#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef WIN32
#include <winsock2.h>
#else
#include <sys/select.h>
#endif

#include <fcntl.h>
#include <glib.h>
#include <lcm/lcm.h>

static int64_t timestamp_seconds(int64_t v)
{
    return v / 1000000;
}

static int64_t timestamp_useconds(int64_t v)
{
    return v % 1000000;
}

static void timestamp_to_timeval(int64_t v, struct timeval *tv)
{
    tv->tv_sec = (long) timestamp_seconds(v);
    tv->tv_usec = (long) timestamp_useconds(v);
}

int test_count = 0;
int test_count2 = 0;
int default_count = 0;
int catchall_count = 0;

static void test_handler(const lcm_recv_buf_t *rbuf, const char *channel, void *u)
{
    test_count++;
}

static void test_handler2(const lcm_recv_buf_t *rbuf, const char *channel, void *u)
{
    test_count2++;
}

static void catchall_handler(const lcm_recv_buf_t *rbuf, const char *channel, void *u)
{
    catchall_count++;
}

static void regex_handler(const lcm_recv_buf_t *rbuf, const char *channel, void *u)
{
    printf("regex handler\n");
}

int main(int argc, char **argv)
{
    int status;

    char *data = "payload";
    int datalen = (int) strlen(data) + 1;

    // lcm_params_t lcm_args;
    // lcm_args.local_iface = INADDR_ANY;
    // lcm_args.mc_addr = inet_addr ("225.0.0.3");
    // lcm_args.mc_port = htons (2006);

    lcm_t *lcm = lcm_create(NULL);
    if (!lcm) {
        fprintf(stderr, "couldn't allocate lcm_t\n");
        return 1;
    }

    printf("LCM: testing handler registration and unregistration... \n");
#define FAIL_IFSNE(expected)                                                        \
    if (status != expected) {                                                       \
        printf("LCM: ERROR in handler registration!  %s:%d\n", __FILE__, __LINE__); \
        return 1;                                                                   \
    }
#define FAIL_IF_BAD_HID(hid)                                                        \
    if (hid == NULL) {                                                              \
        printf("LCM: ERROR in handler registration!  %s:%d\n", __FILE__, __LINE__); \
        return 1;                                                                   \
    }
#define FAIL_IF_GOOD_HID(hid)                                                       \
    if (hid != NULL) {                                                              \
        printf("LCM: ERROR in handler registration!  %s:%d\n", __FILE__, __LINE__); \
        return 1;                                                                   \
    }

    // register a couple handlers
    lcm_subscription_t *h = NULL;
    h = lcm_subscribe(lcm, "TEST", test_handler, 0);
    FAIL_IF_BAD_HID(h);
    lcm_subscription_t *h2 = lcm_subscribe(lcm, "TEST", test_handler2, 0);
    FAIL_IF_BAD_HID(h2);

    // unregister and re-register the first handler
    status = lcm_unsubscribe(lcm, h);
    FAIL_IFSNE(0);
    h = lcm_subscribe(lcm, "TEST", test_handler, 0);
    FAIL_IF_BAD_HID(h);

    // unregister the same handler twice, expect failure the second time
    status = lcm_unsubscribe(lcm, h);
    FAIL_IFSNE(0);
    status = lcm_unsubscribe(lcm, h);
    FAIL_IFSNE(-1);

    // register default and catchall handlers
    h = lcm_subscribe(lcm, ".*", catchall_handler, 0);
    FAIL_IF_BAD_HID(h);

    // register a regex handler
    h = lcm_subscribe(lcm, "TE.*", regex_handler, 0);
    FAIL_IF_BAD_HID(h);

    // transmit a bunch of messages to self-receive
    int fd = lcm_get_fileno(lcm);
    int ntransmitted = 0;
    int ntotransmit = 15;

    printf("LCM: transmitting %d messages to self-receive...\n", ntotransmit * 2);

    int64_t send_interval = 100000;
    int64_t time_to_send = g_get_real_time() + send_interval;
    struct timeval timeout;
    fd_set readfds;

    while (ntransmitted < ntotransmit) {
        int64_t now = g_get_real_time();
        if (time_to_send < now) {
            time_to_send = now;
        }
        timestamp_to_timeval(time_to_send - now, &timeout);
        FD_ZERO(&readfds);
        FD_SET(fd, &readfds);

        status = select(fd + 1, &readfds, 0, 0, &timeout);

        if (status < 0) {
            fprintf(stderr, "ERROR! LCM select failed\n");
            perror("select");
            return 1;
        }

        if (FD_ISSET(fd, &readfds)) {
            lcm_handle(lcm);
        }

        if (g_get_real_time() >= time_to_send) {
            lcm_publish(lcm, "TEST", data, datalen);
            lcm_publish(lcm, "12345", data, datalen);
            ntransmitted++;

            time_to_send = g_get_real_time() + send_interval;
        }
    }

    // should get two more messages..
    FD_ZERO(&readfds);
    FD_SET(fd, &readfds);
    timeout.tv_sec = 0;
    timeout.tv_usec = 100000;
    select(fd + 1, &readfds, 0, 0, &timeout);
    if (FD_ISSET(fd, &readfds)) {
        lcm_handle(lcm);
    }
    FD_ZERO(&readfds);
    FD_SET(fd, &readfds);
    timeout.tv_sec = 0;
    timeout.tv_usec = 100000;
    select(fd + 1, &readfds, 0, 0, &timeout);
    if (FD_ISSET(fd, &readfds)) {
        lcm_handle(lcm);
    }

#undef FAIL_IFSNE

    lcm_destroy(lcm);

    // I was told there was a bug here - removing the +1 from the counts
    int matched = (0 == test_count && ntotransmit == test_count2 &&
                   // ntotransmit == default_count &&
                   ntotransmit * 2 == catchall_count);

    if (!matched) {
        printf(
            "LCM: receive count - "
            "test: %d test2: %d default: %d catchall: %d\n",
            test_count, test_count2, default_count, catchall_count);
        printf("ERROR:  message receive count does not match expected!!\n");
        return 1;
    }
    printf("LCM: OK!\n");
    return 0;
}
