/*
 * category: [data structure]
 * apply status: timerqueue
 * edit status: not
 * build status:
 * description:
 */

#ifndef HEAPUTIL_H
#define HEAPUTIL_H

#pragma once

#include "config.h"

#ifdef __cplusplus
extern "C" {
#endif

/* array based heap helper */

#define heap_parent(x) (((x)-1)/2)
#define heap_left_child(x) ((x)*2+1)
#define heap_right_child(x) ((x)*2+2)

/* calculate heapelement priority, this is the min heap implementation based on the priority */
typedef int (*heap_priority_cmp)(void*, void*);

/** adjust up */
TOOLKIT_API void heap_up(void**arr, int arr_n, int slot, heap_priority_cmp prio_cmp);
/** adjust down */
TOOLKIT_API void heap_down(void**arr, int arr_n, int slot, heap_priority_cmp prio_cmp);

/**
 * arr must have enougth space to place obj 
 * @param arr heap array 
 * @param arr_n [in,out] elements in the array
 * @param obj object to insert
 * @param prio_fn get priority from object
 */
TOOLKIT_API void heap_push(void**arr, int *arr_n, void* obj, heap_priority_cmp prio_cmp);

/**
 * @param arr heap array
 * @param arr_n [in,out] elements in the array
 * @param prio_fn get priority from object
 * @return root value from heap
 */
TOOLKIT_API void* heap_pop(void** arr, int *arr_n, heap_priority_cmp prio_cmp);

#ifdef __cplusplus
} // extern "C" {
#endif

#endif // HEAPUTIL_H