<?php
  /**
   * Copyright (c) 2011 Bart Visscher <bartv@thisnet.nl>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  
  class OC_JSON{
  	static protected $send_content_type_header = false;
  	/**
  	 * set Content-Type header to jsonrequest
  	 */
  	public static function setContentTypeHeader($type='application/json') {
  		if (!self::$send_content_type_header) {
  			// We send json data

  			header( 'Content-Type: '.$type . '; charset=utf-8');

  			self::$send_content_type_header = true;
  		}
  	}
  
  	/**
  	* Check if the app is enabled, send json error msg if not

  	* @param string $app

  	*/
  	public static function checkAppEnabled($app) {
  		if( !OC_App::isEnabled($app)) {
  			$l = OC_L10N::get('lib');

  			self::error(array( 'data' => array( 'message' => $l->t('Application is not enabled'), 'error' => 'application_not_enabled' )));

  			exit();
  		}
  	}
  
  	/**
  	* Check if the user is logged in, send json error msg if not
  	*/
  	public static function checkLoggedIn() {
  		if( !OC_User::isLoggedIn()) {
  			$l = OC_L10N::get('lib');

  			self::error(array( 'data' => array( 'message' => $l->t('Authentication error'), 'error' => 'authentication_error' )));

  			exit();
  		}
  	}
  
  	/**

  	 * Check an ajax get/post call if the request token is valid, send json error msg if not.

  	 */
  	public static function callCheck() {
  		if( !OC_Util::isCallRegistered()) {
  			$l = OC_L10N::get('lib');

  			self::error(array( 'data' => array( 'message' => $l->t('Token expired. Please reload page.'), 'error' => 'token_expired' )));

  			exit();
  		}
  	}
  
  	/**

  	* Check if the user is a admin, send json error msg if not.

  	*/
  	public static function checkAdminUser() {
  		if( !OC_User::isAdminUser(OC_User::getUser())) {
  			$l = OC_L10N::get('lib');

  			self::error(array( 'data' => array( 'message' => $l->t('Authentication error'), 'error' => 'authentication_error' )));

  			exit();
  		}
  	}
  
  	/**

  	 * Check is a given user exists - send json error msg if not
  	 * @param string $user
  	 */
  	public static function checkUserExists($user) {
  		if (!OCP\User::userExists($user)) {
  			$l = OC_L10N::get('lib');

  			OCP\JSON::error(array('data' => array('message' => $l->t('Unknown user'), 'error' => 'unknown_user' )));

  			exit;
  		}
  	}
  
  
  
  	/**

  	* Check if the user is a subadmin, send json error msg if not
  	*/
  	public static function checkSubAdminUser() {
  		if(!OC_SubAdmin::isSubAdmin(OC_User::getUser())) {
  			$l = OC_L10N::get('lib');

  			self::error(array( 'data' => array( 'message' => $l->t('Authentication error'), 'error' => 'authentication_error' )));

  			exit();
  		}
  	}
  
  	/**
  	* Send json error msg
  	*/
  	public static function error($data = array()) {
  		$data['status'] = 'error';
  		self::encodedPrint($data);
  	}
  
  	/**
  	* Send json success msg
  	*/
  	public static function success($data = array()) {
  		$data['status'] = 'success';
  		self::encodedPrint($data);
  	}
  
  	/**
  	 * Convert OC_L10N_String to string, for use in json encodings
  	 */
  	protected static function to_string(&$value) {
  		if ($value instanceof OC_L10N_String) {
  			$value = (string)$value;
  		}
  	}
  
  	/**
  	* Encode and print $data in json format
  	*/
  	public static function encodedPrint($data, $setContentType=true) {

  		if($setContentType) {
  			self::setContentTypeHeader();
  		}

  		echo self::encode($data);
  	}
  
  	/**
  	 * Encode JSON
  	 */
  	public static function encode($data) {
  		if (is_array($data)) {
  			array_walk_recursive($data, array('OC_JSON', 'to_string'));
  		}
  		return json_encode($data);

  	}
  }