<?php
/**
 * Elgg groups plugin
 *
 * @package ElggGroups
 */

elgg_register_event_handler('init', 'system', 'groups_init');

// Ensure this runs after other plugins
elgg_register_event_handler('init', 'system', 'groups_fields_setup', 10000);

/**
 * Initialize the groups plugin.
 */
function groups_init() {

	elgg_register_library('elgg:groups', elgg_get_plugins_path() . 'groups/lib/groups.php');

	// register group entities for search
	register_entity_type('group', '');

	// Set up the menu
	$item = new ElggMenuItem('groups', elgg_echo('groups'), 'pg/groups/all');
	elgg_register_menu_item('site', $item);

	// 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
	$action_base = elgg_get_plugins_path() . 'groups/actions';
	elgg_register_action("groups/edit", "$action_base/edit.php");
	elgg_register_action("groups/delete", "$action_base/delete.php");
	elgg_register_action("groups/join", "$action_base/join.php");
	elgg_register_action("groups/leave", "$action_base/leave.php");
	elgg_register_action("groups/joinrequest", "$action_base/joinrequest.php");
	elgg_register_action("groups/killrequest", "$action_base/groupskillrequest.php");
	elgg_register_action("groups/killinvitation", "$action_base/groupskillinvitation.php");
	elgg_register_action("groups/addtogroup", "$action_base/addtogroup.php");
	elgg_register_action("groups/invite", "$action_base/invite.php");
	elgg_register_action("groups/featured", "$action_base/featured.php", 'admin');

	// Add a page owner handler
	//elgg_register_plugin_hook_handler('page_owner', 'system', 'groups_page_owner_handler');

	// Add some widgets
	elgg_register_widget_type('a_users_groups', elgg_echo('groups:widget:membership'), elgg_echo('groups:widgets:description'));

	// add group activity tool option
	add_group_tool_option('activity', elgg_echo('groups:enableactivity'), true);
	elgg_extend_view('groups/tool_latest', 'groups/profile/activity_module');

	// add link to owner block
	elgg_register_plugin_hook_handler('register', 'menu:owner_block', 'groups_activity_owner_block_menu');


	//extend some views
	elgg_extend_view('profile/icon', 'groups/icon');
	elgg_extend_view('css/screen', 'groups/css');

	// Access permissions
	elgg_register_plugin_hook_handler('access:collections:write', 'all', 'groups_write_acl_plugin_hook');
	//elgg_register_plugin_hook_handler('access:collections:read', 'all', 'groups_read_acl_plugin_hook');

	// Now override icons
	elgg_register_plugin_hook_handler('entity:icon:url', 'group', 'groups_groupicon_hook');

	// Register profile menu hook
	elgg_register_plugin_hook_handler('profile_menu', 'profile', 'forum_profile_menu');
	elgg_register_plugin_hook_handler('profile_menu', 'profile', 'activity_profile_menu');

	// allow ecml in discussion and profiles
	elgg_register_plugin_hook_handler('get_views', 'ecml', 'groups_ecml_views_hook');
	elgg_register_plugin_hook_handler('get_views', 'ecml', 'groupprofile_ecml_views_hook');

	// Register a handler for create groups
	elgg_register_event_handler('create', 'group', 'groups_create_event_listener');

	// Register a handler for delete groups
	elgg_register_event_handler('delete', 'group', 'groups_delete_event_listener');
	
	elgg_register_event_handler('join', 'group', 'groups_user_join_event_listener');
	elgg_register_event_handler('leave', 'group', 'groups_user_leave_event_listener');
	elgg_register_event_handler('pagesetup', 'system', 'groups_submenus');
	elgg_register_event_handler('annotate', 'all', 'group_object_notifications');
}

/**
 * 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 system:init event triggered function and is run at a super
 * low priority to guarantee that it is called after all other plugins have
 * initialized.
 */
function groups_fields_setup() {

	$profile_defaults = array(
		'description' => 'longtext',
		'briefdescription' => 'text',
		'interests' => 'tags',
		//'website' => 'url',
	);

	$profile_defaults = elgg_trigger_plugin_hook('profile:fields', 'group', NULL, $profile_defaults);

	elgg_set_config('group', $profile_defaults);

	// register any tag metadata names
	foreach ($profile_defaults as $name => $type) {
		if ($type == 'tags') {
			elgg_register_tag_metadata_name($name);

			// only shows up in search but why not just set this in en.php as doing it here
			// means you cannot override it in a plugin
			add_translation(get_current_language(), array("tag_names:$name" => elgg_echo("groups:$name")));
		}
	}
}

/**
 * Sets up submenus for the groups system.  Triggered on pagesetup.
 *
 */
function groups_submenus() {

