/*
 MCL
 Copyright (c) 2012-18, Enzo De Sena
 All rights reserved.
 
 Authors: Enzo De Sena, enzodesena@gmail.com
 */


#include "randomop.h"
#include "mcltypes.h"
#include <vector>
#include <cassert>


namespace mcl {
  
RandomGenerator::RandomGenerator(unsigned int seed) :
distribution_norm_(std::normal_distribution<double>(0.0,1.0)),
distribution_uniform_(std::uniform_real_distribution<double>(0.0,1.0)) {
  generator_.seed(seed);
}
  
RandomGenerator::RandomGenerator() :
        distribution_norm_(std::normal_distribution<double>(0.0,1.0)),
        distribution_uniform_(std::uniform_real_distribution<double>(0.0,1.0)) {
  generator_.seed(1u);
}

  
std::vector<Real> RandomGenerator::Randn(const Int size) {
  std::vector<Real> output(size);
  for (Int i = 0; i < size; i++) {
    output[i] = distribution_norm_(generator_);
  }
  return output;
}
  
std::vector<Real> RandomGenerator::Rand(const Int size) {
  std::vector<Real> output(size);
  for (Int i = 0; i < size; i++) {
    output[i] = distribution_uniform_(generator_);
  }
  return output;
}
  
Int RandomGenerator::RandInt(const Int& minimum, const Int& maximum) {
  // number of possible outcomes
  // e.g. max = 2, min = 0 => num_outcomes = 3
  const Int num_outcomes = maximum - minimum + 1;
  Int output = (Int) floor((double) (distribution_uniform_(generator_)*((double) num_outcomes))) + minimum;
  
  ASSERT(output >= minimum);
  ASSERT(output <= maximum);
  return output;
}

} // namespace mcl