<?php
/* For licensing terms, see /license.txt */

use Chamilo\UserBundle\Entity\User;

/**
 * @package chamilo.webservices
 */

require_once __DIR__.'/../inc/global.inc.php';

$libpath = api_get_path(LIBRARY_PATH);

/**
 * Error returned by one of the methods of the web service. Contains an error code and an error message
 */
class WSCMError
{
    /**
     * Error handler. This needs to be a class that implements the interface WSErrorHandler
     *
     * @var WSErrorHandler
     */
    protected static $_handler;

    /**
     * Error code
     *
     * @var int
     */
    public $code;

    /**
     * Error message
     *
     * @var string
     */
    public $message;

    /**
     * Constructor
     *
     * @param int Error code
     * @param string Error message
     */
    public function __construct($code, $message)
    {
        $this->code = $code;
        $this->message = $message;
    }

    /**
     * Sets the error handler
     *
     * @param WSErrorHandler $handler Error handler
     */
    public static function setErrorHandler($handler)
    {
        if ($handler instanceof WSErrorHandler) {
            self::$_handler = $handler;
        }
    }

    /**
     * Returns the error handler
     *
     * @return WSErrorHandler Error handler
     */
    public static function getErrorHandler()
    {
        return self::$_handler;
    }

    /**
     * Transforms the error into an array
     *
     * @return array Associative array with code and message
     */
    public function toArray()
    {
        return array('code' => $this->code, 'message' => $this->message);
    }
}

/**
 * Interface that must be implemented by any error handler
 */
interface WSCMErrorHandler
{
	/**
	 * Handle method
	 *
	 * @param WSError $error Error
	 */
	public function handle($error);
}

/**
 * Main class of the webservice. Webservice classes extend this class
 */
class WSCM
{
	/**
	 * Chamilo configuration
	 *
	 * @var array
	 */
	protected $_configuration;

	/**
	 * Constructor
	 */
	public function __construct()
    {
		$this->_configuration = $GLOBALS['_configuration'];
	}

	/**
	 * Verifies the API key
	 *
	 * @param string $secret_key Secret key
	 * @return mixed WSError in case of failure, null in case of success
	 */
	protected function verifyKey($secret_key)
    {
		$ip = trim($_SERVER['REMOTE_ADDR']);
		// if we are behind a reverse proxy, assume it will send the
		// HTTP_X_FORWARDED_FOR header and use this IP instead
		if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
		  list($ip1, $ip2) = split(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
		  $ip = trim($ip1);
		}
		$security_key = $ip.$this->_configuration['security_key'];

		if (!api_is_valid_secret_key($secret_key, $security_key)) {
			return new WSCMError(1, "API key is invalid");
		} else {
			return null;
		}
	}

	/**
	 * Verifies if the user is valid
	 *
	 * @param string $username of the user in chamilo
	 * @param string $pass of the same user (in MD5 of SHA)
	 *
	 * @return mixed "valid" if username e password are correct! Else, return a message error
	 */
	public function verifyUserPass($username, $pass)
    {
		$login = $username;
		$password = $pass;

        $userRepo = UserManager::getRepository();
        /** @var User $uData */
        $uData = $userRepo->findOneBy([
            'username' => trim(addslashes($login))
        ]);

        if ($uData) {
            if ($uData->getAuthSource() == PLATFORM_AUTH_SOURCE) {
                $passwordEncoded = UserManager::encryptPassword($password, $uData);
                // Check the user's password
                if ($passwordEncoded == $uData->getPassword() && (trim($login) == $uData->getUsername())) {
                    // Check if the account is active (not locked)
                    if ($uData->getActive()) {
                        // Check if the expiration date has not been reached
                        $now = new DateTime();
                        if ($uData->getExpirationDate() > $now || !$uData->getExpirationDate()) {
                            return "valid";
                        } else {
                            return get_lang('AccountExpired');
                        }
                    } else {
                        return get_lang('AccountInactive');
                    }
                } else {
                    return get_lang('InvalidId');
                }
            } else {
                return get_lang('AccountURLInactive');
            }
        }
        return get_lang('InvalidId');
	}