	// Get the page owner entity
	$page_owner = elgg_get_page_owner_entity();

	if (elgg_get_context() == 'groups') {
		if ($page_owner instanceof ElggGroup) {
			if (isloggedin() && $page_owner->canEdit() && !$page_owner->isPublicMembership()) {
				$url = elgg_get_site_url() . "pg/groups/requests/{$page_owner->getGUID()}";
				add_submenu_item(elgg_echo('groups:membershiprequests'), $url, 'groupsactions1');
			}
		} else {
			add_submenu_item(elgg_echo('groups:all'), "pg/groups/world/", 'groupslinks1');

			if ($user = get_loggedin_user()) {
				add_submenu_item(elgg_echo('groups:owned'), "pg/groups/owned/$user->username", 'groupslinks1');
				add_submenu_item(elgg_echo('groups:yours'), "pg/groups/member/$user->username", 'groupslinks1');
				add_submenu_item(elgg_echo('groups:invitations'), "pg/groups/invitations/$user->username", 'groupslinks1');
			}
		}
	}
}

/**
 * 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;
}

/**
 * Groups page handler
 *
 * URLs take the form of
 *  All groups:           pg/groups/all
 *  User's owned groups:  pg/groups/owned/<username>
 *  User's member groups: pg/groups/member/<username>
 *  Group profile:        pg/groups/profile/<guid>/<title>
 *  New group:            pg/groups/add/<guid>
 *  Edit group:           pg/groups/edit/<guid>
 *  Group invitations:    pg/groups/invitations/<username>
 *  Invite to group:      pg/groups/invite/<guid>
 *  Membership requests:  pg/groups/requests/<guid>
 *  Group activity:       pg/groups/activity/<guid>
 *  Group members:        pg/groups/members/<guid>
 *
 * @param array $page Array of url segments for routing
 */
function groups_page_handler($page) {

	elgg_load_library('elgg:groups');

	elgg_push_breadcrumb(elgg_echo('groups'), "pg/groups/all");

	switch ($page[0]) {
		case 'all':
			groups_handle_all_page();
			break;
		case 'owned':
			set_input('username', $page[1]);
			groups_handle_owned_page();
			break;
		case 'member':
			set_input('username', $page[1]);
			groups_handle_mine_page();
			break;
		case 'invitations':
			set_input('username', $page[1]);
			groups_handle_invitations_page();
			break;
		case 'add':
			groups_handle_edit_page('add');
			break;
		case 'edit':
			groups_handle_edit_page('edit', $page[1]);
			break;
		case 'profile':
			groups_handle_profile_page($page[1]);
			break;
		case 'activity':
			groups_handle_activity_page($page[1]);
			break;
		case 'members':
			groups_handle_members_page($page[1]);
			break;
		case 'invite':
			groups_handle_invite_page($page[1]);
			break;
		case 'requests':
			groups_handle_requests_page($page[1]);
			break;
	}
}

/**
 * Handle group icons.
 *
 * @param unknown_type $page
 */
function groups_icon_handler($page) {

	// 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
	$plugin_dir = elgg_get_plugins_path();
	include("$plugin_dir/groups/icon.php");
}

/**
 * Populates the ->getUrl() method for group objects
 *
 * @param ElggEntity $entity File entity
 * @return string File URL
 */
function groups_url($entity) {
	$title = elgg_get_friendly_title($entity->name);

	return "pg/groups/profile/{$entity->guid}/$title";
}

/**
 * Add owner block link
 */
function groups_activity_owner_block_menu($hook, $type, $return, $params) {
	if (elgg_instanceof($params['entity'], 'group')) {
		if ($params['entity']->activity_enable != "no") {
			$url = "pg/groups/activity/{$params['entity']->guid}";
			$item = new ElggMenuItem('activity', elgg_echo('groups:activity'), $url);
			$return[] = $item;
		}
	}

	return $return;
}

/**
 * Groups created so create an access list for it
 */
function groups_create_event_listener($event, $object_type, $object) {
	$ac_name = elgg_echo('groups:group') . ": " . $object->name;
	$group_id = create_access_collection($ac_name, $object->guid);
	if ($group_id) {
		$object->group_acl = $group_id;
	} else {
		// delete group if access creation fails
		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));
	$user = get_loggedin_user();
	if ($user) {
		// Not using this because of recursion.
		// Joining a group automatically add user to ACL,
		// So just see if they're a member of the ACL.
		//$membership = get_users_membership($user->guid);

		$members = get_members_of_access_collection($group->group_acl);
		print_r($members);
		exit;

