/* Copyright (C) 2001-2012 Artifex Software, Inc.
   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 the license contained in the file LICENSE in this distribution.

   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.
*/


/* 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, bool parsed, 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.parsed = parsed;
    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 if (pas->u.s.parsed)
        /* this	string is a "pushed-back" argument		     */
        /* (retrieved by a precedeing arg_next(), but not processed) */
        if (strlen(pas->u.s.str) >= arg_str_max) {
            errprintf(pas->u.s.memory, "Command too long: %s\n", pas->u.s.str);
            *code = gs_error_Fatal;
            return NULL;
        } else {
            strcpy(pal->cstr, pas->u.s.str);
            result = pal->cstr;
            if (pas->u.s.memory)
                gs_free_object(pas->u.s.memory,	pas->u.s.chars,	"arg_next");
            pal->depth--;
            pas--;
            goto at;
        }
    else
        astr = pas->u.s.str, f = NULL, endc = 0;
    result = cstr = pal->cstr;
#define cfsgetc() (f == NULL ? (int)(unsigned char)(*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(pas->u.s.memory,
                          "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(pas->u.s.memory, "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(pas->u.s.memory, "Command too long: %s\n", cstr);
            *code = gs_error_Fatal;
            return NULL;
        }
        /* Allow quotes to protect whitespace. */
        /* (special cases have already been handled and don't reach this point) */
        if (c == '"')
            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) {
            errprintf(pas->u.s.memory, "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(pas->u.s.memory, "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;
}

/* Free a previously arg_copy'd string */
void
arg_free(char *str, gs_memory_t * mem)
{
    gs_free_object(mem, str, "arg_copy");
}