/* urlparser1.c */

/*

 * MIT License

 *

 * Copyright (c) 2024 Roland Mainz <roland.mainz@nrubsig.org>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in all

 * copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 */

/* urlparser1.c - simple URL parser */

#include <stdlib.h>

#include <stdbool.h>

#include <string.h>

#include <stdio.h>

#include "urlparser1.h"

/*

 * Original extended regular expression:

 *

 * "^"

 * "(.+?)"			 // scheme

 * "://"  			 // '://'

 * "("				 // login

 * 	 "(?:"

 * 		 "(.+?)"	 // user (optional)

 * 		 "(?::(.+))?"	 // password (optional)

 * 		 "@"

 * 	 ")?"

 * 	 "("			 // hostport

 * 		 "(.+?)"	 // host

 * 		 "(?::([[:digit:]]+))?" // port (optional)

 * 	 ")"

 * ")"

 * "(?:/(.*?))?"  		 // path (optional)

 * "$"

 */

#define DBGNULLSTR(s) (((s)!=NULL)?(s):"<NULL>")

#if 1

#define D(x) x

#else

#define D(x)

#endif

url_parser_context *url_parser_create_context(const char *in_url, unsigned int flags)

{

	url_parser_context *uctx;

	char *s;

	size_t in_url_len;

	size_t context_len;

	if (!in_url)

		return NULL;

	in_url_len = strlen(in_url);

	context_len = sizeof(url_parser_context) +

		((in_url_len+1)*5);

	uctx = malloc(context_len);

	if (!uctx)

		return NULL;

	s = (void *)(uctx+1);

	uctx->in_url = s;		s+= in_url_len+1;

	(void)strcpy(uctx->in_url, in_url);

	uctx->scheme = s;		s+= in_url_len+1;

	uctx->login.username = s;	s+= in_url_len+1;

	uctx->hostport.hostname = s;	s+= in_url_len+1;

	uctx->path = s;			s+= in_url_len+1;

	uctx->hostport.port = -1;

	return uctx;

}

int url_parser_parse(url_parser_context *uctx)

{

	D((void)fprintf(stderr, "## parser in_url='%s'\n", uctx->in_url));

	char *s;

	const char *urlstr = uctx->in_url;

	size_t slen;

	s = strstr(urlstr, "://");

	if (!s) {

		D((void)fprintf(stderr, "url_parser: Not an URL\n"));

		return -1;

	}

	slen = s-urlstr;

	(void)memcpy(uctx->scheme, urlstr, slen*sizeof(char));

	uctx->scheme[slen] = '\0';

	urlstr += slen + 3;

	D((void)fprintf(stdout, "scheme='%s', rest='%s'\n", uctx->scheme, urlstr));

	s = strstr(urlstr, "@");

	if (s) {

		/* URL has user/password */

		slen = s-urlstr;

		(void)memcpy(uctx->login.username, urlstr, slen*sizeof(char));

		uctx->login.username[slen] = '\0';

		urlstr += slen + 1;

		s = strstr(uctx->login.username, ":");

		if (s) {

			/* found passwd */

			uctx->login.passwd = s+1;

			*s = '\0';

		}

		else

		{

			uctx->login.passwd = NULL;

		}

		/* catch password-only URLs */

		if (uctx->login.username[0] == '\0')

			uctx->login.username = NULL;

	}

	else

	{

		uctx->login.username = NULL;

		uctx->login.passwd = NULL;

	}

	D((void)fprintf(stdout, "login='%s', passwd='%s', rest='%s'\n",

		DBGNULLSTR(uctx->login.username),

		DBGNULLSTR(uctx->login.passwd),

		DBGNULLSTR(urlstr)));

	s = strstr(urlstr, "/");

	if (s) {

		/* URL has hostport */

		slen = s-urlstr;

		(void)memcpy(uctx->hostport.hostname, urlstr, slen*sizeof(char));

		uctx->hostport.hostname[slen] = '\0';

		urlstr += slen;

		s = strstr(uctx->hostport.hostname, ":");

		if (s) {

			/* found port number */

			uctx->hostport.port = atoi(s+1);

			*s = '\0';

		}

	}

	else

	{

		(void)strcpy(uctx->hostport.hostname, urlstr);

		uctx->path = NULL;

		urlstr = NULL;

	}

	D((void)fprintf(stdout, "hostport='%s', port=%d, rest='%s'\n",

		DBGNULLSTR(uctx->hostport.hostname),

		uctx->hostport.port,

		DBGNULLSTR(urlstr)));

	if (!urlstr) {

		return 0;

	}

	(void)strcpy(uctx->path, urlstr);

	D((void)fprintf(stdout, "path='%s'\n", uctx->path));

	return 0;

}

void url_parser_free_context(url_parser_context *c)

{

	free(c);

}

void test_url_parser(const char *instr)

{

	url_parser_context *c;

	c = url_parser_create_context(instr, 0);

	(void)url_parser_parse(c);

	(void)fputc('\n', stdout);

	url_parser_free_context(c);

}

int main(int ac, char *av[])

{

	(void)puts("#start");

	(void)setvbuf(stdout, NULL, _IONBF, 0);

	(void)setvbuf(stderr, NULL, _IONBF, 0);

	(void)test_url_parser("foo://hostbar/baz");

	(void)test_url_parser("foo://myuser@hostbar/baz");

	(void)test_url_parser("foo://myuser:mypasswd@hostbar/baz");

	(void)test_url_parser("foo://myuser:mypasswd@hostbar:666/baz");

	(void)test_url_parser("foo://:mypasswd2@hostbar2:667/baf");

	(void)test_url_parser("foo://hostbar");

	(void)test_url_parser("foo://hostbar:93");

	(void)test_url_parser("foo://");

	(void)test_url_parser("typo:/hostbar");

	(void)test_url_parser("wrong");

	(void)puts("#done");

	return EXIT_SUCCESS;

}

/* urlparser1.h */