//=========================================================
//  MusE
//  Linux Music Editor
//    $Id: dummyaudio.cpp,v 1.3.2.16 2009/12/20 05:00:35 terminator356 Exp $
//  (C) Copyright 2002-2003 Werner Schweer (ws@seh.de)
//=========================================================

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <errno.h>
#include <stdarg.h>
#include <pthread.h>
#include <sys/poll.h>

#include "config.h"
#include "audio.h"
#include "audiodev.h"
#include "globals.h"
#include "song.h"
#include "driver/alsatimer.h"
#include "pos.h"
#include "gconfig.h"
#include "utils.h"

class MidiPlayEvent;

#define DEBUG_DUMMY 0
//---------------------------------------------------------
//   DummyAudioDevice
//---------------------------------------------------------

//static const unsigned dummyFrames = 1024;

enum Cmd {
trSeek,
trStart,
trStop
};

struct Msg {
  enum Cmd cmd;
  int arg;
};


class DummyAudioDevice : public AudioDevice {
      pthread_t dummyThread;
      // Changed by Tim. p3.3.15
      //float buffer[1024];
      float* buffer;
      int _realTimePriority;

   public:
      std::list<Msg> cmdQueue;
      Audio::State state;
      int _framePos;
      int playPos;
      bool realtimeFlag;
      bool seekflag;
      
      DummyAudioDevice();
      virtual ~DummyAudioDevice()
      { 
        // Added by Tim. p3.3.15
        free(buffer); 
      }

      virtual inline int deviceType() { return DUMMY_AUDIO; } // p3.3.52
      
      //virtual void start();
      virtual void start(int);
      
      virtual void stop ();
      virtual int framePos() const { 
            if(DEBUG_DUMMY)
                printf("DummyAudioDevice::framePos %d\n", _framePos);
            return _framePos; 
            }

      virtual float* getBuffer(void* /*port*/, unsigned long nframes)
            {
            // p3.3.30
            //if (nframes > dummyFrames) {
                  //printf("error: segment size > 1024\n");
            if (nframes > segmentSize) {
                  printf("DummyAudioDevice::getBuffer nframes > segment size\n");
                  
                  exit(-1);
                  }
            return buffer;
            }

      virtual std::list<QString> outputPorts(bool midi = false, int aliases = -1);
      virtual std::list<QString> inputPorts(bool midi = false, int aliases = -1);

      virtual void registerClient() {}

      virtual const char* clientName() { return "MusE"; }
      
      //virtual void* registerOutPort(const char*) {
      virtual void* registerOutPort(const char*, bool) {
            return (void*)1;
            }
      //virtual void* registerInPort(const char*) {
      virtual void* registerInPort(const char*, bool) {
            return (void*)2;
            }
      virtual void unregisterPort(void*) {}
      virtual void connect(void*, void*) {}
      virtual void disconnect(void*, void*) {}
      virtual int connections(void* /*clientPort*/) { return 0; }
      virtual void setPortName(void*, const char*) {}
      virtual void* findPort(const char*) { return 0;}
      virtual QString portName(void*) {
            return QString("mops");
            }
      virtual int getState() { 
//            if(DEBUG_DUMMY)
//                printf("DummyAudioDevice::getState %d\n", state);
            return state; }
      virtual unsigned getCurFrame() { 
            if(DEBUG_DUMMY)
                printf("DummyAudioDevice::getCurFrame %d\n", _framePos);
      
      return _framePos; }
      virtual unsigned frameTime() const {
            return lrint(curTime() * sampleRate);
            }
      virtual bool isRealtime() { return realtimeFlag; }
      //virtual int realtimePriority() const { return 40; }
      virtual int realtimePriority() const { return _realTimePriority; }
      virtual void startTransport() {
            if(DEBUG_DUMMY)
                printf("DummyAudioDevice::startTransport playPos=%d\n", playPos);
#if 0            
            Msg trcmd;
            trcmd.cmd = trStart;
            trcmd.arg = playPos;
            cmdQueue.push_front(trcmd);
#else
            state = Audio::PLAY;
#endif            
/*            state = Audio::START_PLAY;
            audio->sync(state, playPos);            
            state = Audio::PLAY;*/
            }
      virtual void stopTransport() {
            if(DEBUG_DUMMY)
                printf("DummyAudioDevice::stopTransport, playPos=%d\n", playPos);
            state = Audio::STOP;
            }
      virtual int setMaster(bool) { return 1; }

