<?php
class UserService {
	var $db;

	function &getInstance(&$db) {
		static $instance;
		if (!isset($instance))
		$instance =& new UserService($db);
		return $instance;
	}

	var $fields = array(
        'primary'   =>  'uId',
        'username'  =>  'username',
        'password'  =>  'password'
        );
        var $profileurl;
        var $tablename;
        var $sessionkey;
        var $cookiekey;
        var $cookietime = 1209600; // 2 weeks

        function UserService(& $db) {
        	$this->db =& $db;
        	$this->tablename = $GLOBALS['tableprefix'] .'users';
        	$this->sessionkey = $GLOBALS['cookieprefix'].INSTALLATION_ID.'-currentuserid';
        	$this->cookiekey = $GLOBALS['cookieprefix'].INSTALLATION_ID.'-login';
        	$this->profileurl = createURL('profile', '%2$s');
        }

        function _checkdns($host) {
        	if (function_exists('checkdnsrr')) {
        		return checkdnsrr($host);
        	} else {
        		return $this->_checkdnsrr($host);
        	}
        }

        function _checkdnsrr($host, $type = "MX") {
        	if(!empty($host)) {
        		@exec("nslookup -type=$type $host", $output);
        		while(list($k, $line) = each($output)) {
        			if(eregi("^$host", $line)) {
        				return true;
        			}
        		}
        		return false;
        	}
        }

        function _getuser($fieldname, $value) {
        	$query = 'SELECT * FROM '. $this->getTableName() .' WHERE '. $fieldname .' = "'. $this->db->sql_escape($value) .'"';

        	if (! ($dbresult =& $this->db->sql_query($query)) ) {
        		message_die(GENERAL_ERROR, 'Could not get user', '', __LINE__, __FILE__, $query, $this->db);
        		return false;
        	}

        	if ($row =& $this->db->sql_fetchrow($dbresult))
        	return $row;
        	else
        	return false;
        }

        function & getUsers($nb=0) {
        	$query = 'SELECT * FROM '. $this->getTableName() .' ORDER BY `uId` DESC';
        	if($nb>0) {
        		$query .= ' LIMIT 0, '.$nb;
        	}
        	if (! ($dbresult =& $this->db->sql_query($query)) ) {
        		message_die(GENERAL_ERROR, 'Could not get user', '', __LINE__, __FILE__, $query, $this->db);
        		return false;
        	}

        	while ($row = & $this->db->sql_fetchrow($dbresult)) {
        		$users[] = $row;
        	}
        	return $users;
        }

        function _randompassword() {
        	$seed = (integer) md5(microtime());
        	mt_srand($seed);
        	$password = mt_rand(1, 99999999);
        	$password = substr(md5($password), mt_rand(0, 19), mt_rand(6, 12));
        	return $password;
        }

        function _updateuser($uId, $fieldname, $value) {
        	$updates = array ($fieldname => $value);
        	$sql = 'UPDATE '. $this->getTableName() .' SET '. $this->db->sql_build_array('UPDATE', $updates) .' WHERE '. $this->getFieldName('primary') .'='. intval($uId);

        	// Execute the statement.
        	$this->db->sql_transaction('begin');
        	if (!($dbresult = & $this->db->sql_query($sql))) {
        		$this->db->sql_transaction('rollback');
        		message_die(GENERAL_ERROR, 'Could not update user', '', __LINE__, __FILE__, $sql, $this->db);
        		return false;
        	}
        	$this->db->sql_transaction('commit');

        	// Everything worked out, so return true.
        	return true;
        }

        function getProfileUrl($id, $username) {
        	return sprintf($this->profileurl, urlencode($id), urlencode($username));
        }

        function getUserByUsername($username) {
        	return $this->_getuser($this->getFieldName('username'), $username);
        }

        function getUser($id) {
        	return $this->_getuser($this->getFieldName('primary'), $id);
        }

        function isLoggedOn() {
        	return ($this->getCurrentUserId() !== false);
        }

