#include "datastorage.h"

#define MAC2STR(a) (a)[0], (a)[1], (a)[2], (a)[3], (a)[4], (a)[5]

int go_next_help(char sort_order[], int i, probe_entry entry,
                 probe_entry next_entry);
int go_next(char sort_order[], int i, probe_entry entry,
            probe_entry next_entry);
int mac_is_equal(uint8_t addr1[], uint8_t addr2[]);
int mac_is_greater(uint8_t addr1[], uint8_t addr2[]);
void print_probe_entry(probe_entry entry);
node *delete_probe_req(node **ret_remove, node *head, uint8_t bssid_addr[],
                       uint8_t client_addr[]);
int mac_is_first_in_list(node *head, uint8_t bssid_addr[],
                         uint8_t client_addr[]);
node *remove_node(node *head, node *curr, node *prev);
node *remove_old_entries(node *head, time_t current_time,
                         long long int threshold);
void print_list_with_head(node *head);

void insert_to_list(probe_entry entry, int inc_counter) {
  pthread_mutex_lock(&list_mutex);

  entry.time = time(0);
  entry.counter = 0;

  // first delete probe request
  // probe_list_head = remove_old_entries(probe_list_head, time(0),
  // TIME_THRESHOLD);
  node *tmp_probe_req = NULL;
  probe_list_head = delete_probe_req(&tmp_probe_req, probe_list_head,
                                     entry.bssid_addr, entry.client_addr);

  if (tmp_probe_req) {
    // local ubus
    tmp_probe_req->data.signal = entry.signal;
    tmp_probe_req->data.time = entry.time;
    if (inc_counter) {
      // when network don't increase counter...
      tmp_probe_req->data.counter++;
    }

    // is this correct?
    probe_list_head = insert(probe_list_head, tmp_probe_req->data);
    free(tmp_probe_req);
  } else {
    printf("New entry!\n");
    probe_list_head = insert(probe_list_head, entry);
  }

  pthread_mutex_unlock(&list_mutex);
}

int go_next_help(char sort_order[], int i, probe_entry entry,
                 probe_entry next_entry) {
  switch (sort_order[i]) {
    // bssid-mac
    case 'b':
      return mac_is_greater(entry.bssid_addr, next_entry.bssid_addr) &&
             mac_is_equal(entry.client_addr, next_entry.client_addr);
      break;

    // client-mac
    case 'c':
      return mac_is_greater(entry.client_addr, next_entry.client_addr);
      break;

    // frequency
    case 'f':
      return entry.freq < next_entry.freq &&
             mac_is_equal(entry.client_addr, next_entry.client_addr);
      break;

    // signal strength (RSSI)
    case 's':
      return entry.signal < next_entry.signal &&
             mac_is_equal(entry.client_addr, next_entry.client_addr);
      break;

    default:
      return 0;
      break;
  }
}

int go_next(char sort_order[], int i, probe_entry entry,
            probe_entry next_entry) {
  int conditions = 1;
  for (int j = 0; j < i; j++) {
    i &= !(go_next(sort_order, j, entry, next_entry));
  }
  return conditions && go_next_help(sort_order, i, entry, next_entry);
}

node *insert(node *head, probe_entry entry) {
  node *temp, *prev, *next;
  temp = (node *)malloc(sizeof(node));
  temp->data = entry;
  temp->ptr = NULL;

  // length of sorting string
  // char sort_string[] = "cfsb";
  int i = 0;

  if (!head) {
    head = temp;
  } else {
    prev = NULL;
    next = head;
    while (next) {
      if (go_next(sort_string, i, entry, next->data)) {
        prev = next;
        next = next->ptr;
      } else if (i < strlen(sort_string)) {
        i++;
      } else {
        break;
      }
    }
    if (!next) {
      prev->ptr = temp;
    } else {
      if (prev) {
        temp->ptr = prev->ptr;
        prev->ptr = temp;
      } else {
        temp->ptr = head;
        head = temp;
      }
    }
  }
  return head;
}

node *delete_probe_req(node **ret_remove, node *head, uint8_t bssid_addr[],
                       uint8_t client_addr[]) {
  if (!head) {
    return head;
  }

  if (mac_is_equal(client_addr, head->data.client_addr) &&
      mac_is_equal(bssid_addr, head->data.bssid_addr)) {
    node *temp = head;
    head = head->ptr;
    *ret_remove = temp;
    // don't free pointer
    // free(temp);
    return head;
  }

  node *prev = NULL;
  node *next = head;
  while (next) {
    if (mac_is_greater(next->data.client_addr, client_addr)) {
      break;
    }

