#include "measure.h"

void measure_parse(int size, struct measure_conf* mc) {
  struct timespec curr;
  uint64_t micro_sec;
  if (size != mc->payload_size) {
    perror("read error, payload has wrong size");
    exit(EXIT_FAILURE);
  }
  struct measure_packet* head = (struct measure_packet*) mc->payload;
  if (clock_gettime(CLOCK_MONOTONIC, &curr) == -1){
    perror("clock_gettime error");
    exit(EXIT_FAILURE);
  }

  micro_sec = elapsed_micros (&head->emit_time, &curr);
  uint8_t is_slow = head->flag >> 7;
  uint8_t is_vanilla = (head->flag & 0x40) >> 6;
  uint8_t link_id = head->flag & 0x3f;
  printf(
    "[%s] Packet %llu latency %luµs with flag %d sent on link %d with vanilla %d\n",
    current_human_datetime(),
    (unsigned long long)head->counter,
    micro_sec,
    is_slow,
    link_id,
    is_vanilla);

  if (!mc->is_server && head->counter >= mc->max_measure) {
    printf("Measurement done\n");
    exit(EXIT_SUCCESS);
  }
}

void measure_prepare(struct measure_conf* mc) {
  if (mc->interval <= 0) mc->interval = 1000;
  if (mc->max_measure <= 0) mc->max_measure = 1;
  if (mc->payload_size < sizeof(struct measure_packet)) mc->payload_size = sizeof(struct measure_packet);

  if ((mc->payload = malloc(sizeof(char) * mc->payload_size)) == NULL) {
    perror("payload malloc failed");
    exit(EXIT_FAILURE);
  }
  memset(mc->payload, 0, mc->payload_size);

  char *my_msg = "Tu n'es pas tout a fait la misere,\nCar les levres les plus pauvres te denoncent\nPar un sourire.";
  size_t msg_len = strlen(my_msg);
  size_t cursor_msg = 0;
  for (size_t i = sizeof(struct measure_packet); i < mc->payload_size; i++) {
    mc->payload[i] = my_msg[cursor_msg];
    cursor_msg = (cursor_msg + 1) % msg_len;
  }
}
struct measure_packet* measure_generate(struct measure_conf* mc) {
  struct measure_packet* head = (struct measure_packet*)mc->payload;
  mc->counter++;

  head->counter = mc->counter;
  head->is_echo = mc->is_rtt && !mc->is_server;
  head->flag = 0;
  if (clock_gettime(CLOCK_MONOTONIC, &head->emit_time) == -1) {
    perror("clock_gettime error");
    exit(EXIT_FAILURE);
  }
  return head;
}

void measure_next_tick(struct measure_conf *mc, struct timespec *next) {
  struct measure_packet *head = (struct measure_packet*) mc->payload;
  struct timespec now, *sent_at = &head->emit_time;
  mc->counter = head->counter;

  if (clock_gettime(CLOCK_MONOTONIC, &now) == -1) {
    perror("clock_gettime error");
    exit(EXIT_FAILURE);
  }
  memcpy(next, sent_at, sizeof(struct timespec));

  while(!timespec_gt (next, &now)) {
    next->tv_nsec += mc->interval * 1000000L;
    if (next->tv_nsec > ONE_SEC) {
      next->tv_sec += next->tv_nsec / ONE_SEC;
      next->tv_nsec = next->tv_nsec % ONE_SEC;
    }
    mc->counter++;
  }
  mc->counter--;
  printf("interval: %ld\n", mc->interval);
  printf("sent_at: sec=%ld nsec=%ld \n", (uint64_t) sent_at->tv_sec, (uint64_t) sent_at->tv_nsec);
  printf("now: sec=%ld nsec=%ld \n", (uint64_t) now.tv_sec, (uint64_t) now.tv_nsec);
  printf("next: sec=%ld nsec=%ld \n", (uint64_t) next->tv_sec, (uint64_t) next->tv_nsec);
}

uint8_t measure_need_reply(struct measure_conf* mc) {
  return mc->is_server && ((struct measure_packet*)mc->payload)->is_echo;
};