        function &getCurrentUser($refresh = FALSE, $newval = NULL) {
        	static $currentuser;
        	if (!is_null($newval)) //internal use only: reset currentuser
        	$currentuser = $newval;
        	else if ($refresh || !isset($currentuser)) {
        		if ($id = $this->getCurrentUserId())
        		$currentuser = $this->getUser($id);
        		else
        		return null;
        	}
        	return $currentuser;
        }

        function isAdmin($userid) {
        	$user = $this->getUser($userid);
        	
        	if(isset($GLOBALS['admin_users'])
        	&& in_array($user['username'], $GLOBALS['admin_users'])) {
        		return true;
        	} else {
        		return false;
        	}
        }

        function getCurrentUserId() {
        	if (isset($_SESSION[$this->getSessionKey()])) {
        		//echo "session";die($_SESSION[$this->getSessionKey()]);
        		return $_SESSION[$this->getSessionKey()];
        	} else if (isset($_COOKIE[$this->getCookieKey()])) {
        		//echo "cookie";die();

        		$cook = split(':', $_COOKIE[$this->getCookieKey()]);
        		//cookie looks like this: 'id:md5(username+password)'
        		$query = 'SELECT * FROM '. $this->getTableName() .
                     ' WHERE MD5(CONCAT('.$this->getFieldName('username') .
                                     ', '.$this->getFieldName('password') .
                     ')) = \''.$this->db->sql_escape($cook[1]).'\' AND '.
        		$this->getFieldName('primary'). ' = '. $this->db->sql_escape($cook[0]);

        		if (! ($dbresult =& $this->db->sql_query($query)) ) {
        			message_die(GENERAL_ERROR, 'Could not get user', '', __LINE__, __FILE__, $query, $this->db);
        			return false;
        		}

        		if ($row = $this->db->sql_fetchrow($dbresult)) {
        			$_SESSION[$this->getSessionKey()] = $row[$this->getFieldName('primary')];
        			return $_SESSION[$this->getSessionKey()];
        		}
        	}
        	return false;
        }

        function login($username, $password, $remember = FALSE) {
        	$password = $this->sanitisePassword($password);
        	$query = 'SELECT '. $this->getFieldName('primary') .' FROM '. $this->getTableName() .' WHERE '. $this->getFieldName('username') .' = "'. $this->db->sql_escape($username) .'" AND '. $this->getFieldName('password') .' = "'. $this->db->sql_escape($password) .'"';

        	if (! ($dbresult =& $this->db->sql_query($query)) ) {
        		message_die(GENERAL_ERROR, 'Could not get user', '', __LINE__, __FILE__, $query, $this->db);
        		return false;
        	}

        	if ($row =& $this->db->sql_fetchrow($dbresult)) {
        		$id = $_SESSION[$this->getSessionKey()] = $row[$this->getFieldName('primary')];
        		if ($remember) {
        			$cookie = $id .':'. md5($username.$password);
        			setcookie($this->cookiekey, $cookie, time() + $this->cookietime, '/');
        		}
        		return true;
        	} else {
        		return false;
        	}
        }

        function logout() {
        	@setcookie($this->getCookiekey(), '', time() - 1, '/');
        	unset($_COOKIE[$this->getCookiekey()]);
        	session_unset();
        	$this->getCurrentUser(TRUE, false);
        }

        function getWatchlist($uId) {
        	// Gets the list of user IDs being watched by the given user.
        	$query = 'SELECT watched FROM '. $GLOBALS['tableprefix'] .'watched WHERE uId = '. intval($uId);

        	if (! ($dbresult =& $this->db->sql_query($query)) ) {
        		message_die(GENERAL_ERROR, 'Could not get watchlist', '', __LINE__, __FILE__, $query, $this->db);
        		return false;
        	}

