// Template array classes
/*

Copyright (C) 1993, 1994, 1995, 1996, 1997, 2000, 2001, 2002, 2003,
              2004, 2005, 2006, 2007 John W. Eaton
Copyright (C) 2008, 2009 Jaroslav Hajek <highegg@gmail.com>

This file is part of Octave.

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

Octave 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 General Public License
for more details.

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

*/

#if !defined (octave_Array_h)
#define octave_Array_h 1

#include <cassert>
#include <cstddef>

#include <iostream>
#include <algorithm>

#include "dim-vector.h"
#include "idx-vector.h"
#include "lo-utils.h"
#include "oct-sort.h"
#include "quit.h"

// One dimensional array class.  Handles the reference counting for
// all the derived classes.

template <class T>
class
Array
{
protected:

  //--------------------------------------------------------------------
  // The real representation of all arrays.
  //--------------------------------------------------------------------

  class ArrayRep
  {
  public:

    T *data;
    octave_idx_type len;
    int count;

    ArrayRep (T *d, octave_idx_type l, bool copy = false) 
      : data (copy ? new T [l] : d), len (l), count (1) 
        { 
          if (copy)
            std::copy (d, d + l, data);
        }

    ArrayRep (void) : data (0), len (0), count (1) { }

    explicit ArrayRep (octave_idx_type n) : data (new T [n]), len (n), count (1) { }

    explicit ArrayRep (octave_idx_type n, const T& val)
      : data (new T [n]), len (n), count (1)
      {
        std::fill (data, data + n, val);
      }

    ArrayRep (const ArrayRep& a)
      : data (new T [a.len]), len (a.len), count (1)
      {
        std::copy (a.data, a.data + a.len, data);
      }
 
    ~ArrayRep (void) { delete [] data; }

    octave_idx_type length (void) const { return len; }

  private:

    // No assignment!

    ArrayRep& operator = (const ArrayRep& a);
  };

  //--------------------------------------------------------------------

public:

  void make_unique (void);

  typedef T element_type;

protected:

  typename Array<T>::ArrayRep *rep;

  dim_vector dimensions;

  // Rationale:
  // slice_data is a pointer to rep->data, denoting together with slice_len the
  // actual portion of the data referenced by this Array<T> object. This allows
  // to make shallow copies not only of a whole array, but also of contiguous
  // subranges. Every time rep is directly manipulated, slice_data and slice_len
  // need to be properly updated.

  T* slice_data;
  octave_idx_type slice_len;

  Array (T *d, octave_idx_type n)
    : rep (new typename Array<T>::ArrayRep (d, n)), dimensions (n) 
    { 
      slice_data = rep->data;
      slice_len = rep->len;
    }

  Array (T *d, const dim_vector& dv)
    : rep (new typename Array<T>::ArrayRep (d, get_size (dv))),
      dimensions (dv) 
    { 
      slice_data = rep->data;
      slice_len = rep->len;
    }

  // slice constructor
  Array (const Array<T>& a, const dim_vector& dv,
         octave_idx_type l, octave_idx_type u)
    : rep(a.rep), dimensions (dv)
    {
      rep->count++;
      slice_data = a.slice_data + l;
      slice_len = std::min (u, a.slice_len) - l;
    }

private:

  typename Array<T>::ArrayRep *nil_rep (void) const
    {
      static typename Array<T>::ArrayRep *nr
	= new typename Array<T>::ArrayRep ();

      return nr;
    }

  template <class U>
  T *
  coerce (const U *a, octave_idx_type len)
  {
    T *retval = new T [len];

    for (octave_idx_type i = 0; i < len; i++)
      retval[i] = T (a[i]);

    return retval;
  }

public:

