#include <stdio.h>

#include "ping_pong.h"
#include "timespec.h"
#include "packet.h"

int handle_ping_pong(int sockfd,
                     void * buf, ssize_t length,
                     struct link_state * link_state
                     )
{
  struct event * evt = (struct event *)buf;
  switch (evt->type) {
  case EVENT_TYPE__PING:
    {
      if (length != (sizeof (struct packet_ping_pong))) {
        printf("handle_ping_pong: ping: invalid length\n");
        return 0; // recoverable
      }

      //printf("recv ping; send pong\n");
      struct packet_ping_pong * ping_pkt = (struct packet_ping_pong *)buf;
      int ret = packet_send_pong(sockfd, &link_state->dest_addr, &ping_pkt->time);
      if (ret == -1) {
        return -1;
      }
    }
    break;
  case EVENT_TYPE__PONG:
    {
      if (length != (sizeof (struct packet_ping_pong))) {
        printf("handle_ping_pong: pong: invalid length\n");
        return 0; // recoverable
      }

      //printf("recv pong\n");
      struct packet_ping_pong * ping_pkt = (struct packet_ping_pong *)buf;
      struct timespec now;
      int ret = clock_gettime(CLOCK_MONOTONIC_RAW, &now);
      assert(ret != -1);
      link_state->last_pong = now;

      struct timespec * rtt = &link_state->ping_pong_rtt[link_state->rtt_ix];
      link_state->rtt_ix = (link_state->rtt_ix + 1) % RTT_AVERAGE_SAMPLES;
      *rtt = timespec_sub(&now, &ping_pkt->time);
      printf("pong rtt: %ld.%09ld\n", rtt->tv_sec, rtt->tv_nsec);
      struct timespec average_rtt = timespec_average(link_state->ping_pong_rtt, RTT_AVERAGE_SAMPLES);

      ret = packet_send_average_rtt(sockfd, &link_state->dest_addr, &average_rtt);
      if (ret == -1) {
        return -1;
      }
    }
    break;
  case EVENT_TYPE__AVERAGE_RTT:
    {
      if (length != (sizeof (struct packet_average_rtt))) {
        printf("handle_average_rtt: average_rtt: invalid length\n");
        return 0; // recoverable
      }
      struct packet_average_rtt * ping_pkt = (struct packet_average_rtt *)buf;

      printf("recv average_rtt: %ld.%09ld\n", ping_pkt->offset.tv_sec, ping_pkt->offset.tv_nsec);

      link_state->remote_average_rtt = ping_pkt->offset;
    }
    break;
  default:
    break;
  }
  return 0;
}