/* Copyright (C) 2000 artofcode LLC.  All rights reserved.
  
  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 2 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, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.

*/

/*$Id: ziodevs.c,v 1.5.2.1.2.1 2003/01/17 00:49:06 giles Exp $ */
/* %stdxxx IODevice implementation for PostScript interpreter */
#include "stdio_.h"
#include "ghost.h"
#include "gp.h"
#include "gpcheck.h"
#include "oper.h"
#include "stream.h"
#include "gxiodev.h"		/* must come after stream.h */
				/* and before files.h */
#include "files.h"
#include "store.h"

/* Define the special devices. */
const char iodev_dtype_stdio[] = "Special";
#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 STDIN_BUF_SIZE 128
/*#define ref_stdin ref_stdio[0] *//* in files.h */
bool gs_stdin_is_interactive;	/* exported for command line only */
private iodev_proc_init(stdin_init);
private iodev_proc_open_device(stdin_open);
const gx_io_device gs_iodev_stdin =
    iodev_special("%stdin%", stdin_init, stdin_open);

#define STDOUT_BUF_SIZE 128
/*#define ref_stdout ref_stdio[1] *//* in files.h */
private iodev_proc_open_device(stdout_open);
const gx_io_device gs_iodev_stdout =
    iodev_special("%stdout%", iodev_no_init, stdout_open);

#define STDERR_BUF_SIZE 128
/*#define ref_stderr ref_stdio[2] *//* in files.h */
private iodev_proc_open_device(stderr_open);
const gx_io_device gs_iodev_stderr =
    iodev_special("%stderr%", iodev_no_init, stderr_open);

/* ------- %stdin, %stdout, and %stderr ------ */

/*
 * According to Adobe, it is legal to close the %std... files and then
 * re-open them later.  However, the re-opened file object is not 'eq' to
 * the original file object (in our implementation, it has a different
 * read_id or write_id).
 */

private int
    s_stdin_read_process(P4(stream_state *, stream_cursor_read *,
			    stream_cursor_write *, bool));

private int
stdin_init(gx_io_device * iodev, gs_memory_t * mem)
{
    gs_stdin_is_interactive = true;
    return 0;
}

/* Read from stdin into the buffer. */
/* If interactive, only read one character. */
private int
s_stdin_read_process(stream_state * st, stream_cursor_read * ignore_pr,
		     stream_cursor_write * pw, bool last)
{
    FILE *file = ((stream *) st)->file;		/* hack for file streams */
    int wcount = (int)(pw->limit - pw->ptr);
    int count;

    if (wcount <= 0)
	return 0;
    count = gp_stdin_read( (char*) pw->ptr + 1, wcount,
			   gs_stdin_is_interactive, file);
    pw->ptr += (count < 0) ? 0 : count;
    return ((count < 0) ? ERRC : (count == 0) ? EOFC : count);
}

private int
stdin_open(gx_io_device * iodev, const char *access, stream ** ps,
	   gs_memory_t * mem)
{
    i_ctx_t *i_ctx_p = (i_ctx_t *)iodev->state;	/* see above */
    stream *s;

    if (!streq1(access, 'r'))
	return_error(e_invalidfileaccess);
    if (file_is_invalid(s, &ref_stdin)) {
	/****** stdin SHOULD NOT LINE-BUFFER ******/
	gs_memory_t *mem = imemory_system;
	byte *buf;

	s = file_alloc_stream(mem, "stdin_open(stream)");
	/* We want stdin to read only one character at a time, */
	/* but it must have a substantial buffer, in case it is used */
	/* by a stream that requires more than one input byte */
	/* to make progress. */
	buf = gs_alloc_bytes(mem, STDIN_BUF_SIZE, "stdin_open(buffer)");
	if (s == 0 || buf == 0)
	    return_error(e_VMerror);
	sread_file(s, gs_stdin, buf, STDIN_BUF_SIZE);
	s->procs.process = s_stdin_read_process;
	s->save_close = s_std_null;
	s->procs.close = file_close_file;
	make_file(&ref_stdin, a_readonly | avm_system, s->read_id, s);
	*ps = s;
	return 1;
    }
    *ps = s;
    return 0;
}
/* This is the public routine for getting the stdin stream. */
int
zget_stdin(i_ctx_t *i_ctx_p, stream ** ps)
{
    stream *s;
    gx_io_device *iodev;
    int code;