      virtual void seekTransport(const Pos &p)
      {
            if(DEBUG_DUMMY)
                printf("DummyAudioDevice::seekTransport frame=%d topos=%d\n",playPos, p.frame());
#if 0            
            Msg trcmd;
            trcmd.cmd = trSeek;
            trcmd.arg = p.frame();
            cmdQueue.push_front(trcmd);
            playPos = p.frame();
#else
            seekflag = true;
            //pos = n;
            playPos = p.frame();
#endif            
            
      }
      virtual void seekTransport(unsigned pos) {
            if(DEBUG_DUMMY)
                printf("DummyAudioDevice::seekTransport frame=%d topos=%d\n",playPos,pos);
#if 0            
            Msg trcmd;
            trcmd.cmd = trSeek;
            trcmd.arg = pos;
            cmdQueue.push_front(trcmd);
            playPos = pos;
#else
            seekflag = true;
            //pos = n;
            playPos = pos;
#endif            
/*
            Audio::State tempState = state;
            state = Audio::START_PLAY;
            audio->sync(state, playPos);            
            state = tempState;*/
            }
      virtual void setFreewheel(bool) {}
      void setRealTime() { realtimeFlag = true; }
      };

DummyAudioDevice* dummyAudio = 0;

DummyAudioDevice::DummyAudioDevice() 
      {
      // Added by Tim. p3.3.15
      // p3.3.30
      //posix_memalign((void**)&buffer, 16, sizeof(float) * dummyFrames);
      posix_memalign((void**)&buffer, 16, sizeof(float) * config.dummyAudioBufSize);
      
      dummyThread = 0;
      realtimeFlag = false;
      seekflag = false;
      state = Audio::STOP;
      //startTime = curTime();
      _framePos = 0;
      playPos = 0;
      cmdQueue.clear();
      }

//---------------------------------------------------------
//   exitDummyAudio
//---------------------------------------------------------

void exitDummyAudio()
{
      if(dummyAudio)
        delete dummyAudio;
      dummyAudio = NULL;      
      audioDevice = NULL;      
}

//---------------------------------------------------------
//   initDummyAudio
//---------------------------------------------------------

bool initDummyAudio()
      {
      dummyAudio = new DummyAudioDevice();
      audioDevice = dummyAudio;
      return false;
      }

//---------------------------------------------------------
//   outputPorts
//---------------------------------------------------------

std::list<QString> DummyAudioDevice::outputPorts(bool midi, int /*aliases*/)
      {
      std::list<QString> clientList;
      if(!midi)
      {
        clientList.push_back(QString("output1"));
        clientList.push_back(QString("output2"));
      }  
      return clientList;
      }

//---------------------------------------------------------
//   inputPorts
//---------------------------------------------------------

std::list<QString> DummyAudioDevice::inputPorts(bool midi, int /*aliases*/)
      {
      std::list<QString> clientList;
      if(!midi)
      {
        clientList.push_back(QString("input1"));
        clientList.push_back(QString("input2"));
      }  
      return clientList;
      }

//---------------------------------------------------------
//   dummyLoop
//---------------------------------------------------------

static void* dummyLoop(void* ptr)
      {
      //unsigned int tickRate = 25;
      
      // p3.3.30
      //sampleRate = 25600;
      sampleRate = config.dummyAudioSampleRate;
      //segmentSize = dummyFrames;
      segmentSize = config.dummyAudioBufSize;
#if 0      
      //unsigned int tickRate = sampleRate / dummyFrames;
      unsigned int tickRate = sampleRate / segmentSize;
      
      AlsaTimer timer;
      fprintf(stderr, "Get alsa timer for dummy driver:\n");
      timer.setFindBestTimer(false);
      int fd = timer.initTimer();
      if (fd==-1) {
      //  QMessageBox::critical( 0, /*tr*/(QString("Failed to start timer for dummy audio driver!")),
      //        /*tr*/(QString("No functional timer was available.\n"
      //                   "Alsa timer not available, check if module snd_timer is available and /dev/snd/timer is available")));
        fprintf(stderr, "Failed to start timer for dummy audio driver! No functional timer was available.\n" 
                         "Alsa timer not available, check if module snd_timer is available and /dev/snd/timer is available\n");
        pthread_exit(0);
      }

