/* Copyright (C) 2001-2006 artofcode LLC.
   All Rights Reserved.
  
   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied, modified
   or distributed except as expressly authorized under the terms of that
   license.  Refer to licensing information at http://www.artifex.com/
   or contact Artifex Software, Inc.,  7 Mt. Lassen Drive - Suite A-134,
   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
*/

/* $Id: gsargs.c 6651 2006-03-13 16:18:19Z stefan $ */
/* Command line argument list management */
#include "ctype_.h"
#include "stdio_.h"
#include "string_.h"
#include "gsexit.h"
#include "gsmemory.h"
#include "gsargs.h"
#include "gserrors.h"

/* Initialize an arg list. */
void
arg_init(arg_list * pal, const char **argv, int argc,
	 FILE * (*arg_fopen) (const char *fname, void *fopen_data),
	 void *fopen_data)
{
    pal->expand_ats = true;
    pal->arg_fopen = arg_fopen;
    pal->fopen_data = fopen_data;
    pal->argp = argv + 1;
    pal->argn = argc - 1;
    pal->depth = 0;
}

/* Push a string onto an arg list. */
int
arg_push_memory_string(arg_list * pal, char *str, gs_memory_t * mem)
{
    arg_source *pas;

    if (pal->depth == arg_depth_max) {
	lprintf("Too much nesting of @-files.\n");
	return 1;
    }
    pas = &pal->sources[pal->depth];
    pas->is_file = false;
    pas->u.s.chars = str;
    pas->u.s.memory = mem;
    pas->u.s.str = str;
    pal->depth++;
    return 0;
}

/* Clean up an arg list. */
void
arg_finit(arg_list * pal)
{
    while (pal->depth) {
	arg_source *pas = &pal->sources[--(pal->depth)];

	if (pas->is_file)
	    fclose(pas->u.file);
	else if (pas->u.s.memory)
	    gs_free_object(pas->u.s.memory, pas->u.s.chars, "arg_finit");
    }
}

/* Get the next arg from a list. */
/* Note that these are not copied to the heap. */
const char *
arg_next(arg_list * pal, int *code)
{
    arg_source *pas;
    FILE *f;
    const char *astr = 0;	/* initialized only to pacify gcc */
    char *cstr;
    const char *result;
    int endc;
    int c, i;
    bool in_quote, eol;

  top:pas = &pal->sources[pal->depth - 1];
    if (pal->depth == 0) {
	if (pal->argn <= 0)	/* all done */
	    return 0;
	pal->argn--;
	result = *(pal->argp++);
	goto at;
    }
    if (pas->is_file)
	f = pas->u.file, endc = EOF;
    else
	astr = pas->u.s.str, f = NULL, endc = 0;
    result = cstr = pal->cstr;
#define cfsgetc() (f == NULL ? (*astr ? *astr++ : 0) : fgetc(f))
#define is_eol(c) (c == '\r' || c == '\n')
    i = 0;
    in_quote = false;
    eol = true;
    c = cfsgetc();
    for (i = 0;;) {
	if (c == endc) {
	    if (in_quote) {
		cstr[i] = 0;
		errprintf("Unterminated quote in @-file: %s\n", cstr);
		*code = gs_error_Fatal;
		return NULL;
	    }
	    if (i == 0) {
		/* EOF before any argument characters. */
		if (f != NULL)
		    fclose(f);
		else if (pas->u.s.memory)
		    gs_free_object(pas->u.s.memory, pas->u.s.chars,
				   "arg_next");
		pal->depth--;
		goto top;
	    }
	    break;
	}
	/* c != endc */
	if (isspace(c)) {
	    if (i == 0) {
		c = cfsgetc();
		continue;
	    }
	    if (!in_quote)
		break;
	}
	/* c isn't leading or terminating whitespace. */
	if (c == '#' && eol) {
	    /* Skip a comment. */
	    do {
		c = cfsgetc();
	    } while (!(c == endc || is_eol(c)));
	    if (c == '\r')
		c = cfsgetc();
	    if (c == '\n')
		c = cfsgetc();
	    continue;
	}
	if (c == '\\') {
	    /* Check for \ followed by newline. */
	    c = cfsgetc();
	    if (is_eol(c)) {
		if (c == '\r')
		    c = cfsgetc();
		if (c == '\n')
		    c = cfsgetc();
		eol = true;
		continue;
	    }
	    /* \ anywhere else is treated as a printing character. */
	    /* This is different from the Unix shells. */
	    if (i == arg_str_max - 1) {
		cstr[i] = 0;
		errprintf("Command too long: %s\n", cstr);
		*code = gs_error_Fatal;
		return NULL;
	    }
	    cstr[i++] = '\\';
	    eol = false;
	    continue;
	}
	/* c will become part of the argument */
	if (i == arg_str_max - 1) {
	    cstr[i] = 0;
	    errprintf("Command too long: %s\n", cstr);
	    *code = gs_error_Fatal;
	    return NULL;
	}
	/* If input is coming from an @-file, allow quotes */
	/* to protect whitespace. */
	if (c == '"' && f != NULL)
	    in_quote = !in_quote;
	else
	    cstr[i++] = c;
	eol = is_eol(c);
	c = cfsgetc();
    }
    cstr[i] = 0;
    if (f == NULL)
	pas->u.s.str = astr;
  at:if (pal->expand_ats && result[0] == '@') {
	if (pal->depth == arg_depth_max) {
	    lprintf("Too much nesting of @-files.\n");
	    *code = gs_error_Fatal;
	    return NULL;
	}
	result++;		/* skip @ */
	f = (*pal->arg_fopen) (result, pal->fopen_data);
	if (f == NULL) {
	    errprintf("Unable to open command line file %s\n", result);
	    *code = gs_error_Fatal;
	    return NULL;
	}
	pal->depth++;
	pas++;
	pas->is_file = true;
	pas->u.file = f;
	goto top;
    }
    return result;
}

/* Copy an argument string to the heap. */
char *
arg_copy(const char *str, gs_memory_t * mem)
{
    char *sstr = (char *)gs_alloc_bytes(mem, strlen(str) + 1, "arg_copy");

    if (sstr == 0) {
	lprintf("Out of memory!\n");
	return NULL;
    }
    strcpy(sstr, str);
    return sstr;
}
