/*
    Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file

    This file is part of 0MQ.

    0MQ 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 3 of the License, or
    (at your option) any later version.

    0MQ 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 this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "testutil.hpp"
#if defined (ZMQ_HAVE_WINDOWS)
#   include <winsock2.h>
#   include <ws2tcpip.h>
#   include <stdexcept>
#   define close closesocket
typedef SOCKET raw_socket;
#else
#   include <arpa/inet.h>
typedef int raw_socket;
#endif

//  Read one event off the monitor socket; return value and address
//  by reference, if not null, and event number by value. Returns -1
//  in case of error.

static int
get_monitor_event (void *monitor)
{
    for (int i = 0; i < 2; i++) {
        //  First frame in message contains event number and value
        zmq_msg_t msg;
        int rc = zmq_msg_init (&msg);
        assert (rc == 0);
        if (zmq_msg_recv (&msg, monitor, ZMQ_DONTWAIT) == -1) {
            msleep (SETTLE_TIME);
            continue;           //  Interruped, presumably
        }
        assert (zmq_msg_more (&msg));

        uint8_t *data = (uint8_t *) zmq_msg_data (&msg);
        uint16_t event = *(uint16_t *) (data);

        //  Second frame in message contains event address
        rc = zmq_msg_init (&msg);
        assert (rc == 0);
        if (zmq_msg_recv (&msg, monitor, 0) == -1) {
            return -1;              //  Interruped, presumably
        }
        assert (!zmq_msg_more (&msg));

        return event;
    }
    return -1;
}

static void
recv_with_retry (raw_socket fd, char *buffer, int bytes) {
  int received = 0;
    while (true) {
      int rc = recv(fd, buffer + received, bytes - received, 0);
      assert(rc > 0);
      received += rc;
      assert(received <= bytes);
      if (received == bytes) break;
    }
}

static void
mock_handshake (raw_socket fd) {
    const uint8_t zmtp_greeting[33] = { 0xff, 0, 0, 0, 0, 0, 0, 0, 0, 0x7f, 3, 0, 'N', 'U', 'L', 'L', 0 };
    char buffer [128];
    memset (buffer, 0, sizeof(buffer));
    memcpy (buffer, zmtp_greeting, sizeof(zmtp_greeting));

    int rc = send (fd, buffer, 64, 0);
    assert (rc == 64);

    recv_with_retry (fd, buffer, 64);

    const uint8_t zmtp_ready [43] = {
        4, 41, 5, 'R', 'E', 'A', 'D', 'Y', 11, 'S', 'o', 'c', 'k', 'e', 't', '-', 'T', 'y', 'p', 'e',
        0, 0, 0, 6, 'D', 'E', 'A', 'L', 'E', 'R', 8, 'I', 'd', 'e', 'n', 't', 'i', 't', 'y',
        0, 0, 0, 0
    };

    memset(buffer, 0, sizeof(buffer));
    memcpy(buffer, zmtp_ready, 43);
    rc = send(fd, buffer, 43, 0);
    assert (rc == 43);

    recv_with_retry(fd, buffer, 43);
}

static void
prep_server_socket(void * ctx, int set_heartbeats, void ** server_out, void ** mon_out)
{
    int rc;
    //  We'll be using this socket in raw mode
    void *server = zmq_socket (ctx, ZMQ_ROUTER);
    assert (server);

    int value = 0;
    rc = zmq_setsockopt (server, ZMQ_LINGER, &value, sizeof (value));
    assert (rc == 0);

    if (set_heartbeats) {
        value = 50;
        rc = zmq_setsockopt (server, ZMQ_HEARTBEAT_IVL, &value, sizeof(value));
        assert (rc == 0);
    }

    rc = zmq_bind (server, "tcp://127.0.0.1:5556");
    assert (rc == 0);

    //  Create and connect a socket for collecting monitor events on dealer
    void *server_mon = zmq_socket (ctx, ZMQ_PAIR);
    assert (server_mon);

    rc = zmq_socket_monitor (server, "inproc://monitor-dealer",
          ZMQ_EVENT_CONNECTED | ZMQ_EVENT_DISCONNECTED | ZMQ_EVENT_ACCEPTED);
    assert (rc == 0);

    //  Connect to the inproc endpoint so we'll get events
    rc = zmq_connect (server_mon, "inproc://monitor-dealer");
    assert (rc == 0);

    *server_out = server;
    *mon_out = server_mon;
}

// This checks for a broken TCP connection (or, in this case a stuck one
// where the peer never responds to PINGS). There should be an accepted event
// then a disconnect event.
static void
test_heartbeat_timeout (void)
{
    int rc;

