<?php
	/**
	 * Elgg groups plugin
	 * 
	 * @package ElggGroups
	 * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2
	 * @author Curverider Ltd
	 * @copyright Curverider Ltd 2008
	 * @link http://elgg.com/
	 */

	/**
	 * Initialise the groups plugin.
	 * Register actions, set up menus
	 */
	function groups_init()
	{
    	
    	global $CONFIG;
		
		// Set up the menu for logged in users
		if (isloggedin()) 
		{
			add_menu(elgg_echo('groups'), $CONFIG->wwwroot . "pg/groups/member/" . $_SESSION['user']->username,'groups');
			add_menu(elgg_echo('groups:alldiscussion'),$CONFIG->wwwroot."mod/groups/discussions.php");
		}
		else
		{
			add_menu(elgg_echo('groups'), $CONFIG->wwwroot . "pg/groups/world/");
		}
		
		// Register a page handler, so we can have nice URLs
		register_page_handler('groups','groups_page_handler');
		
		// Register a URL handler for groups
		register_entity_url_handler('groups_url','group','all');
		
		// Register an icon handler for groups
		register_page_handler('groupicon','groups_icon_handler');
		
		// Register some actions
		register_action("groups/edit",false, $CONFIG->pluginspath . "groups/actions/edit.php");
		register_action("groups/join",false, $CONFIG->pluginspath . "groups/actions/join.php");
		register_action("groups/leave",false, $CONFIG->pluginspath . "groups/actions/leave.php");
		register_action("groups/joinrequest",false, $CONFIG->pluginspath . "groups/actions/joinrequest.php");
		
		register_action("groups/addtogroup",false, $CONFIG->pluginspath . "groups/actions/addtogroup.php");
		
		// Use group widgets
		use_widgets('groups');
		
		// Add a page owner handler
		add_page_owner_handler('groups_page_owner_handler');
		
		// Add some widgets
		//add_widget_type('group_members_widget',elgg_echo('groups:widgets:members:title'), elgg_echo('groups:widgets:members:description'), 'groups');
		//add_widget_type('group_entities_widget',elgg_echo('groups:widgets:entities:title'), elgg_echo('groups:widgets:entities:description'), 'groups');
		add_widget_type('a_users_groups',elgg_echo('groups:widget:membership'), elgg_echo('groups:widgets:description'), 'profile');
		
		
		//extend some views
		extend_view('profile/icon','groups/icon');
		extend_view('css','groups/css');
		
		// Write access permissions
		register_plugin_hook('access:collections:write', 'all', 'groups_write_acl_plugin_hook');
		
		// For now, we'll hard code the groups profile items as follows:
		// TODO make this user configurable
		
		// Language short codes must be of the form "groups:key"
		// where key is the array key below
		/*$CONFIG->group = array(
		
			'name' => 'text',
			'description' => 'longtext',
			'briefdescription' => 'text',
			'interests' => 'tags',
			'website' => 'url',
							   
		);*/
		
		// Now override icons
		register_plugin_hook('entity:icon:url', 'group', 'groups_groupicon_hook');
	}
	
	/**
	 * This function loads a set of default fields into the profile, then triggers a hook letting other plugins to edit
	 * add and delete fields.
	 *
	 * Note: This is a secondary system:init call and is run at a super low priority to guarantee that it is called after all
	 * other plugins have initialised.
	 */
	function groups_fields_setup()
	{
		global $CONFIG;
		
		$profile_defaults = array(
		
			'name' => 'text',
			'description' => 'longtext',
			'briefdescription' => 'text',
			'interests' => 'tags',
			'website' => 'url',
							   
		);
		
		$CONFIG->group = trigger_plugin_hook('profile:fields', 'group', NULL, $profile_defaults);
	}
	
	/**
	 * Sets up submenus for the groups system.  Triggered on pagesetup.
	 *
	 */
	function groups_submenus() {
		
		global $CONFIG;
		
		// Get the page owner entity
			$page_owner = page_owner_entity();
		
