<?php
  /**
   * ownCloud
   *
   * @author Frank Karlitschek
   * @author Jakob Sack
   * @copyright 2012 Frank Karlitschek frank@owncloud.org
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
   * License as published by the Free Software Foundation; either
   * version 3 of the License, or any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
   *
   * You should have received a copy of the GNU Affero General Public
   * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
   *
   */
  /*
   *
   * The following SQL statement is just a help for developers and will not be
   * executed!
   *
   * CREATE TABLE  `preferences` (
   * `userid` VARCHAR( 255 ) NOT NULL ,
   * `appid` VARCHAR( 255 ) NOT NULL ,
   * `configkey` VARCHAR( 255 ) NOT NULL ,
   * `configvalue` VARCHAR( 255 ) NOT NULL
   * )
   *
   */

  namespace OC;
  
  use \OC\DB\Connection;

  /**
   * This class provides an easy way for storing user preferences.
   */

  class Preferences {

  	/**
  	 * @var \OC\DB\Connection
  	 */

  	protected $conn;

  	/**
  	 * 3 dimensional array with the following structure:
  	 * [ $userId =>
  	 *     [ $appId =>
  	 *         [ $key => $value ]
  	 *     ]
  	 * ]
  	 *
  	 * @var array $cache
  	 */
  	protected $cache = array();
  
  	/**
  	 * @param \OC\DB\Connection $conn
  	 */

  	public function __construct(Connection $conn) {
  		$this->conn = $conn;
  	}

  	/**

  	 * Get all users using the preferences
  	 * @return array an array of user ids

  	 *
  	 * This function returns a list of all users that have at least one entry
  	 * in the preferences table.
  	 */

  	public function getUsers() {
  		$query = 'SELECT DISTINCT `userid` FROM `*PREFIX*preferences`';

  		$result = $this->conn->executeQuery($query);

  
  		$users = array();

  		while ($userid = $result->fetchColumn()) {

  			$users[] = $userid;

  		}
  
  		return $users;
  	}
  
  	/**

  	 * @param string $user
  	 * @return array[]
  	 */
  	protected function getUserValues($user) {
  		if (isset($this->cache[$user])) {
  			return $this->cache[$user];
  		}
  		$data = array();
  		$query = 'SELECT `appid`, `configkey`, `configvalue` FROM `*PREFIX*preferences` WHERE `userid` = ?';
  		$result = $this->conn->executeQuery($query, array($user));
  		while ($row = $result->fetch()) {
  			$app = $row['appid'];
  			if (!isset($data[$app])) {
  				$data[$app] = array();
  			}
  			$data[$app][$row['configkey']] = $row['configvalue'];
  		}
  		$this->cache[$user] = $data;
  		return $data;
  	}
  
  	/**
  	 * Get all apps of an user

  	 * @param string $user user

  	 * @return integer[] with app ids

  	 *
  	 * This function returns a list of all apps of the user that have at least
  	 * one entry in the preferences table.
  	 */

  	public function getApps($user) {
  		$data = $this->getUserValues($user);
  		return array_keys($data);

  	}
  
  	/**

  	 * Get the available keys for an app

  	 * @param string $user user
  	 * @param string $app the app we are looking for

  	 * @return array an array of key names

  	 *
  	 * This function gets all keys of an app of an user. Please note that the
  	 * values are not returned.
  	 */

  	public function getKeys($user, $app) {
  		$data = $this->getUserValues($user);
  		if (isset($data[$app])) {
  			return array_keys($data[$app]);
  		} else {
  			return array();

  		}

  	}
  
  	/**

  	 * Gets the preference

  	 * @param string $user user
  	 * @param string $app app
  	 * @param string $key key
  	 * @param string $default = null, default value if the key does not exist
  	 * @return string the value or $default
  	 *
  	 * This function gets a value from the preferences table. If the key does
  	 * not exist the default value will be returned
  	 */

  	public function getValue($user, $app, $key, $default = null) {
  		$data = $this->getUserValues($user);
  		if (isset($data[$app]) and isset($data[$app][$key])) {
  			return $data[$app][$key];

  		} else {

  			return $default;
  		}
  	}
  
  	/**

  	 * sets a value in the preferences

  	 * @param string $user user
  	 * @param string $app app
  	 * @param string $key key
  	 * @param string $value value

  	 * @param string $preCondition only set value if the key had a specific value before
  	 * @return bool true if value was set, otherwise false

  	 *
  	 * Adds a value to the preferences. If the key did not exist before, it
  	 * will be added automagically.
  	 */

  	public function setValue($user, $app, $key, $value, $preCondition = null) {

  		// Check if the key does exist

  		$query = 'SELECT `configvalue` FROM `*PREFIX*preferences`'
  			. ' WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?';
  		$oldValue = $this->conn->fetchColumn($query, array($user, $app, $key));
  		$exists = $oldValue !== false;

  		if($oldValue === strval($value)) {
  			// no changes
  			return true;
  		}
  		
  		$affectedRows = 0;
  
  		if (!$exists && $preCondition === null) {

  			$data = array(
  				'userid' => $user,
  				'appid' => $app,
  				'configkey' => $key,
  				'configvalue' => $value,
  			);

