/*******************************************************************************
*                         Goggles Audio Player Library                         *
********************************************************************************
*           Copyright (C) 2010-2021 by Sander Jansen. All Rights Reserved      *
*                               ---                                            *
* 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 3 of the License, or            *
* (at your option) any later version.                                          *
*                                                                              *
* This program 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 this program.  If not, see http://www.gnu.org/licenses.           *
********************************************************************************/
#include "ap_defs.h"
#include "ap_output_plugin.h"

extern "C" {
#include <pulse/pulseaudio.h>
}

using namespace ap;

void pulse_quit(pa_mainloop_api*,int){
  GM_DEBUG_PRINT("[pulse] pulse_quit\n");
  }


namespace ap {


class PulseOutput : public OutputPlugin {
protected:
  static PulseOutput* instance;
protected:
  friend struct ::pa_io_event;
  friend struct ::pa_time_event;
  friend struct ::pa_defer_event;
protected:
  pa_mainloop_api  api;
  pa_context     * pulse_context = nullptr;
  pa_stream      * stream        = nullptr;
  pa_volume_t      pulsevolume   = PA_VOLUME_MUTED;
protected:
  static void sink_info_callback(pa_context*, const pa_sink_input_info *,int eol,void*);
  static void context_subscribe_callback(pa_context *c,pa_subscription_event_type_t, uint32_t,void*);
protected:
  FXbool open();
public:
  PulseOutput(OutputContext*);

  /// Configure
  FXbool configure(const AudioFormat &);

  /// Write frames to playback buffer
  FXbool write(const void*, FXuint);

  /// Return delay in no. of frames
  FXint delay();

  /// Empty Playback Buffer Immediately
  void drop();

  /// Wait until playback buffer is emtpy.
  void drain();

  /// Pause
  void pause(FXbool);

  /// Change Volume
  void volume(FXfloat);

  /// Close Output
  void close();

  /// Get Device Type
  FXchar type() const { return DevicePulse; }

  /// Destructor
  virtual ~PulseOutput();
  };


}






struct pa_io_event : public Reactor::Input {
public:
  static pa_io_event*      recycle;
  pa_io_event_cb_t         callback         = nullptr;
  pa_io_event_destroy_cb_t destroy_callback = nullptr;
  void *                   userdata         = nullptr;
protected:

  /// Convert mode flags to pulseaudio flags
  static pa_io_event_flags_t toPulse(FXuchar mode) {
    int event=PA_IO_EVENT_NULL;
    event=((mode&Reactor::Input::IsReadable)  ? PA_IO_EVENT_INPUT : 0) |
          ((mode&Reactor::Input::IsWritable)  ? PA_IO_EVENT_OUTPUT : 0) |
          ((mode&Reactor::Input::IsException) ? (PA_IO_EVENT_ERROR|PA_IO_EVENT_HANGUP) : 0);
    return (pa_io_event_flags_t)event;
    }

  /// Convert pulseaudio flags to mode flags
  static FXuchar fromPulse(pa_io_event_flags_t flags) {
    return (((flags&PA_IO_EVENT_INPUT)  ? Reactor::Input::Readable  : 0) |
            ((flags&PA_IO_EVENT_OUTPUT) ? Reactor::Input::Writable  : 0) |
            ((flags&PA_IO_EVENT_ERROR)  ? Reactor::Input::Exception : 0) |
            ((flags&PA_IO_EVENT_HANGUP) ? Reactor::Input::Exception : 0));
    }
public:
  pa_io_event(FXInputHandle h,FXuchar m) : Reactor::Input(h,m),callback(nullptr),destroy_callback(nullptr),userdata(nullptr) {
    }

  virtual void onSignal() {
    callback(&(PulseOutput::instance->api),this,handle,toPulse(mode),userdata);
    }

  static pa_io_event * create(pa_mainloop_api*,int fd,pa_io_event_flags_t events, pa_io_event_cb_t cb, void *userdata) {
    pa_io_event * event;
    if (recycle) {
      event         = recycle;
      event->handle = fd;
      event->mode   = fromPulse(events);
      recycle       = nullptr;
      }
    else {
      event = new pa_io_event(fd,fromPulse(events));
      }
    event->callback         = cb;
    event->userdata         = userdata;
    event->destroy_callback = nullptr;
    PulseOutput::instance->context->getReactor().addInput(event);
    return event;
    }

