/****************************************************************************
 * apps/examples/i2schar/i2schar_main.c
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you 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.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sys/types.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <errno.h>
#include <debug.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <nuttx/audio/audio.h>
#include <nuttx/audio/i2s.h>

#include "i2schar.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Types
 ****************************************************************************/

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/****************************************************************************
 * Public Data
 ****************************************************************************/

struct i2schar_state_s g_i2schar;

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: i2schar_devpath
 ****************************************************************************/

static void i2schar_devpath(FAR struct i2schar_state_s *i2schar,
                            FAR const char *devpath)
{
  /* Get rid of any old device path */

  if (i2schar->devpath)
    {
      free(i2schar->devpath);
    }

  /* Then set-up the new device path by copying the string */

  i2schar->devpath = strdup(devpath);
}

/****************************************************************************
 * Name: i2schar_help
 ****************************************************************************/

static void i2schar_help(FAR struct i2schar_state_s *i2schar)
{
  printf("Usage: i2schar [OPTIONS]\n");
  printf("\nArguments are \"sticky\".\n");
  printf("For example, once the I2C character device is\n");
  printf("specified, that device will be reused until it is changed.\n");
  printf("\n\"sticky\" OPTIONS include:\n");
  printf("  [-p devpath] selects the I2C character device path.  "
         "Default: %s Current: %s\n",
         CONFIG_EXAMPLES_I2SCHAR_DEVPATH,
         g_i2schar.devpath ? g_i2schar.devpath : "NONE");
#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
  printf("  [-l [0|1]] enables/disables loopback mode "
         "(0=disable, 1=enable, no value=enable).  "
         "Default: disabled Current: %s\n",
         g_i2schar.loopback ? "enabled" : "disabled");
#endif
#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
  printf("  [-t count] selects the number of audio buffers to send.  "
         "Default: %d Current: %d\n",
         CONFIG_EXAMPLES_I2SCHAR_TXBUFFERS, i2schar->txcount);
#endif
#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
  printf("  [-r count] selects the number of audio buffers to receive.  "
         "Default: %d Current: %d\n",
         CONFIG_EXAMPLES_I2SCHAR_RXBUFFERS, i2schar->rxcount);
#endif
  printf("  [-h] shows this message and exits\n");
}

/****************************************************************************
 * Name: arg_string
 ****************************************************************************/

static int arg_string(FAR char **arg, FAR char **value)
{
  FAR char *ptr = *arg;

  if (ptr[2] == '\0')
    {
      *value = arg[1];
      return 2;
    }
  else
    {
      *value = &ptr[2];
      return 1;
    }
}

/****************************************************************************
 * Name: arg_decimal
 ****************************************************************************/

static int arg_decimal(FAR char **arg, FAR long *value)
{
  FAR char *string;
  int ret;

  ret = arg_string(arg, &string);
  *value = strtol(string, NULL, 10);
  return ret;
}

/****************************************************************************
 * Name: parse_args
 ****************************************************************************/

static void parse_args(FAR struct i2schar_state_s *i2schar,
                       int argc,
                       FAR char **argv)
{
  FAR char *ptr;
  FAR char *str;
  long value;
  int index;
  int nargs;

  for (index = 1; index < argc; )
    {
      ptr = argv[index];
      if (ptr[0] != '-')
        {
          printf("Invalid options format: %s\n", ptr);
          exit(0);
        }

      switch (ptr[1])
        {
          case 'p':
            nargs = arg_string(&argv[index], &str);
            i2schar_devpath(i2schar, str);
            index += nargs;
            break;

#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
          case 'l':

