#include "le.h"
#include <stdlib.h>

struct llist * create_l(){
    struct llist * ptr;

    ptr = malloc(sizeof(struct llist));
    ptr->cabeca = NULL;
    ptr->tam = 0;

    return ptr;
}

elem * create_node(int val){

    elem * ptr;

    ptr = malloc(sizeof(elem));

    ptr->val = val;
    ptr->next = NULL;

    return ptr;

}

int insert_l(struct llist * desc, elem * prev, elem * item){

    //Adição no ínicio
    if(prev == NULL){
        if(desc->cabeca == NULL){
            desc->cabeca = item;
            desc->tam++;
            return 1;
        }

        item->next = desc->cabeca;

        desc->cabeca = item;
        desc->tam++;
        return 1;
    }

    item->next = prev->next;
    prev->next = item;

    desc->tam++;

    return 1;
}

int delete_l(struct llist * desc, elem * prev){

    elem * temp;

    if(prev == NULL){
        temp = desc->cabeca;
        desc->cabeca = temp->next;
        desc->tam--;
        free(temp);

        return 1;
    }

    temp = prev->next;
    prev->next = temp->next;
    desc->tam--;
    free(temp);

    return 1;

}

elem * get_l(struct llist * desc, int pos){

    int i;
    elem *ptr;

    if(pos > desc->tam || pos < 1)
        return NULL;

    if(pos == 1)
        return desc->cabeca;

    ptr = desc->cabeca;

    for(i = 0; i < pos; i++){
        ptr = ptr->next;
    }

    return ptr;
}

int set_l(struct llist * desc, int pos, int val){

    elem *ptr;

    ptr = get_l(desc, pos);

    if(ptr == NULL)
        return 0;

    ptr->val = val;

    return 1;

}

elem * locate_l(struct llist * desc, elem * prev, int val){

    elem *ptr;

    if(prev == NULL)
        ptr = desc->cabeca;

    else
        ptr = prev;


    while(ptr != NULL){
        if(ptr->val == val)
            return ptr;

        ptr = ptr->next;
    }

    return NULL;
}

int length_l(struct llist * desc){
    return desc->tam;
}

void destroy_l(struct llist * desc){

    int i;

    if(desc->cabeca == NULL)
        free(desc);

    else {

        for(i = 0; i < desc->tam; i++){
            delete_l(desc, NULL);
        }

        free(desc);
    }
}