/* Copyright (C) 1993, 1995, 1997, 1998, 1999 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU Ghostscript is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
  to anyone for the consequences of using it or for whether it serves any
  particular purpose or works at all, unless he says so in writing.  Refer
  to the GNU General Public License for full details.
  
  Everyone is granted permission to copy, modify and redistribute GNU
  Ghostscript, but only under the conditions described in the GNU General
  Public License.  A copy of this license is supposed to have been given
  to you along with GNU Ghostscript so you can know your rights and
  responsibilities.  It should be in a file named COPYING.  Among other
  things, the copyright notice and this notice must be preserved on all
  copies.
*/

/*$RCSfile: ziodev.c,v $ $Revision: 1.3.2.1 $ */
/* Standard IODevice implementation */
#include "memory_.h"
#include "stdio_.h"
#include "string_.h"
#include "ghost.h"
#include "gp.h"
#include "gpcheck.h"
#include "oper.h"
#include "stream.h"
#include "ialloc.h"
#include "iscan.h"
#include "ivmspace.h"
#include "gxiodev.h"		/* must come after stream.h */
				/* and before files.h */
#include "files.h"
#include "scanchar.h"		/* for char_EOL */
#include "store.h"

/* Import the dtype of the stdio IODevices. */
extern const char iodev_dtype_stdio[];

/* Define the special devices. */
#define iodev_special(dname, init, open) {\
    dname, iodev_dtype_stdio,\
	{ init, open, iodev_no_open_file, iodev_no_fopen, iodev_no_fclose,\
	  iodev_no_delete_file, iodev_no_rename_file, iodev_no_file_status,\
	  iodev_no_enumerate_files, NULL, NULL,\
	  iodev_no_get_params, iodev_no_put_params\
	}\
}

/*
 * We need the current context pointer for accessing / opening the %std
 * IODevices.  However, this is not available to the open routine.
 * Therefore, we use the hack of storing this pointer in the IODevice state
 * pointer just before calling the open routines.  We clear the pointer
 * immediately afterwards so as not to wind up with dangling references.
 */

#define LINEEDIT_BUF_SIZE 20	/* initial size, not fixed size */
private iodev_proc_open_device(lineedit_open);
const gx_io_device gs_iodev_lineedit =
    iodev_special("%lineedit%", iodev_no_init, lineedit_open);

#define STATEMENTEDIT_BUF_SIZE 50	/* initial size, not fixed size */
private iodev_proc_open_device(statementedit_open);
const gx_io_device gs_iodev_statementedit =
    iodev_special("%statementedit%", iodev_no_init, statementedit_open);

/* ------ Operators ------ */

/* <int> .getiodevice <string|null> */
private int
zgetiodevice(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gx_io_device *iodev;
    const byte *dname;

    check_type(*op, t_integer);
    if (op->value.intval != (int)op->value.intval)
	return_error(e_rangecheck);
    iodev = gs_getiodevice((int)(op->value.intval));
    if (iodev == 0)		/* index out of range */
	return_error(e_rangecheck);
    dname = (const byte *)iodev->dname;
    if (dname == 0)
	make_null(op);
    else
	make_const_string(op, a_readonly | avm_foreign,
			  strlen((const char *)dname), dname);
    return 0;
}

/* ------ %lineedit and %statementedit ------ */

private int
line_collect(gx_io_device * iodev, const char *access, stream ** ps,
	     gs_memory_t * mem, uint initial_buf_size, bool statement)
{
    uint count = 0;
    bool in_eol = false;
    int code;
    gx_io_device *indev = gs_findiodevice((const byte *)"%stdin", 6);
    /* HACK: get the context pointer from the IODevice.  See above. */
    i_ctx_t *i_ctx_p = (i_ctx_t *)iodev->state;
    stream *s;
    stream *ins;
    gs_string str;
    /*
     * buf exists only for stylistic parallelism: all occurrences of
     * buf-> could just as well be str. .
     */
    gs_string *const buf = &str;

