/**

 * FreeRDP: A Remote Desktop Protocol Implementation

 * Audio Output Virtual Channel

 *

 * Copyright (c) 2015 Rozhuk Ivan <rozhuk.im@gmail.com>

 * Copyright 2015 Thincast Technologies GmbH

 * Copyright 2015 DI (FH) Martin Haimberger <martin.haimberger@thincast.com>

 *

 * 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.

 */

#include <freerdp/config.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <winpr/crt.h>

#include <winpr/string.h>

#include <winpr/cmdline.h>

#include <winpr/sysinfo.h>

#include <winpr/collections.h>

#include <err.h>

#include <errno.h>

#include <fcntl.h>

#include <libgen.h>

#include <limits.h>

#include <unistd.h>

#include <oss-includes.h>

#include <sys/ioctl.h>

#include <freerdp/types.h>

#include <freerdp/settings.h>

#include <freerdp/channels/log.h>

#include "rdpsnd_main.h"

typedef struct

{

  rdpsndDevicePlugin device;

  int pcm_handle;

  int mixer_handle;

  int dev_unit;

  int supported_formats;

  UINT32 latency;

  AUDIO_FORMAT format;

} rdpsndOssPlugin;

#define OSS_LOG_ERR(_text, _error)                                        \

  do                                                                    \

  {                                                                     \

    if ((_error) != 0)                                                \

    {                                                                 \

      char ebuffer[256] = WINPR_C_ARRAY_INIT;                       \

      WLog_ERR(TAG, "%s: %i - %s", (_text), (_error),               \

               winpr_strerror((_error), ebuffer, sizeof(ebuffer))); \

    }                                                                 \

  } while (0)

static int rdpsnd_oss_get_format(const AUDIO_FORMAT* format)

{

  switch (format->wFormatTag)

  {

    case WAVE_FORMAT_PCM:

      switch (format->wBitsPerSample)

      {

        case 8:

          return AFMT_S8;

        case 16:

          return AFMT_S16_LE;

        default:

          break;

      }

      break;

    default:

      break;

  }

  return 0;

}

static BOOL rdpsnd_oss_format_supported(rdpsndDevicePlugin* device, const AUDIO_FORMAT* format)

{

  int req_fmt = 0;

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)device;

  if (device == nullptr || format == nullptr)

    return FALSE;

  switch (format->wFormatTag)

  {

    case WAVE_FORMAT_PCM:

      if (format->cbSize != 0 || format->nSamplesPerSec > 48000 ||

          (format->wBitsPerSample != 8 && format->wBitsPerSample != 16) ||

          (format->nChannels != 1 && format->nChannels != 2))

        return FALSE;

      break;

    default:

      return FALSE;

  }

  req_fmt = rdpsnd_oss_get_format(format);

  /* Check really supported formats by dev. */

  if (oss->pcm_handle != -1)

  {

    if ((req_fmt & oss->supported_formats) == 0)

      return FALSE;

  }

  else

  {

    if (req_fmt == 0)

      return FALSE;

  }

  return TRUE;

}

static BOOL rdpsnd_oss_set_format(rdpsndDevicePlugin* device, const AUDIO_FORMAT* format,

                                  UINT32 latency)

{

  int tmp = 0;

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)device;

  if (device == nullptr || oss->pcm_handle == -1 || format == nullptr)

    return FALSE;

  oss->latency = latency;

  CopyMemory(&(oss->format), format, sizeof(AUDIO_FORMAT));

  tmp = rdpsnd_oss_get_format(format);

  if (ioctl(oss->pcm_handle, SNDCTL_DSP_SETFMT, &tmp) == -1)

  {

    OSS_LOG_ERR("SNDCTL_DSP_SETFMT failed", errno);

    return FALSE;

  }

  tmp = format->nChannels;

  if (ioctl(oss->pcm_handle, SNDCTL_DSP_CHANNELS, &tmp) == -1)

  {

    OSS_LOG_ERR("SNDCTL_DSP_CHANNELS failed", errno);

    return FALSE;

  }

  tmp = (int)format->nSamplesPerSec;

  if (ioctl(oss->pcm_handle, SNDCTL_DSP_SPEED, &tmp) == -1)

  {

    OSS_LOG_ERR("SNDCTL_DSP_SPEED failed", errno);

    return FALSE;

  }

  tmp = format->nBlockAlign;

  if (ioctl(oss->pcm_handle, SNDCTL_DSP_SETFRAGMENT, &tmp) == -1)

  {

    OSS_LOG_ERR("SNDCTL_DSP_SETFRAGMENT failed", errno);

    return FALSE;

  }

  return TRUE;

}

static void rdpsnd_oss_open_mixer(rdpsndOssPlugin* oss)

{

  int devmask = 0;

  char mixer_name[PATH_MAX] = "/dev/mixer";

  if (oss->mixer_handle != -1)

    return;

  if (oss->dev_unit != -1)

