/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
 *            audioin.cc
 *
 *  Wed Sep 30 11:36:18 CEST 2009
 *  Copyright 2011 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of libaudioin.
 *
 *  libaudioin is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  libaudioin is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with libaudioin; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
#include "audioin.h"

// Use the newer ALSA API
#define ALSA_PCM_NEW_HW_PARAMS_API

#include <asoundlib.h>
#include <exception>
#include <stdlib.h>
#include <unistd.h>
#include <string>

class AudioIn {
public:
  class CouldNotOpenPCMDevice : public std::exception {};
  class UnableToSetHWParams : public std::exception {};
  class PcmBufferTooSmall : public std::exception {};
  class OverRun : public std::exception {};
  class ReadError : public std::exception {};
  class ShortRead : public std::exception {};
  class CouldNotInitialiseParams : public std::exception {};
  class CouldNotSetAccessMode : public std::exception {};
  class CouldNotSetFormat : public std::exception {};
  class CouldNotSetChannelNumber : public std::exception {};
  class UnableToSetSampleRate : public std::exception {};
  class UnableToSetPeriodSize : public std::exception {};
  class MixerInitilisationFailed : public std::exception {};
  class MixerNotInitialised : public std::exception {};
  class InvalidMixerLevel : public std::exception {};
  class IllegalChannelNumber : public std::exception {};
  class CouldNotSetMixerLevel : public std::exception {};

  AudioIn(std::string device, std::string mixer, unsigned int srate, int ch);
  ~AudioIn();

  /**
   * Reads a number of samples from the soundcard.
   * The returned signal is a 16bit mono pcm signal.
   */
  size_t read(void *buf, size_t size);

  int set_level(unsigned int channel, float level);

  unsigned int get_samplerate();

  void set_enable_noise_fix(bool fixit);

private:
  bool noisefix;
  unsigned int samplerate;
  int channels;
  snd_pcm_t *handle;
  snd_pcm_hw_params_t *params;
  unsigned int val;
  int dir;
  snd_pcm_uframes_t frames;

  snd_mixer_t *mixhnd;
  snd_mixer_elem_t *elem;
  long lvl_min, lvl_max;
};

AudioIn::AudioIn(std::string device, std::string mixer_interface,
                 unsigned int srate, int ch)
{
  int open_mode = 0;
  //open_mode |= SND_PCM_NONBLOCK;
  //open_mode |= SND_PCM_NO_AUTO_RESAMPLE;
  //open_mode |= SND_PCM_NO_AUTO_CHANNELS;
  //open_mode |= SND_PCM_NO_AUTO_FORMAT;
  //open_mode |= SND_PCM_NO_SOFTVOL;
  elem = NULL;
  mixhnd = NULL;

  noisefix = false;
  
  samplerate = 0;

	int rc;

  // Open PCM device for recording (capture).
  rc = snd_pcm_open(&handle, device.c_str(), SND_PCM_STREAM_CAPTURE, open_mode);
  if (rc < 0) throw CouldNotOpenPCMDevice();

  // Allocate a hardware parameters object.
  snd_pcm_hw_params_alloca(&params);

  // Fill it in with default values.
  rc = snd_pcm_hw_params_any(handle, params);
  if (rc < 0) throw CouldNotInitialiseParams();

  // Set the desired hardware parameters.

  // Interleaved mode
  rc = snd_pcm_hw_params_set_access(handle, params,
                                    SND_PCM_ACCESS_RW_INTERLEAVED);
  if (rc < 0) throw CouldNotSetAccessMode();

  // Signed 16-bit little-endian format
  rc = snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_S16_LE);
  if (rc < 0) throw CouldNotSetFormat();

  // Set channels (stereo/mono)
  rc = snd_pcm_hw_params_set_channels(handle, params, ch);
  channels = ch;
  if (rc < 0) throw CouldNotSetChannelNumber();

  // Set sampling rate
  samplerate = srate;  
  rc = snd_pcm_hw_params_set_rate_near(handle, params, &samplerate, &dir);
  if(rc < 0) throw UnableToSetSampleRate();
  //if(samplerate != srate) throw UnableToSetSampleRate();

  // NOTE: Setting period size to 32 frames will force use of lowest possible value.
  frames = 512;
  rc = snd_pcm_hw_params_set_period_size_near(handle, params, &frames, &dir);
  if(rc < 0) throw UnableToSetPeriodSize();
 
  // Write the parameters to the driver
  rc = snd_pcm_hw_params(handle, params);
  if (rc < 0) throw UnableToSetHWParams();

  //
  // Set up mixer
  //
  snd_mixer_selem_id_t *mixer;

