user.php

<?php


class User {
	
	// static
	private static $_current_user = null;
	
	// non-static
	private $_data = array();
	
	// static
	
	public static function current() {
		if (!User::$_current_user) {
			if (!empty($_COOKIE['user_id'])) {
				$id = $_COOKIE['user_id'];
				$signature = $_COOKIE['user_signature'];
				$user = User::find_by_id($id);
				if ($user && ($signature == $user->signature()))
					User::$_current_user = $user;
			}
		}
		return User::$_current_user;
	}
	
	public static function require_login() {
		$user = User::current();
		if (!$user)
			return false;
		else
			return true;
	}
	
	public static function create($email, $password = null) {
		$db = $GLOBALS['db'];
		$m_users = $db->users;
		$user_data = $m_users->findOne(array('email' => $email));
		if ($user_data) // if it already exists, don't create
			return false;
		$user = new User();
		$user->email = $email;
		if (!empty($password))
			$user->password_hash = sha1($password);
		return true;
	}
	
	public static function signup($email, $password = null) {
		$success = User::create($email, $password);
		if ($success)
			User::login($email, $password);
		return $success;
	}
	
	public static function login($email, $password = null) {
		$db = $GLOBALS['db'];
		$m_users = $db->users;
		$user_data = $m_users->findOne(array('email' => $email));
		if ($user_data) {
			if (!empty($user_data['password_hash']) && (sha1($password) != $user_data['password_hash']))
				return false;
			$id = $user_data['_id']->__toString();
			$user = User::find_by_id($id);
			User::$_current_user = $user;
			setcookie('user_id', $id, time()+60*60*24*30*12*2, '/', ''); // two years
			setcookie('user_signature', $user->signature(), time()+60*60*24*30*12*2, '/', ''); // two years
			return true;
		} else
			return false;
	}
	
	public static function logout() {
		setcookie('user_id', '', 1, '/', '');
		setcookie('user_signature', '', 1, '/', '');
	}
	
	public static function find_by_id($id) {
		if ($id) {
			$db = $GLOBALS['db'];
			$m_users = $db->users;
			$user_data = $m_users->findOne(array('_id' => new MongoID($id)));
			if ($user_data) {
				$user = new User();
				$user->_init_data($user_data);
				return $user;
			} else
				return null;
		}
	}
	
	// non-static
	
	public function _init_data($data) {
		$this->_data = $data;
	}
	
	public function signature() {
		$id = $this->_id->__toString();
		if (!empty($this->password_hash))
			$password_hash = $this->password_hash;
		else
			$password_hash = '';
		return sha1($id.$password_hash);
	}
	
	public function __get($key) {
		if (isset($this->_data[$key]))
			return $this->_data[$key];
		else
			return null;
	}
	public function __set($key, $value) {
		$this->_data[$key] = $value;
		$this->_save();
	}
	
	private function _save() {
		$db = $GLOBALS['db'];
		$m_users = $db->users;
		$m_users->save($this->_data);
	}
}