<?php
	/**************************************************************************\
	* phpGroupWare API - Hooks                                                 *
	* This file written by Dan Kuykendall <seek3r@phpgroupware.org>            *
	* Allows applications to "hook" into each other                            *
	* Copyright (C) 2000 - 2002 Dan Kuykendall                                 *
	* ------------------------------------------------------------------------ *
	* This library is part of the phpGroupWare API                             *
	* http://www.phpgroupware.org/api                                          * 
	* ------------------------------------------------------------------------ *
	* This library is free software; you can redistribute it and/or modify it  *
	* under the terms of the GNU Lesser General Public License as published by *
	* the Free Software Foundation; either version 2.1 of the License,         *
	* or any later version.                                                    *
	* This library 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 Lesser General Public License for more details.              *
	* You should have received a copy of the GNU Lesser General Public License *
	* along with this library; if not, write to the Free Software Foundation,  *
	* Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA            *
	\**************************************************************************/
	/* $Id$ */

	/*!
	@class hooks
	@abstract  class which gives ability for applications to set and use hooks to communicate with each other
	@author    Dan Kuykendall
	@copyright LGPL
	@package   phpgwapi
	@access    public
	*/

	class hooks
	{
		var $found_hooks = Array();
		var $db = '';

		function hooks($db='')
		{
			$this->db = $db ? $db : $GLOBALS['phpgw']->db;	// this is to allow setup to set the db

			$this->db->query("SELECT hook_appname, hook_location, hook_filename FROM phpgw_hooks",__LINE__,__FILE__);
			while( $this->db->next_record() )
			{
				$this->found_hooks[$this->db->f('hook_appname')][$this->db->f('hook_location')] = $this->db->f('hook_filename');
			}
			//echo '<pre>';
			//print_r($this->found_hooks);
			//echo '</pre>';
		}

		/*!
		@function process
		@abstract executes all the hooks (the user has rights to) for a given location 
		@syntax process($args,$order='',$no_permission_check = False)
		@param $args location-name as string or array:
		@param $args['location'] location-name
		@param $order or $args['order'] array of appnames (as value), which should be executes first
		@param $args is passed to the hook, if its a new method-hook
		@param $no_permission_check if True execute all hooks, not only the ones a user has rights to
		@note $no_permission_check should *ONLY* be used when it *HAS* to be. (jengo)
		@returns array with results of each hook call (with appname as key): \
			False if no hook exists, True if old hook exists \
			and whatever the new methode-hook returns (can be True or False too!).
		*/
		function process($args, $order = '', $no_permission_check = False)
		{
			//echo "<p>hooks::process("; print_r($args); echo ")</p>\n";
			if ($order == '')
			{
				$order = is_array($args) && isset($args['order']) ? $args['order'] : 
					array($GLOBALS['phpgw_info']['flags']['currentapp']);
			}

			/* First include the ordered apps hook file */
			foreach($order as $appname)
			{
				$results[$appname] = $this->single($args,$appname,$no_permission_check);

				if (!isset($results[$appname]))	// happens if the methode hook has no return-value
				{
					$results[$appname] = False;
				}
			}

			/* Then add the rest */
			if ($no_permission_check)
			{
				$apps = $GLOBALS['phpgw_info']['apps'];
			}
			else
			{
				$apps = $GLOBALS['phpgw_info']['user']['apps'];
			}
			foreach($apps as $app)
			{
				$appname = $app['name'];
				if (!isset($results[$appname]))
				{
					$results[$appname] = $this->single($args,$appname,$no_permission_check);
				}
			}
			return $results;
		}

