#pragma once

#include <algorithm>
#include <cmath>
#include <cstdint>
#include <sstream>

constexpr int64_t DIPHA_MAGIC = 8067171840;
constexpr int64_t DIPHA_DISTANCE_MATRIX = 7;
constexpr int64_t DIPHA_PERSISTENCE_DIAGRAM = 2;
constexpr int64_t DIPHA_WEIGHTED_BOUNDARY_MATRIX = 0;
inline constexpr double PI = 4*std::atan(1);

template <typename T> inline void reverse_endianness(T & x)
{
  uint8_t * p = reinterpret_cast<uint8_t *>(&x);
  std::reverse(p, p + sizeof(T));
}

template <typename T> inline T read_le(std::istream & s)
{
  T result;
  s.read(reinterpret_cast<char *>(&result), sizeof(T));
  #ifdef BIGENDIAN
  reverse_endianness(result);
  #endif
  return result;
}

template <typename T> inline void write_le(std::ostream & s, T value)
{
  #ifdef BIGENDIAN
  reverse_endianness(value);
  #endif
  s.write(reinterpret_cast<char *>(&value), sizeof(T));
}

template <typename T> inline T read_be(std::istream & s)
{
  T result;
  s.read(reinterpret_cast<char *>(&result), sizeof(T));
  #ifndef BIGENDIAN
  reverse_endianness(result);
  #endif
  return result;
}

template <typename T> inline void write_be(std::ostream & s, T value)
{
  #ifndef BIGENDIAN
  reverse_endianness(value);
  #endif
  s.write(reinterpret_cast<char *>(&value), sizeof(T));
}

enum class Message_tag : int { result, work };

template <typename T> inline T unroll_upper_tri(T n, T i, T j)
{
  return i*(n-1) - ((i-1)*i)/2 + j;
}

template <typename T> inline T unroll_full(T n, T i, T j)
{
  return i*n + j;
}