        	$arrWatch = array();
        	if ($this->db->sql_numrows($dbresult) == 0)
        	return $arrWatch;
        	while ($row =& $this->db->sql_fetchrow($dbresult))
        	$arrWatch[] = $row['watched'];
        	return $arrWatch;
        }

        function getWatchNames($uId, $watchedby = false) {
        	// Gets the list of user names being watched by the given user.
        	// - If $watchedby is false get the list of users that $uId watches
        	// - If $watchedby is true get the list of users that watch $uId
        	if ($watchedby) {
        		$table1 = 'b';
        		$table2 = 'a';
        	} else {
        		$table1 = 'a';
        		$table2 = 'b';
        	}
        	$query = 'SELECT '. $table1 .'.'. $this->getFieldName('username') .' FROM '. $GLOBALS['tableprefix'] .'watched AS W, '. $this->getTableName() .' AS a, '. $this->getTableName() .' AS b WHERE W.watched = a.'. $this->getFieldName('primary') .' AND W.uId = b.'. $this->getFieldName('primary') .' AND '. $table2 .'.'. $this->getFieldName('primary') .' = '. intval($uId) .' ORDER BY '. $table1 .'.'. $this->getFieldName('username');

        	if (!($dbresult =& $this->db->sql_query($query))) {
        		message_die(GENERAL_ERROR, 'Could not get watchlist', '', __LINE__, __FILE__, $query, $this->db);
        		return false;
        	}

        	$arrWatch = array();
        	if ($this->db->sql_numrows($dbresult) == 0) {
        		return $arrWatch;
        	}
        	while ($row =& $this->db->sql_fetchrow($dbresult)) {
        		$arrWatch[] = $row[$this->getFieldName('username')];
        	}
        	return $arrWatch;
        }

        function getWatchStatus($watcheduser, $currentuser) {
        	// Returns true if the current user is watching the given user, and false otherwise.
        	$query = 'SELECT watched FROM '. $GLOBALS['tableprefix'] .'watched AS W INNER JOIN '. $this->getTableName() .' AS U ON U.'. $this->getFieldName('primary') .' = W.watched WHERE U.'. $this->getFieldName('primary') .' = '. intval($watcheduser) .' AND W.uId = '. intval($currentuser);

        	if (! ($dbresult =& $this->db->sql_query($query)) ) {
        		message_die(GENERAL_ERROR, 'Could not get watchstatus', '', __LINE__, __FILE__, $query, $this->db);
        		return false;
        	}

        	$arrWatch = array();
        	if ($this->db->sql_numrows($dbresult) == 0)
        	return false;
        	else
        	return true;
        }

        function setWatchStatus($subjectUserID) {
        	if (!is_numeric($subjectUserID))
        	return false;

        	$currentUserID = $this->getCurrentUserId();
        	$watched = $this->getWatchStatus($subjectUserID, $currentUserID);

        	if ($watched) {
        		$sql = 'DELETE FROM '. $GLOBALS['tableprefix'] .'watched WHERE uId = '. intval($currentUserID) .' AND watched = '. intval($subjectUserID);
        		if (!($dbresult =& $this->db->sql_query($sql))) {
        			$this->db->sql_transaction('rollback');
        			message_die(GENERAL_ERROR, 'Could not add user to watch list', '', __LINE__, __FILE__, $sql, $this->db);
        			return false;
        		}
        	} else {
        		$values = array(
                'uId' => intval($currentUserID),
                'watched' => intval($subjectUserID)
        		);
        		$sql = 'INSERT INTO '. $GLOBALS['tableprefix'] .'watched '. $this->db->sql_build_array('INSERT', $values);
        		if (!($dbresult =& $this->db->sql_query($sql))) {
        			$this->db->sql_transaction('rollback');
        			message_die(GENERAL_ERROR, 'Could not add user to watch list', '', __LINE__, __FILE__, $sql, $this->db);
        			return false;
        		}
        	}

        	$this->db->sql_transaction('commit');
        	return true;
        }

        function addUser($username, $password, $email) {
        	// Set up the SQL UPDATE statement.
        	$datetime = gmdate('Y-m-d H:i:s', time());
        	$password = $this->sanitisePassword($password);
        	$values = array('username' => $username, 'password' => $password, 'email' => $email, 'uDatetime' => $datetime, 'uModified' => $datetime);
        	$sql = 'INSERT INTO '. $this->getTableName() .' '. $this->db->sql_build_array('INSERT', $values);