  static void destroy(pa_io_event* event){
    if (event->destroy_callback)
      event->destroy_callback(&PulseOutput::instance->api,event,event->userdata);
    PulseOutput::instance->context->getReactor().removeInput(event);
    if (recycle==nullptr)
      recycle=event;
    else
      delete event;
    }

  static void enable(pa_io_event*event,pa_io_event_flags_t events) {
    event->mode = fromPulse(events);
    }

  static void set_destroy(pa_io_event *event, pa_io_event_destroy_cb_t cb){
    event->destroy_callback=cb;
    }
  };





struct pa_time_event : public Reactor::Timer {
public:
  static pa_time_event*       recycle;
  pa_time_event_cb_t          callback = nullptr;
  pa_time_event_destroy_cb_t  destroy_callback  = nullptr;
  void*                       userdata = nullptr;
public:
  pa_time_event() {}

  virtual void onExpired() {
    struct timeval tv;
    tv.tv_usec = ( time / NANOSECONDS_PER_MICROSECOND ) % 1000000;
    tv.tv_sec  = time / NANOSECONDS_PER_SECOND;
    callback(&(PulseOutput::instance->api),this,&tv,userdata);
    }

  static pa_time_event * create(pa_mainloop_api*,const struct timeval *tv, pa_time_event_cb_t cb, void *userdata) {
    FXTime time = (tv->tv_sec*NANOSECONDS_PER_SECOND) + (tv->tv_usec*NANOSECONDS_PER_MICROSECOND);
    pa_time_event * event;
    if (recycle) {
      event   = recycle;
      recycle = nullptr;
      }
    else {
      event = new pa_time_event();
      }
    event->callback = cb;
    event->userdata = userdata;
    PulseOutput::instance->context->getReactor().addTimer(event,time);
    return event;
    }

  static void destroy(pa_time_event* event){
    if (event->destroy_callback)
      event->destroy_callback(&PulseOutput::instance->api,event,event->userdata);
    PulseOutput::instance->context->getReactor().removeTimer(event);
    if (recycle==nullptr)
      recycle=event;
    else
      delete event;
    }

  static void restart(pa_time_event* event, const struct timeval *tv){
    FXTime time = (tv->tv_sec*NANOSECONDS_PER_SECOND) + (tv->tv_usec*NANOSECONDS_PER_MICROSECOND);
    PulseOutput::instance->context->getReactor().removeTimer(event);
    PulseOutput::instance->context->getReactor().addTimer(event,time);
    }

  static void set_destroy(pa_time_event *event, pa_time_event_destroy_cb_t cb){
    event->destroy_callback=cb;
    }
  };








struct pa_defer_event : public Reactor::Deferred {
public:
  static pa_defer_event*      recycle;
  pa_defer_event_cb_t         callback = nullptr;
  pa_defer_event_destroy_cb_t destroy_callback = nullptr;
  void*                       userdata = nullptr;
public:
  pa_defer_event() {}

  virtual void run() {
    callback(&PulseOutput::instance->api,this,userdata);
    }

  static pa_defer_event* create(pa_mainloop_api*, pa_defer_event_cb_t cb, void *userdata){
    pa_defer_event * event;
    if (recycle) {
      event   = recycle;
      recycle = nullptr;
      }
    else  {
      event = new pa_defer_event();
      }
    event->callback         = cb;
    event->userdata         = userdata;
    event->destroy_callback = nullptr;

    PulseOutput::instance->context->getReactor().addDeferred(event);
    return event;
    };

  static void toggle_enabled(pa_defer_event*event,int b) {
    if (b)
      event->enable();
    else
      event->disable();
    }

  static void destroy(pa_defer_event* event){
    if (event->destroy_callback)
      event->destroy_callback(&PulseOutput::instance->api,event,event->userdata);

