#include <iostream>
#include <stdexcept>
#include <sstream>
#include <vector>
  
#include "polygon.h"

// Only one of the constructors required!
Polygon::Polygon(std::initializer_list<int> l)
  : sides{}
{
  for ( int i : l )
  {
    sides.push_back(i);
  }
  validate();
}

Polygon::Polygon(int a, int b)
  : sides{a, b}
{
  validate();
}

Polygon& Polygon::operator+=(int rhs)
{
  sides.push_back(rhs);
  validate();
  return *this;
}
  
Polygon Polygon::operator+(int rhs) const
{
  Polygon ret{*this};
  ret += rhs;
  return ret;
}

double Polygon::circumference() const
{
  int sum{0};
  for ( int i : sides )
  {
    sum += i;
  }
  return sum + max_side();
}
  
std::ostream& Polygon::print(std::ostream& os) const
{
  os << '[';
  for ( int i : sides )
  {
    os << i << ", ";
  }
  return os << max_side() << ']';
}
  
int Polygon::max_side() const
{
  int max{0};
  for ( int i : sides )
  {
    if ( i > max )
      max = i;
  }
  return max;
}

void Polygon::validate() const
{
  for ( int i : sides )
  {
    if ( i <= 0 )
    {
      throw std::invalid_argument("Bad polygon: Sides must be > 0.0");
    }
  }
  if ( sides.size() < 2 )
  {
    throw std::invalid_argument("Bad polygon: To few sides");
  }
}

Polygon operator+(int lhs, Polygon const& rhs)
{
  return rhs + lhs;
}

std::ostream& operator<<(std::ostream& os, Polygon const& rhs)
{
  return rhs.print(os);
}