/*
    ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

/**
 * @file    hal_buffers.c
 * @brief   I/O Buffers code.
 *
 * @addtogroup HAL_BUFFERS
 * @{
 */

#include "hal.h"

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local variables and types.                                         */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   Initializes an input double buffer object.
 *
 * @param[out] ibqp     pointer to the @p io_buffers_queue_t object
 * @param[in] bp        pointer to a memory area allocated for buffers
 * @param[in] size      buffer size, including the size field which is the
 *                      size of a @p size_t
 * @param[in] n         number of buffers
 * @param[in] infy      callback called when a buffer is returned to the queue
 * @param[in] link      application defined pointer
 *
 * @init
 */
void ibqObjectInit(input_buffers_queue_t *ibqp, uint8_t *bp,
                   size_t size, size_t n,
                   dbnotify_t infy, void *link) {

  osalDbgCheck((ibqp != NULL) && (bp != NULL) && (size >= sizeof(size_t) + 2));

  ibqp->bcounter = 0;
  ibqp->brdptr   = bp;
  ibqp->bwrptr   = bp;
  ibqp->btop     = bp + (size * n);     /* Pre-calculated for speed.*/
  ibqp->bsize    = size;
  ibqp->bn       = n;
  ibqp->buffers  = bp;
  ibqp->ptr      = NULL;
  ibqp->notify   = infy;
  ibqp->link     = link;
}

/**
 * @brief   Gets a buffer for posting in the queue.
 * @note    The function always returns the same buffer if called repeatedly.
 *
 * @param[out] ibqp     pointer to the @p input_buffers_queue_t object
 * @return              A pointer to the next buffer to be filled.
 * @retval NULL         if the queue is full.
 *
 * @iclass
 */
uint8_t *ibqGetNextBufferI(input_buffers_queue_t *ibqp) {

  osalDbgCheckClassI();

  if (ibqIsFullI(ibqp)) {
    return NULL;
  }

  return ibqp->bwrptr + sizeof (size_t);
}

/**
 * @brief   Posts a buffer in the queue.
 *
 * @param[out] ibqp     pointer to the @p input_buffers_queue_t object
 * @param[in] size      used size of the buffer
 *
 * @iclass
 */
void ibqPostBufferI(io_buffers_queue_t *ibqp, size_t size) {

  osalDbgCheckClassI();
  osalDbgAssert(!ibqIsFullI(ibqp), "buffered queue full");

  /* Writing size field in the buffer.*/
  *((size_t *)ibqp->bwrptr) = size;

  /* Posting the buffer in the queue.*/
  ibqp->bcounter++;
  ibqp->bwrptr += ibqp->bsize;
  if (ibqp->bwrptr >= ibqp->btop) {
    ibqp->bwrptr = ibqp->buffers;
  }

  /* Waking up one waiting thread, if any.*/
  osalThreadDequeueNextI(&ibqp->waiting, MSG_OK);
}

/**
 * @brief   Input queue read with timeout.
 * @details This function reads a byte value from an input queue. If
 *          the queue is empty then the calling thread is suspended until a
 *          new buffer arrives in the queue or a timeout occurs.
 * @note    The callback is invoked before reading the character from the
 *          buffer or before entering the suspended state.
 *
 * @param[in] ibqp      pointer to the @p input_buffers_queue_t object
 * @param[in] timeout   the number of ticks before the operation timeouts,
 *                      the following special values are allowed:
 *                      - @a TIME_IMMEDIATE immediate timeout.
 *                      - @a TIME_INFINITE no timeout.
 *                      .
 * @return              A byte value from the queue.
 * @retval MSG_TIMEOUT  if the specified time expired.
 * @retval MSG_RESET    if the queue has been reset.
 *
 * @api
 */
msg_t ibqGetTimeout(input_buffers_queue_t *ibqp, systime_t timeout) {

}

/**
 * @brief   Input queue read with timeout.
 * @details The function reads data from an input queue into a buffer.
 *          The operation completes when the specified amount of data has been
 *          transferred or after the specified timeout or if the queue has
 *          been reset.
 * @note    The function is not atomic, if you need atomicity it is suggested
 *          to use a semaphore or a mutex for mutual exclusion.
 * @note    The callback is invoked before reading each character from the
 *          buffer or before entering the state @p THD_STATE_WTQUEUE.
 *
 * @param[in] ibqp      pointer to the @p input_buffers_queue_t object
 * @param[out] bp       pointer to the data buffer
 * @param[in] n         the maximum amount of data to be transferred, the
 *                      value 0 is reserved
 * @param[in] timeout   the number of ticks before the operation timeouts,
 *                      the following special values are allowed:
 *                      - @a TIME_IMMEDIATE immediate timeout.
 *                      - @a TIME_INFINITE no timeout.
 *                      .
 * @return              The number of bytes effectively transferred.
 *
 * @api
 */
size_t ibqReadTimeout(input_buffers_queue_t *ibqp, uint8_t *bp,
                      size_t n, systime_t timeout) {

}

/** @} */