#include <sys/queue.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "../core/plugins.h"
#include "api.h"

typedef struct p11_msg_t {
  api_plugin_t from;
  void *content;
  size_t content_size;
  uint8_t priority;
  unsigned read: 1;
  TAILQ_ENTRY(p11_msg_t) entries;
} p11_msg_t;

TAILQ_HEAD(slisthead, p11_msg_t) p11_msgs[256];
static uint8_t p11_plugin_counter;
static uint32_t p11_depth = 0;

extern internal_plugin_t *plugins_g[256];

static void init_queues() {
  static uint8_t first_time = 1;

  if (first_time) {
    for (size_t i = 0; i < sizeof p11_msgs / sizeof *p11_msgs; ++i)
      TAILQ_INIT(&p11_msgs[i]);
    first_time = 0;
  }
  if (p11_depth == 0)
    p11_plugin_counter = get_current_plugin_id();
}

uint32_t api_send_message_instant(api_plugin_t dest, void *content, size_t content_size, uint8_t priority) {
  uint32_t r;

  init_queues();
  p11_depth++;
  if (p11_depth > 10) {
    p11_depth--;
    return 4;
  }
  r = api_send_message(dest, content, content_size, priority);
  if (r == 0) {
    uint32_t sender_id = p11_plugin_counter;
    p11_plugin_counter = dest.id;
    if (plugins_g[dest.id] == NULL
	|| plugins_g[dest.id]->run_instant == NULL)
      r = 3;
    else {
      plugins_g[dest.id]->run_instant();
      r = 0;
    }
    p11_plugin_counter = sender_id;
  }
  p11_depth--;
  return r;
}

uint32_t api_send_message(api_plugin_t dest, void *content, size_t content_size, uint8_t priority) {
  p11_msg_t *new_msg;

  init_queues();
  if ((new_msg = malloc(sizeof *new_msg)) == NULL
      || (new_msg->content = malloc(content_size)) == NULL)
    return 1;
  // TODO: check if destination plugin exists
  memcpy(new_msg->content, content, content_size);
  memcpy(&(new_msg->from), &p11_plugin_counter, sizeof p11_plugin_counter);
  new_msg->priority = priority;
  new_msg->content_size = content_size;
  new_msg->read = 0;
  // TODO: manage priority
  TAILQ_INSERT_TAIL(&p11_msgs[dest.id], new_msg, entries);
  printf("[%i] send a message (%p) to %i. It's %lu long and has priority %i.\n", p11_plugin_counter, content, dest.id, content_size, priority);
  return 0;

}

uint32_t api_receive_message(api_plugin_t *from, void **content, size_t *content_size) {
  p11_msg_t *msg;

  // TODO: manage sender selection
  init_queues();
  p11_plugin_counter = get_current_plugin_id();
  msg = TAILQ_FIRST(&(p11_msgs[p11_plugin_counter]));
  while (msg) {
    if (msg->read == 0) {
      *content = msg->content;
      *content_size = msg->content_size;
      *from = msg->from;
      msg->read = 1;
      printf("[%u] receive a message (%p) from %i. It's %lu long and has priority %i.\n", p11_plugin_counter, *content, from->id, *content_size, msg->priority);
      return 0;
    }
    msg = TAILQ_NEXT(msg, entries);
  }
  return 2;
}

void api_clear_read_messages(uint8_t full) {
  p11_msg_t *msg;

  init_queues();
  TAILQ_FOREACH(msg, &p11_msgs[p11_plugin_counter], entries) {
    if (full == 1
	|| msg->read == 1) {
      free(msg->content);
      TAILQ_REMOVE(&p11_msgs[p11_plugin_counter], msg, entries);
      free(msg);
    }
  }
}