#ifndef NNTRAIN_INC_CPP
#define NNTRAIN_INC_CPP


#include "nnlayer.inc.cpp"


class Trainer {
public:
  double trainRatio;
  int sizeX, sizeY, count;
  double *x, *y;


  explicit Trainer(double trainRatio = 0.5): trainRatio(trainRatio), sizeX(), sizeY(), count(), x(), y() { }

  Trainer(double trainRatio, int sizeX, int sizeY, int count):
    Trainer(trainRatio)
    { init(sizeX, sizeY, count); }

  ~Trainer()
    { deinit(); }


  void init(int sizeX, int sizeY, int count) {
    deinit();
    assert(sizeX > 0);
    assert(sizeY > 0);
    assert(count > 0);
    this->sizeX = sizeX;
    this->sizeY = sizeY;
    this->count = count;
    x = new double[(sizeX + sizeY)*count];
    y = x + sizeX*count;
    memset(x, 0, sizeof(*x)*(sizeX + sizeY)*count);
  }

  void deinit() {
    if (!count) return;
    delete[] x;
    sizeX = sizeY = count = 0;
    x = y = nullptr;
  }


  double trainSimple(Layer &l, int successCount, double qmin, int reportStep) {
    assert(count);
    assert(!l.prev);
    assert(sizeX == l.size);
    assert(sizeY == l.back().size);
    assert(successCount > 0);
    assert(qmin > 0);

    printf("training: %d, %lf\n", successCount, qmin);
    double *res = new double[successCount];
    double *rp = res, *re = res + successCount;
    double rsum = 0;
    int rcount = 0;
    memset(res, 0, sizeof(*res)*successCount);

    int success = 0, total = 0, nextReport = reportStep;
    double avg = 0;
    for(int i = 0; i < 1000000000; ++i) {
      int index = rand() % count;

      double target = avg*0.5;
      double q = 0;
      for(int i = 0; i < 10; ++i) {
        double qq = l.trainPass(trainRatio, x + sizeX*index, y + sizeY*index, target);
        if (q < qq) q = qq;
        ++total;
        if (qq <= target) break;
        break;
      }


      rcount += (q > qmin) - (*rp > qmin);
      rsum += q - *rp;
      *rp++ = q;
      if (rp == re) rp = res;

      int cnt = i+1 < successCount ? i+1 : successCount;
      avg = rsum/cnt;

      if (q > qmin) success = 0; else ++success;

      if (total >= nextReport || success >= successCount) {
        printf("  iterations: %d, error rate: %lf, avg res: %lf\n", total, rcount/(double)cnt, avg);
        nextReport = total + reportStep;
      }
      if (success >= successCount) break;
    }

    delete[] res;
    printf("done\n");
    return rsum/successCount;
  }


  double trainBlock(Layer &l, int successCount, int blockSize, double qmin, int reportStep = 0) {
    assert(count);
    assert(!l.prev);
    assert(sizeX == l.size);
    assert(sizeY == l.back().size);
    assert(blockSize > 0 && qmin > 0);
    assert(reportStep >= 0);

    printf("training: %d, %lf\n", blockSize, qmin);
    double **blockXY = new double*[blockSize*2];
    double qmin2 = qmin*0.9;
    double qmin3 = qmin2*0.9;

    int success = 0;
    int total = 0, nextReport = reportStep;
    int repeats, blockRepeats;
    double qmax0, qsum0, qmax, qsum;
    for(int i = 0; i < 1000000; ++i) {
      for(int i = 0; i < blockSize; ++i) {
        int index = rand() % count;
        blockXY[i*2 + 0] = x + sizeX*index;
        blockXY[i*2 + 1] = y + sizeY*index;
      }

      repeats = blockRepeats = 0;
      qmax0 = qsum0 = 0;
      for(int i = 0; i < 1000; ++i) {
        double **xy = blockXY;
        qmax = 0, qsum = 0;
        for(int i = 0; i < blockSize; ++i, xy += 2) {
          double q0 = 0;
          for(int i = 0; i < 100; ++i) {
            double q = l.trainPass(trainRatio, xy[0], xy[1], qmin3);
            if (!i) q0 = q;
            ++repeats;
            if (q < qmin3) break;
          }
          qsum += q0;
          if (qmax < q0) qmax = q0;
        }
        if (!i) { qmax0 = qmax; qsum0 = qsum; }
        ++blockRepeats;
        if (qmax <= qmin2) break;
      }
      total += repeats;


      if (qmax0 > qmin) success = 0; else ++success;

      if (total >= nextReport || success >= successCount) {
        nextReport = total + reportStep;
        printf("  blocks %d (samples: %d, total: %d, repeats: %3d (%lf)): %lf -> %lf, %lf -> %lf\n",
          i+1, (i+1)*blockSize, total, blockRepeats-1, repeats/(double)(blockRepeats*blockSize) - 1, qmax0, qmax, qsum0/blockSize, qsum/blockSize);
      }
      if (success >= successCount) break;
    }

    delete[] blockXY;
    printf("done\n");
    return qmax0;
  }


  bool loadSymbolMap(const char *filename, int sizeX, int sizeY) {
    deinit();

    FILE *f = fopen(filename, "rb");
    if (!f)
      return printf("cannot open file '%s' for read\n", filename), false;
    fseek(f, 0, SEEK_END);
    size_t fs = ftell(f);
    fseek(f, 0, SEEK_SET);

    size_t testSize = sizeX + 1;
    int count = fs/testSize;
    if (!count)
      return printf("file '%s' is lesser minimal size\n", filename), fclose(f), false;

    unsigned char *data = new unsigned char[testSize*count];
    memset(data, 0, testSize*count);
    if (!fread(data, testSize*count, 1, f))
      return printf("cannot read from file '%s'\n", filename), delete[] data, fclose(f), false;

    fclose(f);

    init(sizeX, sizeY, count);
    const unsigned char *pd = data;
    const double delta = 0;
    double *ey = y + sizeY*count;
    for(double *py = y; py < ey; ++py)
      *py = delta;
    for(double *px = x, *py = y; py < ey; py += sizeY) {
      for(double *ex = px + sizeX; px < ex; ++px, ++pd)
        *px = *pd/255.0;
      assert(*pd < sizeY);
      py[*pd++] = 1 - delta;
    }
    delete[] data;

    return true;
  }


  void printSymbol(int index, int width) {
    assert(index >= 0 && index < count);
    assert(width > 0);
    for(int i = 0; i < sizeX; ++i) {
      if (i && !(i % width)) printf("\n");
      printf("%c", x[sizeX*index + i] > 0 ? '#' : '.');
    }
    printf("\n");
    for(int i = 0; i < sizeY; ++i)
      printf(" %4.1lf", y[sizeY*index + i]);
    printf("\n");
  }
};


#endif