/*

Copyright (C) 2004-2011 David Bateman
Copyright (C) 1998-2004 Andy Adler
Copyright (C) 2010 VZLU Prague

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/>.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <cstdlib>
#include <string>

#include "variables.h"
#include "utils.h"
#include "pager.h"
#include "defun.h"
#include "gripes.h"
#include "quit.h"
#include "unwind-prot.h"

#include "ov-re-sparse.h"
#include "ov-cx-sparse.h"
#include "ov-bool-sparse.h"

DEFUN (issparse, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Loadable Function} {} issparse (@var{x})\n\
Return true if @var{x} is a sparse matrix.\n\
@seealso{ismatrix}\n\
@end deftypefn")
{
   if (args.length() != 1)
     {
       print_usage ();
       return octave_value ();
     }
   else
     return octave_value (args(0).is_sparse_type ());
}

DEFUN (sparse, args, ,
    "-*- texinfo -*-\n\
@deftypefn  {Loadable Function} {@var{s} =} sparse (@var{a})\n\
@deftypefnx {Loadable Function} {@var{s} =} sparse (@var{i}, @var{j}, @var{sv}, @var{m}, @var{n}, @var{nzmax})\n\
@deftypefnx {Loadable Function} {@var{s} =} sparse (@var{i}, @var{j}, @var{sv})\n\
@deftypefnx {Loadable Function} {@var{s} =} sparse (@var{i}, @var{j}, @var{s}, @var{m}, @var{n}, \"unique\")\n\
@deftypefnx {Loadable Function} {@var{s} =} sparse (@var{m}, @var{n})\n\
Create a sparse matrix from the full matrix or row, column, value triplets.\n\
If @var{a} is a full matrix, convert it to a sparse matrix representation,\n\
removing all zero values in the process.\n\
\n\
Given the integer index vectors @var{i} and @var{j}, a 1-by-@code{nnz} vector\n\
of real of complex values @var{sv}, overall dimensions @var{m} and @var{n}\n\
of the sparse matrix.  The argument @code{nzmax} is ignored but accepted for\n\
compatibility with @sc{matlab}.  If @var{m} or @var{n} are not specified\n\
their values are derived from the maximum index in the vectors @var{i} and\n\
@var{j} as given by @code{@var{m} = max (@var{i})},\n\
@code{@var{n} = max (@var{j})}.\n\
\n\
@strong{Note}: if multiple values are specified with the same\n\
@var{i}, @var{j} indices, the corresponding values in @var{s} will\n\
be added.\n\
\n\
The following are all equivalent:\n\
\n\
@example\n\
@group\n\
s = sparse (i, j, s, m, n)\n\
s = sparse (i, j, s, m, n, \"summation\")\n\
s = sparse (i, j, s, m, n, \"sum\")\n\
@end group\n\
@end example\n\
\n\
Given the option \"unique\". if more than two values are specified for the\n\
same @var{i}, @var{j} indices, the last specified value will be used.\n\
\n\
@code{sparse(@var{m}, @var{n})} is equivalent to\n\
@code{sparse ([], [], [], @var{m}, @var{n}, 0)}\n\
\n\
If any of @var{sv}, @var{i} or @var{j} are scalars, they are expanded\n\
to have a common size.\n\
@seealso{full}\n\
@end deftypefn")
{
   octave_value retval;
   int nargin = args.length ();

   // Temporarily disable sparse_auto_mutate if set (it's obsolete anyway).
   unwind_protect frame;
   frame.protect_var (Vsparse_auto_mutate);
   Vsparse_auto_mutate = false;

   if (nargin == 1)
     {
       octave_value arg = args (0);
       if (arg.is_bool_type ())
         retval = arg.sparse_bool_matrix_value ();
       else if (arg.is_complex_type ())
         retval = arg.sparse_complex_matrix_value ();
       else if (arg.is_numeric_type ())
         retval = arg.sparse_matrix_value ();
       else
         gripe_wrong_type_arg ("sparse", arg);
     }
   else if (nargin == 2)
     {
       octave_idx_type m = 0, n = 0;
       if (args(0).is_scalar_type () && args(1).is_scalar_type ())
         {
           m = args(0).idx_type_value ();
           n = args(1).idx_type_value ();
         }
       else
         error ("sparse: dimensions M,N must be scalar");

