## Copyright (C) 2016 Colin B. Macdonald
##
## This file is part of Pytave.
##
## Pytave 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.
##
## This software 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 this software; see the file COPYING.
## If not, see <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @documentencoding UTF-8
## @defop  Method   @@pyobject subsasgn (@var{x}, @var{idx}, @var{rhs})
## @defopx Operator @@pyobject {@var{x}.@var{property} =} {@var{rhs}}
## @defopx Operator @@pyobject {@var{x}@{@var{i}@} =} {@var{rhs}}
## @defopx Operator @@pyobject {@var{x}@{@var{i}, @var{j}, @dots{}@} =} {@var{rhs}}
## @defopx Operator @@pyobject {@var{x}@{@var{a}@} =} {@var{rhs}}
## Indexed assignment to Python objects.
##
## @seealso{@@pyobject/subsref}
## @end defop

function r = subsasgn(x, idx, rhs)

  if (nargin != 3)
    print_usage ();
  endif

  ## If rhs is a pyobject but x is not, dispatch to the builtin subsasgn
  if (! isa (x, "pyobject"))
    r = builtin ("subsasgn", x, idx, rhs);
    return;
  endif

  switch idx.type
    case "."
      assert (ischar (idx.subs))
      pycall ("setattr", x, idx.subs, rhs);
      r = x;

    case "{}"
      ## XXX: doesn't support slices or anything like that yet

      ## Subtract one from index: do this for lists, numpy arrays, etc
      x_is_sequence = any (isa (x, {"py.collections.Sequence", ...
                                    "py.numpy.ndarray"}));
      for i = 1:length (idx.subs)
        j = idx.subs{i};
        if (x_is_sequence && isindex (j) && isnumeric (j))
          idx.subs{i} = cast (j, class (sizemax ())) - 1;
        endif
      endfor

      if (isscalar (idx.subs))
        ind = idx.subs{1};
      else
        ind = pycall ("tuple", idx.subs);
      endif

      pycall ("operator.setitem", x, ind, rhs);
      r = x;

    otherwise
      idx
      rhs
      error ("@pyobject/subsasgn: not implemented")
  endswitch
endfunction


%!test
%! pyexec ("class MyClass: a = 1")
%! t = pyeval ("MyClass()");
%! t.b = 6;
%! assert (t.b, 6)

%!test
%! % list indexing
%! L = pyeval ("[10., 20.]");
%! L{2} = "Octave";
%! assert (length (L) == 2)
%! assert (L{1}, 10)
%! assert (char (L{2}), "Octave")

%!test
%! % dict assignment, adding new keys
%! d = pyeval ("dict()");
%! d{"a"} = 3;
%! d{"b"} = 4;
%! assert (d{"a"}, 3)
%! assert (d{"b"}, 4)

%!test
%! % dict assignment, update existing key
%! d = pyeval ("{'a':1}");
%! d{"a"} = 3;
%! assert (d{"a"}, 3)

%!test
%! % dict assignment, other keys (e.g., Issue #10).
%! d = pyeval ("dict()");
%! d{"5"} = 10;
%! d{5.5} = 11;
%! d{5} = 12;
%! assert (d{"5"}, 10)
%! assert (d{5.5}, 11)
%! assert (d{5}, 12)

## Test that depends on implicit creation of NumPy arrays, do we want this?
%!xtest
%! % 2D array indexing
%! A = pyobject ([1.1 2 3; 4 5 6]);
%! A{1, 1} = 10;
%! A{1, 3} = 30;
%! A{2, 1} = 40;
%! assert (A{1, 1}, 10)
%! assert (A{1, 3}, 30)
%! assert (A{2, 1}, 40)
%! assert (A{2, 2}, 5)

## Test of string key assignment, fails in the general case
%!xtest
%! d = pyobject (struct ());
%! d{"value"} = 1;