  // Open mixer device
  if(snd_mixer_open(&mixhnd, 0) != 0) throw MixerInitilisationFailed();

  if(snd_mixer_attach(mixhnd, device.c_str()) != 0)
    throw MixerInitilisationFailed();

  if(snd_mixer_selem_register(mixhnd, NULL, NULL) < 0)
    throw MixerInitilisationFailed();

  if(snd_mixer_load(mixhnd) < 0)
    throw MixerInitilisationFailed();
 
  // Obtain mixer element
  snd_mixer_selem_id_alloca(&mixer);
  if(mixer == NULL) throw MixerInitilisationFailed();
  snd_mixer_selem_id_set_name(mixer, mixer_interface.c_str());
 
  elem = snd_mixer_find_selem(mixhnd, mixer);
  if(elem == NULL) throw MixerInitilisationFailed();

  if(snd_mixer_selem_get_capture_volume_range(elem, &lvl_min, &lvl_max) != 0) {
    throw MixerInitilisationFailed();
  }

  if(snd_mixer_selem_set_capture_switch(elem,
                                        SND_MIXER_SCHN_FRONT_LEFT, 1) != 0) {
    throw MixerInitilisationFailed();
  }

  if(snd_mixer_selem_set_capture_switch(elem,
                                        SND_MIXER_SCHN_FRONT_RIGHT, 1) != 0) {
    throw MixerInitilisationFailed();
  }

  // Obtain mixer enumeration element "Input Source" and set it to 2 (line).
  snd_mixer_selem_id_set_name(mixer, "Input Source");
 
  snd_mixer_elem_t *iselem = snd_mixer_find_selem(mixhnd, mixer);
  if(iselem == NULL) return;

  if(snd_mixer_selem_is_enumerated(iselem)) {
    // Set to line-in
    for(int i = 0; i < 3; i++) {
      char name[16];
      snd_mixer_selem_get_enum_item_name(iselem, i, sizeof(name), name);
      if(std::string(name) == "Line") {
        snd_mixer_selem_set_enum_item(iselem, SND_MIXER_SCHN_MONO, i);
      }
    }
  }
}

AudioIn::~AudioIn()
{
  if(handle) {
    snd_pcm_drain(handle);
    snd_pcm_close(handle);
  }
  if(mixhnd) snd_mixer_close(mixhnd);
}

size_t AudioIn::read(void *buf, size_t size)
{
	int rc;

	if(size < frames * sizeof(short) * channels) {
		throw PcmBufferTooSmall();
	}

	rc = snd_pcm_readi(handle, buf, frames);
	if (rc == -EPIPE) {
		// EPIPE means overrun
		snd_pcm_prepare(handle);
    throw OverRun();
		return 0;
	} else if (rc < 0) {
    throw ReadError();
	} else if (rc != (int)frames) {
    throw ShortRead();
	}

	return rc * sizeof(short) * channels;
}

unsigned int AudioIn::get_samplerate()
{
  return samplerate;
}

int AudioIn::set_level(unsigned int channel, float level)
{

  if(!elem) throw MixerNotInitialised();

  if(level > 1.0 || level < 0.0) throw InvalidMixerLevel();

  long lvl = ((lvl_max - lvl_min) * level) + lvl_min;

  snd_mixer_selem_channel_id_t ch;
  switch(channel) {
  case 0:
    ch = SND_MIXER_SCHN_FRONT_LEFT;
    break;
  case 1:
    ch = SND_MIXER_SCHN_FRONT_RIGHT;
    break;
  default:
    throw IllegalChannelNumber();
    break;
  }
  if(snd_mixer_selem_set_capture_volume(elem, ch, lvl) != 0) {
    throw CouldNotSetMixerLevel();
  }
  return 0;
}


#define MAGIC 0xdeadbeef

struct ai_t {
  unsigned int magic;
  AudioIn *ai;
};

struct ai_t *ai_init(int *err, const char *device, const char *mixer,
                     unsigned int srate, unsigned int ch)
{
  *err = NO_ERROR;

  struct ai_t *handle = new ai_t;
  handle->magic = MAGIC;

  if(handle == NULL) {
    *err = OUT_OF_MEMORY;
    return NULL;
  }

  try {
    handle->ai = new AudioIn(device, mixer, srate, ch);
  } catch(AudioIn::CouldNotOpenPCMDevice &e) { *err = COULD_NOT_OPEN_DEVICE;
  } catch(AudioIn::UnableToSetHWParams &e) { *err = COULD_NOT_SET_HW_PARAMS;
  } catch(AudioIn::CouldNotInitialiseParams &e) { *err = COULD_NOT_INIT_PARAMS;
  } catch(AudioIn::CouldNotSetAccessMode &e) { *err = COULD_NOT_SET_ACCESS_MODE;
  } catch(AudioIn::CouldNotSetFormat &e) { *err = COULD_NOT_SET_FORMAT;
  } catch(AudioIn::CouldNotSetChannelNumber &e) { *err = COULD_NOT_SET_CHANNELS;
  } catch(AudioIn::UnableToSetSampleRate &e) { *err = COULD_NOT_SET_SAMPLE_RATE;
  } catch(AudioIn::UnableToSetPeriodSize &e) { *err = COULD_NOT_SET_PERIOD_SIZE;
  } catch(AudioIn::MixerInitilisationFailed &e) { *err = MIXER_INIT_FAILED;
  }

