#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>

#define SEEDFILE "./seeds.txt"
#define SURVIVOR 4
#define CHILDREN 7
#define DEFLIVES 10

#define SIGMOID(x) tanh(x)
#define DSGMOID(x) (1 - x*x)
#define RAND rand() / RAND_MAX

void getError(double r, double t, double ox, double oy, double *err) {
  err[0] = (r * cos(t)) - ox;
  err[1] = (r * sin(t)) - oy;
}


struct Network {
  int layers;
  int *neuNums;
  double *synDefs;
  double **neurons;
  double ***synapses;
  double rate;
};

void constructNetwork(struct Network *net) {
  int l, i, o, nl;

  net->neurons = malloc(sizeof(*net->neurons) * net->layers);
  net->synapses = malloc(sizeof(*net->synapses) * (net->layers - 1));

  for (l = 0, nl = 1; nl < net->layers; l++, nl++) {
    net->neurons[l] = malloc(sizeof(*net->neurons[l]) * net->neuNums[l]);
    net->synapses[l] = malloc(sizeof(*net->synapses[l]) * net->neuNums[l]);

    for (i = 0; i < net->neuNums[l]; i++) {
      net->synapses[l][i] = malloc(sizeof(*net->synapses[l][i]) * net->neuNums[nl]);

      for (o = 0; o < net->neuNums[nl]; o++) {
    net->synapses[l][i][o] = net->synDefs[l] * RAND;
      }
    }
  }
  net->neurons[l] = malloc(sizeof(*net->neurons[l]) * net->neuNums[l]);
}

void fireNeurons(struct Network *net) {
  int i, o, inpLay, outLay;
  for (inpLay = 0, outLay = 1; outLay < net->layers; inpLay++, outLay++) {
    for (o = 0; o < net->neuNums[outLay]; o++) {
      net->neurons[outLay][o] = 0;
      for (i = 0; i < net->neuNums[inpLay]; i++) {
    net->neurons[outLay][o] += net->synapses[inpLay][i][o] * net->neurons[inpLay][i];
      }
      net->neurons[outLay][o] = SIGMOID(net->neurons[outLay][o]);
    }
  }
}

void adjustSynapses(struct Network *net, double *err) {
  int inpLay, outLay, i, o;
  double tmpErr;
  double *nxtErr;

  for (outLay = net->layers - 1, inpLay = outLay - 1; inpLay >= 0; inpLay--, outLay--) {
    nxtErr = malloc(sizeof(*nxtErr) * net->neuNums[inpLay]);
    for (i = 0; i < net->neuNums[inpLay]; i++) {
      tmpErr = 0;
      for (o = 0; o < net->neuNums[outLay]; o++) {
    tmpErr += err[o] * net->synapses[inpLay][i][o];
    net->synapses[inpLay][i][o] += net->rate * err[o] * net->neurons[inpLay][i];
      }
      nxtErr[i] = DSGMOID(net->neurons[inpLay][i]) * tmpErr;
    }

    free(err);
    err = nxtErr;
    nxtErr = 0;
  }
  free(err);
}

void trainSilent(struct Network *net, unsigned int lim) {
  double *err;
  int outLay;

  outLay = net->layers - 1;
  net->neurons[0][0] = 1;
  while (lim--) {
    net->neurons[0][1] = 2 * M_PI * RAND;
    fireNeurons(net);
    err = malloc(sizeof(*err) * 2);
    getError(net->neurons[0][0], net->neurons[0][1], net->neurons[outLay][0], net->neurons[outLay][1], err);
    adjustSynapses(net, err);
  }
}

double trainReturnError(struct Network *net, unsigned int lim) {
  double c = 0;
  int outLay;
  unsigned int t;
  double *err;

  net->neurons[0][0] = 1;
  c = 0;
  outLay = net->layers - 1;
  t = lim;

  while (lim--) {
    net->neurons[0][1] = 2 * M_PI * RAND;
    fireNeurons(net);
    err = malloc(sizeof(*err) * 2);
    getError(net->neurons[0][0], net->neurons[0][1], net->neurons[outLay][0], net->neurons[outLay][1], err);
    c += hypot(err[0], err[1]);
    adjustSynapses(net, err);
  }

  return c / t;
}

int main() {
  double r;
  int i = 0;
  struct Network net;
  printf("Here we go!\n");

  srand(time(NULL));

  net.layers = 3;
  net.neuNums = malloc(sizeof(*net.neuNums) * 3);
  net.neuNums[0] = 2;
  net.neuNums[1] = 15;
  net.neuNums[2] = 2;
  net.synDefs = malloc(sizeof(*net.synDefs) * 2);
  net.synDefs[0] = 0.1;
  net.synDefs[1] = 0.1;
  net.rate = 0.1;
  constructNetwork(&net);

  printf("Network successfully constructed\n");

  for (i = 1; i <= 200; i++) {
    r = trainReturnError(&net, 5000);
  }

  printf("%d: %f\n", i, r);
  printf("Finished!\n");
  return 0;
}