      /* Depending on nature of the timer, the requested tickRate might not
       * be available.  The return value is the nearest available frequency,
       * so use this to reset our dummpy sampleRate to keep everything 
       * consistent.
       */
      tickRate = timer.setTimerFreq( /*250*/ tickRate );
      
      // p3.3.31
      // If it didn't work, get the actual rate.
      if(tickRate == 0)
        tickRate = timer.getTimerFreq();
        
      sampleRate = tickRate * segmentSize;
      timer.startTimer();
#endif        

      DummyAudioDevice *drvPtr = (DummyAudioDevice *)ptr;

      ///pollfd myPollFd;

      ///myPollFd.fd = fd;
      ///myPollFd.events = POLLIN;


      /*
      doSetuid();
      struct sched_param rt_param;
      int rv;
      memset(&rt_param, 0, sizeof(sched_param));
      int type;
      rv = pthread_getschedparam(pthread_self(), &type, &rt_param);
      if (rv != 0)
            perror("get scheduler parameter");
      if (type != SCHED_FIFO) {
            fprintf(stderr, "Driver thread not running SCHED_FIFO, trying to set...\n");

            memset(&rt_param, 0, sizeof(sched_param));
            //rt_param.sched_priority = 1;
            rt_param.sched_priority = realtimePriority();
            rv = pthread_setschedparam(pthread_self(), SCHED_FIFO, &rt_param);
            if (rv != 0)
                  perror("set realtime scheduler");
            memset(&rt_param, 0, sizeof(sched_param));
            rv = pthread_getschedparam(pthread_self(), &type, &rt_param);
            if (rv != 0)
                  perror("get scheduler parameter");
            if (type == SCHED_FIFO) {
                  drvPtr->setRealTime();
                  fprintf(stderr, "Thread succesfully set to SCHED_FIFO\n");
                  }
                  else {
                  fprintf(stderr, "Unable to set thread to SCHED_FIFO\n");
                  }
            }
      undoSetuid();
      */
      
#ifndef __APPLE__
      doSetuid();
      //if (realTimePriority) {
      if (realTimeScheduling) {
            //
            // check if we really got realtime priviledges
            //
            int policy;
            if ((policy = sched_getscheduler (0)) < 0) {
                printf("cannot get current client scheduler for audio dummy thread: %s!\n", strerror(errno));
                }
            else
                {
                if (policy != SCHED_FIFO)
                          printf("audio dummy thread _NOT_ running SCHED_FIFO\n");
                else if (debugMsg) {
                        struct sched_param rt_param;
                    memset(&rt_param, 0, sizeof(sched_param));
                        int type;
                    int rv = pthread_getschedparam(pthread_self(), &type, &rt_param);
                        if (rv == -1)
                                perror("get scheduler parameter");
                    printf("audio dummy thread running SCHED_FIFO priority %d\n",
                             rt_param.sched_priority);
                    }
                }
            }
      undoSetuid();
#endif
      