    PulseOutput::instance->context->getReactor().removeDeferred(event);

    if (recycle==nullptr)
      recycle = event;
    else
      delete event;
    }

  static void set_destroy(pa_defer_event *event, pa_defer_event_destroy_cb_t cb){
    event->destroy_callback=cb;
    }
  };


pa_io_event    * pa_io_event::recycle;
pa_time_event  * pa_time_event::recycle;
pa_defer_event * pa_defer_event::recycle;














namespace ap {












PulseOutput * PulseOutput::instance = nullptr;

PulseOutput::PulseOutput(OutputContext * ctx) : OutputPlugin(ctx) {
  FXASSERT(instance==nullptr);
  instance                = this;
  api.userdata            = this;
  api.io_new              = pa_io_event::create; //pulse_io_new;
  api.io_free             = pa_io_event::destroy;// pulse_io_free;
  api.io_enable           = pa_io_event::enable; //pulse_io_enable;
  api.io_set_destroy      = pa_io_event::set_destroy;//pulse_io_set_destroy;
  api.defer_new           = pa_defer_event::create; //pulse_defer_new;
  api.defer_free          = pa_defer_event::destroy; //pulse_defer_free;
  api.defer_enable        = pa_defer_event::toggle_enabled; //pulse_defer_enable;
  api.defer_set_destroy   = pa_defer_event::set_destroy; //pulse_defer_set_destroy;
  api.time_new            = pa_time_event::create;  //pulse_time_new;
  api.time_restart        = pa_time_event::restart; //pulse_time_restart;
  api.time_free           = pa_time_event::destroy; //pulse_time_free;
  api.time_set_destroy    = pa_time_event::set_destroy; //pulse_time_set_destroy;
  api.quit                = pulse_quit;
  pa_io_event::recycle    = nullptr;
  pa_time_event::recycle  = nullptr;
  pa_defer_event::recycle = nullptr;
  }

PulseOutput::~PulseOutput() {
  close();
  instance=nullptr;
  }

static FXbool to_pulse_format(const AudioFormat & af,pa_sample_format & pulse_format){
  switch(af.format) {
    case AP_FORMAT_U8       : pulse_format=PA_SAMPLE_U8;    break;
    case AP_FORMAT_S16_LE   : pulse_format=PA_SAMPLE_S16LE; break;
    case AP_FORMAT_S16_BE   : pulse_format=PA_SAMPLE_S16BE; break;
    case AP_FORMAT_S24_LE   : pulse_format=PA_SAMPLE_S24_32LE;  break;
    case AP_FORMAT_S24_BE   : pulse_format=PA_SAMPLE_S24_32BE;  break;
    case AP_FORMAT_S24_3LE  : pulse_format=PA_SAMPLE_S24LE;  break;
    case AP_FORMAT_S24_3BE  : pulse_format=PA_SAMPLE_S24BE;  break;
    case AP_FORMAT_S32_LE   : pulse_format=PA_SAMPLE_S32LE;  break;
    case AP_FORMAT_S32_BE   : pulse_format=PA_SAMPLE_S32BE;  break;
    case AP_FORMAT_FLOAT_LE : pulse_format=PA_SAMPLE_FLOAT32LE;  break;
    case AP_FORMAT_FLOAT_BE : pulse_format=PA_SAMPLE_FLOAT32BE;  break;
    default                 : return false; break;
    }
  return true;
  }


static FXbool to_gap_format(pa_sample_format pulse_format,AudioFormat & af){
  switch(pulse_format) {
    case PA_SAMPLE_U8       : af.format = AP_FORMAT_U8;       break;
    case PA_SAMPLE_S16LE    : af.format = AP_FORMAT_S16_LE;   break;
    case PA_SAMPLE_S16BE    : af.format = AP_FORMAT_S16_BE;   break;
    case PA_SAMPLE_S24LE    : af.format = AP_FORMAT_S24_3LE;   break;
    case PA_SAMPLE_S24BE    : af.format = AP_FORMAT_S24_3BE;   break;
    case PA_SAMPLE_S24_32LE : af.format = AP_FORMAT_S24_LE;  break;
    case PA_SAMPLE_S24_32BE : af.format = AP_FORMAT_S24_BE;  break;
    case PA_SAMPLE_S32LE    : af.format = AP_FORMAT_S32_LE;   break;
    case PA_SAMPLE_S32BE    : af.format = AP_FORMAT_S32_BE;   break;
    case PA_SAMPLE_FLOAT32LE: af.format = AP_FORMAT_FLOAT_LE; break;
    case PA_SAMPLE_FLOAT32BE: af.format = AP_FORMAT_FLOAT_BE; break;
    default                 : return false;
    }
  return true;
  }



