#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include "list_ops.h"


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

    
    memcpy(list->elements, elements, length * sizeof(list_element_t));

    
    return list;
}


list_t *append_list(list_t *list1, list_t *list2) {
   
    size_t new_length = list1->length + list2->length;

   
    list_t* combined_list = (list_t*)malloc(sizeof(list_t) + new_length * sizeof(list_element_t));

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

   
    combined_list->length = new_length;

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


    return combined_list;
}


list_t *filter_list(list_t *list, bool (*filter)(list_element_t)) {
    size_t filtered_length = 0;

   
    for (size_t i = 0; i < list->length; ++i) {
        if (filter(list->elements[i])) {
            ++filtered_length;
        }
    }


    list_t* filtered_list = (list_t*)malloc(sizeof(list_t) + filtered_length * sizeof(list_element_t));

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

    
    filtered_list->length = filtered_length;

    
    size_t j = 0;
    for (size_t i = 0; i < list->length; ++i) {
        if (filter(list->elements[i])) {
            filtered_list->elements[j++] = list->elements[i];
        }
    }

   
    return filtered_list;
}


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* mapped_list = (list_t*)malloc(sizeof(list_t) + list->length * sizeof(list_element_t));

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

    
    mapped_list->length = list->length;

   
    for (size_t i = 0; i < list->length; ++i) {
        mapped_list->elements[i] = map(list->elements[i]);
    }

   
    return mapped_list;
}

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 result = initial;

    for (size_t i = 0; i < list->length; ++i) {
        result = foldl(result, list->elements[i]);
    }

    return result;
}


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 result = initial;







    for (size_t i = list->length; i > 0; --i) {
        result = foldr(list->elements[i - 1], result);
    }

    return result;
}


list_t *reverse_list(list_t *list) {
    
    list_t* reversed_list = (list_t*)malloc(sizeof(list_t) + list->length * sizeof(list_element_t));

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

    
    reversed_list->length = list->length;

    
    for (size_t i = 0; i < list->length; ++i) {
        reversed_list->elements[i] = list->elements[list->length - i - 1];
    }

    
    return reversed_list;
}

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