		// Submenu items for all group pages
			if ($page_owner instanceof ElggGroup && get_context() == 'groups') {
				if (isloggedin()) {
					if ($page_owner->canEdit()) {
						add_submenu_item(elgg_echo('groups:edit'),$CONFIG->wwwroot . "mod/groups/edit.php?group_guid=" . $page_owner->getGUID(), '1groupsactions');
						add_submenu_item(elgg_echo('groups:invite'),$CONFIG->wwwroot . "mod/groups/invite.php?group_guid={$page_owner->getGUID()}", '1groupsactions');
					}
					if ($page_owner->isMember($_SESSION['user'])) {
						add_submenu_item(elgg_echo('groups:leave'), $CONFIG->wwwroot . "action/groups/leave?group_guid=" . $page_owner->getGUID(), '1groupsactions');
					} else {
						if ($page_owner->isPublicMembership())
						{
							add_submenu_item(elgg_echo('groups:join'),$CONFIG->wwwroot . "action/groups/join?group_guid={$page_owner->getGUID()}", '1groupsactions');		
						}
						else
						{
							add_submenu_item(elgg_echo('groups:joinrequest'),$CONFIG->wwwroot . "action/groups/joinrequest?group_guid={$page_owner->getGUID()}", '1groupsactions');		
						}
					}
				}
				
				add_submenu_item(elgg_echo('groups:forum'),$CONFIG->wwwroot . "pg/groups/forum/{$page_owner->getGUID()}/", '1groupslinks');		
					
			}
		
		// Add submenu options
			if (get_context() == 'groups' && !($page_owner instanceof ElggGroup)) {
				if (isloggedin()) {
					add_submenu_item(elgg_echo('groups:new'), $CONFIG->wwwroot."pg/groups/new/", '1groupslinks');
					add_submenu_item(elgg_echo('groups:owned'), $CONFIG->wwwroot . "pg/groups/owned/" . $_SESSION['user']->username, '1groupslinks');
					add_submenu_item(elgg_echo('groups:yours'), $CONFIG->wwwroot . "pg/groups/member/" . $_SESSION['user']->username, '1groupslinks');
				}
				add_submenu_item(elgg_echo('groups:all'), $CONFIG->wwwroot . "pg/groups/world/", '1groupslinks');
			}
		
	}
	
	/**
	 * Set a page owner handler.
	 *
	 */
	function groups_page_owner_handler()
	{
		$group_guid = get_input('group_guid');
		if ($group_guid)
		{
			$group = get_entity($group_guid);
			if ($group instanceof ElggGroup)
				return $group->owner_guid;
		}
		
		return false;
	}
	
	/**
	 * Group page handler
	 *
	 * @param array $page Array of page elements, forwarded by the page handling mechanism
	 */
	function groups_page_handler($page) 
	{
		global $CONFIG;
		
		
		if (isset($page[0]))
		{
			// See what context we're using
			switch($page[0])
			{
				case "new" :
					include($CONFIG->pluginspath . "groups/new.php");
          		break;
    			case "world":  
					set_context('groups');
					set_page_owner(0);
   					include($CONFIG->pluginspath . "groups/all.php");
          		break;
          		case "forum":
          		    set_input('group_guid', $page[1]);
   					include($CONFIG->pluginspath . "groups/forum.php");	
          		break;
    			case "owned" :
    				// Owned by a user
    				if (isset($page[1]))
    					set_input('username',$page[1]);
    					
    				include($CONFIG->pluginspath . "groups/index.php");	
    			break;
    			case "member" :
    				// User is a member of
    				if (isset($page[1]))
    					set_input('username',$page[1]);
    					
    				include($CONFIG->pluginspath . "groups/membership.php");	
    			break;    				
    			default:
    				set_input('group_guid', $page[0]);
    				include($CONFIG->pluginspath . "groups/groupprofile.php");
    			break;
			}
		}
		
	}
	
	/**
	 * Handle group icons.
	 *
	 * @param unknown_type $page
	 */
	function groups_icon_handler($page) {
			
		global $CONFIG;
		
		// The username should be the file we're getting
		if (isset($page[0])) {
			set_input('group_guid',$page[0]);
		}
		if (isset($page[1])) {
			set_input('size',$page[1]);
		}
		// Include the standard profile index
		include($CONFIG->pluginspath . "groups/graphics/icon.php");
		
	}
	
	/**
	 * Populates the ->getUrl() method for group objects
	 *
	 * @param ElggEntity $entity File entity
	 * @return string File URL
	 */
	function groups_url($entity) {
		
		global $CONFIG;
		
		$title = friendly_title($entity->name);
		
		return $CONFIG->url . "pg/groups/{$entity->guid}/$title/";
		
	}
	
	/**
	 * Groups created, so add users to access lists.
	 */
	function groups_create_event_listener($event, $object_type, $object)
	{
		//if (($event == 'create') && ($object_type == 'group') && ($object instanceof ElggGroup))
		//{
			$group_id = create_access_collection(elgg_echo('groups:group') . ": " . $object->name);
			if ($group_id)
			{
				 $object->group_acl = $group_id;
			}
			else
				return false;
		//}
		
		return true;
	}
	
	/**
	 * Hook to listen to read access control requests and return all the groups you are a member of.
	 */
	function groups_read_acl_plugin_hook($hook, $entity_type, $returnvalue, $params)
	{
		