  if(*err != NO_ERROR) {
    handle->magic = 0;
    delete handle;
    return NULL;
  }

  return handle;
}

int ai_read(int *err, struct ai_t *handle, void *pcm, unsigned int maxsize)
{
  if(*err == 42) { // Magic debug function
    short *p = (short*)pcm;
    for(size_t i = 0; i < maxsize / sizeof(short); i++) {
      p[i] = i;
    }
    *err = NO_ERROR;
    return maxsize;
  }

  *err = NO_ERROR;

  if(handle == NULL || handle->magic != MAGIC || handle->ai == NULL) {
    *err = MISSING_HANDLE;
    return -1;
  }

  try {
    return handle->ai->read(pcm, maxsize);
  } catch(AudioIn::PcmBufferTooSmall &e) { *err = BUFFER_TOO_SMALL;
  } catch(AudioIn::OverRun &e) { *err = BUFFER_OVERRUN;
  } catch(AudioIn::ReadError &e) { *err = READ_ERROR;
  } catch(AudioIn::ShortRead &e) { *err = SHORT_READ;
  }

  return -1;
}

int ai_get_samplerate(int *err, struct ai_t *handle)
{
  *err = NO_ERROR;

  if(handle == NULL || handle->magic != MAGIC || handle->ai == NULL) {
    *err = MISSING_HANDLE;
    return -1;
  }

  return (int)handle->ai->get_samplerate();
}
 

int ai_set_mixer_level(int *err, struct ai_t *handle, unsigned int channel,
                       float level)
{
  *err = NO_ERROR;

  if(handle == NULL || handle->magic != MAGIC || handle->ai == NULL) {
    *err = MISSING_HANDLE;
    return -1;
  }

  try {
    return handle->ai->set_level(channel, level);
  } catch(AudioIn::MixerNotInitialised &e) { *err = MIXER_NOT_INITIALISED;
  } catch(AudioIn::InvalidMixerLevel &e) { *err = INVALID_MIXER_LEVEL;
  } catch(AudioIn::IllegalChannelNumber &e) { *err = INVALID_CHANNEL_NUMBER;
  } catch(AudioIn::CouldNotSetMixerLevel &e) { *err = COULD_NOT_SET_MIXER_LEVEL;
  }

  return -1;
}
  
void ai_close(int *err, struct ai_t *handle)
{
  *err = NO_ERROR;

  if(handle == NULL || handle->magic != MAGIC || handle->ai == NULL) {
    *err = MISSING_HANDLE;
    return;
  }

  delete handle->ai;
  handle->ai = NULL;
  handle->magic = 0;
  delete handle;
}

#ifdef TEST_AUDIOIN
//deps:
//cflags: $(ALSA_CFLAGS)
//libs: $(ALSA_LIBS)

#include <test.h>
#include "test_audio.h"
#include <string.h>

TEST_BEGIN;
int err;
struct ai_t *h;

h = ai_init(&err, "default", "H/W Multi", 44100, 2);
TEST_EQUAL_INT(err, 0, "Check for errors.");
TEST_NOTEQUAL(h, NULL, "Check handle.");

ai_close(&err, h);
TEST_EQUAL_INT(err, 0, "Check for errors.");

h = ai_init(&err, "default", "H/W Multi", 22050, 1);
TEST_EQUAL_INT(err, 0, "Check for errors.");
TEST_NOTEQUAL(h, NULL, "Check handle.");

char pcm[1880]; // Hold exactly one frame.
int r;

r = ai_read(&err, h, pcm, 0);
TEST_EQUAL_INT(r, -1, "We should read something.");
TEST_EQUAL_INT(err, BUFFER_TOO_SMALL, "Check for errors.");

for(int i = 0; i < 100; i++) {
  r = ai_read(&err, h, pcm, sizeof(pcm));
}
TEST_EQUAL_INT(err, 0, "Check for errors.");
TEST_NOTEQUAL_INT(r, 0, "We should read something.");

char ref[sizeof(pcm)];
memset(ref, 0, sizeof(ref));
double diff = compareBuffers(r/sizeof(short), 1, pcm, ref);
TEST_LESS_THAN_FLOAT(diff, 1000.0, "Compare buffers (with no mic on the soundcard)");

short p[1024];
err = 42;
ai_read(&err, h, p, sizeof(p));
for(size_t i = 0; i < sizeof(p) / sizeof(short); i++) {
  TEST_EQUAL_INT(p[i], i, "Compare slide.");
}

ai_close(&err, h);

TEST_END;

#endif/*TEST_AUDIOIN*/