#ifdef DEBUG
static void context_state_callback(pa_context *c,void*){
  fxmessage("[pulse] context_state_callback:");
  switch(pa_context_get_state(c)) {
    case PA_CONTEXT_UNCONNECTED : fxmessage(" unconnected\n"); break;
    case PA_CONTEXT_CONNECTING  : fxmessage(" connecting\n"); break;
    case PA_CONTEXT_AUTHORIZING : fxmessage(" authorizing\n"); break;
    case PA_CONTEXT_SETTING_NAME: fxmessage(" setting name\n"); break;
    case PA_CONTEXT_READY       : fxmessage(" ready\n"); break;
    case PA_CONTEXT_FAILED      : fxmessage(" failed\n"); break;
    case PA_CONTEXT_TERMINATED  : fxmessage(" terminated\n"); break;
    default                     : fxmessage(" unknown\n"); break;
    }
  }

static void stream_state_callback(pa_stream *s,void*){
  fxmessage("[pulse] stream_state_callback:");
  switch(pa_stream_get_state(s)) {
    case PA_STREAM_UNCONNECTED : fxmessage(" unconnected\n"); break;
    case PA_STREAM_CREATING    : fxmessage(" creating\n"); break;
    case PA_STREAM_READY       : fxmessage(" ready\n"); break;
    case PA_STREAM_FAILED      : fxmessage(" failed\n"); break;
    case PA_STREAM_TERMINATED  : fxmessage(" terminated\n"); break;
    default                     : fxmessage(" unknown\n"); break;
    }
  }
#endif


//static void stream_write_callback(pa_stream*s,size_t,void *){
//  GM_DEBUG_PRINT("stream_write_callback %d\n",pa_stream_get_state(s));
//  }

void PulseOutput::sink_info_callback(pa_context*, const pa_sink_input_info * info,int /*eol*/,void*userdata){
  PulseOutput * out = static_cast<PulseOutput*>(userdata);
  if (info) {
    pa_volume_t value = pa_cvolume_avg(&info->volume);
    if (out->pulsevolume!=value) {
      out->context->notify_volume((float)value / (float)PA_VOLUME_NORM);
      }
    }
  }

void PulseOutput::context_subscribe_callback(pa_context * pulse_context, pa_subscription_event_type_t type, uint32_t index, void *userdata){
  PulseOutput * out = static_cast<PulseOutput*>(userdata);

  if (out->stream==nullptr)
    return;

  if (pa_stream_get_index(out->stream)!=index)
    return;

  if ((type&PA_SUBSCRIPTION_EVENT_FACILITY_MASK)!=PA_SUBSCRIPTION_EVENT_SINK_INPUT)
    return;

  if ((type&PA_SUBSCRIPTION_EVENT_TYPE_MASK)==PA_SUBSCRIPTION_EVENT_CHANGE ||
      (type&PA_SUBSCRIPTION_EVENT_TYPE_MASK)==PA_SUBSCRIPTION_EVENT_NEW) {
    pa_operation *operation = pa_context_get_sink_input_info(pulse_context,index,sink_info_callback,userdata);
    if (operation) pa_operation_unref(operation);
    }
  }




FXbool PulseOutput::open() {

  /// Start the mainloop
  //if (eventloop==nullptr) {
   // eventloop = new PulseReactor();
   // }

  /// Get a context
  if (pulse_context==nullptr) {
    pulse_context = pa_context_new(&api,"Goggles Music Manager");
#ifdef DEBUG
    pa_context_set_state_callback(pulse_context,context_state_callback,this);
#endif
    pa_context_set_subscribe_callback(pulse_context,context_subscribe_callback,this);
    }

