/** \file browserhelp.c
 * use the default browser based help
 */

/*  XTrkCad - Model Railroad CAD
 *  Copyright (C) 2015 Martin Fischer
 *
 *  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 <stdlib.h>
#include <assert.h>
#include <string.h>
#include <limits.h>

//#include "misc.h"

#include "gtkint.h"
#include "i18n.h"

extern wBool_t CheckHelpTopicExists(const char * topic);

#include "dynstring.h"

#define debug 0

#define DEFAULTBROWSERCOMMAND "xdg-open"

#define  HELPERRORTEXT 			"Help Error - help information can not be found.\n" \
								"The help information you requested cannot be shown.\n" \
								"Usually this is an installation problem, Make sure that a default browser" \
                                " is configured and that XTrackCAD and the included " \
								"HTML files are installed properly and can be found via the XTRKCADLIB environment " \
								"variable.\n Also make sure that the user has sufficient access rights to read these" \
 								"files."
/**
 * Create a fully qualified url from a topic. The library path is converted to
 * an absolute path first. The url is then created from that path.
 *
 * \param helpUrl OUT pointer to url, free by caller
 * \param topic IN the help topic
 */

static void
TopicToUrl(char **helpUrl, const char *topic)
{
	DynString url;
	DynStringMalloc(&url, 16);
	char *realPath;

	realPath = realpath(wGetAppLibDir(), NULL);

	if(realPath) {
		// build up the url line
		DynStringCatCStrs(&url,
		                  "file://",
		                  realPath,
		                  "/html/",
		                  topic,
		                  ".html",
		                  NULL);

		*helpUrl = strdup(DynStringToCStr(&url));
		DynStringFree(&url);
		free(realPath);
	} else {
		wNoticeEx( NT_ERROR, _("Not enough memory for realpath()"), _("Exit"), NULL);
		wExit(0);
	}
}
/**
 * Invoke the system's default browser to display help for <topic>. First the
 * system's standard xdg-open command is attempted. If that is not available, the
 * version included with the XTrackCAD installation is executed.
 *
 * \param topic IN topic string
 */

void wHelp(const char * topic)
{
	int rc;
	char *url;
//    char *currentPath;

	assert(topic != NULL);
	assert(strlen(topic));

	if (!CheckHelpTopicExists(topic)) { return; }

	TopicToUrl(&url, topic);
	printf(">%s<\n", url);
	rc = wOpenFileExternal(url);

	if (!rc) {
		wNotice(HELPERRORTEXT, _("Cancel"), NULL);
	}

	free(url);
}