	/**
	 * Gets the real user id based on the user id field name and value.
	 * Note that if the user id field name is "chamilo_user_id", it will use the user id
	 * in the system database
	 *
	 * @param string $user_id_field_name User id field name
	 * @param string $user_id_value User id value
	 * @return mixed System user id if the user was found, WSError otherwise
	 */
    protected function getUserId($user_id_field_name, $user_id_value)
    {
        if ($user_id_field_name == "chamilo_user_id") {
            if (UserManager::is_user_id_valid(intval($user_id_value))) {
                return intval($user_id_value);
            } else {
                return new WSCMError(100, "User not found");
            }
        } else {
            $user_id = UserManager::get_user_id_from_original_id(
                $user_id_value,
                $user_id_field_name
            );
            if ($user_id == 0) {
                return new WSCMError(100, "User not found");
            } else {
                return $user_id;
            }
        }
    }

	/**
	 * Gets the real course id based on the course id field name and value.
	 * Note that if the course id field name is "chamilo_course_id", it will use the course id
	 * in the system database
	 *
	 * @param string $course_id_field_name Course id field name
	 * @param string $course_id_value Course id value
	 * @return mixed System course id if the course was found, WSError otherwise
	 */
	protected function getCourseId($course_id_field_name, $course_id_value)
    {
        if ($course_id_field_name == "chamilo_course_id") {
            if (CourseManager::get_course_code_from_course_id($course_id_value) != null) {
                return intval($course_id_value);
            } else {
                return new WSCMError(200, "Course not found");
            }
        } else {
            $courseId = CourseManager::get_course_code_from_original_id(
                $course_id_value,
                $course_id_field_name
            );
            if (empty($courseId)) {
                return new WSCMError(200, "Course not found");
            } else {
                return $courseId;
            }
        }
	}

	/**
	 * Gets the real session id based on the session id field name and value.
	 * Note that if the session id field name is "chamilo_session_id", it will use the session id
	 * in the system database
	 *
	 * @param string $session_id_field_name Session id field name
	 * @param string $session_id_value Session id value
	 * @return mixed System session id if the session was found, WSError otherwise
	 */
	protected function getSessionId($session_id_field_name, $session_id_value)
	{
		if ($session_id_field_name == "chamilo_session_id") {
			$session = SessionManager::fetch((int) $session_id_value);
			if (!empty($session)) {
				return intval($session_id_value);
			} else {
				return new WSCMError(300, "Session not found");
			}
		} else {
			$session_id = SessionManager::getSessionIdFromOriginalId(
				$session_id_value,
				$session_id_field_name
			);
			if ($session_id == 0) {
				return new WSCMError(300, "Session not found");
			} else {
				return $session_id;
			}
		}
	}

	/**
	 * Handles an error by calling the WSError error handler
	 *
	 * @param WSError $error Error
	 */
	protected function handleError($error)
	{
		$handler = WSCMError::getErrorHandler();
		$handler->handle($error);
	}

	/**
	 * Gets a successful result
	 *
	 * @return array Array with a code of 0 and a message 'Operation was successful'
	 */
	protected function getSuccessfulResult()
	{
		return array('code' => 0, 'message' => 'Operation was successful');
	}

	/**
	 * Test function. Returns the string success
	 *
	 * @return string Success
	 */
	public function test()
	{
		return "success";
	}

	/**
	 * *Strictly* reverts PHP's nl2br() effects (whether it was used in XHTML mode or not)
	 * @param string $string
	 * @return string
	 */
	public function nl2br_revert($string)
    {
		return preg_replace('`<br(?: /)?>([\\n\\r])`', '$1', $string);
	}
}