		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) {
	$page_owner = elgg_get_page_owner_entity();
	if (!$loggedin = get_loggedin_user()) {
		return $returnvalue;
	}

	// only insert group access for current group
	if ($page_owner instanceof ElggGroup && $loggedin) {
		if ($page_owner->isMember($loggedin)) {
			$returnvalue[$page_owner->group_acl] = elgg_echo('groups:group') . ': ' . $page_owner->name;

			unset($returnvalue[ACCESS_FRIENDS]);
		}
	} else {
		// if the user owns the group, remove all access collections manually
		// this won't be a problem once the group itself owns the acl.
		$groups = elgg_get_entities_from_relationship(array(
					'relationship' => 'member',
					'relationship_guid' => $loggedin->getGUID(),
					'inverse_relationship' => FALSE,
					'limit' => 999
				));

		if ($groups) {
			foreach ($groups as $group) {
				unset($returnvalue[$group->group_acl]);
			}
		}
	}

	return $returnvalue;
}

/**
 * Groups deleted, so remove access lists.
 */
function groups_delete_event_listener($event, $object_type, $object) {
	delete_access_collection($object->group_acl);

	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) {

	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()) {
			$url = elgg_get_site_url() . "pg/groupicon/{$entity->guid}/$size/$icontime.jpg";

			return $url;
		}
	}
}

/**
 * Grabs groups by invitations
 * Have to override all access until there's a way override access to getter functions.
 *
 * @param $user_guid
 * @return unknown_type
 */
function groups_get_invited_groups($user_guid, $return_guids = FALSE) {
	$ia = elgg_set_ignore_access(TRUE);
	$invitations = elgg_get_entities_from_relationship(array('relationship' => 'invited', 'relationship_guid' => $user_guid, 'inverse_relationship' => TRUE, 'limit' => 9999));
	elgg_set_ignore_access($ia);

	if ($return_guids) {
		$guids = array();
		foreach ($invitations as $invitation) {
			$guids[] = $invitation->getGUID();
		}

		return $guids;
	}

	return $invitations;
}

/**
 * Function to use on groups for access. It will house private, loggedin, public,
 * and the group itself. This is when you don't want other groups or channels in the access options available
 * Returns an array
 * */
function group_access_options($group) {
	$access_array = array(0 => 'private', 1 => 'logged in users', 2 => 'public', $group->group_acl => 'Group: ' . $group->name);
	return $access_array;
}

function activity_profile_menu($hook, $entity_type, $return_value, $params) {

	if ($params['owner'] instanceof ElggGroup) {
		$return_value[] = array(
			'text' => elgg_echo('Activity'),
			'href' => "pg/groups/activity/{$params['owner']->getGUID()}"
		);
	}
	return $return_value;
}

/**
 * Parse ECML on group discussion views
 */
function groups_ecml_views_hook($hook, $entity_type, $return_value, $params) {
	$return_value['forum/viewposts'] = elgg_echo('groups:ecml:discussion');

	return $return_value;
}

/**
 * Parse ECML on group profiles
 */
function groupprofile_ecml_views_hook($hook, $entity_type, $return_value, $params) {
	$return_value['groups/groupprofile'] = elgg_echo('groups:ecml:groupprofile');

	return $return_value;
}


/**
 * Discussion
 *
 */

elgg_register_event_handler('init', 'system', 'discussion_init');

/**
 * Initialize the discussion component
 */
function discussion_init() {

	elgg_register_library('elgg:discussion', elgg_get_plugins_path() . 'groups/lib/discussion.php');

	register_page_handler('discussion', 'discussion_page_handler');

	register_entity_url_handler('discussion_override_topic_url', 'object', 'groupforumtopic');
	//register_extender_url_handler('group_topicpost_url', 'annotation', 'group_topic_post');

	$action_base = elgg_get_plugins_path() . 'groups/actions/discussion';
	elgg_register_action('discussion/save', "$action_base/save.php");
	elgg_register_action('discussion/delete', "$action_base/delete.php");

	// add link to owner block
	elgg_register_plugin_hook_handler('register', 'menu:owner_block', 'discussion_owner_block_menu');

	// add the forum tool option
	add_group_tool_option('forum', elgg_echo('groups:enableforum'), true);
	elgg_extend_view('groups/tool_latest', 'discussion/group_module');

	// notifications
	register_notification_object('object', 'groupforumtopic', elgg_echo('groupforumtopic:new'));
	elgg_register_plugin_hook_handler('object:notifications', 'object', 'group_object_notifications_intercept');
	elgg_register_plugin_hook_handler('notify:entity:message', 'object', 'groupforumtopic_notify_message');