  			$affectedRows = $this->conn->insert('*PREFIX*preferences', $data);
  		} elseif ($exists) {
  			$data = array($value, $user, $app, $key);
  			$sql  = "UPDATE `*PREFIX*preferences` SET `configvalue` = ?"
  					. " WHERE `userid` = ? AND `appid` = ? AND `configkey` = ?";
  
  			if ($preCondition !== null) {
  				if (\OC_Config::getValue( 'dbtype', 'sqlite' ) === 'oci') {
  					//oracle hack: need to explicitly cast CLOB to CHAR for comparison
  					$sql .= " AND to_char(`configvalue`) = ?";
  				} else {
  					$sql .= " AND `configvalue` = ?";
  				}
  				$data[] = $preCondition;
  			}
  			$affectedRows = $this->conn->executeUpdate($sql, $data);
  		}
  
  		// only add to the cache if we already loaded data for the user
  		if ($affectedRows > 0 && isset($this->cache[$user])) {
  			if (!isset($this->cache[$user][$app])) {
  				$this->cache[$user][$app] = array();
  			}
  			$this->cache[$user][$app][$key] = $value;
  		}
  
  		return ($affectedRows > 0) ? true : false;
  
  	}
  
  	/**
  	 * Gets the preference for an array of users
  	 * @param string $app
  	 * @param string $key
  	 * @param array $users
  	 * @return array Mapped values: userid => value
  	 */
  	public function getValueForUsers($app, $key, $users) {
  		if (empty($users) || !is_array($users)) {
  			return array();
  		}
  
  		$chunked_users = array_chunk($users, 50, true);
  		$placeholders_50 = implode(',', array_fill(0, 50, '?'));
  
  		$userValues = array();
  		foreach ($chunked_users as $chunk) {
  			$queryParams = $chunk;
  			array_unshift($queryParams, $key);
  			array_unshift($queryParams, $app);
  
  			$placeholders = (sizeof($chunk) == 50) ? $placeholders_50 : implode(',', array_fill(0, sizeof($chunk), '?'));
  
  			$query = 'SELECT `userid`, `configvalue` '
  				. ' FROM `*PREFIX*preferences` '
  				. ' WHERE `appid` = ? AND `configkey` = ?'
  				. ' AND `userid` IN (' . $placeholders . ')';
  			$result = $this->conn->executeQuery($query, $queryParams);
  
  			while ($row = $result->fetch()) {
  				$userValues[$row['userid']] = $row['configvalue'];
  			}
  		}
  
  		return $userValues;
  	}
  
  	/**
  	 * Gets the users for a preference
  	 * @param string $app
  	 * @param string $key
  	 * @param string $value
  	 * @return array
  	 */
  	public function getUsersForValue($app, $key, $value) {
  		$users = array();
  
  		$query = 'SELECT `userid` '
  			. ' FROM `*PREFIX*preferences` '
  			. ' WHERE `appid` = ? AND `configkey` = ? AND ';
  
  		if (\OC_Config::getValue( 'dbtype', 'sqlite' ) === 'oci') {
  			//FIXME oracle hack: need to explicitly cast CLOB to CHAR for comparison
  			$query .= ' to_char(`configvalue`)= ?';

  		} else {

  			$query .= ' `configvalue` = ?';

  		}

  
  		$result = $this->conn->executeQuery($query, array($app, $key, $value));
  
  		while ($row = $result->fetch()) {
  			$users[] = $row['userid'];
  		}
  
  		return $users;

  	}
  
  	/**

  	 * Deletes a key

  	 * @param string $user user
  	 * @param string $app app
  	 * @param string $key key

  	 *
  	 * Deletes a key.
  	 */

  	public function deleteKey($user, $app, $key) {

  		$where = array(
  			'userid' => $user,
  			'appid' => $app,
  			'configkey' => $key,
  		);
  		$this->conn->delete('*PREFIX*preferences', $where);

  
  		if (isset($this->cache[$user]) and isset($this->cache[$user][$app])) {
  			unset($this->cache[$user][$app][$key]);
  		}

  	}
  
  	/**

  	 * Remove app of user from preferences

  	 * @param string $user user
  	 * @param string $app app

  	 *

  	 * Removes all keys in preferences belonging to the app and the user.

  	 */

  	public function deleteApp($user, $app) {

  		$where = array(
  			'userid' => $user,
  			'appid' => $app,
  		);
  		$this->conn->delete('*PREFIX*preferences', $where);

  
  		if (isset($this->cache[$user])) {
  			unset($this->cache[$user][$app]);
  		}

  	}
  
  	/**

  	 * Remove user from preferences

  	 * @param string $user user

  	 *

  	 * Removes all keys in preferences belonging to the user.

  	 */

  	public function deleteUser($user) {

  		$where = array(
  			'userid' => $user,
  		);
  		$this->conn->delete('*PREFIX*preferences', $where);

  
  		unset($this->cache[$user]);

  	}
  
  	/**

  	 * Remove app from all users

  	 * @param string $app app

  	 *
  	 * Removes all keys in preferences belonging to the app.
  	 */

  	public function deleteAppFromAllUsers($app) {

  		$where = array(
  			'appid' => $app,
  		);
  		$this->conn->delete('*PREFIX*preferences', $where);

  
  		foreach ($this->cache as &$userCache) {
  			unset($userCache[$app]);
  		}

  	}
  }

  require_once __DIR__ . '/legacy/' . basename(__FILE__);