/*************************************************************************
          Record-ALSA.h  -  device for audio recording via ALSA
                             -------------------
    begin                : Sun Jul 24 2005
    copyright            : (C) 2005 by Thomas Eschenbacher
    email                : Thomas.Eschenbacher@gmx.de
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program 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.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef RECORD_ALSA_H
#define RECORD_ALSA_H

#include "config.h"
#ifdef HAVE_ALSA_SUPPORT

/*
 * use the new ALSA HW/SW params API, needed to compile under SuSE-9.0
 * (workaround as seen in http://www.linuxjournal.com/article/6735)
 */
#define ALSA_PCM_NEW_HW_PARAMS_API
#define ALSA_PCM_NEW_SW_PARAMS_API

#include <alsa/asoundlib.h>

#include <QList>
#include <QMap>
#include <QString>

#include "libkwave/Compression.h"
#include "libkwave/SampleFormat.h"

#include "RecordDevice.h"

namespace Kwave
{
    class RecordALSA: public Kwave::RecordDevice
    {
    public:

        /** Constructor */
        RecordALSA();

        /** Destructor */
        ~RecordALSA() override;

        /**
         * Open the record device.
         * @param dev path of the record device
         * @retval QString() if successful
         * @retval QString::number(ENODEV) if device not found
         * @retval QString::number(EBUSY) if device is busy
         * @retval QString::number(EINVAL) on invalid parameters
         * @retval QString(...) device specific error message
         *                      (already translated)
         */
        QString open(const QString &dev) override;

        /**
         * Read the raw audio data from the record device.
         * @param buffer array of bytes to receive the audio data
         *        might be resized for alignment
         * @param offset offset in bytes within the buffer
         * @return number of bytes read, zero or negative if failed
         */
        virtual int read(QByteArray &buffer, unsigned int offset)
            override;

        /** Close the device */
        int close() override;

        /** return a string list with supported device names */
        QStringList supportedDevices() override;

        /**
         * Detect the minimum and maximum number of tracks.
         * If the detection fails, minimum and maximum are set to zero.
         * @param min receives the lowest supported number of tracks
         * @param max receives the highest supported number of tracks
         * @return zero or positive number if ok,
         *         negative error number if failed
         */
        virtual int detectTracks(unsigned int &min, unsigned int &max)
            override;

        /**
         * Try to set a new number of tracks.
         * @note the device must be open
         * @param tracks the number of tracks to be set, can be modified and
         *        decreased to the next supported number of tracks if the
         *        underlying driver supports that.
         * @return zero on success, negative error code if failed
         */
        int setTracks(unsigned int &tracks) override;

        /** Returns the current number of tracks */
        int tracks() override;

        /** get a list of supported sample rates */
        QList<double> detectSampleRates() override;

        /**
         * Try to set a new sample rate.
         * @param new_rate the sample rate to be set [samples/second], can
         *        be modified and rounded up/down to the nearest supported
         *        sample rate if the underlying driver supports that.
         * @return zero on success, negative error code if failed
         */
        int setSampleRate(double &new_rate) override;

        /** Returns the current sample rate of the device */
        double sampleRate() override;

        /**
         * Gets a list of supported compression types. If no compression is
         * supported, the list might be empty.
         */
        virtual QList<Kwave::Compression::Type> detectCompressions()
            override;

        /**
         * Try to set a new compression type.
         * @param new_compression the identifier of the new compression
         * @return zero on success, negative error code if failed
         * @see class Compression
         */
        virtual int setCompression(Kwave::Compression::Type new_compression)
            override;

        /** Returns the current compression type (0==none) */
        Kwave::Compression::Type compression() override;

        /**
         * Detect a list of supported bits per sample.
         * @note this depends on the compression type
         * @return a list of bits per sample, empty if failed
         */
        QList<unsigned int> supportedBits() override;

        /**
         * Set the resolution in bits per sample
         * @param new_bits resolution [bits/sample]
         */
        int setBitsPerSample(unsigned int new_bits) override;

        /**
         * Returns the current resolution in bits per sample or a negative
         * error code if failed
         */
        int bitsPerSample() override;

        /**
         * Gets a list of supported sample formats.
         * @note this depends on the current setting of the compression!
         */
        virtual QList<Kwave::SampleFormat::Format> detectSampleFormats()
            override;

        /**
         * Try to set a new sample format (signed/unsigned)
         * @param new_format the identifier for the new format
         * @return zero on success, negative error code if failed
         * @see class SampleFormat
         */
        virtual int setSampleFormat(Kwave::SampleFormat::Format new_format)
            override;

        /** Returns the current sample format (signed/unsigned) */
        Kwave::SampleFormat::Format sampleFormat() override;

        /** Returns the current endianness (big/little) */
        Kwave::byte_order_t endianness() override;

    private:

        /**
         * Walk through the list of all known formats and collect the
         * ones that are supported into "m_supported_formats".
         */
        void detectSupportedFormats();

        /**
         * Initialize the ALSA device with current parameters and
         * prepare it for recording.
         * @return zero on success or negative error code
         *         -EINVAL or -EIO
         */
        int initialize();

        /**
         * create a ALSA device format (enum) from parameters.
         * @param compression the compression type
         * @see Compression
         * @param bits the number of bits per sample, related
         *        to the decoded stream
         * @param sample_format the sample format, as defined in
         *        libaudiofile (signed or unsigned)
         * @return the index of the best matching format within the list
         *         of known formats, or -1 if no match was found
         */
        int mode2format(Kwave::Compression::Type compression, int bits,
                        Kwave::SampleFormat::Format sample_format);

        /** scan all ALSA devices, re-creates m_device_list */
        void scanDevices();

        /**
         * Translate a verbose device name into a ALSA hardware device name.
         *
         * @param name verbose name of the device
         * @return device name that can be used for snd_pcm_open()
         */
        QString alsaDeviceName(const QString &name);

    private:

        /** handle of the source device or null if not open */
        snd_pcm_t *m_handle;

        /** ALSA hardware parameters */
        snd_pcm_hw_params_t *m_hw_params;

        /** ALSA software parameters */
        snd_pcm_sw_params_t *m_sw_params;

        /** result of the "open" call, of interest when m_handle == 0 */
        int m_open_result;

        /**
         * dictionary for translating verbose device names
         * into ALSA hardware device names
         */
        static QMap<QString, QString> m_device_list;

        /** number of tracks [0...N-1] */
        unsigned int m_tracks;

        /** sample rate  */
        double m_rate;

        /** compression mode */
        Kwave::Compression::Type m_compression;

        /** resolution [bits per sample] */
        unsigned int m_bits_per_sample;

        /**
         * Number of bytes per sample, already multiplied with
         * the number of channels (m_channels)
         */
        unsigned int m_bytes_per_sample;

        /** sample format (signed int, unsigned int, float, ... */
        Kwave::SampleFormat::Format m_sample_format;

        /**
         * list of supported formats of the current device, indices in
         * the global list of known formats.
         * Only valid after a successful call to "open()",
         * otherwise empty
         */
        QList<int> m_supported_formats;

        /** true if initialize() has been successfully been run */
        bool m_initialized;

        /** size of the transfer buffer in bytes */
        unsigned int m_buffer_size;

        /** number of samples per period */
        snd_pcm_uframes_t m_chunk_size;

    };
}

#endif /* HAVE_ALSA_SUPPORT */

#endif /* RECORD_ALSA_H */

//***************************************************************************
//***************************************************************************