/***********************************************************
(C) Copyright 2003 A.M. Kuchling.  All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name of A.M. Kuchling not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.

A.M. KUCHLING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
EVENT SHALL A.M. KUCHLING BE LIABLE FOR ANY SPECIAL, INDIRECT OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.

******************************************************************/

/* $Id: _sanemodule.c 20715 2003-02-11 17:46:51Z akuchlin $ */

/* SaneDev objects */

#include "Python.h"
#include "PIL/Imaging.h"
#include <sane/sane.h>

static PyObject *ErrorObject;

typedef struct {
	PyObject_HEAD
	SANE_Handle h;
} SaneDevObject;

/* Raise a SANE exception */
PyObject * 
PySane_Error(SANE_Status st)
{
  const char *string;
  
  if (st==SANE_STATUS_GOOD) {Py_INCREF(Py_None); return (Py_None);}
  string=sane_strstatus(st);
  PyErr_SetString(ErrorObject, string);
  return NULL;
}

staticforward PyTypeObject SaneDev_Type;

#define SaneDevObject_Check(v)	((v)->ob_type == &SaneDev_Type)

static SaneDevObject *
newSaneDevObject(void)
{
	SaneDevObject *self;
	self = PyObject_NEW(SaneDevObject, &SaneDev_Type);
	if (self == NULL)
		return NULL;
	self->h=NULL;
	return self;
}

/* SaneDev methods */

static void
SaneDev_dealloc(SaneDevObject *self)
{
  if (self->h) sane_close(self->h);
  self->h=NULL;
  PyObject_DEL(self);
}

static PyObject *
SaneDev_close(SaneDevObject *self, PyObject *args)
{
  if (!PyArg_ParseTuple(args, ""))
    return NULL;
  if (self->h) sane_close(self->h);
  self->h=NULL;
  Py_INCREF(Py_None);
  return (Py_None);
}

static PyObject *
SaneDev_get_parameters(SaneDevObject *self, PyObject *args)
{
  SANE_Status st;
  SANE_Parameters p;
  char *format="unknown format";
  
  if (!PyArg_ParseTuple(args, ""))
    return NULL;
  if (self->h==NULL)
    {
      PyErr_SetString(ErrorObject, "SaneDev object is closed");
      return NULL;
    }
  st=sane_get_parameters(self->h, &p);
  if (st) return PySane_Error(st);
  switch (p.format)
    {
    case(SANE_FRAME_GRAY): format="L"; break;
    case(SANE_FRAME_RGB): format="RGB"; break;
    case(SANE_FRAME_RED): format="R"; break;
    case(SANE_FRAME_GREEN): format="G"; break;
    case(SANE_FRAME_BLUE): format="B"; break;
    }
  
  return Py_BuildValue("si(ii)ii", format, p.last_frame, p.pixels_per_line, p.lines, 
		       p.depth, p.bytes_per_line);
}


static PyObject *
SaneDev_fileno(SaneDevObject *self, PyObject *args)
{
  SANE_Status st;
  SANE_Int fd;
  
  if (!PyArg_ParseTuple(args, ""))
    return NULL;
  if (self->h==NULL)
    {
      PyErr_SetString(ErrorObject, "SaneDev object is closed");
      return NULL;
    }
  st=sane_get_select_fd(self->h, &fd);
  if (st) return PySane_Error(st);
  return PyInt_FromLong(fd);
}

static PyObject *
SaneDev_start(SaneDevObject *self, PyObject *args)
{
  SANE_Status st;
  
  if (!PyArg_ParseTuple(args, ""))
    return NULL;
  if (self->h==NULL)
    {
      PyErr_SetString(ErrorObject, "SaneDev object is closed");
      return NULL;
    }
  st=sane_start(self->h);
  if (st) return PySane_Error(st);
  Py_INCREF(Py_None);
  return Py_None;
}

static PyObject *
SaneDev_cancel(SaneDevObject *self, PyObject *args)
{
  if (!PyArg_ParseTuple(args, ""))
    return NULL;
  if (self->h==NULL)
    {
      PyErr_SetString(ErrorObject, "SaneDev object is closed");
      return NULL;
    }
  sane_cancel(self->h);
  Py_INCREF(Py_None);
  return Py_None;
}