  /// Try connecting
  GM_DEBUG_PRINT("[pulse] pa_context_connect()\n");
  if (pa_context_get_state(pulse_context)==PA_CONTEXT_UNCONNECTED) {
    if (pa_context_connect(pulse_context,nullptr,PA_CONTEXT_NOFLAGS,nullptr)<0) {
      GM_DEBUG_PRINT("[pulse] pa_context_connect failed\n");
      return false;
      }
    }

  /// Wait until we're connected to the pulse daemon
  GM_DEBUG_PRINT("[pulse] wait for connection\n");
  pa_context_state_t state;
  while((state=pa_context_get_state(pulse_context))!=PA_CONTEXT_READY) {
    if (state==PA_CONTEXT_FAILED || state==PA_CONTEXT_TERMINATED){
      GM_DEBUG_PRINT("[pulse] Unable to connect to pulsedaemon\n");
      return false;
      }
    context->wait_plugin_events();
    }

  pa_operation* operation = pa_context_subscribe(pulse_context,PA_SUBSCRIPTION_MASK_SINK_INPUT,nullptr,this);
  if (operation) pa_operation_unref(operation);


  GM_DEBUG_PRINT("[pulse] ready()\n");
  return true;
  }

void PulseOutput::close() {
#ifdef DEBUG
  context->getReactor().debug();
#endif

  if (stream) {
    GM_DEBUG_PRINT("[pulse] disconnecting stream\n");
    pa_stream_disconnect(stream);
    pa_stream_unref(stream);
    stream=nullptr;
    }

  if (pulse_context) {
    GM_DEBUG_PRINT("[pulse] disconnecting context\n");
    pa_context_disconnect(pulse_context);
    pa_context_unref(pulse_context);
    pulse_context=nullptr;
    }
#ifdef DEBUG
  context->getReactor().debug();
#endif

  delete pa_io_event::recycle;
  delete pa_time_event::recycle;
  delete pa_defer_event::recycle;
  pa_io_event::recycle    = nullptr;
  pa_time_event::recycle  = nullptr;
  pa_defer_event::recycle = nullptr;
  pulsevolume             = PA_VOLUME_MUTED;
  af.reset();
  }




void PulseOutput::volume(FXfloat v) {
  if (pulse_context && stream) {
    pulsevolume = (pa_volume_t)(v*PA_VOLUME_NORM);
    pa_cvolume cvol;
    pa_cvolume_set(&cvol,af.channels,pulsevolume);
    pa_operation* operation = pa_context_set_sink_input_volume(pulse_context,pa_stream_get_index(stream),&cvol,nullptr,nullptr);
    pa_operation_unref(operation);
    }
  }

FXint PulseOutput::delay() {
  FXint value=0;
  if (stream) {
    pa_usec_t latency;
    int negative;
    if (pa_stream_get_latency(stream,&latency,&negative)>=0){
      value = (latency*af.rate) / 1000000;
      }
    }
  return value;
  }

void PulseOutput::drop() {
  if (stream) {
    pa_operation* operation = pa_stream_flush(stream,nullptr,0);
    pa_operation_unref(operation);
    }
  }

void PulseOutput::drain() {
  if (stream) {
    pa_operation * operation = pa_stream_drain(stream,nullptr,nullptr);
    while (pa_operation_get_state(operation) == PA_OPERATION_RUNNING)
      context->wait_plugin_events();
    pa_operation_unref(operation);
    }
  }

void PulseOutput::pause(FXbool) {
  }

FXbool PulseOutput::configure(const AudioFormat & fmt){
  const pa_sample_spec * config=nullptr;
  pa_operation *operation=nullptr;

  if (!open())
    return false;

  if (stream && fmt==af)
    return true;

  if (stream) {
    pa_stream_disconnect(stream);
    pa_stream_unref(stream);
    stream=nullptr;
    }

  pa_sample_spec spec;
  pa_channel_map cmap;

  if (!to_pulse_format(fmt,spec.format))
    goto failed;

  spec.rate     = fmt.rate;
  spec.channels = fmt.channels;