        	// Execute the statement.
        	$this->db->sql_transaction('begin');
        	if (!($dbresult = & $this->db->sql_query($sql))) {
        		$this->db->sql_transaction('rollback');
        		message_die(GENERAL_ERROR, 'Could not insert user', '', __LINE__, __FILE__, $sql, $this->db);
        		return false;
        	}
        	$this->db->sql_transaction('commit');

        	// Everything worked out, so return true.
        	return true;
        }

        function updateUser($uId, $password, $name, $email, $homepage, $uContent) {
        	if (!is_numeric($uId))
        	return false;

        	// Set up the SQL UPDATE statement.
        	$moddatetime = gmdate('Y-m-d H:i:s', time());
        	if ($password == '')
        	$updates = array ('uModified' => $moddatetime, 'name' => $name, 'email' => $email, 'homepage' => $homepage, 'uContent' => $uContent);
        	else
        	$updates = array ('uModified' => $moddatetime, 'password' => $this->sanitisePassword($password), 'name' => $name, 'email' => $email, 'homepage' => $homepage, 'uContent' => $uContent);
        	$sql = 'UPDATE '. $this->getTableName() .' SET '. $this->db->sql_build_array('UPDATE', $updates) .' WHERE '. $this->getFieldName('primary') .'='. intval($uId);

        	// Execute the statement.
        	$this->db->sql_transaction('begin');
        	if (!($dbresult = & $this->db->sql_query($sql))) {
        		$this->db->sql_transaction('rollback');
        		message_die(GENERAL_ERROR, 'Could not update user', '', __LINE__, __FILE__, $sql, $this->db);
        		return false;
        	}
        	$this->db->sql_transaction('commit');

        	// Everything worked out, so return true.
        	return true;
        }

        function getAllUsers ( ) {
        	$query = 'SELECT * FROM '. $this->getTableName();

        	if (! ($dbresult =& $this->db->sql_query($query)) ) {
        		message_die(GENERAL_ERROR, 'Could not get users', '', __LINE__, __FILE__, $query, $this->db);
        		return false;
        	}

        	$rows = array();

        	while ( $row = $this->db->sql_fetchrow($dbresult) ) {
        		$rows[] = $row;
        	}

        	return $rows;
        }

        function deleteUser($uId) {
        	$query = 'DELETE FROM '. $this->getTableName() .' WHERE uId = '. intval($uId);

        	if (!($dbresult = & $this->db->sql_query($query))) {
        		message_die(GENERAL_ERROR, 'Could not delete user', '', __LINE__, __FILE__, $query, $this->db);
        		return false;
        	}

        	return true;
        }


        function sanitisePassword($password) {
        	return sha1(trim($password));
        }

        function generatePassword($uId) {
        	if (!is_numeric($uId))
        	return false;

        	$password = $this->_randompassword();

        	if ($this->_updateuser($uId, $this->getFieldName('password'), $this->sanitisePassword($password)))
        	return $password;
        	else
        	return false;
        }

        function isReserved($username) {
        	if (in_array($username, $GLOBALS['reservedusers'])) {
        		return true;
        	} else {
        		return false;
        	}
        }
        
        function isValidUsername($username) {
        	if (strlen($username) > 24) {
        		// too long usernames are cut by database and may cause bugs when compared 
        		return false;
        	} elseif (preg_match('/(\W)/', $username) > 0) {
        		// forbidden non-alphanumeric characters
        		return false;
        	}
        	return true;
        }        

        

        function isValidEmail($email) {
        	if (eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,6})$", $email)) {
        		list($emailUser, $emailDomain) = split("@", $email);

        		// Check if the email domain has a DNS record
        		if ($this->_checkdns($emailDomain)) {
        			return true;
        		}
        	}
        	return false;
        }

        // Properties
        function getTableName()       { return $this->tablename; }
        function setTableName($value) { $this->tablename = $value; }

        function getFieldName($field)         { return $this->fields[$field]; }
        function setFieldName($field, $value) { $this->fields[$field] = $value; }

        function getSessionKey()       { return $this->sessionkey; }
        function setSessionKey($value) { $this->sessionkey = $value; }

        function getCookieKey()       { return $this->cookiekey; }
        function setCookieKey($value) { $this->cookiekey = $value; }
}
?>