            /* Check if a value is provided */

            if (ptr[2] == '\0' && index + 1 < argc &&
                argv[index + 1][0] != '-')
              {
                /* Value provided as next argument */

                long loopback = strtol(argv[index + 1], NULL, 10);

                if (loopback == 0)
                  {
                    i2schar->loopback = false;
                  }
                else if (loopback == 1)
                  {
                    i2schar->loopback = true;
                  }
                else
                  {
                    printf("Invalid loopback value: %ld (must be 0 or 1)\n",
                           loopback);
                    exit(1);
                  }

                index += 2;
              }
            else if (ptr[2] == '\0')
              {
                /* No value provided, default to enable */

                i2schar->loopback = true;
                index += 1;
              }

            else
              {
                /* Value provided as part of the same argument */

                long loopback = strtol(&ptr[2], NULL, 10);

                if (loopback == 0)
                  {
                    i2schar->loopback = false;
                  }
                else if (loopback == 1)
                  {
                    i2schar->loopback = true;
                  }
                else
                  {
                    printf("Invalid loopback value: %ld (must be 0 or 1)\n",
                           loopback);
                    exit(1);
                  }

                index += 1;
              }
            break;
#endif

#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
          case 'r':
#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
            if (i2schar->loopback)
              {
                printf("i2schar_main: Warning: -r argument "
                       "ignored in loopback mode\n");
                index += 1;
                break;
              }
#endif

            nargs = arg_decimal(&argv[index], &value);
            if (value < 0)
              {
                printf("Count must be non-negative: %ld\n", value);
                exit(1);
              }

            i2schar->rxcount = (uint32_t)value;
            index += nargs;
            break;
#endif

#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
          case 't':
#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
            if (i2schar->loopback)
              {
                printf("i2schar_main: Warning: -t argument "
                       "ignored in loopback mode\n");
                index += 1;
                break;
              }
#endif

            nargs = arg_decimal(&argv[index], &value);
            if (value < 0)
              {
                printf("Count must be non-negative: %ld\n", value);
                exit(1);
              }

            i2schar->txcount = (uint32_t)value;
            index += nargs;
            break;
#endif

          case 'h':
            i2schar_help(i2schar);
            exit(0);

          default:
            printf("Unsupported option: %s\n", ptr);
            i2schar_help(i2schar);
            exit(1);
        }
    }
}

#ifdef CONFIG_EXAMPLES_I2SCHAR_TX

/****************************************************************************
 * Name: i2schar_prepare_tx_buffer
 ****************************************************************************/

static struct ap_buffer_s *i2schar_prepare_tx_buffer(uint32_t data_width)
{
  FAR struct ap_buffer_s *apb;
  struct audio_buf_desc_s desc;
  int ret;
  int j;
  uint32_t crap = 0;

  /* Allocate an audio buffer of the configured size */

  desc.numbytes   = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE;
  desc.u.pbuffer = &apb;

  ret = apb_alloc(&desc);
  if (ret < 0)
    {
      printf("i2schar_prepare_tx_buffer: ERROR: failed to "
             "allocate buffer: %d\n", ret);
      return NULL;
    }

  /* Fill the audio buffer with sequential data based on data width */

  if (data_width == 8)
    {
      uint8_t *ptr8 = (uint8_t *)apb->samp;

      /* 8-bit data: fill with sequential bytes */

      for (j = 0; j < CONFIG_EXAMPLES_I2SCHAR_BUFSIZE; j++)
        {
          *ptr8++ = crap++;
        }
    }
  else if (data_width == 16)
    {
      /* 16-bit data: fill with sequential 16-bit values */

      uint16_t *ptr16 = (uint16_t *)apb->samp;
      int samples_16bit = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE / 2;
      for (j = 0; j < samples_16bit; j++)
        {
          *ptr16++ = crap++;
        }
    }
  else if (data_width == 24)
    {
      /* 24-bit data: fill with sequential 24-bit values (3 bytes each) */

      uint8_t *ptr8 = apb->samp;
      int samples_24bit = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE / 3;
      for (j = 0; j < samples_24bit; j++)
        {
          /* Store 24-bit value in little-endian format */