    (void)sprintf_s(mixer_name, PATH_MAX - 1, "/dev/mixer%i", oss->dev_unit);

  if ((oss->mixer_handle = open(mixer_name, O_RDWR)) < 0)

  {

    OSS_LOG_ERR("mixer open failed", errno);

    oss->mixer_handle = -1;

    return;

  }

  if (ioctl(oss->mixer_handle, SOUND_MIXER_READ_DEVMASK, &devmask) == -1)

  {

    OSS_LOG_ERR("SOUND_MIXER_READ_DEVMASK failed", errno);

    close(oss->mixer_handle);

    oss->mixer_handle = -1;

    return;

  }

}

/* Build the OSS PCM device path (/dev/dsp or /dev/dsp<unit>). */

static void rdpsnd_oss_pcm_device_name(const rdpsndOssPlugin* oss, char* dev_name, size_t size)

{

  if (oss->dev_unit != -1)

    (void)sprintf_s(dev_name, size, "/dev/dsp%i", oss->dev_unit);

  else

    (void)sprintf_s(dev_name, size, "/dev/dsp");

}

static BOOL rdpsnd_oss_open(rdpsndDevicePlugin* device, const AUDIO_FORMAT* format, UINT32 latency)

{

  char dev_name[PATH_MAX] = { 0 };

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)device;

  if (device == nullptr || oss->pcm_handle != -1)

    return TRUE;

  rdpsnd_oss_pcm_device_name(oss, dev_name, sizeof(dev_name));

  WLog_INFO(TAG, "open: %s", dev_name);

  if ((oss->pcm_handle = open(dev_name, O_WRONLY)) < 0)

  {

    OSS_LOG_ERR("sound dev open failed", errno);

    oss->pcm_handle = -1;

    return FALSE;

  }

  if (ioctl(oss->pcm_handle, SNDCTL_DSP_GETFMTS, &oss->supported_formats) == -1)

  {

    OSS_LOG_ERR("SNDCTL_DSP_GETFMTS failed", errno);

    close(oss->pcm_handle);

    oss->pcm_handle = -1;

    return FALSE;

  }

  rdpsnd_oss_set_format(device, format, latency);

  rdpsnd_oss_open_mixer(oss);

  return TRUE;

}

static void rdpsnd_oss_close(rdpsndDevicePlugin* device)

{

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)device;

  if (device == nullptr)

    return;

  if (oss->pcm_handle != -1)

  {

    WLog_INFO(TAG, "close: dsp");

    close(oss->pcm_handle);

    oss->pcm_handle = -1;

  }

  if (oss->mixer_handle != -1)

  {

    WLog_INFO(TAG, "close: mixer");

    close(oss->mixer_handle);

    oss->mixer_handle = -1;

  }

}

static void rdpsnd_oss_free(rdpsndDevicePlugin* device)

{

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)device;

  if (device == nullptr)

    return;

  rdpsnd_oss_close(device);

  free(oss);

}

static UINT32 rdpsnd_oss_get_volume(rdpsndDevicePlugin* device)

{

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)device;

  WINPR_ASSERT(oss);

  int vol = 0;

  /* On error return 50% volume. */

  UINT32 dwVolumeLeft = ((50 * 0xFFFF) / 100);  /* 50% */

  UINT32 dwVolumeRight = ((50 * 0xFFFF) / 100); /* 50% */

  UINT32 dwVolume = ((dwVolumeLeft << 16) | dwVolumeRight);

  if (device == nullptr || oss->mixer_handle == -1)

    return dwVolume;

  if (ioctl(oss->mixer_handle, MIXER_READ(SOUND_MIXER_VOLUME), &vol) == -1)

  {

    OSS_LOG_ERR("MIXER_READ", errno);

    return dwVolume;

  }

  dwVolumeLeft = (((vol & 0x7f) * 0xFFFF) / 100);

  dwVolumeRight = ((((vol >> 8) & 0x7f) * 0xFFFF) / 100);

  dwVolume = ((dwVolumeLeft << 16) | dwVolumeRight);

  return dwVolume;

}

static BOOL rdpsnd_oss_set_volume(rdpsndDevicePlugin* device, UINT32 value)

{

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)device;

  WINPR_ASSERT(oss);

  if (device == nullptr || oss->mixer_handle == -1)

    return FALSE;

  unsigned left = (((value & 0xFFFF) * 100) / 0xFFFF);

  unsigned right = ((((value >> 16) & 0xFFFF) * 100) / 0xFFFF);

  left |= (right << 8);

  if (ioctl(oss->mixer_handle, MIXER_WRITE(SOUND_MIXER_VOLUME), &left) == -1)

  {

    OSS_LOG_ERR("WRITE_MIXER", errno);

    return FALSE;

  }

  return TRUE;

}

static UINT rdpsnd_oss_play(rdpsndDevicePlugin* device, const BYTE* data, size_t size)

