#include <stdlib.h>
#include <string.h>
#include "list.h"

int list_init(List *list, void (*destroy)(void *data)) {
    if (list == NULL) {
        return -1;
    }
    list->size = 0;
    list->head = NULL;
    list->tail = NULL;
    list->destroy = destroy;
    return 0;
}

void list_destroy(List *list) {
    void *data;
    while (list_size(list) > 0) {
        if (list_delete_after(list, NULL, (void **)&data) > 0
            && list->destroy != NULL) {
                list->destroy(data);
        }
    }
    
    memset(list, 0, sizeof(List));
    return;
}

int list_insert_after(List *list, ListElem *ele, const void *data) {
    ListElem *tmpElem;
    if ((tmpElem = (ListElem *)malloc(sizeof(ListElem))) == NULL) {
        return -1;
    }
    tmpElem->data = (void *)data;
    if (ele == NULL) {
        if (list_size(list) == 0) {
            list->tail = tmpElem;
        }
        tmpElem->next = list->head;
        list->head = tmpElem;
    } else {
        if (ele->next == NULL) {
            list->tail = tmpElem;
        }
        tmpElem->next = ele->next;
        ele->next = tmpElem;
    }
    list->size++;
    return 0;
}

int list_delete_after(List *list, ListElem *ele, void **data) {
    ListElem *tmpElem;
    if (list_size(list) == 0) {
        return -1;
    }
    if (ele == NULL) {
        tmpElem = list->head;
        list->head = list->head->next;
        if (list_size(list) == 1) {
            list->tail = NULL;
        }
    } else {
        if (ele->next == NULL) {
            return -1;
        }
        tmpElem = ele->next;
        ele->next = ele->next->next;
        if (ele->next == NULL) {
            list->tail = ele;
        }
    }
    *data = tmpElem->data;
    free(tmpElem);
    list->size--;
    return 0;
}