<?php

use CCR\DB;

// @class XDUserProfile

class XDUserProfile {

const TARGET_SCHEMA = 'moddb.UserProfiles';

/*

CREATE TABLE moddb.UserProfiles (

user_id INT(11), primary key(user_id),

serialized_profile_data BLOB

);

*/

// Class constants (used as keys for accessing/setting values in the profile) -------------

const INITIAL_TAB = 0;

const LAST_VISITED_TAB = 1;

const DASHBOARD_CHARTS = 2;

// Private variables --------------------------------

private $_pdo; // PDO Handle (set in __construct)

private $_user_id; // User ID (set in __construct)

private $_profile_data; // Represents cached profile data

// -----------------------------------------------------

// @function __construct()

//

// @param int $user_id [user id pertaining to the user whose profile you want to manage]

function __construct($user_id) {

$this->_pdo = DB::factory('database');

$this->_user_id = $user_id;

$this->_load();

}//__construct

// -----------------------------------------------------

// @function setValue()

//

// @param String $param [The parameter / key]

// @param Object $value [The object to be mapped to the parameter / key]

public function setValue($param, $value) {

$this->_profile_data[$param] = $value;

}//setValue

// -----------------------------------------------------

// @function getDump()

//

// NOTE: Should be used for debugging purposes only

public function getDump() {

print '<pre>';

print_r($this->_profile_data);

print '</pre>';

}//getDump

// -----------------------------------------------------

// @function valueExists()

//

// @param String $param

//

// @return boolean [Indicating whether a value already exists for a given parameter]

public function valueExists($param) {

return (isset($this->_profile_data[$param]));

}//valueExists

// -----------------------------------------------------

// @function fetchValue()

//

// @param String $param

//

// @return Object [The value of corresponding datatype mapped to the parameter of interest]

// If there is no mapping, then NULL is returned

public function fetchValue($param) {

return (isset($this->_profile_data[$param])) ? $this->_profile_data[$param] : NULL;

}//fetchValue

// -----------------------------------------------------

// @function dropValue()

//

// Removes an item from the local cache (made permanent by a subsequent call to save())

//

// @param String $param [The parameter identifying the item to be discarded]

public function dropValue($param) {

// NOTE: The actual value will stay in the profile cache until a call to save() is made.

if (isset($this->_profile_data[$param])) {

unset($this->_profile_data[$param]);

}

}//dropValue

// -----------------------------------------------------

// @function clear()

//

// Clear local cache as well as data in the persistence model (implicit save)

public function clear() {

$this->_profile_data = array();

$this->_pdo->execute(

'DELETE FROM '.self::TARGET_SCHEMA.' WHERE user_id=:user_id',

array(

'user_id' => $this->_user_id

)

);

}//clear

// -----------------------------------------------------

// @function reload()

//

// Re-Populate local cache with data currently in the persistence model

// NOTE: Any unsaved data will be lost as the result of calling reload()

public function reload() {

$this->_load();

}//reload

// -----------------------------------------------------

// @function _load()

//

// Discard what is in the local cache and (re-)populate it with data in the persistence model

// NOTE: Any unsaved data will be lost as the result of calling load()

private function _load() {

$this->_profile_data = array();

$results = $this->_pdo->query('SELECT serialized_profile_data FROM '.self::TARGET_SCHEMA.' WHERE user_id=:user_id',

array(

'user_id' => $this->_user_id

)

);

if (count($results) > 0) {

$this->_profile_data = @unserialize($results[0]['serialized_profile_data']);

if (!is_array($this->_profile_data)) {

// Unserialization failed -- initialize to an empty array

$this->_profile_data = array();

}

}//if (count($results) > 0)

}//_load

// -----------------------------------------------------

// @function save()

//

// Writes cached profile data back to the persistence model in a serialized format

//

// @throws Exception if there was an issue executing the SQL command to write the data to the DB

public function save() {

$this->_pdo->execute('LOCK TABLES '.self::TARGET_SCHEMA.' WRITE');

$this->_pdo->execute('BEGIN');

// BEGIN Critical Section ========================

$targetQuery = 'INSERT INTO '.self::TARGET_SCHEMA.' (user_id, serialized_profile_data) VALUES (:user_id, :serialized_profile_data)';

$targetQuery .= ' ON DUPLICATE KEY UPDATE serialized_profile_data=:serialized_profile_data';

try {

$serialized = serialize($this->_profile_data);

$this->_pdo->execute(

$targetQuery,

array(

'serialized_profile_data' => $serialized,

'user_id' => $this->_user_id

)

);

$this->_pdo->execute('COMMIT');

$this->_pdo->execute('UNLOCK TABLES');

}

catch(Exception $e) {

$this->_pdo->execute('ROLLBACK');

$this->_pdo->execute('UNLOCK TABLES');

throw new Exception($e->getMessage());

}

}//save

}//XDUserProfile