{

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)device;

  if (device == nullptr || oss->mixer_handle == -1)

    return 0;

  while (size > 0)

  {

    ssize_t status = write(oss->pcm_handle, data, size);

    if (status < 0)

    {

      OSS_LOG_ERR("write fail", errno);

      rdpsnd_oss_close(device);

      rdpsnd_oss_open(device, nullptr, oss->latency);

      break;

    }

    data += status;

    if ((size_t)status <= size)

      size -= (size_t)status;

    else

      size = 0;

  }

  return 10; /* TODO: Get real latency in [ms] */

}

static int rdpsnd_oss_parse_addin_args(rdpsndDevicePlugin* device, const ADDIN_ARGV* args)

{

  int status = 0;

  char* str_num = nullptr;

  char* eptr = nullptr;

  DWORD flags = 0;

  const COMMAND_LINE_ARGUMENT_A* arg = nullptr;

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)device;

  COMMAND_LINE_ARGUMENT_A rdpsnd_oss_args[] = {

    { "dev", COMMAND_LINE_VALUE_REQUIRED, "<device>", nullptr, nullptr, -1, nullptr, "device" },

    { nullptr, 0, nullptr, nullptr, nullptr, -1, nullptr, nullptr }

  };

  flags =

      COMMAND_LINE_SIGIL_NONE | COMMAND_LINE_SEPARATOR_COLON | COMMAND_LINE_IGN_UNKNOWN_KEYWORD;

  status = CommandLineParseArgumentsA(args->argc, args->argv, rdpsnd_oss_args, flags, oss,

                                      nullptr, nullptr);

  if (status < 0)

    return status;

  arg = rdpsnd_oss_args;

  errno = 0;

  do

  {

    if (!(arg->Flags & COMMAND_LINE_VALUE_PRESENT))

      continue;

    CommandLineSwitchStart(arg) CommandLineSwitchCase(arg, "dev")

    {

      str_num = _strdup(arg->Value);

      if (!str_num)

        return ERROR_OUTOFMEMORY;

      {

        long val = strtol(str_num, &eptr, 10);

        if ((errno != 0) || (val < INT32_MIN) || (val > INT32_MAX))

        {

          free(str_num);

          return CHANNEL_RC_NULL_DATA;

        }

        oss->dev_unit = (int)val;

      }

      if (oss->dev_unit < 0 || *eptr != '\0')

        oss->dev_unit = -1;

      free(str_num);

    }

    CommandLineSwitchEnd(arg)

  } while ((arg = CommandLineFindNextArgumentA(arg)) != nullptr);

  return status;

}

/**

 * Function description

 *

 * @return 0 on success, otherwise a Win32 error code

 */

FREERDP_ENTRY_POINT(UINT VCAPITYPE oss_freerdp_rdpsnd_client_subsystem_entry(

    PFREERDP_RDPSND_DEVICE_ENTRY_POINTS pEntryPoints))

{

  const ADDIN_ARGV* args = nullptr;

  rdpsndOssPlugin* oss = (rdpsndOssPlugin*)calloc(1, sizeof(rdpsndOssPlugin));

  if (!oss)

    return CHANNEL_RC_NO_MEMORY;

  oss->device.Open = rdpsnd_oss_open;

  oss->device.FormatSupported = rdpsnd_oss_format_supported;

  oss->device.GetVolume = rdpsnd_oss_get_volume;

  oss->device.SetVolume = rdpsnd_oss_set_volume;

  oss->device.Play = rdpsnd_oss_play;

  oss->device.Close = rdpsnd_oss_close;

  oss->device.Free = rdpsnd_oss_free;

  oss->pcm_handle = -1;

  oss->mixer_handle = -1;

  oss->dev_unit = -1;

  args = pEntryPoints->args;

  if (rdpsnd_oss_parse_addin_args(&oss->device, args) < 0)

  {

    free(oss);

    return ERROR_INVALID_PARAMETER;

  }

  /* Only register the backend if the OSS device actually exists and is

   * writable. On systems without OSS (no /dev/dsp) this leaves rdpsnd->device

   * unset so subsystem selection falls through to the next available backend.

   * Otherwise oss gets selected and the first audio the server streams fails

   * to open the device, which aborts the whole RDP connection. */

  {

    char dev_name[PATH_MAX] = { 0 };

    rdpsnd_oss_pcm_device_name(oss, dev_name, sizeof(dev_name));

    if (access(dev_name, W_OK) != 0)

    {

      WLog_WARN(TAG, "OSS device %s not available (errno %d), skipping oss backend", dev_name,

                errno);

      free(oss);

      return CHANNEL_RC_INITIALIZATION_ERROR;

    }

  }

  pEntryPoints->pRegisterRdpsndDevice(pEntryPoints->rdpsnd, (rdpsndDevicePlugin*)oss);

  return CHANNEL_RC_OK;

}