 0) {
        if (errno != EINTR && errno != EAGAIN && errno != EWOULDBLOCK) {
            return -1;
        } 
        
        co_poll(co_get_epoll_ct(), &pf, 1, atm);
    }

    set_fd_nonblock(client_fd);

    return client_fd;
}

ssize_t srs_read(srs_netfd_t stfd, void *buf, size_t nbyte, srs_utime_t timeout)
{
	struct pollfd pf = { 0 };
    pf.fd = stfd;
    pf.events = (POLLIN | POLLERR | POLLHUP);

    int n;
    while ((n = ::read(stfd, buf, nbyte)) < 0) {
        if (errno != EINTR && errno != EAGAIN && errno != EWOULDBLOCK) {
            return -1;
        } 

        co_poll(co_get_epoll_ct(), &pf, 1, timeout);
    }

    return n;
}

bool srs_is_never_timeout(srs_utime_t tm)
{
    return tm == SRS_UTIME_NO_TIMEOUT;
}

SrsStSocket::SrsStSocket()
{
    stm = rtm = SRS_UTIME_NO_TIMEOUT;
    rbytes = sbytes = 0;
}

SrsStSocket::~SrsStSocket()
{
}

srs_error_t SrsStSocket::initialize(srs_netfd_t fd)
{
    stfd = fd;
    return srs_success;
}

void SrsStSocket::set_recv_timeout(srs_utime_t tm)
{
    rtm = tm;
}

srs_utime_t SrsStSocket::get_recv_timeout()
{
    return rtm;
}

void SrsStSocket::set_send_timeout(srs_utime_t tm)
{
    stm = tm;
}

srs_utime_t SrsStSocket::get_send_timeout()
{
    return stm;
}

int64_t SrsStSocket::get_recv_bytes()
{
    return rbytes;
}

int64_t SrsStSocket::get_send_bytes()
{
    return sbytes;
}

srs_error_t SrsStSocket::read(void* buf, size_t size, ssize_t* nread)
{
    srs_error_t err = srs_success;
    
    ssize_t nb_read;
    if (rtm == SRS_UTIME_NO_TIMEOUT) {
        nb_read = srs_read(stfd, buf, size, -1);
    } else {
        nb_read = srs_read(stfd, buf, size, rtm / 1000);
    }
    
    if (nread) {
        *nread = nb_read;
    }

    // On success a non-negative integer indicating the number of bytes actually read is returned
    // (a value of 0 means the network connection is closed or end of file is reached).
    // Otherwise, a value of -1 is returned and errno is set to indicate the error.
    if (nb_read <= 0) {
        // @see https://github.com/ossrs/srs/issues/200
        if (nb_read < 0 && errno == ETIME) {
            return srs_error_new(ERROR_SOCKET_TIMEOUT, "timeout %d ms", srsu2msi(rtm));
        }
        
        if (nb_read == 0) {
            errno = ECONNRESET;
        }
        
        return srs_error_new(ERROR_SOCKET_READ, "read");
    }
    
    rbytes += nb_read;
    
    return err;
}

srs_error_t SrsStSocket::read_fully(void* buf, size_t size, ssize_t* nread)
{
    srs_error_t err = srs_success;
    
    ssize_t nb_read = 0;

    int wait_read_bytes = size;
    while (wait_read_bytes > 0) {
        int bytes = ::read(stfd, buf, wait_read_bytes);
        if (bytes > 0) {
            nb_read += bytes;
            wait_read_bytes -= bytes;
            if (nb_read == (ssize_t)size) {
                break;
            }
        } else if (bytes == 0) {
            break;
        } else {
            if (errno != EWOULDBLOCK && errno != EAGAIN && errno != EINTR)
                break;
        }
    }
 
    if (nread) {
        *nread = nb_read;
    }
    
    // On success a non-negative integer indicating the number of bytes actually read is returned
    // (a value less than nbyte means the network connection is closed or end of file is reached)
    // Otherwise, a value of -1 is returned and errno is set to indicate the error.
    if (nb_read != (ssize_t)size) {
        // @see https://github.com/ossrs/srs/issues/200
        if (nb_read < 0 && errno == ETIME) {
            return srs_error_new(ERROR_SOCKET_TIMEOUT, "timeout %d ms", srsu2msi(rtm));
        }
        
        if (nb_read >= 0) {
            errno = ECONNRESET;
        }
        
        return srs_error_new(ERROR_SOCKET_READ_FULLY, "read fully");
    }
    
    rbytes += nb_read;
    
    return err;
}

srs_error_t SrsStSocket::write(void* buf, size_t size, ssize_t* nwrite)
{
    srs_error_t err = srs_success;
    
    ssize_t nb_write = 0;

	struct pollfd pf = { 0 };
    pf.fd = stfd;
    pf.events = (POLLOUT | POLLERR | POLLHUP);

    srs_utime_t wtm = stm;
    if (wtm != SRS_UTIME_NO_TIMEOUT)
        wtm = stm / 1000;

    int wait_write_bytes = size;
    while (wait_write_bytes > 0) {
        int n = 0;
        if ((n = ::write(stfd, buf, size)) < 0) {
            if (errno != EINTR && errno != EAGAIN && errno != EWOULDBLOCK) {
                break;
            }

