#include "ring_queue.h"

#include "logger.h"
#include "memory/kmemory.h"

b8 ring_queue_create (u32 stride, u32 capacity, void *memory, ring_queue *out_queue) {
	if (!out_queue) {
		KERROR("ring_queue_create requires a valid pointer to hold the queue.");
		return false;
	}

	out_queue->length = 0;
	out_queue->capacity = capacity;
	out_queue->stride = stride;
	out_queue->head = 0;
	out_queue->tail = -1;
	if (memory) {
		out_queue->owns_memory = false;
		out_queue->block = memory;
	} else {
		out_queue->owns_memory = true;
		out_queue->block = kallocate(capacity * stride, MEMORY_TAG_RING_QUEUE);
	}

	return true;
}

void ring_queue_destroy (ring_queue *queue) {
	if (queue) {
		if (queue->owns_memory) {
			kfree(queue->block);
		}
		kzero_memory(queue, sizeof(ring_queue));
	}
}

b8 ring_queue_enqueue (ring_queue *queue, void *value) {
	if (queue && value) {
		if (queue->length == queue->capacity) {
			KERROR("ring_queue_enqueue - Attempted to enqueue value in full ring queue: %p", queue);
			return false;
		}

		queue->tail = (queue->tail + 1) % queue->capacity;

		kcopy_memory(queue->block + (queue->tail * queue->stride), value, queue->stride);
		queue->length++;
		return true;
	}

	KERROR("ring_queue_enqueue requires valid pointers to queue and value.");
	return false;
}

b8 ring_queue_dequeue (ring_queue *queue, void *out_value) {
	if (queue && out_value) {
		if (queue->length == 0) {
			KERROR("ring_queue_dequeue - Attempted to dequeue value in empty ring queue: %p", queue);
			return false;
		}

		kcopy_memory(out_value, queue->block + (queue->head * queue->stride), queue->stride);
		queue->head = (queue->head + 1) % queue->capacity;
		queue->length--;
		return true;
	}

	KERROR("ring_queue_dequeue requires valid pointers to queue and out_value.");
	return false;
}

b8 ring_queue_peek (const ring_queue *queue, void *out_value) {
	if (queue && out_value) {
		if (queue->length == 0) {
			KERROR("ring_queue_peek - Attempted to peek value in empty ring queue: %p", queue);
			return false;
		}

		kcopy_memory(out_value, queue->block + (queue->head * queue->stride), queue->stride);
		return true;
	}

	KERROR("ring_queue_peek requires valid pointers to queue and out_value.");
	return false;
}