  Array (void)
    : rep (nil_rep ()), dimensions () 
    { 
      rep->count++; 
      slice_data = rep->data;
      slice_len = rep->len;
    }

  explicit Array (octave_idx_type n)
    : rep (new typename Array<T>::ArrayRep (n)), dimensions (n) 
    { 
      slice_data = rep->data;
      slice_len = rep->len;
    }

  explicit Array (octave_idx_type n, const T& val)
    : rep (new typename Array<T>::ArrayRep (n)), dimensions (n)
    {
      slice_data = rep->data;
      slice_len = rep->len;
      fill (val);
    }

  // Type conversion case.
  template <class U>
  Array (const Array<U>& a)
    : rep (new typename Array<T>::ArrayRep (coerce (a.data (), a.length ()), a.length ())),
      dimensions (a.dims ())
    {
      slice_data = rep->data;
      slice_len = rep->len;
    }

  // No type conversion case.
  Array (const Array<T>& a)
    : rep (a.rep), dimensions (a.dimensions)
    {
      rep->count++;
      slice_data = a.slice_data;
      slice_len = a.slice_len;
    }

public:

  Array (const dim_vector& dv)
    : rep (new typename Array<T>::ArrayRep (get_size (dv))),
      dimensions (dv) 
    { 
      slice_data = rep->data;
      slice_len = rep->len;
    }

  Array (const dim_vector& dv, const T& val)
    : rep (new typename Array<T>::ArrayRep (get_size (dv))),
      dimensions (dv)
    {
      slice_data = rep->data;
      slice_len = rep->len;
      fill (val);
    }

  Array (const Array<T>& a, const dim_vector& dv);

  virtual ~Array (void);

  Array<T>& operator = (const Array<T>& a);

  void fill (const T& val); 

  octave_idx_type capacity (void) const { return slice_len; }
  octave_idx_type length (void) const { return capacity (); }
  octave_idx_type nelem (void) const { return capacity (); }
  octave_idx_type numel (void) const { return nelem (); }

  octave_idx_type dim1 (void) const { return dimensions(0); }
  octave_idx_type dim2 (void) const { return dimensions(1); }
  octave_idx_type dim3 (void) const { return dimensions(2); }

  octave_idx_type rows (void) const { return dim1 (); }
  octave_idx_type cols (void) const { return dim2 (); }
  octave_idx_type columns (void) const { return dim2 (); }
  octave_idx_type pages (void) const { return dim3 (); }

  size_t byte_size (void) const { return numel () * sizeof (T); }

  dim_vector dims (void) const { return dimensions; }

  Array<T> squeeze (void) const;
  
  void chop_trailing_singletons (void) 
  { dimensions.chop_trailing_singletons (); }
  
  static octave_idx_type get_size (octave_idx_type r, octave_idx_type c);
  static octave_idx_type get_size (octave_idx_type r, octave_idx_type c, octave_idx_type p);
  static octave_idx_type get_size (const dim_vector& dv);

  octave_idx_type compute_index (const Array<octave_idx_type>& ra_idx) const;

  T range_error (const char *fcn, octave_idx_type n) const;
  T& range_error (const char *fcn, octave_idx_type n);

  T range_error (const char *fcn, octave_idx_type i, octave_idx_type j) const;
  T& range_error (const char *fcn, octave_idx_type i, octave_idx_type j);

  T range_error (const char *fcn, octave_idx_type i, octave_idx_type j, octave_idx_type k) const;
  T& range_error (const char *fcn, octave_idx_type i, octave_idx_type j, octave_idx_type k);

  T range_error (const char *fcn, const Array<octave_idx_type>& ra_idx) const;
  T& range_error (const char *fcn, const Array<octave_idx_type>& ra_idx);

  // No checking, even for multiple references, ever.

