#include <stdarg.h>
#include <stdlib.h>
#include "lighting.h"

/* Returns a pointer to the next unused item on the heap */
void* new_from_heap(Heap* heap)
{
	/* Grow heap if necessary */
	if (heap->count == heap->capacity) {
		int i;
		heap->capacity += heap->step;
		heap->data = realloc(heap->data, sizeof(void*) *
				heap->capacity);
		for (i = heap->count; i < heap->capacity; i++)
			heap->data[i] = heap->create();
	}
	return heap->data[heap->count++];
}

/* Removes a pointer from the heap */
void delete_from_heap(Heap* heap, void* data)
{
	int index;

	/* Find the index of the given data */
	for (index = 0; index < heap->count; index++)
		if (heap->data[index] == data) break;

	/* Couldn't find it? */
	if (index == heap->count) return;

	/* Remove the pointer */
	heap->count--;
	if (index < heap->count) {
		void* tmp = heap->data[index];
		heap->data[index] = heap->data[heap->count];
		heap->data[heap->count] = tmp;
	}
}

/* Calls a function on all the data in the heap */
void _process_heap(Heap* heap, void (*proc)(void*))
{
	void** data = heap->data;
	void** data_end = data + heap->count;
	for (; data < data_end; data++)
		proc(*data);
}

/* Calls a function on all the data in the heap */
void process_heap_va(Heap* heap, void (*proc)(void*, va_list), ...)
{
	va_list ap;
	void** data = heap->data;
	void** data_end = data + heap->count;
	for (; data < data_end; data++) {
		va_start(ap, proc);
		proc(*data, ap);
		va_end(ap);
	}
}

/* Empties the heap (the old pointer array will be recycled) */
void empty_heap(Heap* heap)
{
	heap->count = 0;
}

/* Creates a heap */
void _create_heap(Heap* heap, int capacity, int step, void*(*create)(void),
void(*destroy)(void*))
{
	int i;
	heap->data = malloc(sizeof(void*) * capacity);
	for (i = 0; i < capacity; i++)
		heap->data[i] = create();
	heap->count = 0;
	heap->capacity = capacity;
	heap->step = step;
	heap->create = create;
	heap->destroy = destroy;
}

/* Deallocates the entire heap */
/* Doesn't deallocate things the nodes refer to */
void destroy_heap(Heap* heap)
{
	int i;
	for (i = 0; i < heap->capacity; i++)
		heap->destroy(heap->data[i]);
	free(heap->data);
	heap->data = NULL;
	heap->count = 0;
	heap->capacity = 0;
}