static PyObject *
SaneDev_get_options(SaneDevObject *self, PyObject *args)
{
  const SANE_Option_Descriptor *d;
  PyObject *list, *value;
  int i=1;
  
  if (!PyArg_ParseTuple(args, ""))
    return NULL;
  if (self->h==NULL)
    {
      PyErr_SetString(ErrorObject, "SaneDev object is closed");
      return NULL;
    }
  if (!(list = PyList_New(0)))
	    return NULL;

  do 
    {
      d=sane_get_option_descriptor(self->h, i);
      if (d!=NULL) 
	{
	  PyObject *constraint;
	  int j;
	  
	  switch (d->constraint_type)
	    {
	    case(SANE_CONSTRAINT_NONE): 
	      Py_INCREF(Py_None); constraint=Py_None; break;
	    case(SANE_CONSTRAINT_RANGE): 
	      constraint=Py_BuildValue("iii", d->constraint.range->min, d->constraint.range->max, d->constraint.range->quant);
	      break;
	    case(SANE_CONSTRAINT_WORD_LIST): 
	      constraint=PyList_New(d->constraint.word_list[0]);
	      for (j=1; j<=d->constraint.word_list[0]; j++)
		PyList_SetItem(constraint, j-1, PyInt_FromLong(d->constraint.word_list[j]));
	      break;
	    case(SANE_CONSTRAINT_STRING_LIST): 
	      constraint=PyList_New(0);
	      for(j=0; d->constraint.string_list[j]!=NULL; j++)
		PyList_Append(constraint, PyString_FromString(d->constraint.string_list[j]) );
	      break;
	    }
	  value=Py_BuildValue("isssiiiiO", i, d->name, d->title, d->desc, d->type,
			      d->unit, d->size, d->cap, constraint);
	  PyList_Append(list, value);
	}
      i++;
    } while (d!=NULL);
  return list;
}

static PyObject *
SaneDev_get_option(SaneDevObject *self, PyObject *args)
{
  SANE_Status st;
  const SANE_Option_Descriptor *d;
  SANE_Int i;
  PyObject *value;
  int n;
  void *v;
  
  if (!PyArg_ParseTuple(args, "i", &n))
    return NULL;
  if (self->h==NULL)
    {
      PyErr_SetString(ErrorObject, "SaneDev object is closed");
      return NULL;
    }
  d=sane_get_option_descriptor(self->h, n);
  v=malloc(d->size+1);
  st=sane_control_option(self->h, n, SANE_ACTION_GET_VALUE,
			 v, &i);

  if (st) {free(v); return PySane_Error(st);}
  
  switch(d->type)
    {
    case(SANE_TYPE_BOOL):
    case(SANE_TYPE_INT):
      value=Py_BuildValue("ii", i, *( (SANE_Int*)v) );
      break;
    case(SANE_TYPE_FIXED):
      value=Py_BuildValue("id", i, SANE_UNFIX((*((SANE_Fixed*)v))) );
      break;
    case(SANE_TYPE_STRING):
      value=Py_BuildValue("is", i, v);
      break;
    case(SANE_TYPE_BUTTON):
    case(SANE_TYPE_GROUP):
      value=Py_BuildValue("iO", i, Py_None);
      break;
    }
  
  free(v);
  return value;
}

static PyObject *
SaneDev_set_option(SaneDevObject *self, PyObject *args)
{
  SANE_Status st;
  const SANE_Option_Descriptor *d;
  SANE_Int i;
  PyObject *value;
  int n;
  void *v;
  
  if (!PyArg_ParseTuple(args, "iO", &n, &value))
    return NULL;
  if (self->h==NULL)
    {
      PyErr_SetString(ErrorObject, "SaneDev object is closed");
      return NULL;
    }
  d=sane_get_option_descriptor(self->h, n);
  v=malloc(d->size+1);

