#include "krunch.h"
#include "thrower.h"
#include <valarray>
#include <iostream>
#include <iomanip>
#include "refout.h"     /* for class ref_to_krunch */
#include "gui.h"
//??? #include "iir_bp.h"
#include "bad_thing.h"
//?? #include "biquad.h"

// forward reference:
void dumpit_cout(const double rp, const double ip);

// typical usage:
//?? biquad butterworth({1., 2., 1.},
//??         {1., -1.99911142347079540116, 0.99911181807963833634});

//////////////////////////////////////////////////////////////////////
// main entry point for krunch job
//
void* krunch(void* _arg){
  using namespace std;
  krunch_arg* arg((krunch_arg*) _arg);

  int num_indic = arg->topwin->ndc8r.size();

  thrower* toss = new thrower[num_indic];

  thrower* flushy = new thrower;

  for (int ii = 0; ii < num_indic; ii++) {
    QMetaObject::Connection rslt = QObject::connect(
        &toss[ii], SIGNAL(_newReading(double,double, double,double)),
        arg->topwin->ndc8r[ii],
        SLOT(setIndication(double,double, double,double)));

    if (!rslt) {
      cout << "Krunch: Failed to connect, column " << ii
      << "  rslt: " << rslt << endl;
      exit(3);
    }
  }

  {
    QMetaObject::Connection rslt = QObject::connect( flushy, SIGNAL(_flush()),
        arg->topwin, SLOT(flush()) );

    if (!rslt) {
      cout << "Krunch: Failed to connect flush: "
                << rslt << endl;
      exit(3);
    }
  }

  alsa_pcm* pcm = arg->pcm;
  int nframe = arg->setup->nframe;

  int left_idx = 0;
  int right_idx = 1;

/// Kludge test:  left_idx = 10; right_idx = 11;
// Be careful to index outside array boundaries:
  int topchan = pcm->nchan - 1;
  if (left_idx  > topchan) left_idx  = topchan;
  if (right_idx > topchan) right_idx = topchan;

#if 0
  if (snd_pcm_state(arg->otherpcm->phndl) != SND_PCM_STATE_RUNNING) {
    cout << "Krunch waits: "
        << arg->otherpcm->alsa_state_name()
        << endl;
  }
#endif
  while (snd_pcm_state(arg->otherpcm->phndl) != SND_PCM_STATE_RUNNING) {
    usleep(1000);
  }

  double left_real(0);
  double left_ineg(0);          // the *negative* of the imaginary part
  double right_real(0);
  double right_ineg(0);          // the *negative* of the imaginary part

//#define PHASE_CHANGE
#ifdef PHASE_CHANGE
  double old_phase(0);
#endif
  double old_cpkp(0), old_fpkp(0);
  double theta(0);
  double dtheta(0);
  int kperno(0);

//////////////////
// main krunch loop
//
// this is a SINGLE loop over TWO variables;
// the cap_buffer is filled in units of nframe
// and emptied (processed) in units of fpkp.
// Parallel code appears in refout.cxx
  int cap_end(nframe * pcm->nchan);
  valarray<datum> cap_buffer(cap_end);
  int cap_idx(cap_end);
  int ref_end(123456);
  int ref_idx(ref_end);
  double decalage(0);

  for (;;) {    // loop over all samples

// loop control for capture (read) process:
    if (cap_idx >= nframe) {
      int didread = arg->setup->read_stuff(pcm, &cap_buffer[0]);
      if (didread != nframe) {
        fprintf(stderr, "Krunch: ignoring peculiar buffer size %d not %d\n",
            didread, nframe);
        continue;
      }
      cap_idx = 0;
    }

// Loop control for reference process.
// Note that frequency and phase-offset only changes at
// the boundary between krunch periods.
    if (ref_idx == ref_end) {
      if (kperno == 0) {
        decalage = arg->otherpcm->ss_time() - pcm->ss_time();
      }

#if 0
        cout << "declalage: " << decalage
             << "  samples: " << decalage * pcm->rate
             << "  skipme: "  << skipme
             << endl;
#endif
      ref_to_krunch kper;
      int didread = read(arg->pipefd, &kper, sizeof(kper));
      if (didread != sizeof(kper)) {
        fprintf(stderr, "Krunch: could not read from pipe: ");
        perror(0);
        exeunt(1);
      }
      if (kperno != kper.period) {
        fprintf(stderr, "Krunch: phase error: expecting %d got %d\n",
                kperno, kper.period);
        exeunt(1);
      }
      double freq = double(pcm->rate) * double(kper.cpkp)
                                / double(kper.fpkp);
// the phase offset:
      theta = (decalage + timeShift) * freq * 2. * M_PI;
      theta += phaseShift * M_PI / 180.;
#ifdef PHASE_CHANGE
      if (theta != old_phase){
        cout << "Krunch: new phase: " << theta
                << "  decalage: " << decalage
                << "  timeShift: " << timeShift
                << "  phaseShift: " << timeShift
                << "  freq: " << freq
                << endl;
        old_phase = theta;
      }
#endif
      left_real = left_ineg = 0.;
      right_real = right_ineg = 0.;
      ref_idx = 0;
      ref_end = kper.fpkp;
      dtheta = 2. * M_PI * kper.cpkp / kper.fpkp;
      // cpkp == cycles per krunch period
      // fpkp == frames per krunch period
      if (old_cpkp != kper.cpkp || old_fpkp != kper.fpkp){
#if 0
        cout.precision(6);
        cout << fixed;
        cout << "Krunch switching to: " << freq
                  << setprecision(1)
                  << "  cpkp: " << kper.cpkp
                  << "  fpkp: " << kper.fpkp
                  << "  dtheta: " << setprecision(20) << dtheta
                  << endl;
#endif
        old_cpkp = kper.cpkp;
        old_fpkp = kper.fpkp;
      }
      kperno++;
    }
    double left  = cap_buffer[cap_idx * pcm->nchan + left_idx ];
    double right = cap_buffer[cap_idx * pcm->nchan + right_idx];

