/*

  * Copyright (C) 2014  J. Ali Harlow <ali@juiblex.co.uk>

  *

  * 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.,

  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

  */

 #include "config.h"

 #include <stdlib.h>

 #include <string.h>

 #include "razor.h"

 #include "razor-internal.h"

 /**

  * razor_path_add_root:

  *

  * Adds a root to a path. path must be an absolute pathname. In POSIX

  * environments this is equivalent to the concationation of root and path.

  * In Microsoft Windows an adjustment may need to be made for a drive letter

  * in path (which will be dropped).

  *

  * Returns: The new pathname.

  **/

 RAZOR_EXPORT char *razor_path_add_root(const char *path, const char *root)

 {

 	if (root && *root)

 		return razor_concat(root, SKIP_DRIVE_LETTER(path), NULL);

 	else

 		return strdup(path);

 }

 #if 0

 /*

  * This should work, but for some reason PathCreateFromUrlW()

  * treats the percent-encoded bytes as being in CP 850 rather

  * than UTF-8 as expected even if we set the codepage.

  */

 RAZOR_EXPORT char *razor_path_from_url(const char *url)

 {

 	UINT saved_cp;

 	HRESULT result;

 	DWORD len = MAX_PATH;

 	wchar_t *url16;

 	wchar_t path16[MAX_PATH];

 	char *path;

 	url16 = razor_utf8_to_utf16(url, -1);

 	saved_cp = GetConsoleCP();

 	SetConsoleCP(CP_UTF8);

 	result = PathCreateFromUrlW(url16, path16, &len, NULL);

 	SetConsoleCP(saved_cp);

 	if (result == S_OK)

 		path = razor_utf16_to_utf8(path16, len);

 	else

 		path = NULL;

 	free(url16);

 	return path;

 }

 #else

 #ifdef MSWIN_API

 static int is_ascii_letter(char c)

 {

 	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');

 }

 #endif

 static int xdigit_value(char c)

 {

 	if (c >= '0' && c <= '9')

 		return c - '0';

 	else

 		return (c | 0x20) - 'a' + 10;

 }

 static int valid_unicode(unsigned unicode)

 {

 	/*

 	 * Within the U+0000..U+10FFFF range defined by RFC3629

 	 * but not in the U+D800..U+DFFF range prohibited in UTF-8.

 	 */

 	return unicode < 0xD800 || (unicode >= 0xE000 && unicode < 0x110000);

 }

 RAZOR_EXPORT char *razor_path_from_url(const char *url)

 {

 	int continuation_bytes = 0;

 	char *path, *p;

 	unsigned char c;

 	unsigned unicode;

 	if (strncmp(url, "file://", 7) == 0)

 		url += 7;

 	else

 		return NULL;

 	if (strncmp(url, "localhost/", 10) == 0)

 		url += 9;

 	else if (strncmp(url, "/", 1) != 0)

 		return NULL;

 #ifdef MSWIN_API

 	/*

 	 * Under MS-Windows, file:///c:/xxx maps to c:/xxx

 	 * Note that PathCreateFromUrl converts / to \ as well.

 	 */

 	if (is_ascii_letter(url[1]) && url[2] == ':' && url[3] == '/')

 		url++;

 #endif

 	p = path = malloc(strlen(url) + 1);

 	while(*url) {

 		if (*url >= 0x7F || *url < 0x20) {

 			free(path);

 			return NULL;

 		} else if (*url != '%') {

 			if (continuation_bytes) {

 				free(path);

 				return NULL;

 			} else

 				*p++ = *url++;

 		} else if (isxdigit(url[1]) && isxdigit(url[2])) {

 			c = xdigit_value(url[1]) * 16 + xdigit_value(url[2]);

 			if (c == '/') {

 				free(path);

 				return NULL;

 			} else if (!continuation_bytes) {

 				if (c >= 0xF5 || c == 0xC0 || c == 0xC1) {

 					free(path);

 					return NULL;

 				} else if (c >= 0xF0) {

 					unicode = c & 7;

 					continuation_bytes = 3;

 				} else if (c >= 0xE0) {

 					unicode = c & 3;

 					continuation_bytes = 2;

 				} else if (c >= 0xC0) {

 					unicode = c & 1;

 					continuation_bytes = 1;

 				}

 			} else if ((c & 0xC0) != 0x80) {

 				free(path);

 				return NULL;

 			} else {

 				unicode <<= 6;

 				unicode |= (c & 0x3F);

 				if (!--continuation_bytes &&

 				    !valid_unicode(unicode)) {

 					free(path);

 					return NULL;

 				}

 			}

 			*p++ = c;

 			url += 3;

 		} else {

 			free(path);

 			return NULL;

 		}

 	}

 	if (continuation_bytes) {

 		free(path);

 		return NULL;

 	}

 	*p++ = '\0';

 	return realloc(path, p - path);

 }

 #endif	/* 0 */