    if (mac_is_equal(client_addr, next->data.client_addr) &&
        mac_is_equal(bssid_addr, next->data.bssid_addr)) {
      node *temp = next;
      prev->ptr = next->ptr;
      // free(temp);
      *ret_remove = temp;
      return head;
    }
    prev = next;
    next = next->ptr;
  }
  return head;
}

void *remove_thread(void *arg) {
  while (1) {
    sleep(TIME_THRESHOLD);
    pthread_mutex_lock(&list_mutex);
    printf("[Thread] : Removing old entries!\n");
    probe_list_head =
        remove_old_entries(probe_list_head, time(0), TIME_THRESHOLD);
    pthread_mutex_unlock(&list_mutex);
    // print_list();
  }
  return 0;
}

node *remove_old_entries(node *head, time_t current_time,
                         long long int threshold) {
  if (head) {
    node *prev = NULL;
    node *next = head;
    while (next) {
      if (next->data.time < current_time - threshold) {
        head = remove_node(head, next, prev);
        // print_list_with_head(head);
        if (prev == NULL)  // removed head
        {
          next = head;
        } else {
          next = prev->ptr;
        }
      } else {
        prev = next;
        next = next->ptr;
      }
    }
  }
  return head;
}

// return headpointer
node *remove_node(node *head, node *curr, node *prev) {
  if (curr == head) {
    node *temp = head;
    head = head->ptr;
    free(temp);
  } else {
    node *temp = curr;
    prev->ptr = curr->ptr;
    free(temp);
  }
  // printf("Removed old entry!\n");
  return head;
}

int mac_is_first_in_list(node *head, uint8_t bssid_addr[],
                         uint8_t client_addr[]) {
  if (!head) {
    return 1;
  }
  node *next = head;
  while (next) {
    if (mac_is_greater(next->data.client_addr, client_addr)) {
      break;
    }

    if (mac_is_equal(client_addr, next->data.client_addr)) {
      print_probe_entry(next->data);
      return mac_is_equal(bssid_addr, next->data.bssid_addr);
    }
    next = next->ptr;
  }
  return 0;
}

int mac_first_in_probe_list(uint8_t bssid_addr[], uint8_t client_addr[]) {
  pthread_mutex_lock(&list_mutex);
  int ret = mac_is_first_in_list(probe_list_head, bssid_addr, client_addr);
  pthread_mutex_unlock(&list_mutex);
  return ret;
}

void free_list(node *head) {
  node *prev = head;
  node *cur = head;
  while (cur) {
    prev = cur;
    cur = prev->ptr;
    free(prev);
  }
}

int mac_is_equal(uint8_t addr1[], uint8_t addr2[]) {
  return memcmp(addr1, addr2, ETH_ALEN * sizeof(uint8_t)) == 0;
}

int mac_is_greater(uint8_t addr1[], uint8_t addr2[]) {
  for (int i = 0; i < ETH_ALEN; i++) {
    if (addr1[i] > addr2[i]) {
      return 1;
    }
    if (addr1[i] < addr2[i]) {
      return 0;
    }

    // if equal continue...
  }
  return 0;
}

void print_list_with_head(node *head) {
  pthread_mutex_lock(&list_mutex);
  printf("------------------\n");
  if (head) {
    node *next;
    next = head;
    while (next) {
      print_probe_entry(next->data);
      next = next->ptr;
    }
  }
  printf("------------------\n");
  pthread_mutex_unlock(&list_mutex);
}

void print_list() {
  pthread_mutex_lock(&list_mutex);
  printf("------------------\n");
  node *head = probe_list_head;
  if (head) {
    node *next;
    next = head;
    while (next) {
      print_probe_entry(next->data);
      next = next->ptr;
    }
  }
  printf("------------------\n");
  pthread_mutex_unlock(&list_mutex);
}

void print_probe_entry(probe_entry entry) {
  char mac_buf_ap[20];
  char mac_buf_client[20];
  char mac_buf_target[20];

  sprintf(mac_buf_ap, "%x:%x:%x:%x:%x:%x", MAC2STR(entry.bssid_addr));
  sprintf(mac_buf_client, "%x:%x:%x:%x:%x:%x", MAC2STR(entry.client_addr));
  sprintf(mac_buf_target, "%x:%x:%x:%x:%x:%x", MAC2STR(entry.target_addr));

  printf(
      "bssid_addr: %s, client_addr: %s, target_addr: %s, signal: %d, freq: "
      "%d, counter: %d\n",
      mac_buf_ap, mac_buf_client, mac_buf_target, entry.signal, entry.freq,
      entry.counter);
}