// Copyright (C) 2014 The Regents of the University of California (Regents).
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//
//     * Neither the name of The Regents or University of California nor the
//       names of its contributors may be used to endorse or promote products
//       derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Please contact the author of this library if you have any questions.
// Author: Chris Sweeney (cmsweeney@cs.ucsb.edu)

// BSD 3-Clause License

// Copyright (c) 2021, Chenyu
// All rights reserved.

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:

// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.

// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.

// 3. Neither the name of the copyright holder nor the names of its
//    contributors may be used to endorse or promote products derived from
//    this software without specific prior written permission.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef UTIL_RANDOM_H_
#define UTIL_RANDOM_H_

#include <Eigen/Core>
#include <chrono>
#include <random>
#include <thread>

namespace gopt {

// A wrapper around the c++11 random generator utilities. This allows for a
// thread-safe random number generator that may be easily instantiated and
// passed around as an object.
class RandomNumberGenerator {
 public:
  // Creates the random number generator using the current time as the seed.
  RandomNumberGenerator();

  // Creates the random number generator using the given seed.
  explicit RandomNumberGenerator(const unsigned seed);

  // Seeds the random number generator with the given value.
  void Seed(const unsigned seed);

  // Get a random double between lower and upper in uniform distribution (inclusive).
  double RandDouble(const double lower, const double upper);

  // Get a random float between lower and upper (inclusive).
  float RandFloat(const float lower, const float upper);

  // Get a random double between lower and upper (inclusive).
  int RandInt(const int lower, const int upper);

  // Generate a number drawn from a gaussian distribution.
  double RandGaussian(const double mean, const double std_dev);
  // Generate a number drawn from a standard gaussian distribution.
  double RandStdGaussian();

  template <typename T>
  void RandShuffle(std::vector<T>* vec);

  // Return eigen types with random initialization. These are just convenience
  // methods. Methods without min and max assign random values between -1 and 1
  // just like the Eigen::Random function.
  Eigen::Vector2d RandVector2d(const double min, const double max);
  Eigen::Vector2d RandVector2d();
  Eigen::Vector3d RandVector3d(const double min, const double max);
  Eigen::Vector3d RandVector3d();
  Eigen::Vector4d RandVector4d(const double min, const double max);
  Eigen::Vector4d RandVector4d();

  Eigen::Vector2d RandnVector2d();
  Eigen::Vector3d RandnVector3d();
  Eigen::Vector4d RandnVector4d();

  inline double Rand(const double lower, const double upper) {
    return RandDouble(lower, upper);
  }

  inline float Rand(const float lower, const float upper) {
    return RandFloat(lower, upper);
  }

  // Sets an Eigen type with random values between -1.0 and 1.0. This is meant
  // to replace the Eigen::Random() functionality.
  template <typename Derived>
  void SetRandom(Eigen::MatrixBase<Derived>* b) {
    for (int r = 0; r < b->rows(); r++) {
      for (int c = 0; c < b->cols(); c++) {
        (*b)(r, c) = Rand(-1.0, 1.0);
      }
    }
  }
};

}  // namespace gopt

#include "utils/random.inl"

#endif  // UTIL_RANDOM_H_