          *ptr8++ = crap & 0xff;
          *ptr8++ = (crap >> 8) & 0xff;
          *ptr8++ = (crap >> 16) & 0xff;
          crap++;
        }
    }
  else if (data_width == 32)
    {
      /* 32-bit data: fill with sequential 32-bit values */

      uint32_t *ptr32 = (uint32_t *)apb->samp;
      int samples_32bit = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE / 4;
      for (j = 0; j < samples_32bit; j++)
        {
          *ptr32++ = crap++;
        }
    }
  else
    {
      uint8_t *ptr = (uint8_t *)apb->samp;

      /* Unknown data width, fall back to byte-by-byte */

      printf("i2schar_prepare_tx_buffer: Unknown data width %"PRIu32", "
             "using byte mode\n", data_width);
      for (j = 0, ptr = apb->samp; j < CONFIG_EXAMPLES_I2SCHAR_BUFSIZE; j++)
        {
          *ptr++ = crap++;
        }
    }

  apb->nbytes = CONFIG_EXAMPLES_I2SCHAR_BUFSIZE;

  printf("i2schar_prepare_tx_buffer: Prepared transmitter buffer "
         "with %"PRIu32"-bit data\n", data_width);

  return apb;
}
#endif

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: i2schar_main
 ****************************************************************************/

int main(int argc, FAR char *argv[])
{
  pthread_attr_t attr;
  pthread_addr_t result;
#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
  pthread_t transmitter;
  int fd;
#endif
#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
  pthread_t receiver;
#endif
#if defined(CONFIG_EXAMPLES_I2SCHAR_RX) & defined(CONFIG_EXAMPLES_I2SCHAR_TX)
  struct sched_param param;
#endif
  FAR struct ap_buffer_s *transmitter_apb = NULL;
  uint32_t data_width = 16; /* Default data width */
  int ret;

  UNUSED(ret);

  /* Check if we have initialized */

  if (!g_i2schar.initialized)
    {
#ifdef CONFIG_EXAMPLES_I2SCHAR_DEVINIT
      /* Initialization of the I2C character device is performed by logic
       * external to this test.
       */

      printf("i2schar_main: Initializing external I2C character device\n");
      ret = i2schar_devinit();
      if (ret != OK)
        {
          printf("i2schar_main: i2schar_devinit failed: %d\n", ret);
          return EXIT_FAILURE;
        }
#endif

      /* Set the default values */

      i2schar_devpath(&g_i2schar, CONFIG_EXAMPLES_I2SCHAR_DEVPATH);

#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
      g_i2schar.txcount = CONFIG_EXAMPLES_I2SCHAR_TXBUFFERS;
#endif
#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
      g_i2schar.rxcount = CONFIG_EXAMPLES_I2SCHAR_RXBUFFERS;
#endif

#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
      g_i2schar.loopback = false;  /* Default to disabled */
#endif

      g_i2schar.initialized = true;
    }

  /* Parse the command line */

  parse_args(&g_i2schar, argc, argv);

#ifdef CONFIG_EXAMPLES_I2SCHAR_TX

  /* Get I2S configuration parameters to set data width */

  fd = open(g_i2schar.devpath, O_RDONLY);
  if (fd >= 0)
    {
      ret = ioctl(fd, I2SIOC_GTXDATAWIDTH, (unsigned long)&data_width);
      if (ret >= 0)
        {
          printf("i2schar_main: TX data width: %" PRIu32 " bits\n",
                 data_width);
        }
      else
        {
          printf("i2schar_main: Failed to get TX data width: %d\n", ret);
          printf("i2schar_main: Using default data width: %" PRIu32 " "
                 "bits\n", data_width);
        }

      close(fd);
    }
  else
    {
      printf("i2schar_main: Failed to open device for data width query: "
             "%d\n", errno);
      printf("i2schar_main: Using default data width: %" PRIu32 " bits\n",
             data_width);
    }

  /* Always prepare the transmitter buffer when transmitter is enabled */

  transmitter_apb = i2schar_prepare_tx_buffer(data_width);

  if (transmitter_apb == NULL)
    {
      printf("i2schar_main: ERROR: failed to prepare transmitter buffer\n");
      return EXIT_FAILURE;
    }
#endif