       if (! error_state)
         {
           if (m >= 0 && n >= 0)
             retval = SparseMatrix (m, n);
           else
             error ("sparse: dimensions M,N must be positive or zero");
         }
     }
   else if (nargin >= 3)
     {
       bool summation = true;
       if (nargin > 3 && args(nargin-1).is_string ())
         {
           std::string opt = args(nargin-1).string_value ();
           if (opt == "unique")
             summation = false;
           else if (opt == "sum" || opt == "summation")
             summation = true;
           else
             error ("sparse: invalid option: %s", opt.c_str ());

           nargin -= 1;
         }

       if (! error_state)
         {
           octave_idx_type m = -1, n = -1, nzmax = -1;
           if (nargin == 6)
             {
               nzmax = args(5).idx_type_value ();
               nargin --;
             }

           if (nargin == 5)
             {
               if (args(3).is_scalar_type () && args(4).is_scalar_type ())
                 {
                   m = args(3).idx_type_value ();
                   n = args(4).idx_type_value ();
                 }
               else
                 error ("sparse: expecting scalar dimensions");


               if (! error_state && (m < 0 || n < 0))
                 error ("sparse: dimensions must be nonnegative");
             }
           else if (nargin != 3)
             print_usage ();

           if (! error_state)
             {
               idx_vector i = args(0).index_vector ();
               idx_vector j = args(1).index_vector ();

               if (args(2).is_bool_type ())
                 retval = SparseBoolMatrix (args(2).bool_array_value (), i, j,
                                            m, n, summation, nzmax);
               else if (args(2).is_complex_type ())
                 retval = SparseComplexMatrix (args(2).complex_array_value (),
                                               i, j, m, n, summation, nzmax);
               else if (args(2).is_numeric_type ())
                 retval = SparseMatrix (args(2).array_value (), i, j,
                                        m, n, summation, nzmax);
               else
                 gripe_wrong_type_arg ("sparse", args(2));
             }

         }
     }

   return retval;
}

DEFUN (spalloc, args, ,
    "-*- texinfo -*-\n\
@deftypefn {Loadable Function} {@var{s} =} spalloc (@var{m}, @var{n}, @var{nz})\n\
Create an @var{m}-by-@var{n} sparse matrix with pre-allocated space for at\n\
most @var{nz} nonzero elements.  This is useful for building the matrix\n\
incrementally by a sequence of indexed assignments.  Subsequent indexed\n\
assignments will reuse the pre-allocated memory, provided they are of one of\n\
the simple forms\n\
\n\
@itemize\n\
@item @code{@var{s}(I:J) = @var{x}}\n\
\n\
@item @code{@var{s}(:,I:J) = @var{x}}\n\
\n\
@item @code{@var{s}(K:L,I:J) = @var{x}}\n\
@end itemize\n\
\n\
@b{and} that the following conditions are met:\n\
\n\
@itemize\n\
@item the assignment does not decrease nnz(@var{S}).\n\
\n\
@item after the assignment, nnz(@var{S}) does not exceed @var{nz}.\n\
\n\
@item no index is out of bounds.\n\
@end itemize\n\
\n\
Partial movement of data may still occur, but in general the assignment will\n\
be more memory and time-efficient under these circumstances.  In particular,\n\
it is possible to efficiently build a pre-allocated sparse matrix from\n\
contiguous block of columns.\n\
\n\
The amount of pre-allocated memory for a given matrix may be queried using\n\
the function @code{nzmax}.\n\
@seealso{nzmax, sparse}\n\
@end deftypefn")
{
   octave_value retval;
   int nargin = args.length ();

   if (nargin == 2 || nargin == 3)
     {
       octave_idx_type m = args(0).idx_type_value ();
       octave_idx_type n = args(1).idx_type_value ();
       octave_idx_type nz = 0;
       if (nargin == 3)
         nz = args(2).idx_type_value ();
       if (error_state)
         ;
       else if (m >= 0 && n >= 0 && nz >= 0)
         retval = SparseMatrix (dim_vector (m, n), nz);
       else
         error ("spalloc: M,N,NZ must be non-negative");
     }
   else
     print_usage ();

   return retval;
}
