#include <functional>
#include <iostream>
#include <fstream>
#include <list>

#include <cmath>

#include "randutils/randutils.hpp"
#include "pcg-cpp/include/pcg_random.hpp"

using Rng = randutils::random_generator<pcg32>;

class Edge {
public:
  unsigned index;
  std::list<double> weights;
  double probability;

  Edge() {
    probability = 0;
  }
};

class Face {
public:
  std::array<std::reference_wrapper<Edge>, 4> edges;

  Face(Edge& a, Edge& b, Edge& c, Edge& d) : edges({a, b, c, d}) {}
};

class AztecDiamond {
public:
  std::vector<Edge> edges;
  std::vector<std::vector<Face>> faces;

  AztecDiamond(unsigned n) : edges(pow(2 * n, 2)), faces(n) {
    for (unsigned i = 0; i < edges.size(); i++) {
      edges[i].index = i;
    }
    for (unsigned i = 1; i <= n; i++) {
      faces[n - i].reserve(pow(i, 2));
      for (unsigned j = 0; j < pow(i, 2); j++) {
        unsigned x = j % (i);
        unsigned y = j / (i);
        unsigned x0 = n - i;
        unsigned y0 = n - i;
        faces[n - i].push_back(Face(
              edges[2 * n * (y0 + 2 * y) + x0 + 2 * x],
              edges[2 * n * (y0 + 2 * y) + x0 + 2 * x + 1],
              edges[2 * n * (y0 + 2 * y + 1) + x0 + 2 * x],
              edges[2 * n * (y0 + 2 * y + 1) + x0 + 2 * x + 1]
              ));
      }
    }
  }

  void computeWeights() {
    for (std::vector<Face>& fs : faces) {
      for (Face& f : fs) {
        double w = f.edges[0].get().weights.back();
        double x = f.edges[1].get().weights.back();
        double y = f.edges[2].get().weights.back();
        double z = f.edges[3].get().weights.back();

        double cellFactor = w * z + x * y;

        f.edges[0].get().weights.push_back(z / cellFactor);
        f.edges[1].get().weights.push_back(y / cellFactor);
        f.edges[2].get().weights.push_back(x / cellFactor);
        f.edges[3].get().weights.push_back(w / cellFactor);
      }
    }

    for (Edge& e : edges) {
      e.weights.pop_back();
    }
  }

  void computeProbabilities() {
    for (auto it = faces.rbegin(); it != faces.rend(); it++) {
      for (Face& f : *it) {
        double p = f.edges[0].get().probability;
        double q = f.edges[1].get().probability;
        double r = f.edges[2].get().probability;
        double s = f.edges[3].get().probability;

        double w = f.edges[0].get().weights.back();
        double x = f.edges[1].get().weights.back();
        double y = f.edges[2].get().weights.back();
        double z = f.edges[3].get().weights.back();

        std::cout << w << " " << x << " " << y << " " << z << std::endl;

        double cellFactor = w * z + x * y;
        double deficit = 1 - p - q - r - s;

        f.edges[0].get().probability = s + deficit * w * z / cellFactor;
        f.edges[1].get().probability = r + deficit * x * y / cellFactor;
        f.edges[2].get().probability = q + deficit * x * y / cellFactor;
        f.edges[3].get().probability = p + deficit * w * z / cellFactor;

        for (Edge& e : f.edges) {
          if (e.weights.empty()) {
            std::cout << "No weights left!" << std::endl;
          } else {
            e.weights.pop_back();
          }
        }
      }
    }
  }
};

int main(int argc, char* argv[]) {
  unsigned n = 100;
  unsigned m = 100;

  int opt;

  while ((opt = getopt(argc, argv, "n:m:")) != -1) {
    switch (opt) {
    case 'n':
      n = atoi(optarg);
      break;
    case 'm':
      m = (unsigned)atof(optarg);
      break;
    default:
      exit(1);
    }
  }

  Rng r;
//  AztecDiamond a(n);



  /* For checking if the faces are appropriately defined.
  for (std::vector<Face>& fs : a.faces) {
    for (Face& f : fs) {
      for (Edge& e : f.edges) {
        unsigned v1 = (1 + (e.index % (2 * n))) / 2 + (n + 1) * ((e.index / 4) / n);
        unsigned v2 = n * (n + 1) + (e.index % (2 * n)) / 2 + n * (((e.index + 2 * n) / 4) / n);

        std::cout << v1 << " " << v2 << " ";
      }
    }
    std::cout << std::endl;
  }
  */

  AztecDiamond a(3);
  for (Edge& e : a.edges) {
    e.weights.push_back(1);
  }

  a.edges[1].weights.front() = 0;
  a.edges[4].weights.front() = 0;
  a.edges[6].weights.front() = 0;
  a.edges[11].weights.front() = 0;
  a.edges[24].weights.front() = 0;
  a.edges[29].weights.front() = 0;
  a.edges[31].weights.front() = 0;
  a.edges[34].weights.front() = 0;

  a.computeWeights();

  for (unsigned i = 0; i < 3; i++) {
    for (unsigned j = 0; j < a.edges.size(); j++) {
        if (j % 6 == 0) {
          std::cout << std::endl;
        }
      if (!a.edges[j].weights.empty()) {
        std::cout << a.edges[j].weights.front() << " ";
        a.edges[j].weights.pop_front();
      }
    }
  }
  std::cout << std::endl;

  for (Edge& e : a.edges) {
    e.weights.push_back(1);
  }

  a.edges[1].weights.front() = 0;
  a.edges[4].weights.front() = 0;
  a.edges[6].weights.front() = 0;
  a.edges[11].weights.front() = 0;
  a.edges[24].weights.front() = 0;
  a.edges[29].weights.front() = 0;
  a.edges[31].weights.front() = 0;
  a.edges[34].weights.front() = 0;

  a.computeWeights();
  a.computeProbabilities();

  for (unsigned i = 0; i < a.edges.size(); i++) {
    if (i%6 == 0) {
      std::cout << std::endl;
    }
    std::cout << a.edges[i].probability << " ";
  }
    std::cout << std::endl;

  return 0;
}