  switch(d->type)
    {
    case(SANE_TYPE_BOOL):
      if (!PyInt_Check(value)) 
	{
	  PyErr_SetString(PyExc_TypeError, "SANE_BOOL requires an integer");
	  free(v);
	  return NULL;
	}
	/* fall through */
    case(SANE_TYPE_INT):
      if (!PyInt_Check(value)) 
	{
	  PyErr_SetString(PyExc_TypeError, "SANE_INT requires an integer");
	  free(v);
	  return NULL;
	}
      *( (SANE_Int*)v) = PyInt_AsLong(value);
      break;
    case(SANE_TYPE_FIXED):
      if (!PyFloat_Check(value)) 
	{
	  PyErr_SetString(PyExc_TypeError, "SANE_FIXED requires a floating point number");
	  free(v);
	  return NULL;
	}
      *( (SANE_Fixed*)v) = SANE_FIX(PyFloat_AsDouble(value));
      break;
    case(SANE_TYPE_STRING):
      if (!PyString_Check(value)) 
	{
	  PyErr_SetString(PyExc_TypeError, "SANE_STRING requires a string");
	  free(v);
	  return NULL;
	}
      strcpy(v, PyString_AsString(value));
      break;
    case(SANE_TYPE_BUTTON): 
    case(SANE_TYPE_GROUP):
      break;
    }
  
  st=sane_control_option(self->h, n, SANE_ACTION_SET_VALUE,
			 v, &i);
  if (st) {free(v); return PySane_Error(st);}
  
  free(v);
  return Py_BuildValue("i", i);
}

static PyObject *
SaneDev_set_auto_option(SaneDevObject *self, PyObject *args)
{
  SANE_Status st;
  const SANE_Option_Descriptor *d;
  SANE_Int i;
  int n;
  
  if (!PyArg_ParseTuple(args, "i", &n))
    return NULL;
  if (self->h==NULL)
    {
      PyErr_SetString(ErrorObject, "SaneDev object is closed");
      return NULL;
    }
  d=sane_get_option_descriptor(self->h, n);
  st=sane_control_option(self->h, n, SANE_ACTION_SET_AUTO,
			 NULL, &i);
  if (st) {return PySane_Error(st);}
  
  return Py_BuildValue("i", i);
 }

#define READSIZE 32768

static PyObject *
SaneDev_snap(SaneDevObject *self, PyObject *args)
{
  SANE_Status st; 
   /* The buffer should be a multiple of 3 in size, so each sane_read
      operation will return an integral number of RGB triples. */
  SANE_Byte buffer[READSIZE];  /* XXX how big should the buffer be? */
  SANE_Int len, lastlen;
  Imaging im;
  SANE_Parameters p;
  int px, py, remain, cplen, bufpos, padbytes;
  long L;
  char errmsg[80];
  union 
    { char c[2];
      INT16 i16;
    } 
  endian;
    
  endian.i16 = 1;
  
  if (!PyArg_ParseTuple(args, "i", &L))
    return NULL;
  if (self->h==NULL)
    {
      PyErr_SetString(ErrorObject, "SaneDev object is closed");
      return NULL;
    }
  im=(Imaging)L;

  st=SANE_STATUS_GOOD; px=py=0;
  /* xxx not yet implemented
     - handscanner support (i.e., unknown image length during start)
     - generally: move the functionality from method snap in sane.py
       down here -- I don't like this cross-dependency.
       we need to call sane_get_parameters here, and we can create
       the result Image object here.
  */
  sane_get_parameters(self->h, &p);
  if (p.format == SANE_FRAME_GRAY)
    {
      switch (p.depth)
        {
          case 1: 
            remain = p.bytes_per_line * im->ysize;
            padbytes = p.bytes_per_line - (im->xsize+7)/8;
            bufpos = 0;
            lastlen = len = 0;
            while (st!=SANE_STATUS_EOF && py < im->ysize)
              {
                while (len > 0 && py < im->ysize)
                  {
                    int i, j, k;
                    j = buffer[bufpos++];
                    k = 0x80;
                    for (i = 0; i < 8 && px < im->xsize; i++)
                      {
                        im->image8[py][px++] = (k&j) ? 0 : 0xFF;
                        k = k >> 1;
                      }
                    len--;
                    if (px >= im->xsize)
                      {
                        bufpos += padbytes;
                        len -= padbytes;
                        py++;
                        px = 0;
                      }
                  }
                st=sane_read(self->h, buffer, 
                             remain<READSIZE ? remain : READSIZE, &len);
                if (st && (st!=SANE_STATUS_EOF))
                  {
                    sane_cancel(self->h);
                    return PySane_Error(st);
                  }
                bufpos -= lastlen;
                lastlen = len;
                remain -= len;
                /* skip possible pad bytes at the start of the buffer */
                len -= bufpos;
              }
            break;
          case 8:
            remain = p.bytes_per_line * im->ysize;
            padbytes = p.bytes_per_line - im->xsize;
            bufpos = 0;
            len = 0;
            while (st!=SANE_STATUS_EOF && py < im->ysize)
              {
                while (len > 0 && py < im->ysize)
                  {
                    cplen = len;
                    if (px + cplen >= im->xsize)
                        cplen = im->xsize - px;
                    memcpy(&im->image8[py][px], &buffer[bufpos], cplen);
                    len -= cplen;
                    bufpos += cplen;
                    px += cplen;
                    if (px >= im->xsize)
                      {
                        px = 0;
                        py++;
                        bufpos += padbytes;
                        len -= padbytes;
                      }
                  }
                bufpos = -len;

