/*
 * This file is part of NetSurf, http://netsurf.sourceforge.net/
 * Licensed under the GNU General Public License,
 *		  http://www.opensource.org/licenses/gpl-license
 * Copyright 2004 Richard Wilson <not_ginger_matt@users.sourceforge.net>
 */

/** \file
 * Interactive help (implementation).
 */

#include <assert.h>
#include <stdio.h>
#include <string.h>
#include "oslib/help.h"
#include "oslib/os.h"
#include "oslib/taskmanager.h"
#include "oslib/wimp.h"
#include "nstheme/riscos/gui.h"
#include "nstheme/riscos/help.h"
#include "nstheme/riscos/wimp.h"
#include "nstheme/utils/messages.h"
#include "nstheme/utils/log.h"


/*	Recognised help keys
	====================

	HelpIconbar	 Iconbar (no icon suffix is used)

	HelpAppInfo	 Application info window
	HelpMain	 Main application window
	HelpSaveAs	 Save as window
	HelpWarning	 Warning window

	HelpIconMenu	 Iconbar menu
	HelpMainMenu	 Main application menu

	The prefixes are followed by either the icon number (eg 'HelpToolbar7'), or a series
	of numbers representing the menu structure (eg 'HelpBrowserMenu3-1-2').
	If '<key><identifier>' is not available, then simply '<key>' is then used. For example
	if 'HelpToolbar7' is not available then 'HelpToolbar' is then tried.

	If an item is greyed out then a suffix of 'g' is added (eg 'HelpToolbar7g'). For this to
	work, windows must have bit 4 of the window flag byte set and the user must be running
	RISC OS 5.03 or greater.
*/

static void ro_gui_interactive_help_broadcast(wimp_message *message, char *token);

/**
 * Attempts to process an interactive help message request
 *
 * \param  message the request message
 */
void ro_gui_interactive_help_request(wimp_message *message) {
	char message_token[32];
	char menu_buffer[4];
	wimp_selection menu_tree;
	help_full_message_request *message_data;
	wimp_w window;
	wimp_i icon;
	unsigned int index;
	bool greyed = false;
	wimp_menu *test_menu;

	/*	Ensure we have a help request
	*/
	if ((!message) || (message->action != message_HELP_REQUEST)) return;

	/*	Initialise the basic token to a null byte
	*/
	message_token[0] = 0x00;

	/*	Get the message data
	*/
	message_data = (help_full_message_request *)message;
	window = message_data->w;
	icon = message_data->i;

	/*	Do the basic window checks
	*/
	if (window == (wimp_w)-2) {
		sprintf(message_token, "HelpIconbar");
	} else if (window == dialog_info) {
		sprintf(message_token, "HelpAppInfo%i", (int)icon);
	} else if (window == dialog_main) {
		sprintf(message_token, "HelpMain%i", (int)icon);
	} else if (window == dialog_saveas) {
		sprintf(message_token, "HelpSaveAs%i", (int)icon);
	} else if (window == dialog_warning) {
		sprintf(message_token, "HelpWarning%i", (int)icon);
	}

	/*	If we've managed to find something so far then we broadcast it
	*/
	if (message_token[0] != 0x00) {
		/*	Check to see if we are greyed out
		*/
		if ((icon >= 0) && (ro_gui_get_icon_shaded_state(window, icon))) {
			strcat(message_token, "g");
		}

		/*	Broadcast out message
		*/
		ro_gui_interactive_help_broadcast(message, &message_token[0]);
		return;
	}

	/*	If we are not on an icon, we can't be in a menu (which stops separators
		giving help for their parent) so we abort. You don't even want to think
		about the awful hack I was considering before I realised this...
	*/
	if (icon == (wimp_i)-1) return;

	/*	As a last resort, check for menu help.
	*/
	if (xwimp_get_menu_state((wimp_menu_state_flags)1,
				&menu_tree,
				window, icon)) return;
	if (menu_tree.items[0] == -1) return;

	/*	Set the prefix
	*/
	if (current_menu == iconbar_menu) {
		sprintf(message_token, "HelpIconMenu");
	} else if (current_menu == main_menu) {
		sprintf(message_token, "HelpMainMenu");
	} else {
		return;
	}

	/*	Decode the menu
	*/
	index = 0;
	test_menu = current_menu;
	while (menu_tree.items[index] != -1) {
		/*	Check if we're greyed out
		*/
		greyed |= test_menu->entries[menu_tree.items[index]].icon_flags & wimp_ICON_SHADED;
		test_menu = test_menu->entries[menu_tree.items[index]].sub_menu;

		/*	Continue adding the entries
		*/
		if (index == 0) {
			sprintf(menu_buffer, "%i", menu_tree.items[index]);
		} else {
			sprintf(menu_buffer, "-%i", menu_tree.items[index]);
		}
		strcat(message_token, menu_buffer);
		index++;
	}
	if (greyed) strcat(message_token, "g");

	/*	Finally, broadcast the menu help
	*/
	ro_gui_interactive_help_broadcast(message, &message_token[0]);
}


/**
 * Broadcasts a help reply
 *
 * \param  message the original request message
 * \param  token the token to look up
 */
static void ro_gui_interactive_help_broadcast(wimp_message *message, char *token) {
	const char *translated_token;
	help_full_message_reply *reply;
	char *base_token;

	/*	Start off with an empty reply
	*/
	reply = (help_full_message_reply *)message;
	reply->reply[0] = '\0';

	/*	Check if the message exists
	*/
	translated_token = messages_get(token);
	if (translated_token == token) {
		/*	We must never provide default help for a 'g' suffix.
		*/
		if (token[strlen(token) - 1] != 'g') {
			/*	Find the key from the token.
			*/
			base_token = token;
			while (base_token[0] != 0x00) {
				if ((base_token[0] == '-') ||
						((base_token[0] >= '0') && (base_token[0] <= '9'))) {
					base_token[0] = 0x00;
				} else {
					++base_token;
				}
			}

			/*	Check if the base key exists and use an empty string if not
			*/
			translated_token = messages_get(token);
		}
	}


	/*	Copy our message string
	*/
	if (translated_token != token) {
		reply->reply[235] = 0;
		strncpy(reply->reply, translated_token, 235);
	}

	/*	Broadcast the help reply
	*/
	reply->size = 256;
	reply->action = message_HELP_REPLY;
	reply->your_ref = reply->my_ref;
	wimp_send_message(wimp_USER_MESSAGE, (wimp_message *)reply, reply->sender);
}