  T& xelem (octave_idx_type n) { return slice_data [n]; }
  T xelem (octave_idx_type n) const { return slice_data [n]; }

  T& xelem (octave_idx_type i, octave_idx_type j) { return xelem (dim1()*j+i); }
  T xelem (octave_idx_type i, octave_idx_type j) const { return xelem (dim1()*j+i); }

  T& xelem (octave_idx_type i, octave_idx_type j, octave_idx_type k) { return xelem (i, dim2()*k+j); }
  T xelem (octave_idx_type i, octave_idx_type j, octave_idx_type k) const { return xelem (i, dim2()*k+j); }

  T& xelem (const Array<octave_idx_type>& ra_idx)
    { return xelem (compute_index (ra_idx)); }

  T xelem (const Array<octave_idx_type>& ra_idx) const
    { return xelem (compute_index (ra_idx)); }

  // FIXME -- would be nice to fix this so that we don't
  // unnecessarily force a copy, but that is not so easy, and I see no
  // clean way to do it.

  T& checkelem (octave_idx_type n)
    {
      if (n < 0 || n >= slice_len)
	return range_error ("T& Array<T>::checkelem", n);
      else
	{
	  make_unique ();
	  return xelem (n);
	}
    }

  T& checkelem (octave_idx_type i, octave_idx_type j)
    {
      if (i < 0 || j < 0 || i >= dim1 () || j >= dim2 ())
	return range_error ("T& Array<T>::checkelem", i, j);
      else
	return elem (dim1()*j+i);
    }

  T& checkelem (octave_idx_type i, octave_idx_type j, octave_idx_type k)
    {
      if (i < 0 || j < 0 || k < 0 || i >= dim1 () || j >= dim2 () || k >= dim3 ())
	return range_error ("T& Array<T>::checkelem", i, j, k);
      else
	return elem (i, dim2()*k+j);
    }

  T& checkelem (const Array<octave_idx_type>& ra_idx)
    {
      octave_idx_type i = compute_index (ra_idx);

      if (i < 0)
	return range_error ("T& Array<T>::checkelem", ra_idx);
      else
	return elem (i);
    }

  T& elem (octave_idx_type n)
    {
      make_unique ();
      return xelem (n);
    }

  T& elem (octave_idx_type i, octave_idx_type j) { return elem (dim1()*j+i); }

  T& elem (octave_idx_type i, octave_idx_type j, octave_idx_type k) { return elem (i, dim2()*k+j); }

  T& elem (const Array<octave_idx_type>& ra_idx)
    { return Array<T>::elem (compute_index (ra_idx)); }

#if defined (BOUNDS_CHECKING)
  T& operator () (octave_idx_type n) { return checkelem (n); }
  T& operator () (octave_idx_type i, octave_idx_type j) { return checkelem (i, j); }
  T& operator () (octave_idx_type i, octave_idx_type j, octave_idx_type k) { return checkelem (i, j, k); }
  T& operator () (const Array<octave_idx_type>& ra_idx) { return checkelem (ra_idx); }
#else
  T& operator () (octave_idx_type n) { return elem (n); }
  T& operator () (octave_idx_type i, octave_idx_type j) { return elem (i, j); }
  T& operator () (octave_idx_type i, octave_idx_type j, octave_idx_type k) { return elem (i, j, k); }
  T& operator () (const Array<octave_idx_type>& ra_idx) { return elem (ra_idx); }
#endif

  T checkelem (octave_idx_type n) const
    {
      if (n < 0 || n >= slice_len)
	return range_error ("T Array<T>::checkelem", n);
      else
	return xelem (n);
    }

  T checkelem (octave_idx_type i, octave_idx_type j) const
    {
      if (i < 0 || j < 0 || i >= dim1 () || j >= dim2 ())
	return range_error ("T Array<T>::checkelem", i, j);
      else
	return elem (dim1()*j+i);
    }

  T checkelem (octave_idx_type i, octave_idx_type j, octave_idx_type k) const
    {
      if (i < 0 || j < 0 || k < 0 || i >= dim1 () || j >= dim2 () || k >= dim3 ())
	return range_error ("T Array<T>::checkelem", i, j, k);
      else
	return Array<T>::elem (i, Array<T>::dim1()*k+j);
    }

  T checkelem (const Array<octave_idx_type>& ra_idx) const
    {
      octave_idx_type i = compute_index (ra_idx);

      if (i < 0)
	return range_error ("T Array<T>::checkelem", ra_idx);
      else
	return Array<T>::elem (i);
    }