#if 0      
      /* unsigned long tick = 0;*/    // prevent compiler warning: unused variable
      for (;;) {
            int _pollWait = 10;   // ms
            unsigned long count = 0;
            while (count < 1 /*250/tickRate*/) // will loop until the next tick occurs
                {
                /*int n = */  poll(&myPollFd, 1 /* npfd */, _pollWait);
                count += timer.getTimerTicks();
                // FIXME FIXME: There is a crash here (or near-lockup, a race condition?) while zipping 
                //               the cursor around in an editor (pianoroll, master edit) while arranger is open.
                while (drvPtr->cmdQueue.size())
                    {
                    Msg &msg = drvPtr->cmdQueue.back();
                    drvPtr->cmdQueue.pop_back();
                    switch(msg.cmd) {
                          case trSeek:
                            {
                            //printf("trSeek\n");
                            drvPtr->playPos = msg.arg;
                            Audio::State tempState = drvPtr->state;
                            drvPtr->state = Audio::START_PLAY;
                            audio->sync(drvPtr->state, msg.arg);
                            drvPtr->state = tempState;
                            }
                            break;
                          case trStart:
                            {
                            //printf("trStart\n");
                            drvPtr->state = Audio::START_PLAY;
                            audio->sync(drvPtr->state, msg.arg);
                            drvPtr->state = Audio::PLAY;
                            }
                            break;
                          case trStop:
                            break;
                          default:
                            printf("dummyLoop: Unknown command!\n");
                        }
                    }
                }
            audio->process(segmentSize);
            int increment = segmentSize; // 1 //tickRate / sampleRate * segmentSize;
            drvPtr->_framePos+=increment;
            if (drvPtr->state == Audio::PLAY) 
                  {
                  drvPtr->playPos+=increment;
                  }
            }
#else
      // Adapted from muse_qt4_evolution. p4.0.20       
      for(;;) 
      {
            //if(audioState == AUDIO_RUNNING)
            if(audio->isRunning())
              //audio->process(segmentSize, drvPtr->state);
              audio->process(segmentSize);
            //else if (audioState == AUDIO_START1)
            //  audioState = AUDIO_START2;
            //usleep(dummyFrames*1000000/AL::sampleRate);
            usleep(segmentSize*1000000/sampleRate);
            //if(dummyAudio->seekflag) 
            if(drvPtr->seekflag) 
            {
              //audio->sync(Audio::STOP, dummyAudio->pos);
              //audio->sync(drvPtr->state, drvPtr->playPos);
              audio->sync(Audio::STOP, drvPtr->playPos);
              
              //dummyAudio->seekflag = false;
              drvPtr->seekflag = false;
            }
            
            //if(dummyAudio->state == Audio::PLAY) 
            //  dummyAudio->pos += dummyFrames;
            drvPtr->_framePos += segmentSize;
            if(drvPtr->state == Audio::PLAY) 
              drvPtr->playPos += segmentSize;
      }
#endif
            
      ///timer.stopTimer();
      pthread_exit(0);
      }

//void DummyAudioDevice::start()
void DummyAudioDevice::start(int priority)
{
      _realTimePriority = priority;
      pthread_attr_t* attributes = 0;

      if (realTimeScheduling && _realTimePriority > 0) {
            attributes = (pthread_attr_t*) malloc(sizeof(pthread_attr_t));
            pthread_attr_init(attributes);

            if (pthread_attr_setschedpolicy(attributes, SCHED_FIFO)) {
                  printf("cannot set FIFO scheduling class for dummy RT thread\n");
                  }
            if (pthread_attr_setscope (attributes, PTHREAD_SCOPE_SYSTEM)) {
                  printf("Cannot set scheduling scope for dummy RT thread\n");
                  }
            // p4.0.16 Dummy was not running FIFO because this is needed.
            if (pthread_attr_setinheritsched(attributes, PTHREAD_EXPLICIT_SCHED)) {
                  printf("Cannot set setinheritsched for dummy RT thread\n");
                  }
                  
            struct sched_param rt_param;
            memset(&rt_param, 0, sizeof(rt_param));
            rt_param.sched_priority = priority;
            if (pthread_attr_setschedparam (attributes, &rt_param)) {
                  printf("Cannot set scheduling priority %d for dummy RT thread (%s)\n",
                     priority, strerror(errno));
                  }
            }
      
      int rv = pthread_create(&dummyThread, attributes, ::dummyLoop, this); 
      if(rv)
      {  
        // p4.0.16: realTimeScheduling is unreliable. It is true even in some clearly non-RT cases.
        // I cannot seem to find a reliable answer to the question of "are we RT or not".
        // MusE was failing with a stock kernel because of PTHREAD_EXPLICIT_SCHED.
        // So we'll just have to try again without attributes.
        if (realTimeScheduling && _realTimePriority > 0) 
          rv = pthread_create(&dummyThread, NULL, ::dummyLoop, this); 
      }
      
      if(rv)
          fprintf(stderr, "creating dummy audio thread failed: %s\n", strerror(rv));

      if (attributes)                      // p4.0.16
      {
        pthread_attr_destroy(attributes);
        free(attributes);
      }
}

void DummyAudioDevice::stop ()
      {
      pthread_cancel(dummyThread);
      pthread_join(dummyThread, 0);
      dummyThread = 0;
      }