/*************************************************************************
    Record-PulseAudio.h  -  device for audio recording via PulesAudio
                             -------------------
    begin                : Sun Okt 20 2013
    copyright            : (C) 2014 by Joerg-Christian Boehme
    email                : joerg@chaosdorf.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 KWAVE_RECORD_PULSEAUDIO_H
#define KWAVE_RECORD_PULSEAUDIO_H

#include "config.h"
#ifdef HAVE_PULSEAUDIO_SUPPORT

#include <poll.h>

#include <pulse/context.h>
#include <pulse/error.h>
#include <pulse/introspect.h>
#include <pulse/mainloop.h>
#include <pulse/proplist.h>
#include <pulse/sample.h>
#include <pulse/stream.h>

#include <QList>
#include <QMutex>
#include <QString>
#include <QStringList>
#include <QWaitCondition>

#include "libkwave/Runnable.h"
#include "libkwave/SampleFormat.h"
#include "libkwave/WorkerThread.h"

#include "RecordDevice.h"

namespace Kwave
{

    class RecordPulseAudio: public Kwave::RecordDevice, public Kwave::Runnable
    {
    public:

        /** Constructor */
        RecordPulseAudio();

        /** Destructor */
        ~RecordPulseAudio() 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(...) device specific error message
         *                      (already translated)
         */
        QString open(const QString& dev) override;

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

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

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

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

        /**
         * Set the resolution in bits per sample
         * @param new_bits resolution [bits/sample]
         * @return zero on success, negative error code if failed
         */
        int setBitsPerSample(unsigned int new_bits) 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;

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

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

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

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

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

        /**
         * 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;

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

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

        /**
         * our own poll function, for timeout support
         * @internal
         */
        int mainloopPoll(struct pollfd *ufds, unsigned long int nfds,
                         int timeout);

    protected:

        /** re-implementation of the threaded mainloop of PulseAudio */
        void run_wrapper(const QVariant &params) override;

    private:

        /**
         * Walk through the list of all known formats and collect the
         * ones that are supported into "m_supported_formats".
         * @param device name of the device
         */
        void detectSupportedFormats(const QString &device);

        /**
         * called from pulse audio to inform about state changes of the
         * server context.
         *
         * @param c pulse server context
         * @param userdata user data, pointer to a RecordPulseAudio object
         */
        static void pa_context_notify_cb(pa_context *c, void *userdata);

        /**
         * called from pulse audio to inform about state changes of the
         * server context.
         *
         * @param c pulse server context
         * @param info pointer to a source info object
         * @param eol if negative: error occurred, zero: more data follows,
         *            positive: end of info, done.
         * @param userdata pointer to a RecordPulseAudio object
         */
        static void pa_source_info_cb(pa_context *c, const pa_source_info *info,
                                      int eol, void *userdata);

        /**
         * called from pulse audio to inform about state changes of a
         * stream.
         *
         * @param p pulse audio stream
         * @param userdata user data, pointer to a RecordPulseAudio object
         */
        static void pa_stream_state_cb(pa_stream *p, void *userdata);

        /**
         * called from pulse audio after data has been read
         *
         * @param p pulse audio stream
         * @param nbytes number of read bytes, maybe (unused)
         * @param userdata user data, pointer to a RecordPulseAudio object
         */
        static void pa_read_cb(pa_stream *p, size_t nbytes, void *userdata);

        /**
         * Callback for pulse sink info.
         *
         * @param c pulse server context
         * @param info pointer to a source info object
         * @param eol if negative: error occurred, zero: more data follows,
         *            positive: end of info, done.
         */
        void notifySourceInfo(pa_context *c, const pa_source_info *info,
                              int eol);

        /**
         * Callback for pulse audio context state changes
         *
         * @param c pulse server context
         */
        void notifyContext(pa_context *c);

        /**
         * Callback for pulse stream state changes
         *
         * @param stream pulse audio stream
         */
        void notifyStreamState(pa_stream *stream);

        /**
         * Callback after reading data.
         *
         * @param stream pulse audio stream
         * @param nbytes number of read bytes, maybe (unused)
         */
        void notifyRead(pa_stream *stream, size_t nbytes);

        /**
         * Try to connect to the PulseAudio server and create a valid context
         */
        bool connectToServer();

        /**
         * Disconnect from the PulseAudio server and clean up
         */
        void disconnectFromServer();

        /** scan all PulseAudio source, re-creates m_device_list */
        void scanDevices();

        /**
         * create a PulseAudio 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
         *        (signed or unsigned)
         * @return the best matching format within the list of known formats,
         *         or PA_SAMPLE_INVALID if no match was found
         */
        pa_sample_format_t mode2format(int compression, int bits,
            Kwave::SampleFormat::Format sample_format);

        /**
         * Initialize the PulseAudio device with current parameters and
         * prepare it for recording.
         * @param buffer_size buffer size
         * @return zero on success or negative error code
         *         -EINVAL or -EIO
         */
        int initialize(uint32_t buffer_size);

    private:

        /** relevant information about a PulseAudio source */
        typedef struct
        {
            QString m_name;               /**< internal name of the source */
            QString m_description;        /**< verbose name of the source  */
            QString m_driver;             /**< internal driver name        */
            quint32 m_card;               /**< index of the card           */
            pa_sample_spec m_sample_spec; /**< accepted sample format      */
        } source_info_t;

    private:

        /** worker thread, running the event loop */
        Kwave::WorkerThread m_mainloop_thread;

        /** lock for the main loop */
        QMutex m_mainloop_lock;

        /** wait condition for mainloopWait/mainloopSignal */
        QWaitCondition m_mainloop_signal;

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

        /** number of tracks [0...N-1] */
        quint8 m_tracks;

        /** sample rate  */
        double m_rate;

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

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

        /**
         * 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<pa_sample_format_t> m_supported_formats;

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

        /** pulse: property list of the context */
        pa_proplist *m_pa_proplist;

        /** pulse: main loop */
        pa_mainloop *m_pa_mainloop;

        /** pulse: context of the connection to the server */
        pa_context *m_pa_context;

        /** pulse: playback stream */
        pa_stream *m_pa_stream;

        /** pulse: device */
        QString m_pa_device;

        /** record plugin name */
        QString m_name;

        /** encoded name of the sink */
        QString m_device;

        /**
         * list of available devices
         * key=full encoded name of the sink, data=info about the sink
         */
        QMap<QString, source_info_t> m_device_list;
    };

}

#endif /* HAVE_PULSEAUDIO_SUPPORT */

#endif // KWAVE_RECORD_PULSEAUDIO_H