}

/**
 * Discussion page handler
 *
 * URLs take the form of
 *  All topics in site:    pg/discussion/all
 *  List topics in forum:  pg/discussion/owner/<guid>
 *  View discussion topic: pg/discussion/view/<guid>
 *  Add discussion topic:  pg/discussion/add/<guid>
 *  Edit discussion topic: pg/discussion/edit/<guid>
 *
 * @param array $page Array of url segments for routing
 */
function discussion_page_handler($page) {

	elgg_load_library('elgg:discussion');

	elgg_push_breadcrumb(elgg_echo('discussion'), 'pg/discussion/all');

	switch ($page[0]) {
		case 'all':
			discussion_handle_all_page();
			break;
		case 'owner':
			discussion_handle_list_page($page[1]);
			break;
		case 'add':
			discussion_handle_edit_page('add', $page[1]);
			break;
		case 'edit':
			discussion_handle_edit_page('edit', $page[1]);
			break;
		case 'view':
			discussion_handle_view_page($page[1]);
			break;
	}
}

/**
 * Override the discussion topic url
 *
 * @param ElggObject $entity Discussion topic
 * @return string
 */
function discussion_override_topic_url($entity) {
	return 'pg/discussion/view/' . $entity->guid;
}

/**
 * Override the annotation url
 *
 * @param ElggAnnotation $annotation
 * @return string
 */
function discussion_override_comment_url($annotation) {
	$parent = get_entity($annotation->entity_guid);
	if ($parent) {
		return 'pg/discussion/view/' . $parent->guid . '#' . $annotation->id;
	}
}

/**
 * Add owner block link
 */
function discussion_owner_block_menu($hook, $type, $return, $params) {
	if (elgg_instanceof($params['entity'], 'group')) {
		if ($params['entity']->forum_enable != "no") {
			$url = "pg/discussion/owner/{$params['entity']->guid}";
			$item = new ElggMenuItem('discussion', elgg_echo('discussion:group'), $url);
			$return[] = $item;
		}
	}

	return $return;
}

/**
 * Event handler for group forum posts
 *
 */
function group_object_notifications($event, $object_type, $object) {

	static $flag;
	if (!isset($flag))
		$flag = 0;

	if (is_callable('object_notifications'))
		if ($object instanceof ElggObject) {
			if ($object->getSubtype() == 'groupforumtopic') {
				//if ($object->countAnnotations('group_topic_post') > 0) {
				if ($flag == 0) {
					$flag = 1;
					object_notifications($event, $object_type, $object);
				}
				//}
			}
		}
}

/**
 * Intercepts the notification on group topic creation and prevents a notification from going out
 * (because one will be sent on the annotation)
 *
 * @param unknown_type $hook
 * @param unknown_type $entity_type
 * @param unknown_type $returnvalue
 * @param unknown_type $params
 * @return unknown
 */
function group_object_notifications_intercept($hook, $entity_type, $returnvalue, $params) {
	if (isset($params)) {
		if ($params['event'] == 'create' && $params['object'] instanceof ElggObject) {
			if ($params['object']->getSubtype() == 'groupforumtopic') {
				return true;
			}
		}
	}
	return null;
}

/**
 * Returns a more meaningful message
 *
 * @param unknown_type $hook
 * @param unknown_type $entity_type
 * @param unknown_type $returnvalue
 * @param unknown_type $params
 */
function groupforumtopic_notify_message($hook, $entity_type, $returnvalue, $params) {
	$entity = $params['entity'];
	$to_entity = $params['to_entity'];
	$method = $params['method'];
	if (($entity instanceof ElggEntity) && ($entity->getSubtype() == 'groupforumtopic')) {

		$descr = $entity->description;
		$title = $entity->title;
		$url = $entity->getURL();

		$msg = get_input('topicmessage');
		if (empty($msg))
			$msg = get_input('topic_post');
		if (!empty($msg))
			$msg = $msg . "\n\n"; else
			$msg = '';

		$owner = get_entity($entity->container_guid);
		if ($method == 'sms') {
			return elgg_echo("groupforumtopic:new") . ': ' . $url . " ({$owner->name}: {$title})";
		} else {
			return get_loggedin_user()->name . ' ' . elgg_echo("groups:viagroups") . ': ' . $title . "\n\n" . $msg . "\n\n" . $entity->getURL();
		}
	}
	return null;
}

/**
 * A simple function to see who can edit a group discussion post
 * @param the comment $entity
 * @param user who owns the group $group_owner
 * @return boolean
 */
function groups_can_edit_discussion($entity, $group_owner) {

	//logged in user
	$user = get_loggedin_userid();

	if (($entity->owner_guid == $user) || $group_owner == $user || isadminloggedin()) {
		return true;
	} else {
		return false;
	}
}