/*
   Receive ODR-DabMux ZMQ ETI output and write to a file.

   The MIT License (MIT)

   Copyright (c) 2018 Matthias P. Braendli

   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 <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <zmq.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <time.h>


#define NUM_FRAMES_PER_ZMQ_MESSAGE 4

struct zmq_dab_message_t
{
    uint32_t version;
    int16_t  buflen[NUM_FRAMES_PER_ZMQ_MESSAGE];
    uint8_t  buf[NUM_FRAMES_PER_ZMQ_MESSAGE*6144];
};

long timespecdiff_ms(struct timespec time, struct timespec oldTime)
{
    long tv_sec;
    long tv_nsec;
    if (time.tv_nsec < oldTime.tv_nsec) {
        tv_sec = time.tv_sec - 1 - oldTime.tv_sec;
        tv_nsec = 1000000000L + time.tv_nsec - oldTime.tv_nsec;
    }
    else {
        tv_sec = time.tv_sec - oldTime.tv_sec;
        tv_nsec = time.tv_nsec - oldTime.tv_nsec;
    }

    return tv_sec * 1000 + tv_nsec / 1000000;
}


void barf()
{
    fprintf(stderr, "Error: %s\n", zmq_strerror(errno));
    exit(1);
}


void do_subscriber(const char* host, int port)
{
    int rc;

    void* ctx  = zmq_ctx_new();
    void* sock = zmq_socket(ctx, ZMQ_SUB);

    char endpoint[256];
    snprintf(endpoint, 256, "tcp://%s:%d", host, port);

    rc = zmq_connect(sock, endpoint);
    fprintf(stderr, "connect %d\n", rc);
    if (rc) barf();

    rc = zmq_setsockopt(sock, ZMQ_SUBSCRIBE, NULL, 0);
    fprintf(stderr, "subscribe %d\n", rc);
    if (rc) barf();


    const int framelen = NUM_FRAMES_PER_ZMQ_MESSAGE * 6144;
    uint8_t eti[framelen];

    struct zmq_dab_message_t message;

    struct timespec time_start;
    size_t total_size = 0;
    size_t num_frames = 0;
    long last_sec = 0;

    while (1) {
        uint8_t* eti_p = eti;

        memset(eti, 0x55, framelen);
        rc = zmq_recv(sock, &message, framelen, 0);

        if (rc > 0 && message.version == 1) {
            uint8_t* buf = message.buf;

            struct timespec time_now;
            clock_gettime(CLOCK_MONOTONIC, &time_now);

            if (num_frames == 0) {
                time_start.tv_nsec = time_now.tv_nsec;
                time_start.tv_sec  = time_now.tv_sec;
                last_sec = time_now.tv_sec;
            }

            if (time_now.tv_sec > last_sec) {
                last_sec = time_now.tv_sec;

                // calculate time_now - time_start in us
                long diff_ms = timespecdiff_ms(time_now, time_start);

                fprintf(stderr, "Received %zu bytes, %zu ETI frames in %ld milliseconds : %f bytes/second; %f ms/frame\n",
                        total_size, num_frames, diff_ms, 1e3 * total_size/diff_ms,
                        (double)diff_ms/num_frames);
            }

            for (int i = 0; i < NUM_FRAMES_PER_ZMQ_MESSAGE; i++) {
                memcpy(eti_p, buf, message.buflen[i]);
                eti_p += 6144;
                buf   += message.buflen[i];

                total_size += message.buflen[i];
                num_frames++;
            }

            write(STDOUT_FILENO, eti, framelen);
        }
        else if (rc < 0) {
            fprintf(stderr, "rc=%d \n", rc);

            barf();
        }
    }

    zmq_close(sock);

    zmq_ctx_destroy(ctx);
}

void usage(char** argv)
{
    fprintf(stderr, "usage: %s host port\n", argv[0]);
    fprintf(stderr, "connects to odr-dabmux' ETI output at tcp://host:port using a ZeroMQ sub socket\n");
    fprintf(stderr, "and outputs raw ETI on stdout\n");
    exit(1);
}

int main(int argc, char** argv)
{
#ifdef GIT_VERSION
    fprintf(stderr, "zmq-sub ETI reader version %s\n", GIT_VERSION);
#else
    fprintf(stderr, "zmq-sub ETI reader version ?\n");
#endif

    if (argc < 3) {
        usage(argv);
    }

    char* host = argv[1];
    int port = atoi(argv[2]);

    fprintf(stderr, "connecting to tcp://%s:%d\n", host, port);

    do_subscriber(host, port);

    return 0;
}