// Copyright (C) 2017-2019   John Donoghue   <john.donoghue@ieee.org>
// Copyright (C) 2012   Andrius Sutas   <andrius.sutas@gmail.com>
//
// This program 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 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, see <http://www.gnu.org/licenses/>.

#include <octave/oct.h>
#include <octave/uint8NDArray.h>

#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif

#ifdef BUILD_I2C
#include <errno.h>

#include "i2c_class.h"
#endif

// PKG_ADD: autoload ("i2c_read", "i2c.oct");
DEFUN_DLD (i2c_read, args, nargout, 
"-*- texinfo -*-\n\
@deftypefn {Loadable Function} {[@var{data}, @var{count}] = } i2c_read (@var{i2c}, @var{n})\n \
\n\
Read from i2c slave device.\n \
\n\
@subsubheading Inputs\n \
@var{i2c} - instance of @var{octave_i2c} class.@*\
@var{n} - number of bytes to attempt to read of type Integer.\n \
\n\
@subsubheading Outputs\n \
The i2c_read() shall return number of bytes successfully read in @var{count} as Integer and the bytes themselves in @var{data} as uint8 array.\n \
@end deftypefn")
{
#ifndef BUILD_I2C
  error ("i2c: Your system doesn't support the I2C interface");
  return octave_value ();
#else
    
  if (args.length () < 1 || args.length () > 2 || args (0).type_id () != octave_i2c::static_type_id ())
    {
      print_usage ();
      return octave_value (-1);
    }

  unsigned int buffer_len = 1;

  if (args.length () > 1)
    {
      if ( !(args (1).OV_ISINTEGER () || args (1).OV_ISFLOAT ()) )
        {
          print_usage ();
          return octave_value (-1);
        }

      buffer_len = args (1).int_value ();
    }

  OCTAVE_LOCAL_BUFFER (uint8_t, buffer, (buffer_len +1));

  if (buffer == NULL)
    {
      error ("i2c_read: cannot allocate requested memory: %s\n", strerror (errno));
      return octave_value (-1);  
    }

  octave_i2c* i2c = NULL;

  const octave_base_value& rep = args (0).get_rep();
  i2c = &((octave_i2c &)rep);

  int retval;
    
  retval = i2c->read (buffer, buffer_len);
    
  octave_value_list return_list;
  uint8NDArray data (dim_vector (1, retval));
    
  for (int i = 0; i < retval; i++)
    data (i) = buffer[i];

  return_list (0) = data;
  return_list (1) = retval; 
        
  return return_list;
#endif
}
