/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0 AND BSD-3-Clause

 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 */

/*
 * Copyright (C) 1987, 1993, 1994 The Regents of the University of California.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file
 * This file was adapted from the NetBSD project's source tree, RCS ID:
 *    NetBSD: getopt.c,v 1.15 1999/09/20 04:39:37 lukem Exp
 *
 * The primary change has been to rename items to the ISC namespace
 * and format in the ISC coding style.
 */

#include <stdbool.h>
#include <stdio.h>

#include <isc/commandline.h>
#include <isc/mem.h>
#include <isc/string.h>
#include <isc/util.h>

/*% Index into parent argv vector. */
int isc_commandline_index = 1;
/*% Character checked for validity. */
int isc_commandline_option;
/*% Argument associated with option. */
char *isc_commandline_argument;
/*% For printing error messages. */
char *isc_commandline_progname;
/*% Print error messages. */
bool isc_commandline_errprint = true;
/*% Reset processing. */
bool isc_commandline_reset = true;

static char endopt = '\0';

#define BADOPT '?'
#define BADARG ':'
#define ENDOPT &endopt

/*!
 * getopt --
 *	Parse argc/argv argument vector.
 */
int
isc_commandline_parse(int argc, char *const *argv, const char *options) {
	static char *place = ENDOPT;
	const char *option; /* Index into *options of option. */

	REQUIRE(argc >= 0 && argv != NULL && options != NULL);

	/*
	 * Update scanning pointer, either because a reset was requested or
	 * the previous argv was finished.
	 */
	if (isc_commandline_reset || *place == '\0') {
		if (isc_commandline_reset) {
			isc_commandline_index = 1;
			isc_commandline_reset = false;
		}

		if (isc_commandline_progname == NULL) {
			isc_commandline_progname = argv[0];
		}

		if (isc_commandline_index >= argc ||
		    *(place = argv[isc_commandline_index]) != '-')
		{
			/*
			 * Index out of range or points to non-option.
			 */
			place = ENDOPT;
			return -1;
		}

		if (place[1] != '\0' && *++place == '-' && place[1] == '\0') {
			/*
			 * Found '--' to signal end of options.  Advance
			 * index to next argv, the first non-option.
			 */
			isc_commandline_index++;
			place = ENDOPT;
			return -1;
		}
	}

	isc_commandline_option = *place++;
	option = strchr(options, isc_commandline_option);

	/*
	 * Ensure valid option has been passed as specified by options string.
	 * '-:' is never a valid command line option because it could not
	 * distinguish ':' from the argument specifier in the options string.
	 */
	if (isc_commandline_option == ':' || option == NULL) {
		if (*place == '\0') {
			isc_commandline_index++;
		}

		if (isc_commandline_errprint && *options != ':') {
			fprintf(stderr, "%s: illegal option -- %c\n",
				isc_commandline_progname,
				isc_commandline_option);
		}

		return BADOPT;
	}

	if (*++option != ':') {
		/*
		 * Option does not take an argument.
		 */
		isc_commandline_argument = NULL;

		/*
		 * Skip to next argv if at the end of the current argv.
		 */
		if (*place == '\0') {
			++isc_commandline_index;
		}
	} else {
		/*
		 * Option needs an argument.
		 */
		if (*place != '\0') {
			/*
			 * Option is in this argv, -D1 style.
			 */
			isc_commandline_argument = place;
		} else if (argc > ++isc_commandline_index) {
			/*
			 * Option is next argv, -D 1 style.
			 */
			isc_commandline_argument = argv[isc_commandline_index];
		} else {
			/*
			 * Argument needed, but no more argv.
			 */
			place = ENDOPT;

			/*
			 * Silent failure with "missing argument" return
			 * when ':' starts options string, per historical spec.
			 */
			if (*options == ':') {
				return BADARG;
			}

			if (isc_commandline_errprint) {
				fprintf(stderr,
					"%s: option requires an argument -- "
					"%c\n",
					isc_commandline_progname,
					isc_commandline_option);
			}

			return BADOPT;
		}

		place = ENDOPT;

		/*
		 * Point to argv that follows argument.
		 */
		isc_commandline_index++;
	}

	return isc_commandline_option;
}

isc_result_t
isc_commandline_strtoargv(isc_mem_t *mctx, char *s, unsigned int *argcp,
			  char ***argvp, unsigned int n) {
	isc_result_t result;

restart:
	/* Discard leading whitespace. */
	while (*s == ' ' || *s == '\t') {
		s++;
	}

	if (*s == '\0') {
		/* We have reached the end of the string. */
		*argcp = n;
		*argvp = isc_mem_cget(mctx, n, sizeof(char *));
	} else {
		char *p = s;
		while (*p != ' ' && *p != '\t' && *p != '\0' && *p != '{') {
			if (*p == '\n') {
				*p = ' ';
				goto restart;
			}
			p++;
		}

		/* do "grouping", items between { and } are one arg */
		if (*p == '{') {
			char *t = p;
			/*
			 * shift all characters to left by 1 to get rid of '{'
			 */
			while (*t != '\0') {
				t++;
				*(t - 1) = *t;
			}
			while (*p != '\0' && *p != '}') {
				p++;
			}
			/* get rid of '}' character */
			if (*p == '}') {
				*p = '\0';
				p++;
			}
			/* normal case, no "grouping" */
		} else if (*p != '\0') {
			*p++ = '\0';
		}

		result = isc_commandline_strtoargv(mctx, p, argcp, argvp,
						   n + 1);
		if (result != ISC_R_SUCCESS) {
			return result;
		}
		(*argvp)[n] = s;
	}

	return ISC_R_SUCCESS;
}
