#include <sys/timerfd.h>
#include "algo_utils.h"
#include "utils.h"
#include "url.h"
#include "proxy.h"
#include "timer.h"

struct thunder_ctx {
  uint16_t recv_id;
  uint16_t emit_id;
  uint8_t selected_link;
  uint8_t total_links;
  uint8_t delta_t_per_link[64];
  uint8_t blacklisted[64];
  struct timespec prev_link_time;
};

void prepare(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
  struct algo_ctx* app_ctx = fdinfo->cat->app_ctx;
  struct thunder_ctx* thunderc = app_ctx->misc;

  thunderc->emit_id++;
  union abstract_packet metadata = {
    .fmt.headers.cmd = CMD_UDP_METADATA_THUNDER,
    .fmt.headers.size = sizeof(metadata.fmt.headers) + sizeof(metadata.fmt.content.udp_metadata_thunder),
    .fmt.headers.flags = 0,
    .fmt.content.udp_metadata_thunder.id = thunderc->emit_id,
    .fmt.content.udp_metadata_thunder.deltat = 0 //@FIXME delta t must be set
  };
  buffer_append_ap (bp, &metadata);
}

void pad(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {


}

int schedule(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
  struct algo_ctx* app_ctx = fdinfo->cat->app_ctx;
  struct thunder_ctx* thunderc = app_ctx->misc;
  struct evt_core_fdinfo *to_fdinfo = NULL;
  struct evt_core_cat* cat = evt_core_get_from_cat (ctx, "tcp-write");

  struct timespec curr;
  int secs, nsecs;
  uint64_t mili_sec;


  do {
    // 1. We choose the link
    thunderc->selected_link = (thunderc->selected_link + 1) % cat->socklist->len;

    // 2. We create the packet template
    union abstract_packet links = {
      .fmt.headers.cmd = CMD_LINK_MONITORING_THUNDER,
      .fmt.headers.size = sizeof(links.fmt.headers) + sizeof(links.fmt.content.link_monitoring_thunder) + sizeof(struct link_info) * (thunderc->total_links - 1),
      .fmt.headers.flags = 0,
      .fmt.content.link_monitoring_thunder.links_status = {}
    };

    to_fdinfo = g_array_index(cat->socklist, struct evt_core_fdinfo*, thunderc->selected_link);

    // 3. We append the template to the buffer
    struct buffer_packet* bp_dup = dup_buffer_tow (&app_ctx->br, bp, to_fdinfo);
    union abstract_packet *new_ap = buffer_append_ap (bp_dup, &links);

    // 4. We compute the time difference
    if (clock_gettime(CLOCK_MONOTONIC, &curr) == -1){
      perror("clock_gettime error");
      exit(EXIT_FAILURE);
    }
    secs = curr.tv_sec - thunderc->prev_link_time.tv_sec;
    nsecs = curr.tv_nsec - thunderc->prev_link_time.tv_nsec;
    thunderc->prev_link_time = curr;
    mili_sec = secs * 1000 + nsecs / 1000000;
    if (mili_sec > 200) mili_sec = 200;

    // 5. We create the array
    struct link_info *li = &new_ap->fmt.content.link_monitoring_thunder.links_status;
    for (int i = 0; i < thunderc->total_links; i++) {
      thunderc->delta_t_per_link[i] += mili_sec;
      li[i].delta_t = thunderc->delta_t_per_link[i];
    }
    li[thunderc->selected_link].delta_t = 0;

    main_on_tcp_write(ctx, to_fdinfo);
  } while (thunderc->blacklisted[thunderc->selected_link]);

  if (ctx->verbose > 1) fprintf(stderr, "    [algo_thunder] Packets sent\n");

  // Release the buffer
  mv_buffer_rtof (&app_ctx->br, fdinfo);

  return 0;
}

void algo_thunder_init(struct evt_core_ctx* ctx, struct algo_ctx* app_ctx, struct algo_params* ap) {
  app_ctx->misc = malloc(sizeof(struct thunder_ctx));
  if (app_ctx->misc == NULL) {
    perror("malloc failed in algo thunder init");
    exit(EXIT_FAILURE);
  }
  memset(app_ctx->misc, 0, sizeof(struct thunder_ctx));
  struct thunder_ctx* thunderc = app_ctx->misc;
  thunderc->selected_link = UINT8_MAX - 1;
}

void classify() {

}

void unpad() {

}

void adapt() {

}

int algo_thunder_on_stream(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
  classify();
  unpad();
  adapt();
  return 0;
}

int algo_thunder_on_datagram(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
  prepare(ctx, fdinfo, bp);
  pad(ctx, fdinfo, bp);
  return schedule(ctx, fdinfo, bp);
}

int algo_thunder_on_err(struct evt_core_ctx *ctx, struct evt_core_fdinfo *fdinfo) {
  if (strstr(fdinfo->cat->name, "udp") != NULL) return 1;
  return 0;
}