#include <iostream>
#include <limits>
#include <stdexcept>

#include "integer.h"

Integer::Integer(int i)
  : value{positive(i)}, negative{i<0}
{
}

Integer::operator int () const
{
  if ( value > std::numeric_limits<int>::max() )
  {
    throw std::range_error{"Overflow"};
  }
  int r = static_cast<int>(value);
  
  return negative ? -r : r;
}

bool Integer::operator==(Integer const& i) const
{
  return value == i.value && negative == i.negative;
}
  
bool Integer::operator<(Integer const& i) const
{
  if ( same_sign(i) )
  {
    if ( negative )
    {
      return i.value < value;
    }
    else
    {
      return value < i.value;
    }
  }
  else
  {
    return negative;
  }
}

Integer& Integer::operator++()
{
  if ( negative )
  {
    --value;
    negative = (value != 0);
  }
  else
  {
    ++value;
  }
  
  return *this;
}
  
std::ostream& operator<<(std::ostream& os, Integer const& i)
{
  if ( i.negative )
  {
    os << '-';
  }
  return os << i.value;
}

bool Integer::same_sign(Integer const& i) const
{
  return negative == i.negative;
}

unsigned int Integer::positive(int i) const
{
  return static_cast<unsigned int>(i < 0 ? -i : i);
}