  T elem (octave_idx_type n) const { return xelem (n); }

  T elem (octave_idx_type i, octave_idx_type j) const { return elem (dim1()*j+i); }

  T elem (octave_idx_type i, octave_idx_type j, octave_idx_type k) const { return elem (i, dim2()*k+j); }

  T elem (const Array<octave_idx_type>& ra_idx) const
    { return Array<T>::elem (compute_index (ra_idx)); }

#if defined (BOUNDS_CHECKING)
  T operator () (octave_idx_type n) const { return checkelem (n); }
  T operator () (octave_idx_type i, octave_idx_type j) const { return checkelem (i, j); }
  T operator () (octave_idx_type i, octave_idx_type j, octave_idx_type k) const { return checkelem (i, j, k); }
  T operator () (const Array<octave_idx_type>& ra_idx) const { return checkelem (ra_idx); }
#else
  T operator () (octave_idx_type n) const { return elem (n); }
  T operator () (octave_idx_type i, octave_idx_type j) const { return elem (i, j); }
  T operator () (octave_idx_type i, octave_idx_type j, octave_idx_type k) const { return elem (i, j, k); }
  T operator () (const Array<octave_idx_type>& ra_idx) const { return elem (ra_idx); }
#endif

  Array<T> reshape (const dim_vector& new_dims) const;

  Array<T> permute (const Array<octave_idx_type>& vec, bool inv = false) const;
  Array<T> ipermute (const Array<octave_idx_type>& vec) const
    { return permute (vec, true); }

  bool is_square (void) const { return (dim1 () == dim2 ()); }

  bool is_empty (void) const { return numel () == 0; }

  Array<T> transpose (void) const;
  Array<T> hermitian (T (*fcn) (const T&) = 0) const;

  const T *data (void) const { return slice_data; }

  const T *fortran_vec (void) const { return data (); }

  T *fortran_vec (void);

  int ndims (void) const { return dimensions.length (); }

  void maybe_delete_dims (void);

  // Indexing without resizing.

  Array<T> index (const idx_vector& i) const;

  Array<T> index (const idx_vector& i, const idx_vector& j) const;

  Array<T> index (const Array<idx_vector>& ia) const;

  static T resize_fill_value (); 

  // Resizing (with fill).

  void resize_fill (octave_idx_type n, const T& rfv);

  void resize_fill (octave_idx_type nr, octave_idx_type nc, const T& rfv);

  void resize_fill (const dim_vector& dv, const T& rfv);

  // Resizing with default fill.
  // Rationale: 
  // These use the default fill value rather than leaving memory uninitialized.
  // Resizing without fill leaves the resulting array in a rather weird state,
  // where part of the data is initialized an part isn't.

  void resize (octave_idx_type n)
    { resize_fill (n, resize_fill_value ()); }

  // FIXME -- this method cannot be defined here because it would
  // clash with
  //
  //   void resize (octave_idx_type, const T&)
  //
  // (these become indistinguishable when T = octave_idx_type).
  // In the future, I think the resize (.., const T& rfv) overloads
  // should go away in favor of using resize_fill.

  // void resize (octave_idx_type nr, octave_idx_type nc)
  //  { resize_fill (nr, nc, resize_fill_value ()); }

  void resize (dim_vector dv)
    { resize_fill (dv, resize_fill_value ()); }

  // FIXME -- these are here for backward compatibility. They should
  // go away in favor of using resize_fill directly.
  void resize (octave_idx_type n, const T& rfv)
    { resize_fill (n, static_cast<T> (rfv)); }

  void resize (octave_idx_type nr, octave_idx_type nc, const T& rfv)
    { resize_fill (nr, nc, rfv); }

  void resize (dim_vector dv, const T& rfv)
    { resize_fill (dv, rfv); }

  // Indexing with possible resizing and fill
  // FIXME -- this is really a corner case, that should better be
  // handled directly in liboctinterp.