    if (file_is_valid(s, &ref_stdin)) {
	*ps = s;
	return 0;
    }
    iodev = gs_findiodevice((const byte *)"%stdin", 6);
    iodev->state = i_ctx_p;
    code = (*iodev->procs.open_device)(iodev, "r", ps, imemory_system);
    iodev->state = NULL;
    return min(code, 0);
}
/* Test whether a stream is stdin. */
bool
zis_stdin(const stream *s)
{
    return (s_is_valid(s) && s->procs.process == s_stdin_read_process);
}

private int
stdout_open(gx_io_device * iodev, const char *access, stream ** ps,
	    gs_memory_t * mem)
{
    i_ctx_t *i_ctx_p = (i_ctx_t *)iodev->state;	/* see above */
    stream *s;

    if (!streq1(access, 'w'))
	return_error(e_invalidfileaccess);
    if (file_is_invalid(s, &ref_stdout)) {
	gs_memory_t *mem = imemory_system;
	byte *buf;

	s = file_alloc_stream(mem, "stdout_open(stream)");
	buf = gs_alloc_bytes(mem, STDOUT_BUF_SIZE, "stdout_open(buffer)");
	if (s == 0 || buf == 0)
	    return_error(e_VMerror);
	swrite_file(s, gs_stdout, buf, STDOUT_BUF_SIZE);
	s->save_close = s->procs.flush;
	s->procs.close = file_close_file;
	make_file(&ref_stdout, a_write | avm_system, s->write_id, s);
	*ps = s;
	return 1;
    }
    *ps = s;
    return 0;
}
/* This is the public routine for getting the stdout stream. */
int
zget_stdout(i_ctx_t *i_ctx_p, stream ** ps)
{
    stream *s;
    gx_io_device *iodev;
    int code;

    if (file_is_valid(s, &ref_stdout)) {
	*ps = s;
	return 0;
    }
    iodev = gs_findiodevice((const byte *)"%stdout", 7);
    iodev->state = i_ctx_p;
    code = (*iodev->procs.open_device)(iodev, "w", ps, imemory_system);
    iodev->state = NULL;
    return min(code, 0);
}

private int
stderr_open(gx_io_device * iodev, const char *access, stream ** ps,
	    gs_memory_t * mem)
{
    i_ctx_t *i_ctx_p = (i_ctx_t *)iodev->state;	/* see above */
    stream *s;

    if (!streq1(access, 'w'))
	return_error(e_invalidfileaccess);
    if (file_is_invalid(s, &ref_stderr)) {
	gs_memory_t *mem = imemory_system;
	byte *buf;

	s = file_alloc_stream(mem, "stderr_open(stream)");
	buf = gs_alloc_bytes(mem, STDERR_BUF_SIZE, "stderr_open(buffer)");
	if (s == 0 || buf == 0)
	    return_error(e_VMerror);
	swrite_file(s, gs_stderr, buf, STDERR_BUF_SIZE);
	s->save_close = s->procs.flush;
	s->procs.close = file_close_file;
	make_file(&ref_stderr, a_write | avm_system, s->write_id, s);
	*ps = s;
	return 1;
    }
    *ps = s;
    return 0;
}
/* This is the public routine for getting the stderr stream. */
int
zget_stderr(i_ctx_t *i_ctx_p, stream ** ps)
{
    stream *s;
    gx_io_device *iodev;
    int code;

    if (file_is_valid(s, &ref_stderr)) {
	*ps = s;
	return 0;
    }
    iodev = gs_findiodevice((const byte *)"%stderr", 7);
    iodev->state = i_ctx_p;
    code = (*iodev->procs.open_device)(iodev, "w", ps, imemory_system);
    iodev->state = NULL;
    return min(code, 0);
}