    left_real += left * cos(theta);
    left_ineg += left * sin(theta);

    right_real += right * cos(theta);
    right_ineg += right * sin(theta);

    theta += dtheta;
    cap_idx++;
    ref_idx++;

// Do a little post-processing.
// This does not replace or even affect the
// loop-control above.
    if (ref_idx >= ref_end) {

// put in the minus sign here, to convert ineg to the
// actual imaginary part with the proper sign.
      do {
        double unit = pow(10., ViCal_dB / 20.);
        unit /= full_swing;
// account for the number of points of points in this krunch period:
        unit /= double(ref_end);
// account for the fact that integral(sin^2) is only 0.5, not 1:
        unit *= 2.;
        if (num_indic <= 0) break;
        toss[0].newReading(0,0, left_real * unit, -left_ineg * unit);
        if (num_indic <= 1) break;
        toss[1].newReading(0,0, right_real * unit, -right_ineg * unit);
        if (num_indic <= 2) break;
        toss[2].newReading(right_real * unit, -right_ineg * unit,
                            left_real * unit, -left_ineg * unit);
      } while (0);
      flushy->flush();
    }
  }
  // should never reach here
  return 0;
}

////////////////////
void dumpit_cout(const double rp, const double ip){
  using namespace std;
  cout.precision(4);
  int wid(12);
  double mag(sqrt(rp*rp + ip*ip));
  double phase(0);
  if (mag) phase = atan2(ip, rp);
  cout
    << " : " << fixed << setw(wid) << rp
    << " "   << fixed << setw(wid) << ip
    << "   " << fixed << setw(wid) << mag
    << " "   << fixed << setw(wid) << phase * 180 / M_PI
    << endl;
}

// Just like snd_pcm_readi(),
// except the buff is always of the type of datum (int32_t),
// no matter what type the raw hardware uses.
// Return value:
//   nonnegative: # of frames read
//   negative: error code
int readi(const alsa_pcm* pcm, datum* buff, const int nframe){
  using namespace std;
  if (pcm->format == SND_PCM_FORMAT_S32_LE) {
    return snd_pcm_readi(pcm->phndl, buff, nframe);
  } else if (pcm->format == SND_PCM_FORMAT_S16_LE) {
    valarray<int16_t> tmp(nframe * pcm->nchan);
    int rslt = snd_pcm_readi(pcm->phndl, &tmp[0], nframe);
    if (rslt <= 0) return rslt;
    int16_t* from (&tmp[0]);
    datum* to (buff);
    int fudge(1<<16);
    for (unsigned int ii = 0; ii < rslt * pcm->nchan; ii++){
      *to++ = *from++ * fudge;
    }
    return rslt;
  } else {
    cerr << "Don't know how to convert pcm data from format "
         <<   snd_pcm_format_name(pcm->format) << endl;
    exeunt(1);
  }
  return 0;             // defeat stupid compiler warning
}

////////////////////////////////////////
// Read some data and maybe write checkfile
int snark::read_stuff(alsa_pcm* pcm, datum* cap_buffer){

  int sts;
  int frames_read;

  for (;;){             // keep trying to read
    frames_read = readi(pcm, &cap_buffer[0], nframe);
    if (frames_read == nframe) break;   // good!
    if (frames_read > 0 ||
        frames_read == -EPIPE) {        // recover from overruns
      if (xrun_verbosity) fprintf(stderr,
                "Read_stuff overrun: requested %i got %i: %s" NL,
                nframe, frames_read, snd_strerror(frames_read));
      snd_pcm_prepare(pcm->phndl);
    } else {                            // unrecoverable error
      fprintf(stderr, "Read_stuff requested %i got %i: %s" NL,
              nframe, frames_read, snd_strerror(frames_read));
      exeunt(1);
    }
  }

  int gotbytes = snd_pcm_frames_to_bytes(pcm->phndl, frames_read);

  if (wcheck_fd >= 0) {
    sts = write(wcheck_fd, &cap_buffer[0], gotbytes);
    if (sts != gotbytes) {
      fprintf(stderr, "Write error on raw output file (%i): %m" NL, wcheck_fd);
      exeunt(1);
    }
    close(wcheck_fd);
    wcheck_fd = -1;
  }

  return frames_read;
}