/*
 * Copyright (c) 2022 Intel Corporation.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/rtio/rtio_executor_simple.h>
#include <zephyr/rtio/rtio.h>
#include <zephyr/kernel.h>

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(rtio_executor_simple, CONFIG_RTIO_LOG_LEVEL);


/**
 * @brief Submit submissions to simple executor
 *
 * The simple executor provides no concurrency instead
 * execution each submission chain one after the next.
 *
 * @param r RTIO context
 *
 * @retval 0 Always succeeds
 */
int rtio_simple_submit(struct rtio *r)
{
	/* TODO For each submission queue entry chain,
	 * submit the chain to the first iodev
	 */
	struct rtio_sqe *sqe = rtio_spsc_consume(r->sq);

	if (sqe != NULL) {
		rtio_iodev_submit(sqe, r);
	}

	return 0;
}

/**
 * @brief Callback from an iodev describing success
 */
void rtio_simple_ok(struct rtio *r, const struct rtio_sqe *sqe, int result)
{
	rtio_cqe_submit(r, result, sqe->userdata);
	rtio_spsc_release(r->sq);
	rtio_simple_submit(r);
}

/**
 * @brief Callback from an iodev describing error
 */
void rtio_simple_err(struct rtio *r, const struct rtio_sqe *sqe, int result)
{
	struct rtio_sqe *nsqe;
	bool chained;

	rtio_cqe_submit(r, result, sqe->userdata);
	chained = sqe->flags & RTIO_SQE_CHAINED;
	rtio_spsc_release(r->sq);

	if (chained) {

		nsqe = rtio_spsc_consume(r->sq);
		while (nsqe != NULL && nsqe->flags & RTIO_SQE_CHAINED) {
			rtio_cqe_submit(r, -ECANCELED, nsqe->userdata);
			rtio_spsc_release(r->sq);
			nsqe = rtio_spsc_consume(r->sq);
		}

		if (nsqe != NULL) {
			rtio_iodev_submit(nsqe, r);
		}

	} else {
		/* Now we can submit the next in the queue if we aren't done */
		rtio_simple_submit(r);
	}
}