#include "linkedList.h"

#include <stdlib.h>

struct _element {
    void* data;
    int key;

    element next_element;
    element prev_element;
};

struct _list {
    int size;

    element head;
    element tail;
};

list createList () {
    list new_list;

    new_list = (list)malloc(sizeof(list));

    new_list->head = NULL;
    new_list->tail = NULL;

    new_list->size = 0;

    return new_list;
}

void destroyList (list l) {
    element temp;


    if ((temp = l->head->next_element) == NULL) {
        free(l->head);
        free(l);

        return;
    }

    while (temp != NULL) {
        temp->next_element->prev_element = l->head;
        temp->next_element = NULL;
        temp->prev_element = NULL;

        free(temp);

        temp = l->head->next_element;
    }

    free(l->head);

    free(l);
}

element listSearch (list l, int key) {
    element temp;

    temp = l->head;

    while (temp != NULL) {
        if (temp->key == key) {
            return temp;
        }

        temp = temp->next_element;
    }

    if (temp == NULL) {
        return NULL;
    }

}

void deleteElement (list l, int key) {
    element to_delete;

    if (l->head->key == key) {
        l->head = to_delete->next_element;
        to_delete->next_element->prev_element = NULL;
    }
    else if (l->tail->key == key) {
        l->tail = to_delete->prev_element;
        to_delete->prev_element->next_element = NULL;
    }
    else {
        to_delete = listSearch(l, key);

        to_delete->prev_element->next_element = to_delete->next_element;
        to_delete->next_element->prev_element = to_delete->prev_element;
    }

    free(to_delete);
    l->size--;

}

void elementInsertNext (list l, void* data, int key) {
    element new_element, location;

    new_element = (element)malloc(sizeof(element));

    if (l->head->key == key) {
        l->head->next_element->prev_element = new_element;
        l->head->next_element = new_element;
    }

    else if (l->tail->key == key) {
        l->tail->next_element = new_element;
        l->tail = new_element;
    }

    else {
        location = listSearch(l, key);

        location->next_element->prev_element = new_element;
        location->next_element = new_element;
    }

    l->size++;

}

void elementInsertPrev (list l, void* data, int key) {
    element new_element, location;

    new_element = (element)malloc(sizeof(element));

    if (l->head->key == key) {
        l->head->next_element = new_element;
        l->head = new_element;
    }

    else if (l->tail->key == key) {
        l->tail->prev_element->next_element = new_element;
        l->tail->prev_element = new_element;
    }

    else {
        location = listSearch(l, key);

        location->prev_element->next_element = new_element;
        location->prev_element = new_element;
    }

    l->size++;
}