#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)

  /* Handle loopback mode */

  if (g_i2schar.loopback)
    {
      printf("i2schar_main: Loopback mode enabled\n");

      /* In loopback mode, we only send/receive one buffer each */

      g_i2schar.txcount = 1;
      g_i2schar.rxcount = 1;
    }
  else
    {
      printf("i2schar_main: Loopback mode disabled\n");
    }
#endif

  sched_lock();
#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
  /* Start the receiver thread */

  printf("i2schar_main: Start receiver thread\n");
  pthread_attr_init(&attr);

#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
  /* Bump the receiver priority from the default so that it will be above
   * the priority of transmitter.  This is important if a loopback test is
   * being performed; it improves the changes that a receiving audio buffer
   * is in place for each transmission.
   */

  pthread_attr_getschedparam(&attr, &param);
  param.sched_priority++;
  pthread_attr_setschedparam(&attr, &param);
#endif

  /* Set the receiver stack size */

  pthread_attr_setstacksize(&attr, CONFIG_EXAMPLES_I2SCHAR_RXSTACKSIZE);

  /* Start the receiver */

  ret = pthread_create(&receiver, &attr, i2schar_receiver,
                       g_i2schar.loopback ? \
                       (pthread_addr_t)transmitter_apb : NULL);
  if (ret != OK)
    {
      sched_unlock();
      printf("i2schar_main: ERROR: failed to Start receiver thread: %d\n",
             ret);
      return EXIT_FAILURE;
    }

  pthread_setname_np(receiver, "receiver");
#endif

#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
  /* Start the transmitter thread */

  printf("i2schar_main: Start transmitter thread\n");
  pthread_attr_init(&attr);

  /* Set the transmitter stack size */

  pthread_attr_setstacksize(&attr, CONFIG_EXAMPLES_I2SCHAR_TXSTACKSIZE);

  /* Start the transmitter */

  ret = pthread_create(&transmitter, &attr, i2schar_transmitter,
                       (pthread_addr_t)transmitter_apb);
  if (ret != OK)
    {
      sched_unlock();
      printf("i2schar_main: ERROR: failed to Start transmitter thread: %d\n",
             ret);
#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
      printf("i2schar_main: Waiting for the receiver thread\n");
      pthread_join(receiver, &result);
#endif
      return EXIT_FAILURE;
    }

  pthread_setname_np(transmitter, "transmitter");
#endif

  sched_unlock();
#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
  printf("i2schar_main: Waiting for the transmitter thread\n");
  ret = pthread_join(transmitter, &result);
  if (ret != OK)
    {
      printf("i2schar_main: ERROR: pthread_join failed: %d\n", ret);
    }
#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
  else if (g_i2schar.loopback && result != NULL)
    {
      printf("i2schar_main: ERROR: Loopback verification failed\n");
      ret = EXIT_FAILURE;
    }
#endif
#endif

#ifdef CONFIG_EXAMPLES_I2SCHAR_RX
  printf("i2schar_main: Waiting for the receiver thread\n");
  ret = pthread_join(receiver, &result);
  if (ret != OK)
    {
      printf("i2schar_main: ERROR: pthread_join failed: %d\n", ret);
    }
#if defined(CONFIG_EXAMPLES_I2SCHAR_TX) && defined(CONFIG_EXAMPLES_I2SCHAR_RX)
  else if (g_i2schar.loopback && result != NULL)
    {
      printf("i2schar_main: ERROR: Loopback verification failed\n");
      ret = EXIT_FAILURE;
    }
#endif
#endif

#ifdef CONFIG_EXAMPLES_I2SCHAR_TX
  /* Clean up transmitter buffer if it was allocated */

  if (transmitter_apb != NULL)
    {
      apb_free(transmitter_apb);
    }
#endif

  return ret;
}