            co_poll(co_get_epoll_ct(), &pf, 1, wtm);
            continue;
        } 

        wait_write_bytes -= n;
        nb_write += n;
    }
    
    if (nwrite) {
        *nwrite = nb_write;
    }
    
    // On success a non-negative integer equal to nbyte is returned.
    // Otherwise, a value of -1 is returned and errno is set to indicate the error.
    if (nb_write <= 0) {
        // @see https://github.com/ossrs/srs/issues/200
        if (nb_write < 0 && errno == ETIME) {
            return srs_error_new(ERROR_SOCKET_TIMEOUT, "write timeout %d ms", srsu2msi(stm));
        }
        
        return srs_error_new(ERROR_SOCKET_WRITE, "write");
    }
    
    sbytes += nb_write;
    
    return err;
}

srs_error_t SrsStSocket::writev(const iovec *iov, int iov_size, ssize_t* nwrite)
{
    srs_error_t err = srs_success;
    
    srs_utime_t tm = stm;
    if (tm != SRS_UTIME_NO_TIMEOUT)
        tm = stm / 1000;

    int wait_write_bytes = 0;
    for (int i = 0; i < iov_size; ++i)
        wait_write_bytes += iov[i].iov_len;

    ssize_t nb_write = 0;
    iovec* cur_iov = (iovec*)iov;
    int cur_iov_size = iov_size;

    while (wait_write_bytes > 0) {
        int n = 0;
        if ((n = ::writev(stfd, cur_iov, cur_iov_size)) < 0) {
            if (errno != EINTR && errno != EAGAIN && errno != EWOULDBLOCK) {
                break;
            }

	        struct pollfd pf = {0};
            pf.fd = stfd;
            pf.events = (POLLOUT | POLLERR | POLLHUP);

            co_poll(co_get_epoll_ct(), &pf, 1, tm);
            continue;
        } 

        wait_write_bytes -= n;
        nb_write += n;

        while (n >= (int)cur_iov->iov_len) {
            n -= cur_iov->iov_len;
            --cur_iov_size;
            ++cur_iov;
        }
        // FIXME: no modify iov
        (*cur_iov).iov_base = (void*)((char*)(*cur_iov).iov_base + n);
        (*cur_iov).iov_len -= n;
    }
    
    if (nwrite) {
        *nwrite = nb_write;
    }
    
    // On success a non-negative integer equal to nbyte is returned.
    // Otherwise, a value of -1 is returned and errno is set to indicate the error.
    if (nb_write <= 0) {
        // @see https://github.com/ossrs/srs/issues/200
        if (nb_write < 0 && errno == ETIME) {
            return srs_error_new(ERROR_SOCKET_TIMEOUT, "writev timeout %d ms", srsu2msi(stm));
        }
        
        return srs_error_new(ERROR_SOCKET_WRITE, "writev");
    }
    
    sbytes += nb_write;
    
    return err;
}

SrsTcpClient::SrsTcpClient(string h, int p, srs_utime_t tm)
{
    stfd = -1;
    io = new SrsStSocket();
    
    host = h;
    port = p;
    timeout = tm;
}

SrsTcpClient::~SrsTcpClient()
{
    close();
    
    srs_freep(io);
}

srs_error_t SrsTcpClient::connect()
{
    srs_error_t err = srs_success;
    
    close();
    
    srs_assert(stfd == -1);
    if ((err = srs_tcp_connect(host, port, timeout, &stfd)) != srs_success) {
        return srs_error_wrap(err, "tcp: connect %s:%d to=%dms", host.c_str(), port, srsu2msi(timeout));
    }
    
    if ((err = io->initialize(stfd)) != srs_success) {
        return srs_error_wrap(err, "tcp: init socket object");
    }
    
    return err;
}

void SrsTcpClient::close()
{
    // Ignore when already closed.
    if (!io) {
        return;
    }
    
    srs_close_stfd(stfd);
}

void SrsTcpClient::set_recv_timeout(srs_utime_t tm)
{
    io->set_recv_timeout(tm);
}

srs_utime_t SrsTcpClient::get_recv_timeout()
{
    return io->get_recv_timeout();
}

void SrsTcpClient::set_send_timeout(srs_utime_t tm)
{
    io->set_send_timeout(tm);
}

srs_utime_t SrsTcpClient::get_send_timeout()
{
    return io->get_send_timeout();
}

int64_t SrsTcpClient::get_recv_bytes()
{
    return io->get_recv_bytes();
}

int64_t SrsTcpClient::get_send_bytes()
{
    return io->get_send_bytes();
}

srs_error_t SrsTcpClient::read(void* buf, size_t size, ssize_t* nread)
{
    return io->read(buf, size, nread);
}

srs_error_t SrsTcpClient::read_fully(void* buf, size_t size, ssize_t* nread)
{
    return io->read_fully(buf, size, nread);
}

srs_error_t SrsTcpClient::write(void* buf, size_t size, ssize_t* nwrite)
{
    return io->write(buf, size, nwrite);
}

srs_error_t SrsTcpClient::writev(const iovec *iov, int iov_size, ssize_t* nwrite)
{
    return io->writev(iov, iov_size, nwrite);
}