    if (strcmp(access, "r"))
	return_error(e_invalidfileaccess);
    s = file_alloc_stream(mem, "line_collect(stream)");
    if (s == 0)
	return_error(e_VMerror);
    /* HACK: see above. */
    indev->state = i_ctx_p;
    code = (indev->procs.open_device)(indev, access, &ins, mem);
    indev->state = 0;
    if (code < 0)
	return code;
    buf->size = initial_buf_size;
    buf->data = gs_alloc_string(mem, buf->size, "line_collect(buffer)");
    if (buf->data == 0)
	return_error(e_VMerror);
rd:
    /*
     * We have to stop 1 character short of the buffer size,
     * because %statementedit must append an EOL.
     */
    buf->size--;
    /* HACK: set %stdin's state so that GNU readline can retrieve it. */
    indev->state = i_ctx_p;
    code = zreadline_from(ins, buf, mem, &count, &in_eol);
    buf->size++;		/* restore correct size */
    indev->state = 0;
    switch (code) {
	case EOFC:
	    code = gs_note_error(e_undefinedfilename);
	    /* falls through */
	case 0:
	    break;
	default:
	    code = gs_note_error(e_ioerror);
	    break;
	case 1:		/* filled buffer */
	    {
		uint nsize;
		byte *nbuf;

#if arch_ints_are_short
		if (nsize == max_uint) {
		    code = gs_note_error(e_limitcheck);
		    break;
		} else if (nsize >= max_uint / 2)
		    nsize = max_uint;
		else
#endif
		    nsize = buf->size * 2;
		nbuf = gs_resize_string(mem, buf->data, buf->size, nsize,
					"line_collect(grow buffer)");
		if (nbuf == 0) {
		    code = gs_note_error(e_VMerror);
		    break;
		}
		buf->data = nbuf;
		buf->size = nsize;
		goto rd;
	    }
    }
    if (code != 0) {
	gs_free_string(mem, buf->data, buf->size, "line_collect(buffer)");
	return code;
    }
    if (statement) {
	/* If we don't have a complete token, keep going. */
	stream st;
	stream *ts = &st;
	scanner_state state;
	ref ignore_value;
	uint depth = ref_stack_count(&o_stack);
	int code;

	/* Add a terminating EOL. */
	buf->data[count++] = char_EOL;
	sread_string(ts, buf->data, count);
sc:
	scanner_state_init_check(&state, false, true);
	code = scan_token(i_ctx_p, ts, &ignore_value, &state);
	ref_stack_pop_to(&o_stack, depth);
	switch (code) {
	    case 0:		/* read a token */
	    case scan_BOS:
		goto sc;	/* keep going until we run out of data */
	    case scan_Refill:
		goto rd;
	    case scan_EOF:
		break;
	    default:		/* error */
		gs_free_string(mem, buf->data, buf->size, "line_collect(buffer)");
		return code;
	}
    }
    buf->data = gs_resize_string(mem, buf->data, buf->size, count,
			   "line_collect(resize buffer)");
    if (buf->data == 0)
	return_error(e_VMerror);
    sread_string(s, buf->data, count);
    s->save_close = s->procs.close;
    s->procs.close = file_close_disable;
    *ps = s;
    return 0;
}

private int
lineedit_open(gx_io_device * iodev, const char *access, stream ** ps,
	      gs_memory_t * mem)
{
    int code = line_collect(iodev, access, ps, mem,
			    LINEEDIT_BUF_SIZE, false);

    return (code < 0 ? code : 1);
}

private int
statementedit_open(gx_io_device * iodev, const char *access, stream ** ps,
		   gs_memory_t * mem)
{
    int code = line_collect(iodev, access, ps, mem,
			    STATEMENTEDIT_BUF_SIZE, true);

    return (code < 0 ? code : 1);
}

/* ------ Initialization procedure ------ */

const op_def ziodev_op_defs[] =
{
    {"1.getiodevice", zgetiodevice},
    op_def_end(0)
};