		/*!
		@function single
		@abstract executes a single hook of a given location and application
		@syntax single($args,$appname='',$no_permission_check = False)
		@param $args location-name as string or array:
		@param $args['location'] location-name
		@param $appname or $args['appname'] name of the app, which's hook to execute, if empty the current app is used
		@param $args is passed to the hook, if its a new method-hook
		@param $no_permission_check if True execute all hooks, not only the ones a user has rights to
		@param $try_unregisterd If true, try to include old file-hook anyway (for setup)
		@note $no_permission_check should *ONLY* be used when it *HAS* to be. (jengo)
		@returns False if no hook exists, True if an old hook exist and whatever the new method-hook returns
		*/
		function single($args, $appname = '', $no_permission_check = False,$try_unregistered = False)
		{
			//echo "<p>hooks::single("; print_r($args); echo ",'$appname','$no_permission_check','$try_unregistered')</p>\n";
			if (is_array($args))
			{
				$location = $args['location'];
			}
			else
			{
				$location = $args;
			}
			if (!$appname)
			{
				$appname = is_array($args) && isset($args['appname']) ? $args['appname'] : $GLOBALS['phpgw_info']['flags']['currentapp'];
			}

			/* First include the ordered apps hook file */
			if (isset($this->found_hooks[$appname][$location]) || $try_unregistered)
			{
				$parts = explode('.',$method = $this->found_hooks[$appname][$location]);
				
				if (count($parts) != 3 || ($parts[1] == 'inc' && $parts[2] == 'php'))
				{
					if ($try_unregistered && empty($methode))
					{
						$method = 'hook_'.$location.'.inc.php';
					}
					$f = PHPGW_SERVER_ROOT . SEP . $appname . SEP . 'inc' . SEP . $method;
					if (file_exists($f) &&
						( $GLOBALS['phpgw_info']['user']['apps'][$appname] || (($no_permission_check || $location == 'config' || $appname == 'phpgwapi') && $appname)) )
					{
						include($f);
						return True;
					}
					else
					{
						return False;
					}
				}
				else	// new style method-hook
				{
					return ExecMethod($method,$args);
				}
			}
			else
			{
				return False;
			}
		}

		/*!
		@function count
		@abstract loop through the applications and count the hooks
		*/
		function count($location)
		{
			$count = 0;
			foreach($GLOBALS['phpgw_info']['user']['apps'] as $appname => $data)
			{
				if (isset($this->found_hooks[$appname][$location]))
				{
					++$count;
				}
			}
			return $count;
		}
		
		/*! 
		@function read()
		@abstract currently not being used
		*/
		function read()
		{
			//if (!is_array($this->found_hooks))
			//{
				$this->hooks();
			//}
			return $this->found_hooks;
		}

		/*!
		@function register_hooks
		@abstract Register and/or de-register an application's hooks
		@syntax register_hooks($appname,$hooks='')
		@param $appname	Application 'name' 
		@param $hooks array with hooks to register, eg $setup_info[$app]['hooks'] or not used for only deregister the hooks
		*/
		function register_hooks($appname,$hooks='')
		{
			if(!$appname)
			{
				return False;
			}
			$db_appname = $this->db->db_addslashes($appname);
			$this->db->query("DELETE FROM phpgw_hooks WHERE hook_appname='$db_appname'",__LINE__,__FILE__);

			if (!is_array($hooks))	// only deregister
			{
				return True;
			}
			//echo "<p>ADDING hooks for: $appname</p>";
			foreach($hooks as $key => $hook)
			{
				if (!is_numeric($key))	// new methode-hook
				{
					$location = $key;
					$filename = $hook;
				}
				else
				{
					$location = $hook;
					$filename = "hook_$hook.inc.php";
				}
				$this->db->query("INSERT INTO phpgw_hooks (hook_appname,hook_location,hook_filename)".
					" VALUES ('$appname','$location','$filename');");
			}
			return True;
		}

		
		/*!
		@function register_all_hooks
		@abstract Register the hooks of all applications (used by admin)
		*/
		function register_all_hooks()
		{
			foreach($GLOBALS['phpgw_info']['apps'] as $appname => $app)
			{			
				$f = PHPGW_SERVER_ROOT . SEP . $appname . SEP . 'setup' . SEP . 'setup.inc.php';
				if(@file_exists($f))
				{
					include($f);
					$this->register_hooks($appname,$setup_info[$appname]['hooks']);
				}
			}
		}
	}
?>