                st=sane_read(self->h, buffer, 
                             remain<READSIZE ? remain : READSIZE, &len);
                if (st && (st!=SANE_STATUS_EOF))
                  {
                    sane_cancel(self->h);
                    return PySane_Error(st);
                  }
                remain -= len;
                len -= bufpos;
              }
              break;
          case 16:
            remain = p.bytes_per_line * im->ysize;
            padbytes = p.bytes_per_line - 2 * im->xsize;
            bufpos = endian.c[0];
            lastlen = len = 0;
            while (st!=SANE_STATUS_EOF && py < im->ysize)
              {
                while (len > 0 && py < im->ysize)
                  {
                    im->image8[py][px++] = buffer[bufpos];
                    bufpos += 2;
                    len -= 2;
                    if (px >= im->xsize)
                      {
                        bufpos += padbytes;
                        len -= padbytes;
                        py++;
                        px = 0;
                      }
                  }
                st=sane_read(self->h, buffer, 
                             remain<READSIZE ? remain : READSIZE, &len);
                if (st && (st!=SANE_STATUS_EOF))
                  {
                    sane_cancel(self->h);
                    return PySane_Error(st);
                  }
                remain -= len;
                bufpos -= lastlen;
                lastlen = len;
                len -= bufpos;
              }
            break;
          default:
            /* other depths are not formally "illegal" according to the 
               Sane API, but it's agreed by Sane developers that other
               depths than 1, 8, 16 should not be used
            */
            sane_cancel(self->h);
            snprintf(errmsg, 80, "unsupported pixel depth: %i", p.depth);
            PyErr_SetString(ErrorObject, errmsg);
            return NULL;
        }
    }
  else if (p.format == SANE_FRAME_RGB)
    {
      int incr, color, pxs, pxmax, bit, val, mask;
      switch (p.depth)
        {
          case 1: 
            remain = p.bytes_per_line * im->ysize;
            padbytes = p.bytes_per_line - ((im->xsize+7)/8) * 3;
            bufpos = 0;
            len = 0;
            lastlen = 0;
            pxmax = 4 * im->xsize;
            while (st!=SANE_STATUS_EOF && py < im->ysize)
              {
                pxs = px;
                for (color = 0; color < 3; color++)
                  {
                    while (len <= 0 && st == SANE_STATUS_GOOD)
                      {
                        st=sane_read(self->h, buffer, 
                                     remain<READSIZE ? remain : READSIZE, &len);
                        if (st && (st!=SANE_STATUS_EOF))
                          {
                            sane_cancel(self->h);
                            return PySane_Error(st);
                          }
                        bufpos -= lastlen;
                        remain -= len;
                        lastlen = len;
                        /* skip possible pad bytes at the start of the buffer */
                        len -= bufpos;
                      }
                    if (st == SANE_STATUS_EOF) break;
                    pxs = px;
                    val = buffer[bufpos++];
                    len--;
                    mask = 0x80;
                    for (bit = 0; (bit < 8) && (px < pxmax); bit++)
                      {
                         ((UINT8**)(im->image32))[py][px] = (val&mask) ? 0xFF : 0;
                        mask = mask >> 1;
                        px += 4;
                      }
                    pxs++;
                    px = pxs;
                  }
                if (st == SANE_STATUS_EOF)
                  break;
                for (bit = 0; bit < 8 && px < pxmax; bit++)
                  {
                     ((UINT8**)(im->image32))[py][px] = 0;
                     px += 4;
                  }
                px -= 3;
                if (px >= pxmax)
                  {
                    bufpos += padbytes;
                    len -= padbytes;
                    py++;
                    px = 0;
                  }
              }
            break;
          case 8:
          case 16:
            if (p.depth == 8)
              {
                padbytes = p.bytes_per_line - 3 * im->xsize;
                bufpos = 0;
                incr = 1;
              }
            else 
              {
                padbytes = p.bytes_per_line - 6 * im->xsize;
                bufpos = endian.c[0];
                incr = 2;
              }
            remain = p.bytes_per_line * im->ysize;
            len = 0;
            lastlen = 0;
            pxmax = 4 * im->xsize;
            /* probably not very efficient. But we have to deal with these
               possible conditions:
               - we may have padding bytes at the end of a scan line
               - the number of bytes read with sane_read may be smaller
                 than the number of pad bytes
               - the buffer may become empty after setting any of the 
                 red/green/blue pixel values
             
