<?php
  
  /**
   * Copyright (c) 2013 Robin Appelman <icewind@owncloud.com>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  
  namespace OC\Group;
  
  class Group {
  	/**
  	 * @var string $id
  	 */
  	private $gid;
  
  	/**
  	 * @var \OC\User\User[] $users
  	 */

  	private $users = array();

  
  	/**

  	 * @var bool $usersLoaded
  	 */
  	private $usersLoaded;
  
  	/**
  	 * @var \OC_Group_Backend[]|\OC_Group_Database[] $backend

  	 */
  	private $backends;
  
  	/**

  	 * @var \OC\Hooks\PublicEmitter $emitter

  	 */
  	private $emitter;
  
  	/**
  	 * @var \OC\User\Manager $userManager
  	 */
  	private $userManager;
  
  	/**
  	 * @param string $gid
  	 * @param \OC_Group_Backend[] $backends
  	 * @param \OC\User\Manager $userManager
  	 * @param \OC\Hooks\PublicEmitter $emitter
  	 */
  	public function __construct($gid, $backends, $userManager, $emitter = null) {
  		$this->gid = $gid;
  		$this->backends = $backends;
  		$this->userManager = $userManager;
  		$this->emitter = $emitter;
  	}
  
  	public function getGID() {
  		return $this->gid;
  	}
  
  	/**
  	 * get all users in the group
  	 *
  	 * @return \OC\User\User[]
  	 */
  	public function getUsers() {

  		if ($this->usersLoaded) {

  			return $this->users;
  		}
  
  		$userIds = array();
  		foreach ($this->backends as $backend) {
  			$diff = array_diff(
  				$backend->usersInGroup($this->gid),
  				$userIds
  			);
  			if ($diff) {
  				$userIds = array_merge($userIds, $diff);
  			}
  		}
  
  		$this->users = $this->getVerifiedUsers($userIds);

  		$this->usersLoaded = true;

  		return $this->users;
  	}
  
  	/**
  	 * check if a user is in the group
  	 *
  	 * @param \OC\User\User $user
  	 * @return bool
  	 */
  	public function inGroup($user) {

  		if (isset($this->users[$user->getUID()])) {
  			return true;
  		}

  		foreach ($this->backends as $backend) {
  			if ($backend->inGroup($user->getUID(), $this->gid)) {

  				$this->users[$user->getUID()] = $user;

  				return true;
  			}
  		}
  		return false;
  	}
  
  	/**
  	 * add a user to the group
  	 *
  	 * @param \OC\User\User $user
  	 */
  	public function addUser($user) {
  		if ($this->inGroup($user)) {
  			return;
  		}
  
  		if ($this->emitter) {
  			$this->emitter->emit('\OC\Group', 'preAddUser', array($this, $user));
  		}
  		foreach ($this->backends as $backend) {
  			if ($backend->implementsActions(OC_GROUP_BACKEND_ADD_TO_GROUP)) {
  				$backend->addToGroup($user->getUID(), $this->gid);
  				if ($this->users) {
  					$this->users[$user->getUID()] = $user;
  				}
  				if ($this->emitter) {
  					$this->emitter->emit('\OC\Group', 'postAddUser', array($this, $user));
  				}
  				return;
  			}
  		}
  	}
  
  	/**
  	 * remove a user from the group
  	 *
  	 * @param \OC\User\User $user
  	 */
  	public function removeUser($user) {
  		$result = false;
  		if ($this->emitter) {
  			$this->emitter->emit('\OC\Group', 'preRemoveUser', array($this, $user));
  		}
  		foreach ($this->backends as $backend) {
  			if ($backend->implementsActions(OC_GROUP_BACKEND_REMOVE_FROM_GOUP) and $backend->inGroup($user->getUID(), $this->gid)) {
  				$backend->removeFromGroup($user->getUID(), $this->gid);
  				$result = true;
  			}
  		}
  		if ($result) {
  			if ($this->emitter) {
  				$this->emitter->emit('\OC\Group', 'postRemoveUser', array($this, $user));
  			}
  			if ($this->users) {
  				foreach ($this->users as $index => $groupUser) {
  					if ($groupUser->getUID() === $user->getUID()) {
  						unset($this->users[$index]);
  						return;
  					}
  				}
  			}
  		}
  	}
  
  	/**
  	 * search for users in the group by userid
  	 *
  	 * @param string $search
  	 * @param int $limit
  	 * @param int $offset
  	 * @return \OC\User\User[]
  	 */
  	public function searchUsers($search, $limit = null, $offset = null) {
  		$users = array();
  		foreach ($this->backends as $backend) {
  			$userIds = $backend->usersInGroup($this->gid, $search, $limit, $offset);

  			$users += $this->getVerifiedUsers($userIds);
  			if (!is_null($limit) and $limit <= 0) {
  				return array_values($users);
  			}
  		}
  		return array_values($users);
  	}
  
  	/**

  	 * returns the number of users matching the search string
  	 *
  	 * @param string $search
  	 * @return int|bool
  	 */
  	public function count($search = '') {
  		$users = false;
  		foreach ($this->backends as $backend) {
  			if($backend->implementsActions(OC_GROUP_BACKEND_COUNT_USERS)) {
  				if($users === false) {
  					//we could directly add to a bool variable, but this would
  					//be ugly
  					$users = 0;
  				}
  				$users += $backend->countUsersInGroup($this->gid, $search);
  			}
  		}
  		return $users;
  	}
  
  	/**

  	 * search for users in the group by displayname
  	 *
  	 * @param string $search
  	 * @param int $limit
  	 * @param int $offset
  	 * @return \OC\User\User[]
  	 */
  	public function searchDisplayName($search, $limit = null, $offset = null) {

  		$users = array();

  		foreach ($this->backends as $backend) {

  			$userIds = $backend->usersInGroup($this->gid, $search, $limit, $offset);

  			$users = $this->getVerifiedUsers($userIds);
  			if (!is_null($limit) and $limit <= 0) {
  				return array_values($users);
  			}
  		}
  		return array_values($users);
  	}
  
  	/**
  	 * delete the group
  	 *
  	 * @return bool
  	 */
  	public function delete() {
  		$result = false;
  		if ($this->emitter) {
  			$this->emitter->emit('\OC\Group', 'preDelete', array($this));
  		}
  		foreach ($this->backends as $backend) {
  			if ($backend->implementsActions(OC_GROUP_BACKEND_DELETE_GROUP)) {
  				$result = true;
  				$backend->deleteGroup($this->gid);
  			}
  		}
  		if ($result and $this->emitter) {
  			$this->emitter->emit('\OC\Group', 'postDelete', array($this));
  		}
  		return $result;
  	}
  
  	/**

  	 * returns all the Users from an array that really exists
  	 * @param string[] $userIds an array containing user IDs
  	 * @return \OC\User\User[] an Array with the userId as Key and \OC\User\User as value

  	 */
  	private function getVerifiedUsers($userIds) {

  		if (!is_array($userIds)) {

  			return array();
  		}
  		$users = array();
  		foreach ($userIds as $userId) {
  			$user = $this->userManager->get($userId);

  			if (!is_null($user)) {

  				$users[$userId] = $user;
  			}
  		}
  		return $users;
  	}
  }