		//error_log("READ: " . var_export($returnvalue));
		$user = $_SESSION['user'];
		if ($user)
		{
			$membership = get_users_membership($user->guid);
			
			if ($membership)
			{					
				foreach ($membership as $group)
					$returnvalue[$user->guid][$group->group_acl] = elgg_echo('groups:group') . ": " . $group->name; 
				return $returnvalue;
			}
		}
	}
	
	/**
	 * Return the write access for the current group if the user has write access to it.
	 */
	function groups_write_acl_plugin_hook($hook, $entity_type, $returnvalue, $params)
	{
		$page_owner = page_owner_entity();
		
		if ($page_owner instanceof ElggGroup)
		{
			if (can_write_to_container())
			{
				$returnvalue[$page_owner->group_acl] = elgg_echo('groups:group') . ": " . $page_owner->name;
			
				return $returnvalue;
			}
		}
	}
	
	/**
	 * Groups deleted, so remove access lists.
	 */
	function groups_delete_event_listener($event, $object_type, $object)
	{
		delete_access_collection($object->access_id);
		
		return true;
	}
	
	/**
	 * Listens to a group join event and adds a user to the group's access control
	 *
	 */
	function groups_user_join_event_listener($event, $object_type, $object) {
		
		$group = $object['group'];
		$user = $object['user'];
		$acl = $group->group_acl;

		add_user_to_access_collection($user->guid, $acl);
		
		return true;
		
	}
	
	/**
	 * Listens to a group leave event and removes a user from the group's access control
	 *
	 */
	function groups_user_leave_event_listener($event, $object_type, $object) {
		
		$group = $object['group'];
		$user = $object['user'];
		$acl = $group->group_acl;

		remove_user_from_access_collection($user->guid, $acl);
		
		return true;
		
	}

	/**
	 * This hooks into the getIcon API and provides nice user icons for users where possible.
	 *
	 * @param unknown_type $hook
	 * @param unknown_type $entity_type
	 * @param unknown_type $returnvalue
	 * @param unknown_type $params
	 * @return unknown
	 */
	function groups_groupicon_hook($hook, $entity_type, $returnvalue, $params)
	{
		global $CONFIG;
		
		if ((!$returnvalue) && ($hook == 'entity:icon:url') && ($params['entity'] instanceof ElggGroup))
		{
			$entity = $params['entity'];
			$type = $entity->type;
			$viewtype = $params['viewtype'];
			$size = $params['size'];
			
			if ($icontime = $entity->icontime) {
				$icontime = "{$icontime}";
			} else {
				$icontime = "default";
			}
			
			$filehandler = new ElggFile();
			$filehandler->owner_guid = $entity->owner_guid;
			$filehandler->setFilename("groups/" . $entity->guid . $size . ".jpg");
			
			if ($filehandler->exists()) {
				$url = $CONFIG->url . "pg/groupicon/{$entity->guid}/$size/$icontime.jpg";
			
				return $url;
			}
		}
	}
	
	// Register a handler for create groups
	register_elgg_event_handler('create', 'group', 'groups_create_event_listener');

	// Register a handler for delete groups
	register_elgg_event_handler('delete', 'group', 'groups_delete_event_listener');
	
	// Make sure the groups initialisation function is called on initialisation
	register_elgg_event_handler('init','system','groups_init');
	register_elgg_event_handler('init','system','groups_fields_setup', 10000); // Ensure this runs after other plugins
	register_elgg_event_handler('join','group','groups_user_join_event_listener');
	register_elgg_event_handler('leave','group','groups_user_leave_event_listener');
	register_elgg_event_handler('pagesetup','system','groups_submenus');
	
	// Register actions
    global $CONFIG;
	register_action("groups/addtopic",false,$CONFIG->pluginspath . "groups/actions/forums/addtopic.php");
	register_action("groups/deletetopic",false,$CONFIG->pluginspath . "groups/actions/forums/deletetopic.php");
	register_action("groups/addpost",false,$CONFIG->pluginspath . "groups/actions/forums/addpost.php");
	register_action("groups/edittopic",false,$CONFIG->pluginspath . "groups/actions/forums/edittopic.php");
	register_action("groups/deletepost",false,$CONFIG->pluginspath . "groups/actions/forums/deletepost.php");
	
?>