            */
            while (st != SANE_STATUS_EOF && py < im->ysize)
              {
                for (color = 0; color < 3; color++)
                  {
                    while (len <= 0 && st == SANE_STATUS_GOOD)
                      {
                        bufpos -= lastlen;
                        if (remain == 0)
                          {
                            PyErr_SetString(ErrorObject, "internal _sane error: premature end of scan");
                            sane_cancel(self->h);
                            return NULL;
                          }
                        st = sane_read(self->h, buffer,
                              remain<(READSIZE) ? remain : (READSIZE), &len);
                        if (st && (st!=SANE_STATUS_EOF))
                          {
                            sane_cancel(self->h);
                            return PySane_Error(st);
                          }
                        lastlen = len;
                        remain -= len;
                        len -= bufpos;
                      }
                    if (st == SANE_STATUS_EOF) break;
                    ((UINT8**)(im->image32))[py][px++] = buffer[bufpos]; 
                    bufpos += incr;
                    len -= incr;
                  }
                if (st == SANE_STATUS_EOF) break;

                ((UINT8**)(im->image32))[py][px++] = 0;

                if (px >= pxmax)
                  {
                    px = 0;
                    py++;
                    bufpos += padbytes;
                    len -= padbytes;
                  }
              }
            break;
          default:
            sane_cancel(self->h);
            snprintf(errmsg, 80, "unsupported pixel depth: %i", p.depth);
            PyErr_SetString(ErrorObject, errmsg);
            return NULL;
        }
      
    }
  else /* should be SANE_FRAME_RED, GREEN or BLUE */
    {
      int lastlen, pxa, pxmax, offset, incr, frame_count = 0;
      /* at least the Sane test backend behaves a bit weird, if 
         it returns "premature EOF" for sane_read, i.e., if the 
         option "return value of sane_read" is set to SANE_STATUS_EOF.
         In this case, the test backend does not advance to the next frame,
         so p.last_frame will never be set...
         So let's count the number of frames we try to acquire
      */
      while (!p.last_frame && frame_count < 4)
        {
          frame_count++;
          st = sane_get_parameters(self->h, &p);
          if (st)
            {
              sane_cancel(self->h);
              return PySane_Error(st);
            }
          remain = p.bytes_per_line * im->ysize;
          bufpos = 0;
          len = 0;
          lastlen = 0;
          py = 0;
          switch (p.format)
            { 
              case SANE_FRAME_RED:
                offset = 0;
                break;
              case SANE_FRAME_GREEN:
                offset = 1;
                break;
              case SANE_FRAME_BLUE:
                offset = 2;
                break;
              default:
                sane_cancel(self->h);
                snprintf(errmsg, 80, "unknown/invalid frame format: %i", p.format);
                PyErr_SetString(ErrorObject, errmsg);
                return NULL;
            }
          px = offset;
          pxa = 3;
          pxmax = im->xsize * 4;
          switch (p.depth)
            {
              case 1:
                padbytes = p.bytes_per_line - (im->xsize+7)/8;
                st = SANE_STATUS_GOOD;
                while (st != SANE_STATUS_EOF && py < im->ysize)
                  {
                    while (len > 0)
                      {
                        int bit, mask, val;
                        val = buffer[bufpos++]; len--;
                        mask = 0x80;
                        for (bit = 0; bit < 8 && px < pxmax; bit++)
                          {
                            ((UINT8**)(im->image32))[py][px] 
                                = val&mask ? 0xFF : 0;
                            ((UINT8**)(im->image32))[py][pxa] = 0;
                            px += 4;
                            pxa += 4;
                            mask = mask >> 1;
                          }
 
