/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set et sw=2 ts=2: */
/***************************************************************************
 *            mixer.h
 *
 *  Tue Sep 23 14:38:54 CEST 2014
 *  Copyright 2014 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of LibAudioIO.
 *
 *  LibAudioIO is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *  
 *  LibAudioIO 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
 *  Lesser General Public License for more details.
 *  
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with LibAudioIO; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
#ifndef __LIBAUDIOIO_MIXER_H__
#define __LIBAUDIOIO_MIXER_H__

// Make API behave like ALSA 1.x.x with ALSA 0.9.x
#define ALSA_PCM_NEW_HW_PARAMS_API

#include <asoundlib.h>

#include <exception>
#include <string>
#include <vector>

/**
 * A Mixer object represents a single group of channels, for example the two
 * channels of a stereo mixer.
 */
class Mixer {
public:
  /**
   * Mixer constructor is not to be called "manually" is is invoked by
   * Device::getMixer()
   */
  Mixer(snd_mixer_t *handle, snd_mixer_elem_t *elem);
  ~Mixer();

  /**
   * Get number of channels in this mixer 'strip'
   */
  int numberOfChannels();

  /**
   * Return true if this mixer is a capture device, false otherwise.
   */
  bool isCapture();

  /**
   * Return true if this mixer is a playback device, false otherwise.
   */
  bool isPlayback();

  /**
   * Return true if this mixer is a enum, false otherwise.
   */
  bool isEnum();

  /**
   * For capture channels only!
   * Set arm for recording flag on all mixer channels.
   */
  void setCapture(bool capture);

  /**
   * Return true if all channels are armed for recording.
   * Return false if not a capture channels strip, or if at least one channel
   * is not armed.
   */
  bool capture();

  /**
   * Set enum value.
   */
  void setEnumValue(std::string value);

  /**
   * Get enum value.
   */
  std::string enumValue();

  /**
   * Get list of possible enum values.
   */
  std::vector<std::string> enumValues();

  /**
   * Set mixer volume level in dB.
   * Returns 0 on succes. On error (no such channel) 1 returned.
   */
  int setLevel(int channel, float level);

  /**
   * Get mixer volume level in dB.
   * On error (no such channel) -INF is returned.
   */
  float level(int channel);

  typedef struct {
    float min;
    float max;
  } range_t;

  /**
   * Poll the valid volume range of this mixer in dB.
   */
  range_t range();

  /**
   * Mute/unmute this mixer (only playback channels).
   */
  void setMuted(bool muted);

  /**
   * Get mute/unmute state of this mixer (only playback channels).
   */
  bool muted();

private:
  snd_mixer_selem_channel_id_t chanId(int idx);

  snd_mixer_t *handle;
  snd_mixer_elem_t *elem;
};

#endif/*__LIBAUDIOIO_MIXER_H__*/