    //  Set up our context and sockets
    void *ctx = zmq_ctx_new ();
    assert (ctx);

    void * server, * server_mon;
    prep_server_socket (ctx, 1, &server, &server_mon);

    struct sockaddr_in ip4addr;
    raw_socket s;

    ip4addr.sin_family = AF_INET;
    ip4addr.sin_port = htons (5556);
#if defined (ZMQ_HAVE_WINDOWS) && (_WIN32_WINNT < 0x0600)
    ip4addr.sin_addr.s_addr = inet_addr ("127.0.0.1");
#else
    inet_pton(AF_INET, "127.0.0.1", &ip4addr.sin_addr);
#endif

    s = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
    rc = connect (s, (struct sockaddr*) &ip4addr, sizeof ip4addr);
    assert (rc > -1);

    // Mock a ZMTP 3 client so we can forcibly time out a connection
    mock_handshake (s);

    // By now everything should report as connected
    rc = get_monitor_event(server_mon);
    assert (rc == ZMQ_EVENT_ACCEPTED);

    // We should have been disconnected
    rc = get_monitor_event(server_mon);
    assert (rc == ZMQ_EVENT_DISCONNECTED);

    close(s);

    rc = zmq_close (server);
    assert (rc == 0);

    rc = zmq_close (server_mon);
    assert (rc == 0);

    rc = zmq_ctx_term (ctx);
    assert (rc == 0);
}

// This checks that peers respect the TTL value in ping messages
// We set up a mock ZMTP 3 client and send a ping message with a TLL
// to a server that is not doing any heartbeating. Then we sleep,
// if the server disconnects the client, then we know the TTL did
// its thing correctly.
static void
test_heartbeat_ttl (void)
{
    int rc, value;

    //  Set up our context and sockets
    void *ctx = zmq_ctx_new ();
    assert (ctx);

    void * server, * server_mon, *client;
    prep_server_socket (ctx, 0, &server, &server_mon);

    client = zmq_socket (ctx, ZMQ_DEALER);
    assert (client != NULL);

    // Set the heartbeat TTL to 0.1 seconds
    value = 100;
    rc = zmq_setsockopt (client, ZMQ_HEARTBEAT_TTL, &value, sizeof (value));
    assert (rc == 0);

    // Set the heartbeat interval to much longer than the TTL so that
    // the socket times out oon the remote side.
    value = 250;
    rc = zmq_setsockopt (client, ZMQ_HEARTBEAT_IVL, &value, sizeof (value));
    assert (rc == 0);

    rc = zmq_connect (client, "tcp://localhost:5556");
    assert (rc == 0);

    // By now everything should report as connected
    rc = get_monitor_event (server_mon);
    assert (rc == ZMQ_EVENT_ACCEPTED);

    msleep (SETTLE_TIME);

    // We should have been disconnected
    rc = get_monitor_event (server_mon);
    assert (rc == ZMQ_EVENT_DISCONNECTED);

    rc = zmq_close (server);
    assert (rc == 0);

    rc = zmq_close (server_mon);
    assert (rc == 0);

    rc = zmq_close (client);
    assert (rc == 0);

    rc = zmq_ctx_term (ctx);
    assert (rc == 0);
}

// This checks for normal operation - that is pings and pongs being
// exchanged normally. There should be an accepted event on the server,
// and then no event afterwards.
static void
test_heartbeat_notimeout (void)
{
    int rc;

    //  Set up our context and sockets
    void *ctx = zmq_ctx_new ();
    assert (ctx);

    void * server, * server_mon;
    prep_server_socket(ctx, 1, &server, &server_mon);

    void * client = zmq_socket (ctx, ZMQ_DEALER);
    rc = zmq_connect (client, "tcp://127.0.0.1:5556");

    // Give it a sec to connect and handshake
    msleep (SETTLE_TIME);

    // By now everything should report as connected
    rc = get_monitor_event(server_mon);
    assert (rc == ZMQ_EVENT_ACCEPTED);

    // We should still be connected because pings and pongs are happenin'
    rc = get_monitor_event (server_mon);
    assert (rc == -1);

    rc = zmq_close (client);
    assert (rc == 0);

    rc = zmq_close (server);
    assert (rc == 0);

    rc = zmq_close (server_mon);
    assert (rc == 0);

    rc = zmq_ctx_term (ctx);
    assert (rc == 0);
}

int main (void)
{
    setup_test_environment ();
    test_heartbeat_timeout ();
    test_heartbeat_ttl ();
    test_heartbeat_notimeout ();
}