                        if (px >= pxmax)
                          {
                            px = offset;
                            pxa = 3;
                            py++;
                            bufpos += padbytes;
                            len -= padbytes;
                          }
                      }
                    while (len <= 0 && st == SANE_STATUS_GOOD && remain > 0)
                      {
                        bufpos -= lastlen;
                        st = sane_read(self->h, buffer,
                              remain<(READSIZE) ? remain : (READSIZE), &len);
                        if (st && (st!=SANE_STATUS_EOF))
                          {
                            sane_cancel(self->h);
                            return PySane_Error(st);
                          }
                        remain -= len;
                        lastlen = len;
                        len -= bufpos;
                      }
                  }
                break;
              case 8:
              case 16:
                if (p.depth == 8)
                  {
                    padbytes = p.bytes_per_line - im->xsize;
                    incr = 1;
                  }
                else
                  {
                    padbytes = p.bytes_per_line - 2 * im->xsize;
                    incr = 2;
                    bufpos = endian.c[0];
                  }
                st = SANE_STATUS_GOOD;
                while (st != SANE_STATUS_EOF && py < im->ysize)
                  {
                    while (len <= 0)
                      {
                        bufpos -= lastlen;
                        if (remain == 0)
                          {
                            PyErr_SetString(ErrorObject, "internal _sane error: premature end of scan");
                            sane_cancel(self->h);
                            return NULL;
                          }
                        st = sane_read(self->h, buffer,
                              remain<(READSIZE) ? remain : (READSIZE), &len);
                        if (st && (st!=SANE_STATUS_EOF))
                          {
                            sane_cancel(self->h);
                            return PySane_Error(st);
                          }
                        if (st == SANE_STATUS_EOF)
                          break;
                        lastlen = len;
                        remain -= len;
                        if (bufpos >= len)
                          len = 0;
                        else
                          len -= bufpos;
                      }
                    if (st == SANE_STATUS_EOF)
                      break;
                    ((UINT8**)(im->image32))[py][px] = buffer[bufpos];
                    ((UINT8**)(im->image32))[py][pxa] = 0;
                    bufpos += incr;
                    len -= incr;
                    px += 4;
                    pxa += 4;

                    if (px >= pxmax)
                      {
                        px = offset;
                        pxa = 3;
                        py++;
                        bufpos += padbytes;
                        len -= padbytes;
                      }
                  }
                break;
              default:
                sane_cancel(self->h);
                snprintf(errmsg, 80, "unsupported pixel depth: %i", p.depth);
                PyErr_SetString(ErrorObject, errmsg);
                return NULL;
            }
          if (!p.last_frame)
            {
              /* all sane_read calls in the above loop may return
                 SANE_STATUS_GOOD, but the backend may need another sane_read
                 call which returns SANE_STATUS_EOF in order to start
                 a new frame.
              */
              do {
                   st = sane_read(self->h, buffer, READSIZE, &len);
                 }
              while (st == SANE_STATUS_GOOD);
              if (st != SANE_STATUS_EOF)
                {
                   sane_cancel(self->h);
                   return PySane_Error(st);
                }
              
              st = sane_start(self->h);
              if (st) return PySane_Error(st);
            }
        }
    }
  sane_cancel(self->h);
  Py_INCREF(Py_None);
  return Py_None;
}

static PyMethodDef SaneDev_methods[] = {
	{"get_parameters",	(PyCFunction)SaneDev_get_parameters,	1},

