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

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

list_t *append_list(list_t *list1, list_t *list2){
    size_t new_len = list1->length + list2->length;
    list_t *new_list = malloc(sizeof(list_t) + sizeof(list_element_t) * new_len);
    new_list->length = new_len;
    memcpy(new_list->elements, list1->elements, list1->length * sizeof(list_element_t));
    memcpy(new_list->elements + list1->length, list2->elements, list2->length * sizeof(list_element_t));
    return new_list;
}

list_t *filter_list(list_t *list, bool (*filter)(list_element_t)){
    list_element_t *buffer = malloc(sizeof(list_element_t) * list->length);
    size_t new_len = 0;
    for(size_t i = 0; i < list->length; i++){
        if(filter(list->elements[i])){
            buffer[new_len++] = list->elements[i];
        }
    }
    list_t *new_list = malloc(sizeof(list_t) + sizeof(list_element_t) * new_len);
    new_list->length = new_len;
    memcpy(new_list->elements, buffer, new_len * sizeof(list_element_t));
    free(buffer);
    return new_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 *new_list = malloc(sizeof(list_t) + sizeof(list_element_t) * list->length);
    new_list->length = list->length;
    for(size_t i = 0; i < list->length; i++){
        new_list->elements[i] = map(list->elements[i]);
    }
    return new_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 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; i--){
        acc = foldr(list->elements[i - 1], acc);
    }
    return acc;
}

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

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