  Array<T> index (const idx_vector& i, bool resize_ok,
                  const T& rfv = resize_fill_value ()) const;

  Array<T> index (const idx_vector& i, const idx_vector& j, 
                  bool resize_ok, const T& rfv = resize_fill_value ()) const;

  Array<T> index (const Array<idx_vector>& ia,
                  bool resize_ok, const T& rfv = resize_fill_value ()) const;

  // Indexed assignment (always with resize & fill).

  void assign (const idx_vector& i, const Array<T>& rhs, 
               const T& rfv = resize_fill_value ());

  void assign (const idx_vector& i, const idx_vector& j, const Array<T>& rhs,
               const T& rfv = resize_fill_value ());

  void assign (const Array<idx_vector>& ia, const Array<T>& rhs,
               const T& rfv = resize_fill_value ());

  // Deleting elements.

  // A(I) = [] (with a single subscript)
  void delete_elements (const idx_vector& i);

  // A(:,...,I,...,:) = [] (>= 2 subscripts, one of them is non-colon)
  void delete_elements (int dim, const idx_vector& i);

  // Dispatcher to the above two.
  void delete_elements (const Array<idx_vector>& ia);

  // FIXME -- are these required? What exactly are they supposed to do?.

  Array<T>& insert (const Array<T>& a, octave_idx_type r, octave_idx_type c);
  Array<T>& insert2 (const Array<T>& a, octave_idx_type r, octave_idx_type c);
  Array<T>& insertN (const Array<T>& a, octave_idx_type r, octave_idx_type c);

  Array<T>& insert (const Array<T>& a, const Array<octave_idx_type>& idx);

  void maybe_economize (void)
    {
      if (rep->count == 1 && slice_len != rep->len)
        {
          ArrayRep *new_rep = new ArrayRep (slice_data, slice_len, true);
          delete rep;
          rep = new_rep;
          slice_data = rep->data;
        }
    }

  void print_info (std::ostream& os, const std::string& prefix) const;

  // Unsafe.  This function exists to support the MEX interface.
  // You should not use it anywhere else.
  void *mex_get_data (void) const { return const_cast<T *> (data ()); }

  Array<T> sort (octave_idx_type dim = 0, sortmode mode = ASCENDING) const;
  Array<T> sort (Array<octave_idx_type> &sidx, octave_idx_type dim = 0,
		 sortmode mode = ASCENDING) const;

  Array<T> diag (octave_idx_type k = 0) const;

  template <class U, class F>
  Array<U>
  map (F fcn) const
  {
    octave_idx_type len = length ();

    const T *m = data ();

    Array<U> result (dims ());
    U *p = result.fortran_vec ();

    for (octave_idx_type i = 0; i < len; i++)
      {
	OCTAVE_QUIT;

	p[i] = fcn (m[i]);
      }

    return result;
  }
};

#define INSTANTIATE_ARRAY(T, API) \
  template class API Array<T>

// FIXME -- these are here for compatibility.  In the current
// implementation, only homogeneous array assignments are actually
// instantiated.  I think heterogeneous indexed assignments are rare
// enough to be implemented via conversion first.  This decision may
// still be revised, that's why these macros stay here.
#define INSTANTIATE_ARRAY_AND_ASSIGN(T, API) \
  INSTANTIATE_ARRAY(T, API)

#define INSTANTIATE_ARRAY_ASSIGN(LT, RT, API)
  // do nothing

#define INSTANTIATE_ARRAY_SORT(T) \
  template class octave_sort<T>; \

#define NO_INSTANTIATE_ARRAY_SORT(T) \
  template <> Array<T> Array<T>::sort \
    (octave_idx_type, sortmode) const { return *this; } \
  template <> Array<T> Array<T>::sort (Array<octave_idx_type> &sidx, \
    octave_idx_type, sortmode) const \
    { sidx = Array<octave_idx_type> (); return *this; }

#endif

/*
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;;; End: ***
*/