	{"get_options",	(PyCFunction)SaneDev_get_options,	1},
	{"get_option",	(PyCFunction)SaneDev_get_option,	1},
	{"set_option",	(PyCFunction)SaneDev_set_option,	1},
	{"set_auto_option",	(PyCFunction)SaneDev_set_auto_option,	1},

	{"start",	(PyCFunction)SaneDev_start,	1},
	{"cancel",	(PyCFunction)SaneDev_cancel,	1},
	{"snap",	(PyCFunction)SaneDev_snap,	1},
	{"fileno",	(PyCFunction)SaneDev_fileno,	1},
 	{"close",	(PyCFunction)SaneDev_close,	1},
	{NULL,		NULL}		/* sentinel */
};

static PyObject *
SaneDev_getattr(SaneDevObject *self, char *name)
{
	return Py_FindMethod(SaneDev_methods, (PyObject *)self, name);
}

staticforward PyTypeObject SaneDev_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
	0,			/*ob_size*/
	"SaneDev",			/*tp_name*/
	sizeof(SaneDevObject),	/*tp_basicsize*/
	0,			/*tp_itemsize*/
	/* methods */
	(destructor)SaneDev_dealloc, /*tp_dealloc*/
	0,			/*tp_print*/
	(getattrfunc)SaneDev_getattr, /*tp_getattr*/
	0, /*tp_setattr*/
	0,			/*tp_compare*/
	0,			/*tp_repr*/
	0,			/*tp_as_number*/
	0,			/*tp_as_sequence*/
	0,			/*tp_as_mapping*/
	0,			/*tp_hash*/
};

/* --------------------------------------------------------------------- */

static PyObject *
PySane_init(PyObject *self, PyObject *args)
{
  SANE_Status st;
  SANE_Int version;
  
  if (!PyArg_ParseTuple(args, ""))
    return NULL;

  /* XXX Authorization is not yet supported */
  st=sane_init(&version, NULL); 
  if (st) return PySane_Error(st);
  return Py_BuildValue("iiii", version, SANE_VERSION_MAJOR(version),
		       SANE_VERSION_MINOR(version), SANE_VERSION_BUILD(version));
}

static PyObject *
PySane_exit(PyObject *self, PyObject *args)
{
  if (!PyArg_ParseTuple(args, ""))
    return NULL;

  sane_exit();
  Py_INCREF(Py_None);
  return Py_None;
}

static PyObject *
PySane_get_devices(PyObject *self, PyObject *args)
{
  SANE_Device **devlist;
  SANE_Device *dev;
  SANE_Status st;
  PyObject *list;
  int local_only, i;
  
  if (!PyArg_ParseTuple(args, "|i", &local_only))
    {
      return NULL;
    }
  
  st=sane_get_devices(&devlist, local_only);
  if (st) return PySane_Error(st);
  if (!(list = PyList_New(0)))
	    return NULL;
  for(i=0; devlist[i]!=NULL; i++)
    {
      dev=devlist[i];
      PyList_Append(list, Py_BuildValue("ssss", dev->name, dev->vendor, dev->model, dev->type));
    }
  
  return list;
}

/* Function returning new SaneDev object */

static PyObject *
PySane_open(PyObject *self, PyObject *args)
{
	SaneDevObject *rv;
	SANE_Status st;
	char *name;

	if (!PyArg_ParseTuple(args, "s", &name))
		return NULL;
	rv = newSaneDevObject();
	if ( rv == NULL )
	    return NULL;
	st = sane_open(name, &(rv->h));
	if (st) 
	  {
	    Py_DECREF(rv);
	    return PySane_Error(st);
	  }
	return (PyObject *)rv;
}

static PyObject *
PySane_OPTION_IS_ACTIVE(PyObject *self, PyObject *args)
{
  SANE_Int cap;
  long lg;
  
  if (!PyArg_ParseTuple(args, "i", &lg))
    return NULL;
  cap=lg;
  return PyInt_FromLong( SANE_OPTION_IS_ACTIVE(cap));
}

static PyObject *
PySane_OPTION_IS_SETTABLE(PyObject *self, PyObject *args)
{
  SANE_Int cap;
  long lg;
  
  if (!PyArg_ParseTuple(args, "i", &lg))
    return NULL;
  cap=lg;
  return PyInt_FromLong( SANE_OPTION_IS_SETTABLE(cap));
}


