/* -*- c++ -*-

   Simple C++ variable array of non-POD objects

   This file is part of the dpp library of C++ template classes

   doc: http://diaxen.ssji.net/dpp/index.html
   repo: https://www.ssji.net/svn/projets/trunk/libdpp

   This program is free software: you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public License
   as published by the Free Software Foundation, either version 3 of
   the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this program.  If not, see
   <http://www.gnu.org/licenses/>.

   (c) 2011 Alexandre Becoulet <alexandre.becoulet@free.fr>

*/

#ifndef DPP_VLARRAY_HH_
#define DPP_VLARRAY_HH_

#include <memory>
#include <stdexcept>

#include <stddef.h>
#include <stdint.h>

/** @file @module{Variable length array} */

namespace dpp {

  /** @short Variable length array iterator class
      @module {Variable length array}
      @header dpp/vlarray
      @internal
  */
  template <typename X, int direction>
  class vlarray_iterator
  {
    template <class, int> friend class vlarray_iterator;
    template <class> friend class vlarray;

    vlarray_iterator(X *vlarray, unsigned int i)
      : _array(vlarray),
	_i(i)
    {
    }

  public:

    typedef X value_type;
    typedef X & reference;
    typedef const X & const_reference;
    typedef X * pointer;
    typedef const X * const_pointer;
    typedef unsigned int size_type;
    typedef int difference_type;

    typedef std::bidirectional_iterator_tag iterator_category;

    vlarray_iterator()
    {
    }

    template <class T>
    vlarray_iterator(const vlarray_iterator<T, direction> &i)
      : _array(i._array),
	_i(i._i)
    {
    }

    X & operator*()
    {
      return _array[_i];
    }

    X * operator->()
    {
      return &_array[_i];
    }

    vlarray_iterator & operator++()
    {
      _i += direction;
      return *this;
    }

    vlarray_iterator operator++(int)
    {
      vlarray_iterator tmp(*this);
      _i += direction;
      return tmp;
    }

    vlarray_iterator & operator--()
    {
      _i -= direction;
      return *this;
    }

    vlarray_iterator operator--(int)
    {
      vlarray_iterator tmp(*this);
      _i -= direction;
      return tmp;
    }

    vlarray_iterator operator-(int x) const
    {
      return vlarray_iterator(_array, _i - x * direction);
    }

    vlarray_iterator operator+(int x) const
    {
      return vlarray_iterator(_array, _i + x * direction);
    }

    difference_type operator-(const vlarray_iterator & i) const
    {
      return (_i - i._i) * direction;
    }

    bool operator<(const vlarray_iterator & i) const
    {
      return _i < i._i;
    }

    bool operator==(const vlarray_iterator &i) const
    {
      return _i == i._i;
    }

    bool operator!=(const vlarray_iterator &i) const
    {
      return _i != i._i;
    }

  private:
    X *_array;
    unsigned int _i;
  };

  /** @short Variable length array class
      @module {Variable length array}
      @header dpp/vlarray

      Variable lenght arrays of non POD types are not supported in
      C++. This class provides a container array which uses storage
      space passed to constructor. The @ref #DPP_VLARRAY macro can be
      used to declare storage space buffer along with array container,
      providing variable lenght array feature:

      @example test/test_vlarray.cc:example
  */
  template <typename X>
  class vlarray
  {
  public:

    /** Variable array declaration macro. @This macro declares a
	buffer array of integers along with a @ref vlarray object and
	pass the buffer array as storage space to the @ref vlarray
	constructor. @hidecontent */
#define DPP_VLARRAY(type, size, name)		\
  uint64_t _##name[sizeof(type) * size / 8 + 1];	\
  ::dpp::vlarray<type> name(_##name, size); /* FIXME size alignment */

    typedef X value_type;
    typedef X & reference;
    typedef const X & const_reference;
    typedef X * pointer;
    typedef const X * const_pointer;
    typedef unsigned int size_type;
    typedef int difference_type;

    typedef vlarray_iterator<X, 1> iterator;
    typedef vlarray_iterator<const X, 1> const_iterator;
    typedef vlarray_iterator<X, -1> reverse_iterator;
    typedef vlarray_iterator<const X, -1> const_reverse_iterator;

    /* @This declare a variable lenght array with given storage space
       and elements count. The default constructor is invoked for all
       new array items. */
    vlarray(void *array, size_t size)
      : _array((X*)array),
	_size(size)
    {
      for (size_t i = 0; i < _size; i++)
	new ((X*)(_array + i)) X();
    }

    /* @This invokes destructor for all array items */
    ~vlarray()
    {
      for (size_t i = 0; i < _size; i++)
	(_array + i)->~X();
    }

    size_t size() const
    {
      return _size;
    }

    size_t capacity() const
    {
      return _size;
    }

    X & operator[](int i)
    {
      return _array[i];
    }

    const X & operator[](int i) const
    {
      return _array[i];
    }

    X & at(int i)
    {
      if (i >= _size)
	throw std::out_of_range("");
      return _array[i];
    }

    const X & at(int i) const
    {
      if (i >= _size)
	throw std::out_of_range("");
      return _array[i];
    }

    /** @This returns @ref iterator to first object in pool */
    iterator begin()
    {
      return iterator(_array, 0);
    }

    /** @This returns end @ref iterator */
    iterator end()
    {
      return iterator(_array, size());
    }

    /** @This returns @ref const_iterator to first object in pool */
    const_iterator begin() const
    {
      return const_iterator(_array, 0);	
    }

    /** @This returns end @ref const_iterator */
    const_iterator end() const
    {
      return const_iterator(_array, size());
    }

    /** @This returns @ref reverse_iterator to last object in pool */
    reverse_iterator rbegin()
    {
      return reverse_iterator(_array, size() - 1);
    }

    /** @This returns end @ref reverse_iterator */
    reverse_iterator rend()
    {
      return reverse_iterator(_array, -1);
    }

    /** @This returns @ref const_reverse_iterator to first object in pool */
    const_reverse_iterator rbegin() const
    {
      return const_reverse_iterator(_array, size() - 1);
    }

    /** @This returns end @ref const_reverse_iterator */
    const_reverse_iterator rend() const
    {
      return const_reverse_iterator(_array, -1);
    }

  private:
    X *_array;
    size_t _size;
  };

}

#endif