#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <ortp/ortp.h>
#include <ucore/iomux.h>
#include <ucore/utils.h>
#include <ucore/string.h>


struct IOMux *mux;

#define errx(x, ...) do { fprintf(stderr, x, __VA_ARGS__); exit(1); } while(0)

struct RTPSender {
    FILE *file;
    char remote_ip[48];
    uint16_t remote_port;
    struct UCTimer timer;
    uint32_t ts;
    struct timespec last_ts;
    RtpSession *rtp_sess;
    RtpProfile *rtp_profile;
    int accum_diff;
    uint8_t frame[160];
};


//returns microsec
int diffts(const struct timespec *a, struct timespec *b)
{
    struct timespec diff;
    diff.tv_sec = b->tv_sec - a->tv_sec;
    diff.tv_nsec = b->tv_nsec - a->tv_nsec;
    if (diff.tv_nsec < 0) {
        diff.tv_sec--;
        diff.tv_nsec += 1000000000;
    }


    return (int) (diff.tv_sec * 1000 + (diff.tv_nsec + 500)/1000);
}

void timer_cb(struct UCTimers *timers, struct UCTimer *timer)
{
    struct RTPSender *s = CONTAINER_OF(timer, struct RTPSender, timer);   
    int rc;
    ssize_t r;
    struct timespec ts;
    int diff;
    int adjust;

    clock_gettime(CLOCK_MONOTONIC, &ts);
    rc = rtp_session_send_with_ts(s->rtp_sess,s->frame, sizeof s->frame, s->ts);
    if(rc < sizeof s->frame) {
        printf("Error, short send of %d bytes\n", rc);
    }
    s->ts += 160;

    r = fread(s->frame,1, sizeof s->frame, s->file);
    if (r <= 0) {
        rtp_session_bye(s->rtp_sess, "Finished");
        return;
    }

    diff = diffts(&s->last_ts, &ts);
    diff -= 20000;

    s->accum_diff += diff;

    if (s->accum_diff > 500) 
        adjust = -1000;
    else if (s->accum_diff < -500)
        adjust = 1000;
    else 
        adjust = s->accum_diff;

    if (s->accum_diff >= 20000 || s->accum_diff <= -20000) {
        s->ts += 160;
        printf("Skew ! accum_diff %d\n", s->accum_diff);
        s->accum_diff -= 20000;
    }


    uc_timers_add(iomux_get_timers(mux), &s->timer, 0, 20 * 1000 + adjust);

    s->last_ts = ts;
}

void init_sender(FILE* file, const char *remote_ip, uint16_t remote_port)
{
    struct RTPSender *s = calloc(1, sizeof *s);

    RtpSession *rtp_sess = rtp_session_new(RTP_SESSION_SENDONLY);
    RtpProfile *rtp_prof = rtp_profile_new("pcmu8000");
    rtp_profile_set_payload(rtp_prof, 0, &payload_type_pcmu8000);
    rtp_session_set_profile(rtp_sess,  rtp_prof);
    //rtp_session_set_local_addr("192.168.1.55", 0);
    rtp_session_set_remote_addr(rtp_sess, remote_ip, remote_port);
    rtp_session_set_blocking_mode(rtp_sess, FALSE);

    s->file = file;
    strcpy(s->remote_ip, remote_ip);
    s->remote_port = remote_port;
    s->rtp_sess = rtp_sess;
    s->rtp_profile = rtp_prof;
    s->timer.callback = timer_cb;
    clock_gettime(CLOCK_MONOTONIC, &s->last_ts);
    uc_timers_add(iomux_get_timers(mux), &s->timer, 0, 20000);
}

int main(int argc, char *argv[])
{
    mux = iomux_create(IOMUX_TYPE_DEFAULT);
    
    FILE *file;
    if(argc != 4) {
        puts("Specify a file name, remote IP and remote port");
        return 1;
    }

    if(strcmp(argv[1], "-") == 0) {
        file = stdin;
    } else {
        file = fopen(argv[1], "rb");
        if(file == NULL) {
            perror("Cannot open file");
            return 1;
        }
    }

    ortp_init();
    ortp_set_log_level_mask(ORTP_DEBUG| ORTP_MESSAGE| ORTP_WARNING| ORTP_ERROR|ORTP_FATAL);
    init_sender(file ,argv[2], atoi(argv[3]));

    iomux_run(mux);


    fclose(file);
    ortp_exit();

    return 0;
}

//compile:
// gcc -Wall -g -O `pkg-config --cflags --libs ortp` ortp-send-simple.c