//
// Created by william on 1/16/24.
//

#include <stddef.h>
#include <malloc.h>
#include <stdlib.h>
#include <assert.h>
#include "linked_list.h"

LinkedList linked_list_init() {
    LinkedList list;
    list.head = NULL;
    list.end = NULL;
    return list;
}

void linked_list_add(LinkedList *list, void *data) {
    LinkedListNode *node = malloc(sizeof(LinkedListNode));
    if (node == NULL) {
        perror("Failed to allocate memory for linked list node");
        exit(EXIT_FAILURE);
    }

    node->data = data;
    node->previous = list->end;
    node->next = NULL;

    if (list->head == NULL) {
        list->head = node;
    }

    if (list->end != NULL) {
        list->end->next = node;
    }

    list->end = node;
}

LinkedListNode *linked_list_get_if(LinkedList *list, bool(*predicate)(void *, void *), void *userdata) {
    LinkedListNode *node = list->head;

    while (node != NULL) {
        if (predicate(node->data, userdata)) {
            return node;
        }

        node = node->next;
    }

    return NULL;
}

LinkedListNode *linked_list_get_near(LinkedList *list, int(*predicate)(void *, void *), void *userdata) {
    LinkedListNode *near_node = list->head;

    int current_distance = predicate(near_node->data, userdata);
    if (current_distance == 0) {
        return near_node;
    }

    // TODO
    int last_distance = 0x7fffffff;
    LinkedListNode *node = near_node->next;
    while (current_distance < last_distance && near_node->next != NULL) {
        node = near_node->next;
        last_distance = current_distance;
        current_distance = predicate(node->data, userdata);
    }

    // After the loop, we have found the nearest node in the list, assuming there is only one point of convergence
    return near_node;
}

void linked_list_uninit(LinkedList *list) {
    assert(list != NULL);

    LinkedListNode *node = list->head;
    while (node != NULL) {
        LinkedListNode *current_node = node;
        node = node->next;

        free(current_node->data);
        free(current_node);
    }
}