  // setup channel map
  pa_channel_map_init(&cmap);
  cmap.channels = fmt.channels;
  for (FXint i=0;i<fmt.channels;i++) {
    switch(fmt.channeltype(i)) {
      case Channel::None        : cmap.map[i] = PA_CHANNEL_POSITION_INVALID;      break;
      case Channel::Mono        : cmap.map[i] = PA_CHANNEL_POSITION_MONO;         break;
      case Channel::FrontLeft   : cmap.map[i] = PA_CHANNEL_POSITION_FRONT_LEFT;   break;
      case Channel::FrontRight  : cmap.map[i] = PA_CHANNEL_POSITION_FRONT_RIGHT;  break;
      case Channel::FrontCenter : cmap.map[i] = PA_CHANNEL_POSITION_FRONT_CENTER; break;
      case Channel::BackLeft    : cmap.map[i] = PA_CHANNEL_POSITION_REAR_LEFT;    break;
      case Channel::BackRight   : cmap.map[i] = PA_CHANNEL_POSITION_REAR_RIGHT;   break;
      case Channel::BackCenter  : cmap.map[i] = PA_CHANNEL_POSITION_REAR_CENTER;  break;
      case Channel::SideLeft    : cmap.map[i] = PA_CHANNEL_POSITION_SIDE_LEFT;    break;
      case Channel::SideRight   : cmap.map[i] = PA_CHANNEL_POSITION_SIDE_RIGHT;   break;
      case Channel::LFE         : cmap.map[i] = PA_CHANNEL_POSITION_LFE;          break;
      default: goto failed;
      }
    }

  stream = pa_stream_new(pulse_context,"Goggles Music Manager",&spec,&cmap);
  if (stream == nullptr)
    goto failed;

#ifdef DEBUG
  pa_stream_set_state_callback(stream,stream_state_callback,this);
#endif

  // Set to recommended values according to PulseAudio docs
  pa_buffer_attr buffer_attributes;
  buffer_attributes.maxlength = -1;  // set to maximum value supported by server (recommended)
  buffer_attributes.tlength = -1;    // server should initialize this to reasonable default
  buffer_attributes.prebuf = -1;     // set to same values as maxlength
  buffer_attributes.minreq = -1;     // server should initialize this to reasonable default
  buffer_attributes.fragsize = -1;   // server should initialize this to reasonable default

  if (pa_stream_connect_playback(stream,nullptr,&buffer_attributes,pa_stream_flags(PA_STREAM_AUTO_TIMING_UPDATE|PA_STREAM_INTERPOLATE_TIMING),nullptr,nullptr)<0)
    goto failed;

  /// Wait until stream is ready
  pa_stream_state_t state;
  while((state=pa_stream_get_state(stream))!=PA_STREAM_READY) {
    if (state==PA_STREAM_FAILED || state==PA_STREAM_TERMINATED){
      goto failed;
      }
    context->wait_plugin_events();
    }

  /// Get Actual Format
  config = pa_stream_get_sample_spec(stream);
  if (!to_gap_format(config->format,af))
    goto failed;
  af.channels=config->channels;
  af.rate=config->rate;
  af.channelmap=fmt.channelmap;

  /// Get Current Volume
  operation = pa_context_get_sink_input_info(pulse_context,pa_stream_get_index(stream),sink_info_callback,this);
  if (operation) pa_operation_unref(operation);

  return true;
failed:
  GM_DEBUG_PRINT("[pulse] Unsupported pulse configuration:\n");
  fmt.debug();
  return false;
  }

FXbool PulseOutput::write(const void * b,FXuint nframes){
  FXASSERT(stream);
  const FXchar * buffer = reinterpret_cast<const FXchar*>(b);
  FXuint total = nframes*af.framesize();
  while(total) {

    if (pa_stream_get_state(stream)!=PA_STREAM_READY)
      return false;

    size_t nbytes = pa_stream_writable_size(stream);
    size_t n = FXMIN(total,nbytes);
    if (n==0) {
      //fxmessage("size %ld\n",nbytes);
      context->wait_plugin_events();
      continue;
      }
    pa_stream_write(stream,buffer,n,nullptr,0,PA_SEEK_RELATIVE);
    total-=n;
    buffer+=n;
    }
  return true;
  }




}


AP_IMPLEMENT_PLUGIN(PulseOutput);