#include <stdlib.h>
#include <string.h>
#include <stdio.h>
// Please implement the header file from the assignment to fulfill the unit tests..
 // You can add any function  
#include "list_ops.h"

list_t *new_list(size_t length, list_element_t elements[]) {
    list_t *list = malloc(sizeof(list_t) + length * sizeof(list_element_t));
    if (!list) return NULL;

    list->length=length;

    if (length>0 && elements!= NULL) {
        memcpy(list->elements, elements, length*sizeof(list_element_t));
    }
    return list;
}

list_t *append_list(list_t *list1, list_t *list2) {
    size_t total_length =list1->length+list2->length;
    list_t *new_list_ptr=malloc(sizeof(list_t)+total_length*sizeof(list_element_t));
    if (!new_list_ptr) return NULL;

    new_list_ptr->length=total_length;

    memcpy(new_list_ptr->elements, list1->elements, list1->length*sizeof(list_element_t));
    memcpy(new_list_ptr->elements+list1->length, list2->elements, list2->length * sizeof(list_element_t));

    return new_list_ptr;
}


list_t *filter_list(list_t *list, bool (*filter)(list_element_t)) {
    list_element_t *temp=malloc(list->length*sizeof(list_element_t));
    if (!temp) return NULL;
    size_t count=0;
    for (size_t i=0; i<list->length; i++) {
        if (filter(list->elements[i])) {
            temp[count++]=list->elements[i];
        }
    }
    list_t *result=new_list(count, temp);
    free(temp);
    return result;
}

size_t length_list(list_t *list) {
    return list->length;
}

list_t *map_list(list_t *list, list_element_t (*map)(list_element_t)) {
    list_t *result = malloc(sizeof(list_t) + list->length * sizeof(list_element_t));
    if (!result) return NULL;
    result->length = list->length;
    for (size_t i = 0; i<list->length; i++) {
        result->elements[i] = map(list->elements[i]);
    }

    return result;
}

list_element_t foldl_list(list_t *list, list_element_t initial, list_element_t (*foldl)(list_element_t, list_element_t)) {
    list_element_t acc = initial;
    for (size_t i=0; i<list->length; i++) {
        acc=foldl(acc, list->elements[i]);
    }
    return acc;
}


list_element_t foldr_list(list_t *list, list_element_t initial, list_element_t (*foldr)(list_element_t, list_element_t)) {
    list_element_t acc = initial;
    for (size_t i=list->length; i-- >0;) {
        acc = foldr(list->elements[i], acc);
    }
    return acc;
}


list_t *reverse_list(list_t *list) {
    list_t *result = malloc(sizeof(list_t)+list->length*sizeof(list_element_t));
    if (!result) return NULL;
    result->length=list->length;
    for (size_t i=0; i<list->length; i++) {
        result->elements[i] = list->elements[list->length-i-1];
    }
    return result;
}

void delete_list(list_t *list) {
    free(list);
}