#include "list.h"


List::List() {
  list = NULL;
  last = NULL;
  size = 0;
  hash = (h_elem **)malloc(sizeof(h_elem) * HASH_SIZE);
  
  memset(hash, 0, HASH_SIZE * sizeof(h_elem));
}


List::~List() {
  l_elem *temp;
  h_elem *t2;
  int i;

  while(list != NULL) {
    temp = list;
    list = list->next;
    free(temp);
  }
  
  for (i = 0; i < HASH_SIZE; i++) {
    t2 = hash[i];
    while(t2) {
      hash[i] = hash[i]->next;
      free(t2);
      t2 = hash[i];
    }
  }
  free(hash);
}

void List::hash_delete(void *data) {
  data = data;

}





void List::hash_insert(l_elem *elem, void *data) {
  
  h_elem *new_elem;
  int bucket = HASH((int)data);

  new_elem = (h_elem *)malloc(sizeof(h_elem));
  new_elem->next = hash[bucket];
  new_elem->data = data;
  new_elem->elem = elem;
  hash[bucket] = new_elem;

}



l_elem *List::find(void *elem) {


  h_elem *h;
  int bucket;

  bucket = HASH((int)elem);
  
  h = hash[bucket];
  while(h) {
    if (h->data == elem) break;
    h = h->next;
  }

  if (!h) return NULL;
  return h->elem;

}



void List::InsertBefore(void *new_elem, void *where) {


  l_elem *new_list_elem;
  l_elem *temp;

  temp = find(where);

  if (temp == NULL) 
    ERROR("Couldn't find element to insert before.");
  
  new_list_elem = (l_elem *)malloc(sizeof(l_elem));

  new_list_elem->next = temp;
  new_list_elem->prev = temp->prev;

  if (temp->prev) temp->prev->next = new_list_elem;
  else list = new_list_elem;

  temp->prev = new_list_elem;
  new_list_elem->data = new_elem;

  hash_insert(new_list_elem, new_elem);

  size++;
}




void List::InsertAfter(void *new_elem, void *where) {
  
  l_elem *new_list_elem;
  l_elem *temp;

  temp = find(where);

  if (temp == NULL) 
    ERROR("Couldn't find element to insert after.");
  
  new_list_elem = (l_elem *)malloc(sizeof(l_elem));

  new_list_elem->prev = temp;
  new_list_elem->next = temp->next;

  if (temp->next) temp->next->prev = new_list_elem;
  else last = new_list_elem;

  temp->next = new_list_elem;
  new_list_elem->data = new_elem;

  hash_insert(new_list_elem, new_elem);

  size++;

}

  
void List::Append(void *new_elem) {

  l_elem *new_list_elem;

  new_list_elem = (l_elem *)malloc(sizeof(l_elem));
  new_list_elem->data = new_elem;

  if (!list) {
    list = last = new_list_elem;
    new_list_elem->next = NULL;
    new_list_elem->prev = NULL;
  } else {
    last->next = new_list_elem;
    new_list_elem->prev = last;
    new_list_elem->next = NULL;
    last = new_list_elem;
  }

  hash_insert(new_list_elem, new_elem);
 
  size++;

}


void List::Delete(void *elem) {

  l_elem *temp;

  temp = find(elem);

  if (!temp) return;
  
  if (temp->prev) {
    temp->prev->next = temp->next;
  } else {
    list = temp->next;
  }

  if (temp->next) {
    temp->next->prev = temp->prev;
  } else {
    last = temp->prev;
  }

  free(temp);

  hash_delete(elem);
  
  size--;
}




/*
 * Circular Next
 *
 * This function returns the next element in the list. Note that the lists
 * are circular, so that if the element you give me is the last element,
 * I'll return the first element in the list as the next element.
 */

void *List::CircularNext(void *elem) {
  
  void *temp;
 
  temp = Next(elem);
  if (temp) return temp;
  if (!list) return NULL;
  return list->data;

}


void *List::Next(void *elem) {

  l_elem *temp;

  temp = find(elem);

  if (!temp) return NULL;

  if (temp->next) 
    return temp->next->data;
  return NULL;
}




void *List::Prev(void *elem) {

  l_elem *temp;
  
  temp = find(elem);
  
  if (!temp) return NULL;

  if (temp->prev)
    return temp->prev->data;
  return NULL;
}



void *List::CircularPrev(void *elem) {
  
  void *temp;

  temp = Prev(elem);
  if (temp) return temp;
  if (last) return last->data;
  return NULL;
}



void *List::First() {

  if (!list) return NULL;
  return list->data;
}

void *List::Last() {

  if (!last) return NULL;
  return last->data;
}


void *List::Number(int num) {

  l_elem *temp;
  int counter;

  counter = 0;
  temp = list;

  while(temp != NULL && counter != num) { 
    temp = temp->next;
    counter++;
  }

  return temp->data;

}


int List::GetNum(void *elem) {

  l_elem *temp;
  int counter;

  counter = 0;
  temp = list;

  while(temp != NULL && temp->data != elem) { 
    temp = temp->next;
    counter++;
  }

  if (temp == NULL) ERROR("Couldn't find elem in GetNum!");

  return counter;
}