/* List of functions defined in the module */

static PyMethodDef PySane_methods[] = {
	{"init",	PySane_init,		1},
	{"exit",	PySane_exit,		1},
	{"get_devices",	PySane_get_devices,	1},
	{"_open",	PySane_open,	1},
	{"OPTION_IS_ACTIVE",	PySane_OPTION_IS_ACTIVE,	1},
	{"OPTION_IS_SETTABLE",	PySane_OPTION_IS_SETTABLE,	1},
	{NULL,		NULL}		/* sentinel */
};


static void
insint(PyObject *d, char *name, int value)
{
	PyObject *v = PyInt_FromLong((long) value);
	if (!v || PyDict_SetItemString(d, name, v))
		Py_FatalError("can't initialize sane module");

	Py_DECREF(v);
}

void
init_sane(void)
{
	PyObject *m, *d;

	/* Create the module and add the functions */
	m = Py_InitModule("_sane", PySane_methods);

	/* Add some symbolic constants to the module */
	d = PyModule_GetDict(m);
	ErrorObject = PyString_FromString("_sane.error");
	PyDict_SetItemString(d, "error", ErrorObject);

	insint(d, "INFO_INEXACT", SANE_INFO_INEXACT);
	insint(d, "INFO_RELOAD_OPTIONS", SANE_INFO_RELOAD_OPTIONS);
	insint(d, "RELOAD_PARAMS", SANE_INFO_RELOAD_PARAMS);

	insint(d, "FRAME_GRAY", SANE_FRAME_GRAY);
	insint(d, "FRAME_RGB", SANE_FRAME_RGB);
	insint(d, "FRAME_RED", SANE_FRAME_RED);
	insint(d, "FRAME_GREEN", SANE_FRAME_GREEN);
	insint(d, "FRAME_BLUE", SANE_FRAME_BLUE);

	insint(d, "CONSTRAINT_NONE", SANE_CONSTRAINT_NONE);
	insint(d, "CONSTRAINT_RANGE", SANE_CONSTRAINT_RANGE);
	insint(d, "CONSTRAINT_WORD_LIST", SANE_CONSTRAINT_WORD_LIST);
	insint(d, "CONSTRAINT_STRING_LIST", SANE_CONSTRAINT_STRING_LIST);

	insint(d, "TYPE_BOOL", SANE_TYPE_BOOL);
	insint(d, "TYPE_INT", SANE_TYPE_INT);
	insint(d, "TYPE_FIXED", SANE_TYPE_FIXED);
	insint(d, "TYPE_STRING", SANE_TYPE_STRING);
	insint(d, "TYPE_BUTTON", SANE_TYPE_BUTTON);
	insint(d, "TYPE_GROUP", SANE_TYPE_GROUP);

	insint(d, "UNIT_NONE", SANE_UNIT_NONE);
	insint(d, "UNIT_PIXEL", SANE_UNIT_PIXEL);
	insint(d, "UNIT_BIT", SANE_UNIT_BIT);
	insint(d, "UNIT_MM", SANE_UNIT_MM);
	insint(d, "UNIT_DPI", SANE_UNIT_DPI);
	insint(d, "UNIT_PERCENT", SANE_UNIT_PERCENT);
	insint(d, "UNIT_MICROSECOND", SANE_UNIT_MICROSECOND);

	insint(d, "CAP_SOFT_SELECT", SANE_CAP_SOFT_SELECT);
	insint(d, "CAP_HARD_SELECT", SANE_CAP_HARD_SELECT);
	insint(d, "CAP_SOFT_DETECT", SANE_CAP_SOFT_DETECT);
	insint(d, "CAP_EMULATED", SANE_CAP_EMULATED);
	insint(d, "CAP_AUTOMATIC", SANE_CAP_AUTOMATIC);
	insint(d, "CAP_INACTIVE", SANE_CAP_INACTIVE);
	insint(d, "CAP_ADVANCED", SANE_CAP_ADVANCED);

	/* handy for checking array lengths: */
	insint(d, "SANE_WORD_SIZE", sizeof(SANE_Word));

	/* Check for errors */
	if (PyErr_Occurred())
		Py_FatalError("can't initialize module _sane");
}