#ifndef Ring3_H
#define Ring3_H

#include "cycle_facade.H"
#include <vector>

template<typename T, template <typename A> class CONT=std::vector>
class Ring {
public:
  typedef typename boost::cycle_facade<typename CONT<T>::iterator> iterator;
  typedef typename boost::cycle_facade<typename CONT<T>::const_iterator> const_iterator;

  Ring() : _size(0) {}

  explicit Ring (size_t n) :
    _size (n), v (n+1), it (boost::make_cycle_facade (v.begin(), v.begin(), v.end())) {}

  Ring (const Ring& r) :
    _size (r._size),
    v (r.v),
    it (boost::make_cycle_facade (v.begin()+r.it.offset(), v.begin(), v.end()))
  {}

  iterator begin() { return it; }

  iterator end() { return it + _size; }

  const iterator begin() const { return it; }

  const iterator end() const { return it + _size; }

  void shift (int n=1) { it += n; }

  void Shift (int n=1) { shift (n); }

  T& operator[] (int n) { return it[n]; }

  const T& operator[] (int n) const { return it[n]; }

  size_t size() const { return _size; }

  void resize (size_t n) {
    v.resize (n+1);
    _size = n;
    it = boost::make_cycle_facade (v.begin(), v.begin(), v.end());
  }

  void insert (iterator pos, const T& value) {
    size_t offset = pos.offset(); // offset from base of v
    v.insert (v.begin()+offset, value);
    it = boost::make_cycle_facade (v.begin()+it.offset(), v.begin(), v.end());
    _size++;
  }

  template<typename in_t>
  void insert (iterator pos, in_t in, in_t inend) {
    size_t offset = pos.offset(); // offset from base of v
    v.insert (v.begin()+offset, in, inend);
    it = boost::make_cycle_facade (v.begin()+it.offset(), v.begin(), v.end());
    _size += inend-in;;
  }

  void erase (iterator pos) {
    size_t offset = pos.offset();
    v.erase (v.begin()+offset);
    it = boost::make_cycle_facade (v.begin()+it.offset(), v.begin(), v.end());
    _size--;
  }

  size_t _size;
  CONT<T> v;
  iterator it;
};

#endif