/* SPDX-License-Identifier: GPL-2.0-or-later */

#pragma once

/** \file
 * \ingroup bli
 * \brief A min-heap / priority queue ADT
 */

#ifdef __cplusplus
extern "C" {
#endif

struct HeapSimple;
typedef struct HeapSimple HeapSimple;

typedef void (*HeapSimpleFreeFP)(void *ptr);

/**
 * Creates a new simple heap, which only supports insertion and removal from top.
 *
 * \note Use when the size of the heap is known in advance.
 */
HeapSimple *BLI_heapsimple_new_ex(unsigned int reserve_num) ATTR_WARN_UNUSED_RESULT;
HeapSimple *BLI_heapsimple_new(void) ATTR_WARN_UNUSED_RESULT;
void BLI_heapsimple_clear(HeapSimple *heap, HeapSimpleFreeFP ptrfreefp) ATTR_NONNULL(1);
void BLI_heapsimple_free(HeapSimple *heap, HeapSimpleFreeFP ptrfreefp) ATTR_NONNULL(1);
/**
 * Insert heap node with a value (often a 'cost') and pointer into the heap,
 * duplicate values are allowed.
 */
void BLI_heapsimple_insert(HeapSimple *heap, float value, void *ptr) ATTR_NONNULL(1);
bool BLI_heapsimple_is_empty(const HeapSimple *heap) ATTR_NONNULL(1);
uint BLI_heapsimple_len(const HeapSimple *heap) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1);
/**
 * Return the lowest value of the heap.
 */
float BLI_heapsimple_top_value(const HeapSimple *heap) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1);
/**
 * Pop the top node off the heap and return its pointer.
 */
void *BLI_heapsimple_pop_min(HeapSimple *heap) ATTR_NONNULL(1);

#ifdef __cplusplus
}
#endif